High-basicity aluminum chlorohydrate (ACH) is helping Australian mining and mineral-processing operations recover more water and produce clearer tailings overflow, even as water licences tighten. ACH combines more than 23% Al2O3 with 82-85% basicity, so it destabilises fine clays and mineral particles at low dose, with a negligible effect on pH and low sludge generation. In a sector where every litre recovered reduces fresh-water intake and tailings risk, that efficiency is decisive. This guide explains what ACH is, why high basicity suits mine-water and tailings circuits, and how to select, dose and apply it. From iron ore and coal to gold, copper and mineral sands, correctly applied ACH improves thickener performance, decant clarity and water recovery, supporting the water-efficiency and environmental obligations of Australian resource projects. With tight water licences and rising tailings responsibility, choosing the right coagulant is now a strategic decision for every Australian resource project. That makes ACH a smart choice for water-constrained sites.

Aluminum chlorohydrate (ACH) is a highly polymerised, water-soluble aluminium coagulant with the formula Al2(OH)5Cl·2H2O. It carries the highest Al2O3 content (over 23%) and the highest basicity (82-85%) of any commercially available aluminium-based solution, and it is supplied as a ready-to-use liquid.

How it works in mineral circuits. Mineral tailings and process slurries are dominated by fine clays, silts and metal hydroxides that carry a negative surface charge, which keeps them suspended. ACH's highly charged, polymerised aluminium species neutralise that charge and gather the fines into dense micro-flocs, allowing thickeners and clarifiers to drop solids far more effectively.

Coagulant plus flocculant. ACH is a coagulant, so it is normally used upstream of a high-molecular-weight anionic flocculant. ACH performs the charge neutralisation that destabilises the fines; the flocculant then bridges the micro-flocs into large, fast-settling aggregates. The two work best as a pair, and ACH's stability makes the sequence predictable and easy to control.

Stable and concentrated. Because it is pre-polymerised, ACH works quickly and performs consistently even in cold or saline process water, and its high concentration keeps freight and storage demands low at remote sites.

Supplied as a ready-to-use liquid, ACH is metered with standard dosing pumps and mixes readily with process water. Its stability in storage means the dose an engineer validates in the lab holds on site, shift after shift.

How it compares with lime and other coagulants. Lime raises pH and adds substantial solids, while conventional aluminium salts consume alkalinity and can be sluggish in cold or saline water. ACH combines high charge, high concentration and pH stability, so it clarifies tailings and process water with less reagent, less sludge and less downstream disturbance to flotation or leaching chemistry.

Water is the defining constraint on many Australian resource projects. Operations in the Pilbara, the Bowen and Surat basins, the Goldfields and the mineral-sands regions must work within water licences set by state regulators such as DWER in Western Australia and the Department of Environment and Science in Queensland, while meeting their own water-efficiency and tailings-management obligations.

More water recovered. Clearer thickener overflow and cleaner decant water can be returned to the process, directly reducing fresh-water intake and the volume drawn against a licence.

Safer, smaller tailings. Better solids capture and higher underflow density reduce the water tied up in tailings storage facilities and ease the pressure on containment and risk management - a growing priority for regulators and communities.

Low dose, low sludge penalty. ACH's high Al2O3 content means less product per tonne treated, and its low water-insoluble content avoids adding unnecessary solids to the circuit.

Negligible pH impact. Because ACH is already heavily neutralised, it barely shifts circuit pH, so it does not disturb downstream chemistry or require alkali correction.

Total cost of ownership is the real test. A coagulant is judged by the cost per tonne of solids treated and by the water it recovers, not by its unit price. A concentrated, predictable ACH that lifts underflow density and overflow clarity often lowers the annual bill through reduced fresh-water purchase, less tailings haulage and fewer process upsets, even before its lower dose is counted.

Seasonality compounds the challenge. Wet-season downpours dilute and re-suspend fines, while dry-season heat and salinity change flocculation behaviour. A coagulant that performs reliably across that swing keeps the whole water balance stable and protects the licence position.

Blending flexibility is another advantage. In very fine or high-clay tailings, ACH can be paired with a high-molecular-weight anionic flocculant; the ACH neutralises charge while the flocculant bridges the aggregates. Because ACH is stable and pre-polymerised, this two-part approach is easy to control and gives engineers a lever to tune both clarity and underflow density.

Environmental and social licence considerations reinforce the case. Cleaner return water and reduced tailings volume help operations demonstrate responsible water stewardship, an increasingly important factor in approvals, community consultation and investor expectations across the Australian resources sector.

Logistics matter too. Remote mine sites face long freight routes and limited storage; a highly concentrated liquid coagulant that ships as drums, IBCs or a flexitank reduces the number of deliveries and the footprint of on-site chemical storage.

ACH repays a structured, test-driven approach. Follow these steps to move from a datasheet to a validated program.

Establish solids concentration, particle size and clay content, pH, salinity and the thickener or clarifier feed rate. Sample across the wet and dry seasons, because both the feed and the water chemistry can change markedly.

Test ACH alone and in combination with your anionic flocculant, measuring settling rate, overflow clarity and underflow density rather than final clarity alone. Because ACH is concentrated, start low and bracket upward.

Dose ACH first under rapid mixing to neutralise charge, then add the flocculant under controlled shear to bridge the flocs. Keep mixing energy within the flocculant manufacturer's limits so the aggregates are not broken apart.

Calibrate metering pumps and set a control range. Monitor underflow density, overflow clarity and water recovery, and review the setpoint whenever the ore body, feed rate or water source changes.

ACH ships in 275 kg drums, 1,350 kg IBCs or a 25 MT flexitank. Keep it sealed and out of rain, heat and sunlight, and never store it with alkaline reagents such as lime, which is common on mine sites, or the product will fail. Follow the safety data sheet and site WHS rules.

Picture a gold or base-metal concentrator whose tailings thickener struggles during the wet season, when high-clay feed dilutes and re-suspends fines. ACH is dosed into the thickener feed, followed by a high-molecular-weight anionic flocculant. The ACH neutralises the clay charge, and the flocculant bridges the micro-flocs. Overflow clarity improves, underflow density rises, and more water is returned to the process, cutting fresh-water draw against the site's licence and reducing the volume tied up in the tailings storage facility.

Do not add the flocculant before the ACH, or the sequence will fail, and do not over-shear the flocs, which breaks them apart and wastes both chemicals. Test with the site's actual process water, because salinity and clay content change dose dramatically, and keep all dosing equipment corrosion-resistant. Where tailings are extremely fine or high in clay, consider raising the ACH dose or pairing it with a coagulant aid, validating the change with a fresh settling test before full-scale rollout. Above all, never store ACH near lime, a reagent found on almost every mine site, because the two react and destroy the product.

Review the dose whenever the ore body, clay content, feed rate or water source changes, because the optimum rarely stays fixed; a quick settling test before each major change keeps the circuit stable. Keep spare drums or an IBC on site so an unexpected feed surge never interrupts treatment.

Yes. ACH is widely used as a coagulant in mineral processing and mine-water circuits, where it destabilises fine clays and silts so thickeners and clarifiers can drop solids efficiently. It is normally paired with a high-molecular-weight anionic flocculant, with ACH added first to neutralise charge and the flocculant added next to build large, fast-settling flocs.

They do different jobs and are used together. ACH is a coagulant: its highly charged, polymerised aluminium neutralises the negative surface charge on fine particles, forming micro-flocs. The anionic flocculant is a long-chain polymer that bridges those micro-flocs into large aggregates. Using ACH upstream sharpens clarity and underflow density.

Dose depends entirely on the slurry, so it must be set by settling tests on the actual tailings. Because ACH is highly concentrated, its dose is low relative to conventional coagulants. Engineers bracket upward from a small starting dose, judging success on settling rate, overflow clarity, underflow density and water recovery.

Yes, directly. By producing clearer thickener overflow and cleaner decant water, ACH lets more water be returned to the process, reducing fresh-water intake in water-scarce regions such as the Pilbara and Goldfields. That supports both water-efficiency targets and compliance with state water licences.

Very little. Because ACH is already heavily neutralised, with basicity of 82-85%, it produces a negligible pH change and consumes almost no alkalinity. That means it will not disrupt downstream flotation or leaching chemistry or require alkali correction, which simplifies control on site.

Keep ACH sealed in a dry, ventilated place away from rain, high temperature and sunlight, and well away from alkaline reagents such as lime or bleach, which would cause it to fail. It ships as drums, IBCs or a flexitank to suit remote logistics. Always follow the safety data sheet and site WHS requirements.

For Australian mining operations facing tight water licences and rising tailings responsibilities, aluminum chlorohydrate is a powerful lever. Its high Al2O3 content and 82-85% basicity give strong charge neutralisation at low dose, with negligible pH impact and low sludge penalty, while pairing it with an anionic flocculant delivers clear overflow and dense underflow. Characterise the slurry, test the dose, fix the coagulant-flocculant sequence, and store the product correctly, and ACH helps a site recover more water, shrink tailings risk and strengthen its environmental and social licence to operate.