Quarry, Aggregate, Sand & Gravel, Mineral Sands, Heavy Minerals & Lithium Brine HVAC Duct Guide — Boral, Hanson, Adbri, Holcim, Wagners, Sibelco, Iluka Eneabba, Pilbara Minerals, Albemarle Kemerton & Lake Resources DLE

Why quarry, aggregate, mineral sands and lithium HVAC is its own discipline

Australia's extractive industries — quarry, aggregate, sand and gravel, mineral sands, heavy minerals, rare earths, lithium hard-rock and lithium brine — share a single dominant occupational hazard that does more long-term damage than every other process risk combined: respirable crystalline silica. The Safe Work Australia Workplace Exposure Standard sits at 0.05 mg/m³ TWA, halved from the previous 0.1 mg/m³ limit and reinforced after the Australian silicosis epidemic that emerged across the early 2020s. That epidemic, concentrated among engineered stone benchtop fabricators but extending across the broader quarry, tunnelling and construction workforce, produced the world's first national Engineered Stone Ban in July 2024 and reshaped how every regulator in Australia approaches dust control on every site that processes crystalline silica-bearing rock. The ban itself does not directly cover natural quarried aggregate, mineral sands or lithium spodumene, but the regulatory aftermath has tightened audit programmes, licence conditions and enforcement across NSW Resources Regulator, VIC Earth Resources Regulator, QLD Mineral and Energy Resources (MEMR), WA Department of Mines and Petroleum (DMP), TAS Mineral Resources, NT Mining, and the state EPAs in every jurisdiction.

Underneath the silica problem sit four further discipline-specific hazards. Heavy mineral concentrate streams at the Iluka Eneabba separation plant and the adjacent Eneabba Rare Earths Refinery carry thorium-232 and uranium-238 decay daughters in the monazite, xenotime and bastnaesite fractions, triggering ARPANSA Radiation Protection Series RPS 9 controls on every transfer point. The blasting agents used at every quarry and hard-rock lithium operation — ANFO ammonium nitrate fuel oil from Orica, Dyno Nobel and Boral Explosives — bring AS 2187 storage compliance and AS/NZS 60079 hazardous area zoning into play around magazines, mixing skids and mobile manufacturing units. The lithium hydroxide downstream supply chain at Albemarle Kemerton runs rotary kilns at 1,000-1,100°C to convert α-spodumene to the acid-leachable β-phase — the highest-temperature unit operation in the Australian lithium sector and a challenging process-duct fabrication problem. And the emerging lithium brine producers — Lake Resources at Lake Lefroy SA, Vulcan Energy on geothermal brine — bring sulfuric acid regeneration, ion-exchange column handling and reverse osmosis chemistry into the LEV scope at material specifications above and beyond conventional galvanised duct.

Stacked together, these hazards make the Australian extractive sector one of the most exposure-intensive heavy industries on the continent, behind only underground hard-rock mining and integrated steelmaking. The HVAC duct fabrication scope on a typical 500 t/h aggregate crushing and screening plant easily exceeds 2,000-4,000 m² of duct across multiple buildings and process areas; a major lithium hydroxide refinery such as Albemarle Kemerton runs 6,000-12,000 m² across the calcination, leach, crystallisation and bagging trains; the Iluka Eneabba integrated MSP and RE Refinery handles a comparable footprint with the additional radiation-controlled duct in 316L stainless. The HVAC contractor's job is to know where the SBKJ sheet-metal fabrication scope ends and where the welded heavy-process duct scope begins, what material grade applies to each section, and how to align the design documentation with AS 1668.2 ventilation, AS/NZS 4254 duct construction, AS 3957 dust hazard practice, AS 1530.4 fire-rated duct, AS/NZS 60079 hazardous area zoning, NFPA 660 combustible dust, AS 2187 explosives storage, AS 1940 flammable liquid, AS 4041 pressure piping and ARPANSA RPS 9 radiation protection in mining.

Australian quarry, aggregate and lithium operators — who is buying HVAC duct

The Australian quarry, aggregate, sand and gravel market is concentrated in five major listed operators plus a handful of substantial independents and a tight set of state regulators. Mineral sands and heavy minerals sit largely with Iluka Resources and a smaller cohort of listed juniors. Lithium has been the fastest-growing sector globally for the past five years and is dominated by six listed producers running hard-rock spodumene operations across WA and NT plus two emerging brine producers. Comfort HVAC duct demand, process LEV duct demand and chemical fume LEV duct demand sit across every site, and the maintenance and shutdown rhythm at the larger sites is the volume driver for any HVAC contractor pursuing this market.

Quarry, aggregate and crushed rock. Boral (ASX:BLD), headquartered in Sydney, is Australia's largest quarry, aggregate and crushed rock producer. The Boral Quarries division operates more than 100 quarries nationally, supplying ready-mix concrete (Boral Concrete), asphalt (Boral Asphalt) and direct aggregate sales. Headline sites include Mt Coot-tha in Brisbane, Coolaroo in Melbourne, Casula in Sydney, plus operations in Adelaide, Perth and Hobart. Hanson Australia (HeidelbergMaterials, ASX:HAN) is the second-largest quarry and aggregate producer, with a national footprint through Sydney, Brisbane, Melbourne, Perth, Adelaide and Hobart. Adbri (ASX:ABC, formerly Adelaide Brighton) operates cement, aggregate, lime and asphalt at Birkenhead SA, Burnett Lime, Cockburn Cement WA and Penrice SA. Holcim Australia (LafargeHolcim) operates across all mainland capitals with quarry, aggregate, concrete and asphalt integration. Pioneer Construction Materials covers Sydney, Brisbane, Perth and Adelaide. Wagners (ASX:WGN) Toowoomba QLD produces concrete, precast and the proprietary New Generation Aggregates range plus geopolymer cement — Wagners has been a noted innovator in low-carbon aggregate alternatives. Independent Cement Lime serves Mt Gambier, Geelong and Wagga Wagga. Quarry Solutions Australia (QSA) and Buderim Quarry (Caloundra Sunshine Coast) round out the QLD market. Bedrock Asphalt Geelong and Northern Construction Materials (NCM) cover regional VIC. The peak body coordinating the sector is Cement Concrete & Aggregates Australia (CCAA), supplemented by Sand and Aggregate Producers Association of Australia (SAPAA), the Quarries Industry Council Australia and the Minerals Council of Australia (MCA).

Cement and lime. Parallel to the quarry market, cement production sits with Boral Cement, Hanson Cement, Adbri Cement, Holcim Australia, Cement Australia, Independent Cement and Cockburn Cement WA. Lime production runs at Burnett Lime, Penrice SA, Cockburn and Mt Gambier facilities. Cement clinker production triggers a separate set of HVAC duct demands covered in the SBKJ Cement Plant HVAC Duct Guide; aggregate quarries supplying the cement plants overlap with the general aggregate operator network described here.

Silica sand and frac sand. Sibelco Australia is the dominant silica sand producer, supplying glass-grade silica, foundry-grade silica, oil and gas frac sand and high-purity quartz for solar PV manufacturing. Sibelco operations at Capel WA, Stradbroke Island QLD and Pacific Sands cover the major Australian silica sand market. The Geological Survey of Australia and state geological surveys (NSW Geological Survey, Geoscience Victoria, GSQ Geological Survey of Queensland, GSWA Geological Survey of WA) coordinate the geological assessment underpinning new silica sand prospects.

Decorative aggregate, landscaping and dimension stone. Smaller-volume but higher-margin producers including Bowman Stone, Lannon Stone, Cobble Stone, MTM Stone Sydney, Tile & Stone and the Royal Australasian Stone Industry cover landscaping aggregate, decorative pebble, garden stone, bluestone, sandstone and granite dimension stone. The dimension stone segment carries additional silica RCS exposure during cutting and finishing operations and is increasingly subject to AS 1715 P3 respiratory protection requirements after the engineered stone ban.

Mineral sands and heavy minerals. Iluka Resources (ASX:ILU) is by a wide margin Australia's largest mineral sands producer. Iluka operates the Eneabba WA mineral sands separation plant — Australia's biggest — and the adjacent integrated Eneabba Rare Earths Refinery, supplying rutile, ilmenite, zircon, leucoxene, monazite and the rare earth element (REE) suite. Iluka also operates Mt Webber WA, Cataby WA, Jacinth-Ambrosia SA and historical East Coast operations. The Iluka Eneabba RE programme is supported by the Eneabba RE Cooperative Research Centre (Eneabba CRC). Strandline Resources (ASX:STA) operates Coburn WA producing zircon and titanium minerals. Mineral Sands Resources (MSR) in NSW, Sheffield Resources, Image Resources, Astron and Cristal Mining cover smaller streams. The peak body is the Heavy Mineral Sands Association with cross-membership of MCA and AMMA (Australian Mines and Metals Association).

Lithium hard-rock spodumene. The Australian lithium sector is now the largest in the world by primary spodumene production. Pilbara Minerals (ASX:PLS) operates Pilgangoora in WA — the largest single hard-rock spodumene operation globally. Mineral Resources (ASX:MIN) operates Mt Marion and the larger Wodgina WA project. IGO (ASX:IGO) holds the joint venture with Albemarle on the Greenbushes WA operation — the highest-grade hard-rock lithium deposit in the world — plus IGO Forrestania WA. Liontown Resources (ASX:LTR) operates Kathleen Valley WA. Core Lithium (ASX:CXO) operates Finniss in the Northern Territory — the first lithium operation in NT. Downstream lithium hydroxide and lithium carbonate refining is dominated by Albemarle Kemerton WA and Albemarle Kwinana Lithium Hydroxide, with Mineral Resources, Pilbara Minerals and the IGO-Albemarle JV all pursuing downstream integration. The peak body is the Australian Lithium Industry Association.

Lithium brine and direct lithium extraction (DLE). The emerging lithium brine sector in Australia is led by Lake Resources NL (ASX:LKE) at Lake Lefroy SA, pursuing direct lithium extraction (DLE) from sub-surface brine. Vulcan Energy Resources (ASX:VUL) pursues geothermal lithium brine from a combination of Australian and European projects. Both companies represent the next-generation Australian lithium production route alongside the established hard-rock spodumene pathway. DLE technology compresses the conventional 12-24 month solar evaporation pond cycle into a days-long process using ion-exchange resin, sorption media and reverse osmosis — fundamentally a wet-process chemical engineering operation with significant chemical fume LEV requirements.

Industry bodies and regulators. The Australian extractive sector is coordinated by Cement Concrete & Aggregates Australia (CCAA) as the aggregate and concrete peak body, Sand and Aggregate Producers Association of Australia (SAPAA) for the sand and gravel sector, the Quarries Industry Council Australia, the Minerals Council of Australia (MCA), the Australian Mines and Metals Association (AMMA), the Heavy Mineral Sands Association, the Australian Lithium Industry Association, Tyre Stewardship Australia (TSA) for mining tyre disposal, the NHVR National Heavy Vehicle Regulator for road transport, Roads Australia, Austroads and the Australian Pavement Research Group (APRG). State mining regulators include the NSW Resources Regulator, VIC Earth Resources Regulator, QLD Mineral and Energy Resources (MEMR), WA Department of Mines and Petroleum (DMP), TAS Mineral Resources and NT Mining. Environmental regulation falls to state EPAs (NSW EPA POEO Act, VIC EPA, QLD DES, SA Mining EPA, WA DWER). Heritage protection is governed by the Aboriginal and Torres Strait Islander Heritage Protection Act 1984, the Native Title Act 1993 and the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC). Radiation safety on monazite, xenotime and bastnaesite handling sits with the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) under RPS 9.

Boral, Hanson, Adbri, Holcim, Pioneer, Wagners and the quarry HVAC duct market

A typical Australian quarry processes hard rock — basalt, granite, dolerite, limestone, sandstone, blue metal, scoria — from open-cut bench operations through primary crushing, secondary and tertiary crushing, screening, washing where required, stockpiling and load-out to road transport. Production rates range from 50 t/h at a small regional quarry to 1,500 t/h at a major Boral or Hanson metropolitan site. A typical quarry footprint covers 50-500 ha of working area plus stockpile, rehabilitation and buffer zones, with the main processing plant occupying 2-10 ha including the primary crushing station, the screening tower, the secondary and tertiary crusher buildings, the conveyor network, the stockpiles, the load-out station, the truck wash, the workshop, the laboratory, the weighbridge office and the central control room.

HVAC duct demand on a quarry breaks into two categories: comfort HVAC for the control room, weighbridge, lab and workshop buildings, and process LEV for the crushing, screening and conveyor dust capture. Comfort HVAC is straightforward galvanised duct on the SBAL-V plus SBTF-1500 spiral tubeformer at typically 200-800 m² of fabricated duct per major quarry. Process LEV is the substantial scope: a 500 t/h crushing and screening plant carries 1,500-3,500 m² of dust extraction duct across 15-30 capture points, fabricated predominantly in 1.5 mm mild steel spiral on the SBFB-1500 with rectangular branches on the SBAL-V.

Boral Quarries' largest sites include Mt Coot-tha in Brisbane (basalt, blue metal, sandstone), Coolaroo in Melbourne (basalt), Casula in Sydney (sandstone, hawkesbury rock), and the major Adelaide and Perth metropolitan quarries. Each of these runs 500-1,500 t/h capacity with substantial baghouse-extracted dust collection and ducting demand. Hanson runs comparable operations on the second-largest national footprint. Adbri's South Australian operations centre on the Birkenhead cement plant and integrated aggregate operations.

Wagners (ASX:WGN) at Toowoomba QLD operates differently from the major listed producers — Wagners has invested heavily in the proprietary New Generation Aggregates (NGA) product range and geopolymer cement substitution alongside conventional aggregate production. Wagners' HVAC scope reflects this: a heavier laboratory and analytical bench fit-out than a conventional quarry, additional fume cupboard LEV on the geopolymer testing benches, and a higher proportion of 316L stainless duct in the analytical building.

Sibelco's silica sand operations at Capel WA, Stradbroke Island and Pacific Sands carry an even higher silica RCS profile than conventional crushed-rock aggregate. Capel produces glass-grade silica at 99%+ SiO2 from selectively mined Eocene-age sand deposits, washing through a wet concentrator, attrition scrubbing, hydrocycloning and final drying. The dry plant LEV is the single highest-priority capture circuit on a Sibelco site, with 316L stainless duct on the wet concentrator deck and 1.5 mm mild steel on the dry handling. Foundry-grade silica for casting applications and frac sand for oil and gas hydraulic fracturing operations are also produced at Capel; both grades require tighter particle-size specifications and additional screening and classification stages.

RCS silica 0.05 silicosis Australian epidemic — the AS 3957 zone

Respirable crystalline silica (RCS) is the single most regulated worker exposure in the Australian extractive sector, and the regulatory framework has tightened dramatically across the past five years. The Safe Work Australia Workplace Exposure Standard (WES) for RCS is 0.05 mg/m³ TWA — half the previous 0.1 mg/m³ limit that prevailed until 2020. The reduction was driven by the Australian silicosis epidemic that emerged in the early 2020s, initially concentrated among engineered stone benchtop fabricators where dry cutting and grinding of high-silica stone slabs (Caesarstone, Smartstone, Quantum Quartz and similar) generated extreme local RCS concentrations and accelerated silicosis cases. The Engineered Stone Ban that came into force across all Australian states on 1 July 2024 prohibits the manufacture, supply, processing and installation of engineered stone benchtops containing crystalline silica — the world's first national ban of its kind.

While the Engineered Stone Ban does not directly cover natural quarried aggregate, mineral sands or lithium spodumene, the regulatory aftermath has dramatically tightened audit programmes across every Australian silica exposure source. NSW Resources Regulator, VIC Earth Resources Regulator, QLD MEMR, WA DMP and TAS Mineral Resources have all reinforced silica dust audit programmes against quarry, aggregate, sand and mineral sands operators. State EPAs have tightened licence conditions on stack emissions and fugitive dust. Safe Work Australia has reissued the harmonised silica exposure guidance, with the 0.05 mg/m³ TWA limit now the binding regulatory standard across every WHS jurisdiction.

The silica RCS source on an Australian quarry, aggregate or mineral sands plant runs across every process operation: front-end loader pickup at the stockpile, ROM dump hopper into the primary jaw crusher (Sandvik, Metso, Terex, McLanahan, Cedarapids, Astec primary jaws at 1,500-2,500 mm gape width), secondary cone crusher discharge, tertiary cone crusher discharge, HSI (Horizontal Shaft Impactor) rotor housing, VSI (Vertical Shaft Impactor) rotor housing, vibrating screen decks (Sandvik, Metso, Schenck, McLanahan, Cedarapids), banana screen multi-deck enclosures, static grid scalping screens, wet screens, trommel screens, conveyor transfer points (every head pulley and tail pulley on every belt conveyor), bucket elevator boots and heads, stacker tail pulley enclosures, stockpile reclaim feeder hoods, weigh feeder discharges into the load-out chute and the load-out chute itself into the truck or railcar.

Quartz sand carries 95-99% SiO2 by mass and is the most aggressive RCS source. Basalt carries 3-15% free silica typically. Limestone carries 1-5% free silica. Dolomite carries 1-3% free silica. Granite carries 20-40% free silica. Mineral sands carry 5-25% free silica depending on the dominant heavy mineral fraction. Spodumene concentrate carries 30-45% silica content (LiAlSi2O6 is approximately 30% Si by weight). Rare earth concentrate from monazite handling carries 5-15% silica. The RCS particulate fraction (≤4 µm aerodynamic diameter, PM4) is the killer because it penetrates the alveolar region of the lung and deposits there, causing silicosis, accelerated silicosis (artificial-stone silicosis), and progressive massive fibrosis over a typical 10-30 year latency.

Engineering controls under AS 3957 (Dust Hazard Identification and Control) follow a strict hierarchy. Source-level enclosures cover every transfer point with full hood capture. Capture velocity 1.0-1.5 m/s at the dust source per AS 3957. Capture flow rates 1,500-5,000 m³/h per major transfer point, with 8,000-15,000 m³/h per primary crusher discharge and 5,000-10,000 m³/h per secondary cone discharge. Trunk extraction duct sized for minimum transport velocity 18-22 m/s to keep silica fines suspended. The central dust collector (typically a pulse-jet baghouse with PTFE-membrane filter media at air-to-cloth ratio 1.0-1.5 m³/m²/min) discharges cleaned air at less than 30 mg/Nm³ total dust to atmosphere per state EPA licence. Collected silica fines are returned to the saleable product where market specification allows, or disposed of as licensed waste.

Administrative controls sit as the second layer. Limit operator residence time at the primary crusher deck, the screening tower deck and the stockpile reclaim hood. Post AS 3957 dust hazard signage at all entry points. Mandate AS 1715 P2 respiratory protection for general plant access and AS 1715 P3 with PAPR (powered air-purifying respirator) for any operator entering the dust collector for maintenance work. Require medical surveillance for RCS-exposed workers per Safe Work Australia code: baseline lung function testing, periodic spirometry, periodic chest X-ray or low-dose CT, plus the new Australian National Silicosis Register reporting since 2023.

Engineered Stone Ban 2024 — the regulatory aftershock

The Engineered Stone Ban that came into force across all Australian states on 1 July 2024 prohibits the manufacture, supply, processing and installation of engineered stone benchtops containing crystalline silica. The ban is the world's first national prohibition on engineered stone, and it followed a series of state-level investigations, ABC Four Corners reporting and the work of the Australian Council of Trade Unions to bring the silicosis epidemic to public attention. The ban itself focuses on engineered stone (manufactured composite stone benchtops typically 90-95% crystalline silica content) rather than natural stone, but its regulatory aftermath has reshaped how every state regulator approaches every silica exposure source.

The practical consequences for HVAC duct fabrication contractors pricing quarry, aggregate, sand, mineral sands and lithium projects are significant. State regulators are now routinely requiring detailed engineering documentation on every silica capture point: capture velocity verification at the hood face, gravimetric sampling at the operator breathing zone over a representative shift, baghouse performance testing at commissioning and at regular intervals throughout operation, and AS 1668.2 commissioning sign-off integrated into the licence-to-operate framework. State EPA licence conditions have been tightened on stack emissions (typically below 30 mg/Nm³ total dust, down from 50 mg/Nm³ in some legacy licences), fugitive dust monitoring at the site boundary, and complaint response timeframes for off-site dust deposition.

The Western Australian Department of Mines and Petroleum (WA DMP) has been particularly active in tightening silica audit programmes against the Pilbara hard-rock lithium operations at Pilgangoora, Mt Marion, Wodgina, Greenbushes, Kathleen Valley and Finniss. Spodumene concentrate handling carries substantial silica RCS exposure at every stage: from the run-of-mine ROM ore through the DMS (Dense Media Separation) circuit, flotation, dewatering, drying, bagging and load-out. The audit cycle has driven significant LEV duct upgrade investment across the WA lithium sector throughout 2024 and 2025.

SBKJ machinery scope on engineered-stone-ban-driven LEV upgrade work is substantial. A typical aggregate plant LEV upgrade adds 200-800 m of 1.5 mm mild steel spiral duct (fabricated on the SBFB-1500), 100-400 m² of rectangular branch duct (fabricated on the SBAL-V), and 50-200 m of 316L stainless duct on the more aggressive corrosive or radiation-controlled capture circuits (fabricated on the SBAL-V configured for stainless coil). The SBPC1500 plasma cutting station handles the heavy plate fabrication for new baghouse plate cut-outs, dust collector inlet plenum plates and flange cut-outs at the dust collector connections. Total LEV upgrade scope per site typically runs $400,000-$2 million depending on the number of capture points and the existing duct condition.

Process zones — the quarry and aggregate plant duct map

To know where the HVAC duct sits on a quarry, aggregate, mineral sands or lithium plant, you need to know where the process gas, dust, fume and radioactive sources are. A modern Australian operation runs through twelve distinct process zones, each with its own ventilation, LEV, hazardous area, dust hazard and radiation signature.

Blast, drill and explosive zone. Open-cut quarry and hard-rock lithium operations blast benches using ANFO (ammonium nitrate fuel oil), emulsion explosives, boosters, blasting caps and detonators supplied by Orica, Dyno Nobel and Boral Explosives. ANFO is 94% prilled ammonium nitrate and 6% diesel fuel oil. AS 2187 (Explosives — Storage, transport and use) governs the magazine; AS/NZS 60079.10.1 Zone 1 applies within 4.5 m of the diesel transfer point on the mobile manufacturing unit (MMU). The state explosives regulator (NSW SafeWork Explosives, VIC WorkSafe, QLD Resources, WA DMP) licenses every magazine. Drilling rigs (Atlas Copco, Sandvik, Caterpillar, Furukawa) generate respirable silica dust at the bit face, controlled by water-flush drilling and dust collector aspiration. Diesel-powered drilling rigs in remote and sometimes confined drilling positions generate CO (WES 30 ppm STEL) and NOx emissions.

Mining, extraction and haul zone. Open-cut benches are mined by hydraulic excavator (Caterpillar 6020-6090, Komatsu PC2000-PC8000, Hitachi EX1900-EX8000, Liebherr R 9800), front-end loader (Caterpillar 988-994, Komatsu WA800-WA1200) or rope shovel (P&H 4100, Caterpillar 7495). Haul trucks (Caterpillar 793-797, Komatsu 830E-980E, Hitachi EH3500-EH5000, Liebherr T 282) carry 100-400 tonnes per load to the primary crusher. Diesel exhaust from this fleet is the dominant emission source in the open pit: CO 30 ppm STEL, NOx, particulate PM2.5, fugitive silica dust from haul road and bench surfaces. Open-pit ventilation is by ambient atmospheric exchange; underground sections (rare in quarrying but present in some hard-rock lithium operations) require dedicated mechanical ventilation per the SBKJ Mining Ventilation HVAC Duct Guide.

Crushing zone — primary, secondary and tertiary. Run-of-mine ore from the haul trucks dumps into the ROM hopper feeding the primary jaw crusher (Sandvik, Metso, Terex, McLanahan, Cedarapids, Astec at 1,500-2,500 mm gape width, typically 200-2,000 t/h throughput). Discharge from the primary jaw passes onto an apron feeder or a heavy-duty conveyor feeding the secondary cone crusher (Sandvik H-series, Metso HP and GP-series, McLanahan secondary cone). Secondary discharge passes through scalping screens and recirculates to tertiary cone crushers (Sandvik H-series fine cone, Metso HP-series, Trio TP-series). Some plants substitute HSI (Horizontal Shaft Impactor — Cedarapids, Lippmann, Tesab) for shaping coarse aggregate or VSI (Vertical Shaft Impactor — Metso Barmac, Sandvik CV-series, Lippmann) for fine aggregate shaping. Crushing zone LEV is the single largest dust capture circuit on the plant: every crusher discharge, every transfer chute, every screening deck top and every conveyor head pulley has a hood capture and aspiration line. Capture flow 5,000-15,000 m³/h per major crusher discharge; trunk transport velocity 18-22 m/s; central baghouse air-to-cloth ratio 1.0-1.5 m³/m²/min. NFPA 660 dust hazard analysis applies where coal, organic or combustible material is present (typically not on pure aggregate but relevant where recycled construction and demolition C&D feed is introduced).

Screening zone — vibrating, banana, scalping and trommel. Screened aggregate is sized at the multi-deck vibrating screens (Sandvik, Metso, Schenck, McLanahan, Cedarapids), the banana screens (curved-deck multi-stage vibrating screens), static grid scalping screens, wet screens (with water spray) and trommel screens (rotating cylindrical screens for clay-bearing aggregate). Screening tower LEV captures the dust generated at every screen deck top, the discharge chute and the cross-belt sampler. Capture flow 3,000-8,000 m³/h per screening deck; LEV trunk on the SBFB-1500 spiral former in 1.5 mm mild steel.

Washing, dewatering and classification zone. Sand, gravel and silica sand operations include a wet processing circuit: log washer, attrition scrubber, wet screen, spiral classifier, screw classifier, hydrocyclone, cone classifier, thickener and dewatering screen. Sibelco Capel WA and Stradbroke Island silica sand operations run substantial wet circuits to upgrade run-of-mine sand to glass-grade or foundry-grade specification. AS 5012 governs tailings management. LEV on the wet circuit captures the airborne mist at the cyclone overflow, the thickener overflow weir and the dewatering screen discharge. Material is 304 or 316L stainless because the wet aggressive environment corrodes galvanised coating. SBAL-V configured for stainless coil fabricates rectangular sections.

Conveyor, stacker and stockpile zone. Aggregate moves between process areas on belt conveyors (overland conveyors up to 5-10 km long on the largest operations, pipe conveyors for fully enclosed transport, conventional troughed belt conveyors for shorter runs), supplied by Manhart, Schenck, Beumer and various Australian fabricators. Stackers (luffing or radial) build conical or kidney-shaped stockpiles 10-30 m high. Reclaim feeders extract stockpile material via apron feeders, plough feeders or front-end loaders. Every transfer point on the conveyor system is a dust source; capping fugitive dust with enclosed conveyor housings, baghouse aspiration at every transfer hood and dust suppression by water spray at exposed stockpiles is the engineering control standard.

Mobile crushing and track-mounted plant. Smaller-volume aggregate operations and quarry expansion projects use mobile crushing plant — Sandvik QH and QJ series, Powerscreen, Terex, Tesab, Striker, Lippmann track-mounted units typically 80-300 t/h capacity. Mobile plant runs diesel-powered with on-board generator, dust suppression by water spray and integral dust collector. AS/NZS 60079 Zone 2 applies in the immediate vicinity of the diesel tank during refuelling. The mobile plant operator cab is air-conditioned and pressurised with two-stage particulate filtration — comparable to a fixed plant control room in design intent but built into the cab structure by the OEM. HVAC fabrication scope on mobile plant is limited to occasional cab AHU duct replacements during maintenance.

Aggregate coating, pre-coated chip and asphalt feed. Boral, Hanson, Adbri, Pioneer and Wagners produce pre-coated chip aggregate for chip-seal road surfacing applications: clean aggregate is bitumen-pre-coated in a dedicated coating plant to improve adhesion in the final spray-seal application. The coating plant LEV captures bitumen aerosol per the SBKJ Asphalt, Bitumen and Hot Mix Asphalt HVAC Duct Guide — AS/NZS 60079 Zone 1 within 3 m of the bitumen tank vent and the coating drum manhole. LEV duct in 316L stainless. The coated chip stockpile area is downwind of the coating drum and downwind of the worker amenities.

Mineral sands separation plant (MSP) zone. Iluka Resources at Eneabba WA, Strandline at Coburn WA and Mineral Sands Resources at NSW operations process heavy mineral concentrate (HMC) through the Mineral Separation Plant (MSP). MSP unit operations include wet concentrator spirals (Reichert spirals — gravity separation by helical spiral channels), upcurrent classifiers (gravity separation by upward water flow), wet high-intensity magnetic separator (WHIMS — separation of magnetic ilmenite and monazite from non-magnetic zircon and rutile), electrostatic separators (separation by surface conductivity — ESP), wet drum magnetic separators (separation of strongly magnetic minerals), shaking tables (final gravity concentration) and centrifugal concentrators (Knelson, Falcon, Sepro for fine particle gravity separation). MSP LEV captures the airborne fine dust at every transfer point and every separator feed and discharge. Material is 316L stainless 1.5 mm throughout because the heavy mineral concentrate is abrasive and radioactive decay daughters demand smooth decontaminable surfaces. SBKJ SBAL-V configured for stainless coil fabricates rectangular branches; SBFB-1500 fabricates round spiral 200-800 mm; SBPC1500 plasma cuts plate.

Rare earth, monazite, xenotime and bastnaesite zone. The Iluka Eneabba Rare Earths Refinery (REC) is the integrated rare earth oxide production facility downstream of the MSP at Eneabba. Feed is monazite, xenotime and bastnaesite concentrate from Iluka's MSP network plus third-party feed. Processing involves sulfuric acid bake (concentrated H2SO4 at 200-300°C), water leach, mixed rare earth carbonate precipitation, solvent extraction (organophosphate, organophosphine and amine extractants in kerosene diluent) and individual oxide finishing (cerium oxide, lanthanum oxide, neodymium oxide, praseodymium oxide, samarium and beyond). Radiation control under ARPANSA RPS 9 is mandatory because monazite and xenotime carry thorium-232 and uranium-238 decay chain daughters at significant concentration. The Eneabba REC programme is supported by the Eneabba RE Cooperative Research Centre.

Lithium hard-rock spodumene concentration zone. Pilbara Minerals Pilgangoora, Mineral Resources Mt Marion and Wodgina, IGO Greenbushes JV with Albemarle, Liontown Kathleen Valley and Core Lithium Finniss all run hard-rock spodumene concentration through DMS (Dense Media Separation) and flotation circuits. ROM ore is crushed, ground to liberation size, processed through DMS modules using ferrosilicon as the dense medium, then flotation cells using collector reagents to upgrade lithium grade. Finished spodumene concentrate runs 6% Li2O content (the global hard-rock benchmark) for export to lithium hydroxide refineries. The concentrator plant LEV scope is dominated by silica RCS dust capture across the crushing, grinding, DMS and flotation circuits.

Lithium hydroxide, carbonate and refining zone. Downstream lithium hydroxide production at Albemarle Kemerton WA, Albemarle Kwinana, Mineral Resources downstream and Pilbara Minerals downstream runs a four-stage refining process: (1) Spodumene calcination in a rotary kiln at 1,000-1,100°C to convert α-spodumene to acid-leachable β-spodumene; (2) Sulfuric acid roast at 250°C to digest the calcined β-spodumene; (3) Water leach, impurity removal and lithium sulfate purification; (4) Conversion to lithium hydroxide (LiOH·H2O) or lithium carbonate (Li2CO3) by sodium hydroxide or sodium carbonate precipitation, crystallisation and drying. AS 1940 governs the sulfuric acid storage; AS 4041 governs the pressure piping; AS/NZS 60079 Zone 1 applies to the natural gas burner gas train on the calcination kiln; NFPA 86 industrial oven design applies to the kiln. LEV is dominated by H2SO4 mist capture (WES 1 mg/m³ STEL), acid gas capture (HF rare, HCl up to 5 mg/m³ STEL), lithium hydroxide and carbonate dust capture under combustible dust controls, and crystalliser vent gases.

Lithium brine and DLE zone. Lake Resources Lake Lefroy SA and Vulcan Energy geothermal brine operations run a different process: brine pumping from sub-surface aquifers, brine pre-treatment (clarification, softening), DLE (Direct Lithium Extraction) ion-exchange resin or sorption columns, reverse osmosis concentration, sodium carbonate precipitation to lithium carbonate, and final crystallisation. DLE plants are enclosed wet-process facilities with significant condensation, humidity control and chemical fume LEV requirements. Sulfuric acid regeneration of the ion-exchange columns is the dominant LEV source. Lithium carbonate dust at the precipitation and bagging stages adds NFPA 660 combustible dust controls.

Aggregate testing laboratory zone. Every quarry and aggregate plant runs a laboratory adjacent to the central control building. Standard tests include Marshall stability (where asphalt-grade aggregate is supplied), Los Angeles abrasion (AS 1141.23), Micro-Deval abrasion (AS 1141.27), shape index and flakiness/elongation (AS 1141.14, AS 1141.15), aggregate crushing value (AS 1141.21), aggregate impact value, sodium sulfate soundness, water absorption, AS 1141 sampling and testing in general, AS 2891 asphalt testing where co-processed, AS 1289 soil testing and field-density testing using nuclear density gauges (under ARPANSA general radiation safety regulation). Lab LEV is conventional galvanised duct on the SBAL-V; fume cupboards on chemical testing benches in 316L stainless to AS/NZS 2982.

Iluka Eneabba mineral sands and the heavy mineral concentrate plant

The Iluka Resources Eneabba operation in Western Australia is Australia's largest mineral sands processing facility and the centrepiece of the country's emerging rare earth supply chain. Eneabba sits in the Northern Perth Basin, with mineral sands ore mined from heavy-mineral-bearing dune sand deposits across a substantial historical and current production footprint. The Eneabba Mineral Separation Plant (MSP) is supplied by heavy mineral concentrate from Iluka's mining operations plus third-party concentrate. The adjacent Eneabba Rare Earths Refinery (REC) is Australia's first integrated mineral sands to individual rare earth oxide facility and is supported by the Eneabba RE Cooperative Research Centre (Eneabba CRC).

The Eneabba MSP processes heavy mineral concentrate through a sequence of wet and dry separation stages. Wet concentrator spirals (Reichert spirals) provide first-stage gravity separation, separating the heavy mineral fraction (rutile, ilmenite, zircon, leucoxene, monazite) from the lighter quartz silica gangue. Upcurrent classifiers provide further gravity separation. Wet drum magnetic separators remove strongly magnetic mineral. Wet high-intensity magnetic separators (WHIMS) separate moderately magnetic ilmenite and monazite from non-magnetic zircon and rutile. Electrostatic separators (ESP — high-voltage drum or plate separators) provide final separation between conductive (rutile, ilmenite) and non-conductive (zircon) mineral. Shaking tables provide final concentration. Centrifugal concentrators (Knelson, Falcon, Sepro) handle fine-particle gravity separation.

HVAC duct demand at Eneabba is substantial across both the MSP and the REC. MSP LEV captures airborne fine dust at every wet concentrator deck, every WHIMS feed and discharge, every electrostatic separator feed, every dryer feed and every product bagging line. Material is 316L stainless 1.5 mm throughout because the heavy mineral concentrate is abrasive and radioactive decay daughters from monazite contamination demand smooth decontaminable surfaces. The smooth 2B-finish interior of 316L stainless allows surface decontamination during shutdown without the lining loss seen on galvanised duct.

The REC sulfuric acid bake stage runs concentrated H2SO4 at 200-300°C in a sealed reactor. Bake vent LEV captures the acid gas evolution (predominantly SO2 and SO3 plus residual H2SO4 mist) and routes the captured stream to a wet scrubber for neutralisation. The reactor is welded heavy fabrication in 904L super-stainless or fluoropolymer-lined steel — outside SBKJ standard sheet-metal scope. Downstream of the bake stage, the water leach stage runs at 60-90°C in 316L stainless tanks with stirred agitation. Solvent extraction circuits use mixer-settler trains with organophosphate, organophosphine and amine extractants in kerosene diluent. Solvent vapour at every mixer-settler discharge is captured by LEV in 316L stainless duct on the SBAL-V configured for stainless coil.

The radiation profile at Eneabba is significant. Monazite at the deposit carries 5-12% combined thorium-232 and uranium-238 by mass. Thorium-232 begins a 10-step radioactive decay chain producing radium-228, thoron (radon-220), polonium and lead-208 daughters. Uranium-238 begins a 14-step chain producing radium-226, radon-222, polonium and lead-206 daughters. Bulk monazite handling, concentrate stockpiles, dryer exhaust, conveyor transfer points and bagging operations all generate radon and thoron gas in the local atmosphere plus alpha-emitting particulate. ARPANSA RPS 9 (Code for Radiation Protection in Mining and Mineral Processing) sets the workplace radiation exposure limit at 20 mSv per year (5-year average), 50 mSv in any single year, with a continuous-monitoring obligation across the radiation-controlled areas.

Engineering controls under ARPANSA RPS 9 include local exhaust ventilation at every monazite, xenotime and bastnaesite transfer point with HEPA filtration on the discharge stack (or specialised radon-trap activated carbon adsorption), positive pressure isolation of control rooms and offices from radiation-controlled areas, AS 1715/1716 respiratory protection with P3 cartridge filters for any worker entering a radiation-controlled area, continuous radon and thoron monitoring with action-level alarms, personnel passive dosimetry on every radiation-exposed worker, and detailed area dosimetry mapping at the start of every shutdown. The smooth interior surface of 316L stainless duct allows wash-down decontamination during shutdown without the surface contamination retention seen on galvanised duct.

SBKJ machinery scope at Eneabba covers the comfort HVAC in the central control building, the MSP control building, the REC control building, the laboratory, the workshop and the amenities — galvanised on the SBAL-V plus SBTF-1500. Process LEV duct in 316L stainless 1.5 mm on the MSP wet concentrator decks, the WHIMS and ESP capture points, the REC acid bake and leach vent capture and the bagging plant — fabricated on the SBAL-V configured for stainless coil and the SBFB-1500 for round spiral. The SBPC1500 plasma cutting station handles heavy plate fabrication for the flange cut-outs and tank head plates. Total HVAC duct scope at Eneabba MSP+REC across the major plant areas runs 8,000-15,000 m² depending on the specific upgrade or new-build scope.

Rare earth monazite radioactive ARPANSA — RPS 9 controls

Rare earth elements (REE) — the fifteen lanthanide elements plus scandium and yttrium — are the strategic critical minerals of the modern energy transition. Permanent magnet motors for electric vehicles and offshore wind turbines depend on neodymium-iron-boron magnets with dysprosium and terbium additions for high-temperature performance. Optical fibre depends on erbium and ytterbium dopants. Phosphor displays depend on europium and yttrium. Catalysts depend on cerium and lanthanum. Australia holds the third-largest known rare earth reserves globally, concentrated in the monazite, xenotime and bastnaesite mineral suites associated with mineral sands deposits and the Mt Weld carbonatite. The Iluka Eneabba REC programme represents Australia's first integrated mine-to-oxide capability and is one of the strategic federal priorities under the Critical Minerals Strategy 2023-2030.

The radiation problem in rare earth processing arises from the geological association of monazite and xenotime with thorium-232 and uranium-238. Monazite is a phosphate mineral with the general formula (Ce,La,Nd,Th)PO4 — thorium routinely substitutes for the trivalent rare earth ions in the crystal lattice at 5-12% concentration by mass. Xenotime is a phosphate of yttrium with similar uranium and thorium substitution at lower concentrations. Bastnaesite is a fluorocarbonate of the rare earths with lower radioactive content but still measurable. Thorium-232 and uranium-238 each have half-lives in the billions of years and decay through long chains producing more biologically active short-half-life daughter isotopes — radium, radon, thoron, polonium and stable lead end-products.

The biologically critical isotopes are radon-222 (half-life 3.8 days, alpha-emitter, inhalation hazard), thoron (radon-220, half-life 56 seconds, alpha-emitter, inhalation hazard), the radon and thoron daughters (polonium-218, polonium-216, polonium-214, polonium-212 — short-half-life alpha emitters), and the long-lived parents (Th-232 and U-238 themselves, plus radium-226 and radium-228) which contribute external gamma exposure. The combined exposure to a worker in a poorly ventilated monazite handling area can run 5-15 mSv per year — well below the 20 mSv occupational limit but significant enough to require active control.

ARPANSA Radiation Protection Series RPS 9 (Code for Radiation Protection in Mining and Mineral Processing) is the binding framework. The Code requires (1) classification of work areas as supervised areas (1-6 mSv/year potential) or controlled areas (6+ mSv/year potential or above 30% of dose limit), (2) engineering controls including ventilation and dust suppression to minimise airborne radioactive dust, (3) personnel dosimetry on every controlled-area worker, (4) routine radiation monitoring including radon and thoron measurement, (5) decontamination procedures and routine surface contamination monitoring, (6) clearance procedures for materials and equipment leaving controlled areas, (7) waste management for radioactive concentrate, scale and process residue, and (8) medical surveillance for radiation-exposed workers.

The HVAC duct fabrication implications are clear. Every LEV duct in a controlled area must be 316L stainless or comparable smooth-finish material to allow surface decontamination during shutdown. Capture velocity at every transfer point must achieve full hood capture (typically 1.5-2.0 m/s at the hood face). HEPA filtration on the discharge stack to capture submicron alpha particulate. Activated carbon adsorption banks where radon and thoron control is the dominant problem. Continuous ambient radon monitoring with action-level alarms. Personnel dosimetry on every controlled-area entry.

The SBKJ machinery scope on a monazite, xenotime or bastnaesite handling LEV scope is the SBAL-V configured for 316L stainless coil for rectangular branches, the SBFB-1500 for round spiral 200-800 mm, and the SBPC1500 plasma cutting station for the heavy plate fabrication. All duct supports, hangers, gaskets and bolting in radiation-controlled areas are specified for decontaminable smooth finish. Field installation is by certified contractors trained in ARPANSA RPS 9 work practice.

Lithium spodumene Pilgangoora Greenbushes Mt Marion — the hard-rock circuit

Australia's lithium hard-rock sector is now the largest in the world by primary spodumene production. The sector emerged from a baseline supplied by Greenbushes WA in the early 2010s, accelerated through the 2017-2020 period with Pilgangoora and Mt Marion ramping up, and reached scale across 2021-2025 with Wodgina, Kathleen Valley, Finniss and the joint-venture downstream investments at Albemarle Kemerton, Albemarle Kwinana and the Mineral Resources, Pilbara Minerals and IGO downstream projects. Combined annual production now exceeds 60% of global hard-rock spodumene supply.

Pilbara Minerals (ASX:PLS) operates Pilgangoora in the Pilbara region of Western Australia. Pilgangoora is the world's largest single hard-rock spodumene operation by capacity, with multi-stage expansion through the 2020s. The Pilgangoora flowsheet runs ROM ore crushing, grinding (rod mill and ball mill), DMS Dense Media Separation using ferrosilicon medium, flotation cells with collector reagents to upgrade the lithium grade, dewatering and final concentrate handling. Production is 6% Li2O spodumene concentrate for export to lithium hydroxide refineries plus emerging downstream lithium hydroxide capacity under the Pilbara Minerals POSCO joint venture at the Korean refinery and the Calix kiln demonstration plant.

Mineral Resources (ASX:MIN) operates Mt Marion (a 50/50 joint venture with Albemarle prior to recent restructuring) and the larger Wodgina WA operation. Mineral Resources is also the world's largest mining services contractor and has invested heavily in the integrated lithium downstream business including processing plant construction at Wodgina. The Wodgina lithium hydroxide downstream development is a major HVAC duct demand source as commissioning progresses through 2025-2026.

IGO (ASX:IGO) holds the joint venture with Albemarle on the Greenbushes WA operation — the highest-grade hard-rock lithium deposit in the world at typically 2.0-2.5% Li2O ROM grade compared to 1.0-1.5% for most other Australian operations. Greenbushes has been producing lithium concentrate continuously since the 1980s and is the foundational asset in the global hard-rock lithium supply chain. IGO also operates Forrestania WA producing nickel and lithium.

Liontown Resources (ASX:LTR) operates Kathleen Valley WA, commissioning during 2024-2025 with a phased ramp to full production through 2026-2027. Core Lithium (ASX:CXO) operates Finniss in the Northern Territory — the first lithium operation in NT — and has been a noted operational case study in the challenges of lithium hard-rock ramp-up during the 2024 lithium price downturn.

The hard-rock concentrator HVAC duct scope is dominated by silica RCS dust capture and aggregate-style transfer point aspiration. ROM ore handling, crushing, grinding and DMS sections generate substantial respirable silica dust at every transfer point — spodumene (LiAlSi2O6) contains approximately 30% silica by weight and crushed concentrate is highly abrasive. LEV duct material is 1.5 mm mild steel in spiral round on the SBFB-1500 for the bulk of the trunk runs, with 316L stainless 1.5 mm in the wet flotation section where chloride and reagent vapour can corrode galvanised. SBAL-V handles rectangular branches; SBTF-1500 spiral tubeformer handles comfort HVAC trunk in the control room and amenities.

The lithium hydroxide downstream supply chain at Albemarle Kemerton WA is the highest-temperature unit operation in the Australian lithium sector. Albemarle Kemerton processes spodumene concentrate (6% Li2O feed) through a four-stage refining: rotary kiln calcination at 1,000-1,100°C to convert α-spodumene to β-spodumene, sulfuric acid roast at 250°C in a horizontal rotary kiln, water leach in 316L stainless tanks at 60-90°C, and final lithium hydroxide crystallisation. The kiln exhaust ductwork from kiln outlet to primary cyclone runs at 1,000-1,100°C in 309S stainless welded heavy fabrication, transitioning to 310S or Inconel near the burner zone. SBKJ SBPC1500 plasma cutting station handles the heavy plate fabrication for kiln flange cut-outs and duct transition plates; the welded heavy fabrication of the hot duct itself sits with submerged-arc welding contractors. After the heat exchanger duty the gas cools to 200-400°C and enters the primary cyclone, then the baghouse for fine particulate capture, then a wet scrubber or dry sorbent injection for acid gas, and finally to the discharge stack.

NFPA 86 (industrial oven design) governs the calcination kiln and burner system. AS/NZS 60079 Zone 1 applies to the natural gas burner gas train. AS 1940 governs sulfuric acid storage at the acid roast feed. AS 4041 governs the pressure piping on the steam and condensate systems. NFPA 660 dust hazard analysis applies to the downstream concentrate, lithium sulfate intermediate and lithium hydroxide product handling. Combustible metal controls under NFPA 484 are rare in lithium hydroxide refining (NFPA 484 covers combustible aluminium, magnesium, titanium metal handling) but become relevant if downstream lithium metal production is pursued.

Lithium brine Lake Resources DLE direct lithium extraction

Lithium brine extraction is the emerging Australian lithium production route. Globally, brine production has historically been concentrated in the South American lithium triangle (Chile, Argentina, Bolivia) where solar evaporation of high-grade brine ponds over 12-24 months produces lithium concentrate. Australian brine projects are pursuing a different model: Direct Lithium Extraction (DLE), a sorption or ion-exchange technology that compresses the conventional evaporation pond cycle into a days-long process.

Lake Resources NL (ASX:LKE) operates the Lake Lefroy SA project — a sub-surface brine resource on the Eyre Peninsula. Lake Resources has previously held the Kachi project in Argentina but is now Australian-focused. The DLE flowsheet at Lake Lefroy runs (1) brine extraction from sub-surface bores, (2) brine pre-treatment including clarification, softening and pH adjustment, (3) DLE column operation using proprietary sorption or ion-exchange media, (4) eluate concentration via reverse osmosis, (5) sodium carbonate precipitation to lithium carbonate Li2CO3, and (6) final crystallisation, washing and drying.

Vulcan Energy Resources (ASX:VUL) pursues geothermal lithium brine — a more ambitious dual-product model that extracts both lithium and geothermal heat from deep brine resources. The Vulcan flowsheet integrates geothermal power generation (typically 0.5-5 MW per well doublet) with the DLE column extraction in a combined low-carbon-footprint operation. Vulcan's primary operations are currently in Europe but the Australian opportunity is significant given the Cooper Basin and other deep geothermal resources.

DLE plant HVAC duct demand is significantly different from hard-rock spodumene processing. DLE plants are predominantly enclosed wet-process facilities with significant condensation, humidity control and chemical fume LEV requirements rather than silica dust handling. The dominant LEV sources are sulfuric acid regeneration of the ion-exchange columns (H2SO4 mist WES 1 mg/m³ STEL, plus residual HF if hydrofluoric acid is used in the elution stage), lithium carbonate precipitation tank vent (Li2CO3 dust per respirable 5 mg/m³ TWA and inhalable 10 mg/m³ TWA), the reverse osmosis concentrate stream vent and the final crystalliser vent.

Material specification on DLE LEV duct is 316L stainless 1.5 mm throughout because sulfuric acid mist is corrosive to galvanised coating and lithium hydroxide intermediate streams attack carbon steel. SBKJ SBAL-V configured for stainless coil handles rectangular branches; SBFB-1500 handles round spiral 200-600 mm; SBPC1500 plasma cuts plate for tank vent flange cut-outs. Discharge to a caustic scrubber or wet electrostatic precipitator (wet ESP) to capture residual acid mist before atmospheric release.

The enclosed wet-process building HVAC design intent at a DLE plant differs from a hard-rock concentrator. The building envelope is sealed and pressurised slightly negative relative to the surrounding atmosphere to prevent fugitive emission release. Make-up air is dehumidified and filtered. Conditioned air supply maintains 22-24°C dry bulb at 40-50% RH (lower humidity than a comfort office to control condensation on cooler chemical equipment surfaces). The building exhaust is captured through the central LEV trunk and discharged through the caustic scrubber and stack.

SBKJ machinery scope at a DLE plant such as Lake Lefroy covers the comfort HVAC in the central control building, the analytical laboratory and the amenities buildings, plus the process LEV duct on the chemical fume capture circuits. SBAL-V plus SBTF-1500 covers comfort HVAC; SBAL-V configured for 316L stainless coil covers the chemical LEV; SBFB-1500 covers round spiral; SBPC1500 plasma cuts plate. Total LEV duct scope at a 10,000 tpa lithium carbonate DLE plant runs 1,500-4,000 m² depending on the specific flowsheet.

Workplace exposure standards — the full WES inventory

Safe Work Australia maintains the Workplace Exposure Standards (WES) for the chemical agents present in the Australian extractive sector. The headline numbers are harmonised across NSW, VIC, QLD, WA, SA, TAS, ACT and NT under the harmonised WHS framework. Critical WES values for quarry, aggregate, mineral sands and lithium plant engineering controls are as follows.

• Respirable crystalline silica (RCS): 0.05 mg/m³ TWA. The killer hazard. From quartz sand, basalt fines, limestone, dolomite, granite, mineral sands, spodumene concentrate and rare earth concentrate. Silicosis epidemic driver behind the Engineered Stone Ban of 2024. Regulator audit priority across NSW Resources Regulator, VIC Earth Resources Regulator, QLD MEMR, WA DMP, TAS Mineral Resources.
• Respirable particulate (general): 5 mg/m³ TWA where no more stringent specific limit applies.
• Inhalable particulate (general): 10 mg/m³ TWA. Covers heavy mineral concentrate, rare earth concentrate, lithium concentrate and baghouse-collected dust.
• Carbon monoxide (CO): 30 ppm STEL, typically 25-30 ppm TWA. Source: diesel exhaust (haul trucks, drilling rigs, mobile crushing plant), LPG forklift, propane heater, ANFO blasting fumes, kiln combustion, aggregate dryer.
• Carbon dioxide (CO2): 5,000 ppm TWA. Source: combustion exhaust plus ANFO blasting reaction (which liberates CO2 stoichiometrically). Confined-space entry guidance requires CO2 below 0.5%.
• Methane (CH4): 1.25% LEL alarm threshold (10% of LEL). Source: LPG natural gas burner supply, underground coal mine workings (rare in quarry, more relevant at some hard-rock lithium underground sections), aggregate plant rare.
• Hydrogen fluoride (HF): 1.8 mg/m³ STEL. Source: rare — aluminium pre-paint etching in the workshop or fluorine-containing flotation reagent at some lithium operations.
• Sulfuric acid mist (H2SO4): 1 mg/m³ STEL. Source: lithium sulfate roast at Albemarle Kemerton; sulfuric acid bake at the Iluka Eneabba REC; ion-exchange column regeneration at DLE plants; legacy mineral processing.
• Mercury (Hg): 0.025 mg/m³ TWA. Source: trace contamination in mineral concentrate, phosphate rock, legacy mineral processing.
• Arsenic (As): 0.05 mg/m³ TWA. Source: trace contamination in mineral concentrate, rare earth concentrate, pyrite and arsenopyrite associated minerals.
• Antimony (Sb): 0.5 mg/m³ TWA. Source: trace contamination in mineral concentrate.
• Manganese (Mn): 0.2 mg/m³ TWA. Source: steel welding during plant maintenance, aggregate plant repair work.
• Lead (Pb): 0.05 mg/m³ TWA. Source: legacy tetraethyl lead from pre-1986 leaded petrol contamination on aged plant, leaded brass fittings, avgas 100LL aviation fuel legacy.
• Chromium VI (Cr VI): 0.05 mg/m³ STEL. Source: stainless steel welding fumes, chromite mineral concentrate handling, chromium-bearing mineral exposure.
• Nickel (Ni): Inhalable Ni 1 mg/m³ TWA; insoluble Ni 0.1 mg/m³ TWA. Source: nickel-bearing mineral concentrate handling (IGO Forrestania, IGO Cosmos), stainless steel welding fumes.
• Beryllium (Be): 0.001 mg/m³ STEL. Source: rare — copper-beryllium alloy spring components in mechanical equipment.
• R32, R410A, R454B, R744 refrigerants: typically only relevant to office and control room HVAC condenser refrigerant inventories under AS/NZS 5149 and AS/NZS 1677.

The engineering controls hierarchy applies WES values in the standard sequence: elimination (substitute lower-silica feed, lower-radiation concentrate stream, lower-acid process), substitution, engineering controls (LEV, baghouse, enclosure, capture-at-source), administrative controls (residence time limits, job rotation, signage), and PPE (AS 1715 respiratory protection, ARPANSA-rated dosimetry) only as the final layer.

Standards inventory — AS, NFPA, ARPANSA and regulator

Australian quarry, aggregate, mineral sands and lithium HVAC design draws on a long list of Standards and regulatory references. The complete inventory routinely referenced on a new plant build or a major shutdown follows.

• AS 1668.1 — fire and smoke control via mechanical air handling systems.
• AS 1668.2 — mechanical ventilation in buildings (outdoor air rates, exhaust rates).
• AS/NZS 4254.1 — ductwork for air-handling systems in buildings, low and medium pressure.
• AS/NZS 4254.2 — ductwork for air-handling systems in buildings, high pressure (spiral and rectangular).
• AS 1530.4 — fire-resistance test of building elements (fire-rated ductwork).
• AS 1657 — fixed platforms, walkways, stairways and ladders.
• AS/NZS 60079 series — hazardous area equipment and installation. AS/NZS 60079.10.1 for gas classification at ANFO storage, diesel storage, LPG forklift, propane, diesel generator and lithium electrolyte handling.
• AS 1940 — storage and handling of flammable and combustible liquids. Diesel, propane LPG, blasting agent emulsion.
• AS 2187 — Explosives — Storage, transport and use. Magazine and mixing skid for ANFO, emulsion, booster and detonator.
• AS 3957 — dust hazard identification and control (combustible and silica dust). The single most binding standard on aggregate, mineral sands and lithium concentrator LEV design.
• AS 1715 — selection, use and maintenance of respiratory protective equipment. P2, P3, PAPR.
• AS 1716 — respiratory protective devices.
• AS/NZS 2982 — laboratory fume cupboards.
• AS 4041 — pressure piping (steam, hot oil, lithium hydroxide process piping).
• AS 2030 — gas cylinders and pressure vessel.
• AS 4801 — occupational health and safety management systems (legacy, now AS/NZS ISO 45001).
• AS 4977 — Mine safety management systems.
• AS 5012 — Tailings storage facilities.
• AS 1141 series — aggregate testing (sieving, density, AS 1141.5, AS 1141.6, AS 1141.14, AS 1141.15, AS 1141.21, AS 1141.23, AS 1141.27).
• AS 1289 — Methods of testing soils for engineering purposes.
• AS 2891 — sampling and testing of asphalt mixes (Marshall, density, voids).
• AS/NZS 1554.1 and AS/NZS 1554.6 — structural and stainless steel welding.
• AS/NZS 5149 and AS/NZS 1677 — refrigeration safety.
• NCC Class 8 industrial buildings, NCC Class 7b storage, NCC Class 5 office/lab.
• NFPA 660 (2025) — Standard for Combustible Dust (consolidated, replacing NFPA 652, 654, 484, 61, 664, 655).
• NFPA 68 — Standard on Explosion Protection by Deflagration Venting.
• NFPA 69 — Standard on Explosion Prevention Systems.
• NFPA 86 — Standard for Ovens and Furnaces (rotary kiln for lithium spodumene calcination, aggregate dryer, mineral sands dryer).
• NFPA 484 — Standard for Combustible Metals (rare — only relevant for downstream lithium metal, Al, Mg, Ti concentrate handling).
• NFPA 30 — Flammable and Combustible Liquids Code.
• ARPANSA RPS 9 — Code for Radiation Protection in Mining and Mineral Processing. The binding standard for monazite, xenotime, bastnaesite, ilmenite, zircon and rare earth concentrate handling.
• ARPANSA RPS 6, RPS 8, RPS 10 — supplementary radiation protection codes for occupational exposure, contamination control, transport of radioactive material.
• Aboriginal and Torres Strait Islander Heritage Protection Act 1984, Native Title Act 1993, EPBC Act 1999 — Federal Indigenous heritage and biodiversity protection.
• State Mining Acts — NSW Mining Act 1992, Victorian Mineral Resources (Sustainable Development) Act 1990, Queensland Mineral and Energy Resources (Common Provisions) Act 2014, Western Australian Mining Act 1978, South Australian Mining Act 1971, Tasmanian Mineral Resources Development Act 1995.
• State EPA Acts — NSW POEO Act 1997, Victorian EP Act 2017, Queensland EP Act 1994, WA Environmental Protection Act 1986, SA Environment Protection Act 1993.
• CCAA, SAPAA, MCA, AMMA, Heavy Mineral Sands Association, Australian Lithium Industry Association — industry body design and best-practice guidance.

Process exhaust ductwork — what sits outside SBKJ scope

The boundary between sheet-metal HVAC fabrication on SBKJ machinery and welded heavy fabrication on submerged-arc and FCAW process duct equipment is sharp and well-defined on a quarry, aggregate, mineral sands or lithium plant. Welded heavy fabrication scope covers:

• Lithium spodumene calcination kiln body — 12-25 mm wall thickness in 309S stainless or refractory-lined carbon steel, rotating at 0.5-2 rpm with internal lifters and seals.
• Kiln exhaust duct from kiln outlet to primary cyclone — 309S/310S/Inconel at 1,000-1,100°C with refractory lining at the burner end. Welded by submerged-arc.
• Primary cyclone body on the kiln exhaust circuit — 12-25 mm carbon steel or 309S stainless welded heavy fabrication.
• Baghouse compartments on the kiln and crushing dust collector circuits — 3-5 mm carbon steel or 304L stainless.
• Sulfuric acid bake reactor at the Iluka Eneabba REC and Albemarle Kemerton — 904L super-stainless or fluoropolymer-lined steel pressure-rated vessel.
• Sulfuric acid storage tank at every lithium hydroxide refinery and rare earth refinery — 904L super-stainless or carbon steel with rubber lining, sized 50,000-500,000 L per tank.
• Lithium hydroxide crystalliser body — 316L or 904L stainless pressure-rated vessel with internal scraped-surface heat exchanger.
• Lithium carbonate precipitation tank — 316L stainless with stirred agitation.
• Stack on every dust collector and acid scrubber discharge — 3-5 mm carbon steel cylindrical chimney 25-60 m tall, set by EPA dispersion modelling.
• ANFO magazine bunker — reinforced concrete with controlled ventilation per AS 2187.
• Mineral sands dryer drum — refractory-lined carbon steel cylindrical shell.
• Wet concentrator deck structure — welded steel frame with 316L stainless deck plating.
• WHIMS and ESP separator housings — proprietary OEM construction in 316L stainless.

What sits inside SBKJ machinery scope — the comfort HVAC duct, the LEV duct from each capture point back to the central dust collector or scrubber, the laboratory fume cupboard exhaust, the radiation-controlled monazite handling LEV in 316L stainless, the chemical fume LEV at the DLE column regeneration and the spodumene concentrator transfer point aspiration — is substantial. A typical Australian project sees 60-80% of total HVAC duct length fabricated on the SBKJ sheet-metal line and 20-40% by welded heavy fabrication contractors. The scope split has to be defined cleanly at the design stage to avoid pricing surprises during the contractor selection process.

SBKJ machinery — model-by-model fit to the extractive sector

The SBKJ machinery range is built around the demands of the heavy-industrial HVAC contractor. Each model fits a specific part of the workflow on a quarry, aggregate, mineral sands or lithium plant project. The full model list and its application follows.

SBAL-V Auto Duct Line. The flagship rectangular duct production line. Galvanised G275 or G300 sheet metal at 0.6-1.5 mm wall thickness in single-shift output of 10,000-15,000 m² per month with TDF flange forming, longitudinal seam locking and notching all integrated. The SBAL-V is the workhorse for control room, weighbridge, laboratory, workshop and amenities comfort HVAC supply and return duct on every quarry and aggregate site. Configured for 316L stainless coil, the SBAL-V also fabricates the rectangular branches of chemical LEV duct at the lithium hydroxide refinery, the rare earth refinery, the DLE plant and the mineral sands separation plant.

SBAL-III Auto Duct Line. The compact secondary auto duct line. SBAL-III fabricates similar rectangular duct in 0.6-1.2 mm wall thickness at lower throughput than the SBAL-V — suited to a workshop where the SBAL-V is fully utilised on primary production and the SBAL-III handles secondary, repair and special-piece fabrication.

SBSF-1525 Sheet Flange Machine. The heavy-gauge flange roll-forming station. Used on 1.0-2.5 mm sheet for TDF (transverse duct flange) production, the SBSF-1525 covers the fire-rated 250°C/2-hour duct under AS 1530.4 plus the heavier-gauge flange production for high-pressure rectangular duct on the central LEV trunk.

SB-ZF1500 Sheet Folder. The CNC press brake for rectangular duct elbow, offset, transition and end-cap production. SB-ZF1500 handles 0.6-2.0 mm sheet with programmable back-gauge and crowning for precision folding. Used in combination with the SBAL-V to produce the full rectangular duct fitting range.

SBFB-1500 Round Duct Spiral Former. The dedicated round spiral duct production line. SBFB-1500 produces spiral round duct at 200-1,500 mm diameter in 0.6-2.0 mm wall thickness in mild steel, galvanised or stainless. Production rate 20-60 m/h depending on diameter and wall thickness. SBFB-1500 is the workhorse on aggregate cold feed extraction, mineral sands separation plant LEV trunk runs, rare earth concentrate handling LEV, lithium spodumene concentrator dust extraction, lithium hydroxide acid mist LEV and DLE plant chemical fume capture.

SBPC1500 Plasma Cutting Station. The heavy-plate plasma cutting and manual cutting station. SBPC1500 cuts 6-25 mm mild steel and 6-20 mm stainless plate with programmable nesting. On a quarry or lithium project the SBPC1500 produces (1) tank flange cut-outs for baghouse, scrubber and silo connections, (2) kiln exhaust duct expansion joint plates, (3) ANFO magazine vent stack plates, (4) sulfuric acid bake reactor flange cut-outs and (5) all the heavy-plate one-off fabrication that sits between the standard sheet-metal duct and the welded heavy fabrication contractor.

SBLR-600 Pittsburgh Lockformer. The longitudinal seam Pittsburgh lock production. SBLR-600 handles 0.5-1.5 mm sheet at 8-16 m/min throughput. Used as a secondary station to the SBAL-V for non-automated production runs, prototype duct and specialised fittings.

SBTF-1500, SBTF-1602 and SBTF-2020 Spiral Tubeformers. The dedicated spiral round duct production for HVAC supply applications. SBTF-1500 covers 100-1,500 mm diameter, SBTF-1602 covers 100-1,600 mm and SBTF-2020 covers up to 2,000 mm. Production rate 15-50 m/h depending on diameter. SBTF spiral tubeformers fabricate the comfort HVAC trunk supply duct in the control room, weighbridge office, laboratory and amenities, in galvanised G275 or G300 sheet at 0.6-1.5 mm.

Quarry control room and laboratory HVAC

The quarry, aggregate or lithium plant central control room is the operational nerve centre. A typical control room is a purpose-built building 5-12 m × 8-15 m floor area housing 3-6 operator workstations facing windows that look out over the primary jaw crusher, secondary cone crusher, screening tower and stockpile conveyors. Computer screens display the SCADA system, instrument readings, conveyor weigh data, mineral grade analysis (where on-line elemental analyser is fitted), crusher discharge tonnage and stockpile inventory.

Control room HVAC design intent is positive pressure (+25 to +50 Pa relative to surrounding plant), two-stage particulate intake filtration (G4 prefilter ISO 16890 ePM10 ≥50% plus F7 or F9 final filter ISO 16890 ePM2.5 ≥85%), thermal comfort 22-24°C dry bulb at 50-60% RH, and acoustic comfort below 55 dBA RMS at the operator workstation. Hermetic sealing of the building envelope — gasketed doors, sealed cable penetrations, double-glazed windows with EPDM gaskets — keeps silica RCS dust, heavy mineral concentrate dust and lithium concentrate dust out of the operator breathing zone.

The HVAC supply duct serving the control room is conventional rectangular galvanised duct in 0.7-1.0 mm wall thickness fabricated on the SBAL-V auto duct line to AS/NZS 4254-1 low-pressure construction tolerances. TDF/TDC flange joints sealed with neoprene gasket and silicone bead. Trunk supply from the rooftop AHU into the control room in spiral round duct on the SBTF-1500/1602/2020 at 200-500 mm diameter.

The aggregate or lithium plant laboratory adjacent to the control room runs aggregate testing under AS 1141 (sieving, Los Angeles abrasion, Micro-Deval abrasion, shape index, flakiness/elongation, aggregate crushing value), AS 1289 soil testing, AS 2891 asphalt testing (where the plant supplies asphalt-grade aggregate), and chemical assay testing on mineral concentrate or lithium concentrate samples. Sample preparation involves crushing, splitting, screening and dissolution — each generating local silica or concentrate dust. Lab LEV at the sample preparation bench and the fume cupboard is mandatory.

Laboratory fume cupboard construction follows AS/NZS 2982. Sash face velocity 0.5 m/s ± 10% across the full sash opening. Duct material 316L stainless 0.8-1.0 mm because chemical fume condensate accumulates on the duct internal surface. Fume cupboard exhaust fan is dedicated (one fan per cupboard, not shared) to allow individual lab shutdown during fan maintenance. Discharge to roof level with downstream HEPA filtration if radioactive monazite or lithium concentrate sample preparation is the dominant use.

AS 1668.2 outdoor air rates apply: 10 L/s/person minimum for offices, 12 L/s/person for control rooms with display screen work, 25 L/s/person for laboratory analytical benches, 50 L/s per WC pan for amenities exhaust. Air balance verification at commissioning measures supply flow, return flow, exhaust flow, room pressure differential to surrounding plant, and capture velocity at each LEV hood.

Project programme — fabrication, install and commissioning

The HVAC fabrication programme for a typical mid-sized quarry or aggregate LEV and comfort HVAC package (1,500-4,000 m² of duct across the control building, the screening tower, the crusher discharge LEV and the conveyor transfer points) runs 4-6 weeks of fabrication time and 3-5 weeks of installation time. Total programme from purchase order to handover is 10-16 weeks excluding design lead time. Design lead time on a quarry project is typically 4-6 weeks for HVAC drawing approval through the operator's engineering review.

For a lithium hydroxide refinery upgrade (Albemarle Kemerton scope, 5,000-12,000 m² of duct across the calcination, leach, crystallisation and bagging plants), fabrication time runs 8-14 weeks and installation runs 6-10 weeks. Total programme 18-28 weeks excluding design. Lithium projects also carry significant ARPANSA-style documentation requirements where radioactive content is present in the feed concentrate, plus AS/NZS 60079 dossier maintenance on every hazardous area zone.

Mineral sands and rare earth refinery projects (Iluka Eneabba MSP+REC scope) typically run shutdown-based with 2-4 week shutdown windows for major LEV upgrades and full-year fabrication programmes for greenfield builds. Iluka's Eneabba REC commissioning programme through 2023-2025 demonstrated the integration challenge of new rare earth refining capability with mineral sands MSP and the requirement for ARPANSA RPS 9 sign-off across every controlled-area duct circuit.

HVAC contractors working around a quarry, aggregate or lithium shutdown coordinate closely with the plant maintenance superintendent and the EPC shutdown coordinator to avoid clashes with crane lifts, scaffold installation, refractory work (on kilns) and electrical isolation lockouts. Pre-shutdown fabrication off-site, modular delivery to site, crane lift on day one and tie-in on days two through five is the typical install sequence for a major LEV upgrade package. Larger lithium and rare earth refinery projects work to a 90-180 day shutdown programme with prefabricated modules delivered for crane lift and final field welding.

ARBS 2026 and the Australian extractive-sector HVAC contractor network

ARBS 2026 — the Air Conditioning, Refrigeration and Building Services exhibition at the International Convention Centre Sydney in May 2026 — is the dominant Australian HVAC industry event of the year. SBKJ Group will be in attendance, with the SBAL-V auto duct line, SBFB-1500 spiral former, SBPC1500 plasma cutting station and SBTF-1500/1602/2020 spiral tubeformer configurations on display. Heavy industrial HVAC contractors working on Boral, Hanson, Adbri, Holcim, Pioneer Construction Materials, Wagners, Sibelco, Iluka Eneabba, Strandline Coburn, Pilbara Minerals Pilgangoora, Mineral Resources Mt Marion and Wodgina, IGO Greenbushes, Liontown Kathleen Valley, Core Lithium Finniss, Albemarle Kemerton, Lake Resources Lake Lefroy or Vulcan Energy quarry, aggregate, mineral sands, rare earth and lithium projects are encouraged to attend.

The CCAA (Cement Concrete & Aggregates Australia) annual conference, the SAPAA (Sand and Aggregate Producers Association of Australia) congress, the MCA (Minerals Council of Australia) annual conference and the Australian Lithium Industry Association annual forum are the other industry events where extractive-sector operators, HVAC contractors and equipment suppliers cross paths. The CCAA technical guidance, MCA Sustainability Framework, SAPAA Best Practice Guide and the ARPANSA RPS 9 Code provide the technical reference points for any HVAC contractor pricing or designing extractive-sector work.

FAQ

Why is respirable crystalline silica the killer hazard on Australian quarry and aggregate plants?

RCS is the single most lethal occupational exposure in the Australian quarry, aggregate, sand and gravel sector. The Safe Work Australia WES sits at 0.05 mg/m³ TWA — halved from 0.1 mg/m³ after the Australian silicosis epidemic. The epidemic produced the world's first national Engineered Stone Ban in 2024 and reshaped how every operator from Boral and Hanson to Adbri, Holcim, Pioneer, Wagners and Sibelco specifies dust extraction. AS 3957 is the binding engineering standard with capture velocity 1.0-1.5 m/s at the source, transport velocity 18-22 m/s in trunk duct, baghouse air-to-cloth 1.0-1.5 m³/m²/min and discharge under 30 mg/Nm³ as the design defaults.

How does the Engineered Stone Ban 2024 affect quarry and aggregate HVAC duct design?

The Engineered Stone Ban that came into force across all Australian states on 1 July 2024 prohibits manufacture, supply, processing and installation of engineered stone benchtops with crystalline silica. The ban does not directly restrict natural quarried stone, sand, gravel, basalt or aggregate, but the regulatory aftermath has dramatically raised regulator scrutiny of every silica exposure source across NSW Resources Regulator, VIC Earth Resources Regulator, QLD MEMR, WA DMP and TAS Mineral Resources. State EPAs have tightened licence conditions on stack emissions. HVAC contractors pricing aggregate plant LEV upgrades face significantly higher engineering documentation requirements, capture velocity verification, baghouse performance testing and AS 1668.2 commissioning sign-off.

How is the ANFO explosives store classified under AS/NZS 60079?

ANFO storage magazines are governed by AS 2187 (Explosives — Storage, transport and use) rather than AS 1940. Ammonium nitrate is Class 5.1 oxidiser, not flammable liquid. However, the diesel fuel oil component, booster charges, detonators and cap-sensitive emulsion explosives trigger AS/NZS 60079.10.1 hazardous area zoning around vent lines, fuel transfer and ventilation outlets. The ANFO mixing skid and the on-bench mobile manufacturing unit (MMU) are typically Zone 1 within 4.5 m of the diesel pump and Zone 2 around the prilled AN auger. All electrical equipment must be Ex-rated to EPL Gb or Gc and certified through IECEx or ANZEx. SBKJ scope is the ventilation duct in 304 or 316 stainless on the SBAL-V and SBFB-1500.

Why does monazite handling at Iluka Eneabba trigger ARPANSA radiation controls?

Monazite is a phosphate of the rare earths plus thorium-232 and uranium-238 impurities at 5-12% combined by mass. Th-232 and U-238 each begin long radioactive decay chains producing radium, radon, thoron, polonium and lead daughters. Bulk monazite handling, concentrate stockpiles, dryer exhaust, conveyor transfer points and bagging operations generate radon and thoron gas plus alpha-emitting particulate. ARPANSA RPS 9 (Code for Radiation Protection in Mining and Mineral Processing) sets the framework with 20 mSv/year (5-year average) and 50 mSv any single year. Engineering controls include LEV at every monazite transfer point with HEPA filtration on the discharge stack, AS 1715/1716 P3 respirators, radon monitoring and personnel dosimetry. LEV duct in 316L stainless 1.5 mm allows surface decontamination during shutdown.

How is lithium spodumene concentrate calcination ventilation designed?

Spodumene at Pilgangoora, Mt Marion, Wodgina, Greenbushes, Kathleen Valley and Finniss is calcined at 1,000-1,100°C in a rotary kiln at Albemarle Kemerton to convert α-spodumene to acid-leachable β-spodumene. Kiln exhaust at 1,000-1,100°C carries spodumene dust, alumina, silica RCS, CO, NOx and CO2. Exhaust duct from kiln outlet to primary cyclone is welded heavy fabrication in 309S stainless with 310S or Inconel near the burner zone. SBKJ SBPC1500 plasma cuts plate for flange and expansion joint fabrication; welded heavy fabrication of the hot duct sits with submerged-arc contractors. After heat exchanger duty the gas cools to 200-400°C and enters cyclone and baghouse for particulate capture. NFPA 86 industrial oven design applies to the kiln; AS/NZS 60079 Zone 1 to the burner gas train; NFPA 660 dust hazard analysis to downstream handling.

What is lithium brine direct lithium extraction (DLE) and how is it ventilated?

Lake Resources Lake Lefroy SA and Vulcan Energy geothermal brine projects are the emerging Australian lithium brine producers. DLE replaces the conventional 12-24 month solar evaporation pond cycle with ion-exchange resin columns, sorption media, nanofiltration and reverse osmosis to extract lithium directly from raw brine in days. DLE plants are enclosed wet-process facilities with significant chemical fume LEV. Sulfuric acid regeneration of ion-exchange columns generates H2SO4 mist (WES 1 mg/m³ STEL). Lithium carbonate at precipitation and bagging is handled under respirable 5 and inhalable 10 mg/m³ TWA. LEV duct in 316L stainless 1.5 mm throughout on the SBAL-V configured for stainless coil; SBFB-1500 for round spiral; SBPC1500 plasma cuts plate. Discharge to caustic scrubber or wet ESP.

Which Australian quarry, mineral sands and lithium operators are the major HVAC duct buyers?

Quarry and aggregate: Boral (ASX:BLD) largest 100+ quarries through Boral Quarries, Boral Concrete and Boral Asphalt. Hanson Australia (HeidelbergMaterials ASX:HAN) second largest national. Adbri (ASX:ABC) at Birkenhead SA, Cockburn WA, Burnett Lime, Penrice. Holcim Australia all capitals. Pioneer Construction Materials in Sydney, Brisbane, Perth, Adelaide. Wagners (ASX:WGN) Toowoomba NGA and geopolymer. Independent Cement Mt Gambier, Geelong, Wagga. Quarry Solutions Australia, Buderim Quarry. Sibelco Capel WA, Stradbroke Island, Pacific Sands silica sand. Mineral sands: Iluka Resources (ASX:ILU) Eneabba MSP and RE Refinery; Strandline (ASX:STA) Coburn; Mineral Sands Resources NSW. Lithium hard-rock: Pilbara Minerals (PLS) Pilgangoora; Mineral Resources (MIN) Mt Marion and Wodgina; IGO (IGO) Greenbushes JV with Albemarle; Liontown (LTR) Kathleen Valley; Core Lithium (CXO) Finniss. Downstream: Albemarle Kemerton, Albemarle Kwinana. Lithium brine: Lake Resources (LKE) Lake Lefroy SA; Vulcan Energy (VUL) geothermal.

What does SBKJ machinery scope cover on an Australian quarry or lithium plant project?

SBKJ comfort HVAC scope: control room, weighbridge, lab, workshop, amenities. Galvanised 0.6-1.5 mm to AS/NZS 4254-1 on the SBAL-V for rectangular and SBTF-1500/1602/2020 for round spiral. The SBAL-V configured for 316L stainless coil fabricates lithium plant sulfuric acid LEV, lithium hydroxide crystallisation vent, mineral sands wet concentrator deck LEV, monazite and rare earth concentrate handling LEV (radiation-controlled), and DLE chemical fume capture. SBAL-III for secondary fabrication. SBSF-1525 for heavy-gauge flange including fire-rated 250°C/2-hour AS 1530.4 duct. SB-ZF1500 for elbow and transition. SBFB-1500 for round spiral aggregate cold feed extraction, mineral sands MSP LEV, rare earth concentrate handling, lithium concentrator dust. SBPC1500 plasma for kiln flange cut-outs, baghouse plates, ANFO magazine vent plates. SBLR-600 Pittsburgh lock. Welded heavy fabrication on kiln exhaust 309S/310S/Inconel, refractory burner sections and large-diameter process ducting sits with submerged-arc fabrication shops.

How is rare earth concentrate handling duct fabricated at Iluka Eneabba RE Refinery?

The Iluka Eneabba RE Refinery (REC), supported by the Eneabba RE CRC, is Australia's first integrated mineral sands concentrate to individual rare earth oxide producer. Feed is monazite, xenotime and bastnaesite. Processing is sulfuric acid bake (concentrated H2SO4 at 200-300°C), water leach, mixed rare earth carbonate precipitation, solvent extraction (organophosphate, organophosphine, amine in kerosene) and individual oxide finishing. LEV is acid gas extraction (H2SO4 mist WES 1 mg/m³ STEL, HF rare, HCl 5 mg/m³ STEL), solvent vapour capture (kerosene, organophosphate, total VOC), radiation-controlled monazite dust capture under ARPANSA RPS 9 (radon, thoron, alpha particulate, gamma), and NFPA 660 combustible dust controls. LEV duct in 316L stainless 1.5-2.0 mm throughout the acid bake and leach, 904L super-stainless or fluoropolymer-lined steel in the most aggressive sections. Comfort HVAC in galvanised on the SBAL-V. SBPC1500 plasma cuts heavy flange plate.

What ventilation rate applies to a quarry crushing plant control room and dust collector baghouse?

Quarry control rooms are small purpose-built buildings 4-8 m × 6-10 m housing 2-4 operator workstations. AS 1668.2 outdoor air rate is 10 L/s/person for offices and 12 L/s/person for control rooms with display screens. Design intent is positive pressure +25 to +50 Pa, two-stage particulate filtration (G4 prefilter ePM10 ≥50% plus F7 or F9 final filter ePM2.5 ≥85%), thermal comfort 22-24°C dry bulb at 50-60% RH, acoustic below 55 dBA RMS. Baghouse extraction on a 500 t/h crushing plant runs 80,000-200,000 m³/h total across 15-30 capture points (primary jaw discharge, vibrating screen decks, transfer points, stockpile conveyors, secondary and tertiary cone discharge). Capture velocity 1.0-1.5 m/s per AS 3957. Trunk transport velocity 18-22 m/s. Baghouse air-to-cloth 1.0-1.5 m³/m²/min with pulse-jet PTFE-membrane bags. Discharge under 30 mg/Nm³ to atmosphere per state EPA licence.

Talk to an SBKJ engineer about your quarry, aggregate, mineral sands or lithium plant HVAC duct fabrication scope →

SBKJ Group contact

SBKJ Group is the Australian-resident supplier of HVAC duct fabrication machinery to the Australian quarry, aggregate, sand and gravel, mineral sands, heavy mineral concentrate, rare earth, lithium hard-rock spodumene and lithium brine DLE market. Based in Box Hill North VIC, SBKJ provides English-language pre-sales engineering, commissioning, training, after-sales service and spare parts across the SBAL-V, SBAL-III, SBSF-1525, SB-ZF1500, SBFB-1500, SBPC1500, SBLR-600 and SBTF-1500/1602/2020 machine range. For HVAC contractors working on Boral, Hanson, Adbri, Holcim, Pioneer, Wagners, Sibelco, Iluka Eneabba, Strandline Coburn, Pilbara Minerals, Mineral Resources, IGO, Liontown, Core Lithium, Albemarle Kemerton, Lake Resources Lake Lefroy or Vulcan Energy projects, SBKJ engineering replies within 12 hours.

• Email: sales@sbkjduct.com
• Phone: +61 435 074 994
• Website: sbkjduct.com
• Location: Box Hill North VIC, Australia
• ARBS 2026: May 2026, ICC Sydney — SBKJ Group on the exhibitor floor