Dust Suppression with Saline Water for Effective Mine Dust Control

Dust Suppression with Saline Water: How to Turn Your Mine’s Biggest Water Challenge into Effective Dust Control

Fresh water is scarce on most Australian mine sites. In the Pilbara, the Goldfields, South Australia’s arid interior and large parts of Queensland’s Bowen Basin, the water available for operational use is drawn from pit dewatering, underground aquifer extraction or recycled process water — and it is frequently saline or hypersaline. Total dissolved solids (TDS) concentrations of 30,000–200,000 mg/L are common in the Eastern Goldfields palaeochannel aquifers. Pilbara operations abstract approximately 550 gigalitres per year from below-water-table mining, with a significant proportion of that water carrying elevated salinity from the aquifer systems it is drawn from.

Many of these operations use their saline water supply directly for dust suppression on haul roads, access roads and operational areas. The reasoning is pragmatic: the water is available, it is on site, and it avoids the cost of sourcing, treating or transporting fresh water to remote locations. But relying on saline water alone for dust control is a strategy with fundamental limitations that become apparent in the conditions where effective suppression is most needed — the hottest, driest, most arid periods when dust generation is at its peak.

This article explains why saline water alone is an unreliable dust suppressant, which product technologies are compatible with saline water supplies, and how polymer-based suppression turns a mine’s saline water from a limitation into an effective dust control asset.

Why Saline Water Alone Is an Unreliable Dust Suppressant

The dust suppression effect of saline water relies on hygroscopy — the tendency of dissolved salts to attract moisture from the atmosphere. When saline water is sprayed on a road surface, the water evaporates and leaves a salt residue in the wearing course. Under ideal conditions — moderate temperatures, moderate to high humidity — this salt residue attracts atmospheric moisture, keeping the road surface damp and binding dust particles together. In coastal or temperate climates, this mechanism can provide useful short-term dust control.

In the arid climates where most Australian mines operate, these ideal conditions rarely exist during the periods when dust control is most critical. The performance of saline water as a dust suppressant is limited by five factors that are characteristic of Australian mining environments.

Low relative humidity. The hygroscopic mechanism requires atmospheric moisture to attract. In the Pilbara, relative humidity during summer afternoons can drop below 10–15%. In the Goldfields, dry conditions persist for months. When humidity is insufficient, the salt residue simply sits on the road surface without attracting moisture, providing no dust suppression at all. The road is dry, dusty and generating particulate matter as if untreated.

Extreme evaporation rates. In arid Australia, evaporation rates exceed 2,500–3,000 mm per year — far exceeding annual rainfall. Water applied to a haul road surface in the Pilbara can evaporate within 20 minutes during summer. The saline water evaporates faster than the salt residue can attract replacement moisture from the atmosphere, resulting in a net-dry surface that offers no suppression.

Variable salt chemistry. Not all salts are equally hygroscopic. Calcium chloride and magnesium chloride are strongly hygroscopic, but the salts in natural groundwater and pit dewatering water are typically a complex mix of sodium chloride (which is less hygroscopic), calcium, magnesium, potassium, bicarbonate and sulphate ions at variable concentrations. The dust suppression effect depends on which salts are dominant and at what concentration — a variable that changes with the aquifer being tapped, the season and the production rate.

Soil salinisation and environmental damage. Chronic application of saline water to haul roads and operational surfaces progressively salinises the surrounding soil. Runoff from saline-treated roads carries dissolved salts into drainage lines and downstream receiving environments. For mine sites with environmental authority conditions limiting salt discharge to waterways, or for operations adjacent to agricultural land, the cumulative salt loading from dust suppression can become a compliance and community relations issue.

Equipment corrosion. Saline water accelerates corrosion on every piece of equipment it contacts — water trucks, spray bars, haul truck bodies, light vehicle undercarriages, standpipe fittings and roadside infrastructure. The corrosion cost does not appear on the dust suppression line item but it manifests in accelerated equipment depreciation, increased maintenance costs and reduced asset life across the fleet.

Which Dust Suppression Products Work with Saline Water?

For mine sites where saline water is the only available supply, the critical question is not whether to use saline water for dust suppression — it may be the only option — but whether the dust suppression product being dosed into that water is compatible with the salinity.

Not all products are. Some polymer emulsions destabilise in high-salinity environments — the dissolved salts interfere with the emulsion chemistry, causing the polymer to precipitate, coagulate or lose its binding effectiveness. Products designed and tested in fresh water may not perform to specification when diluted with water containing 30,000–200,000 mg/L TDS. If a product has not been specifically tested and verified for performance in saline water, its field effectiveness on a Pilbara or Goldfields mine site is unknown.

Dust suppressant product categories: saline water compatibility

How Polymer Technology Turns Saline Water into an Effective Suppression Medium

The fundamental advantage of polymer-based dust suppression in a saline water environment is that the binding mechanism does not depend on hygroscopy. Polymer emulsions form adhesive bonds between soil particles through mechanical and chemical adhesion — the polymer chains physically connect particles into a cohesive matrix that resists tyre shear and wind erosion. This binding mechanism works regardless of the salinity of the carrier water, because the polymer, not the water, is doing the binding.

GRT: Haul-Loc is specifically formulated to be compatible with saline water supplies. Dosed into the water truck supply via SMART Dosing Units at a ratio of 1:10,000, the polymer concentrate is diluted into the site’s available water — whether fresh, brackish or hypersaline — and delivered through the existing spray system. As the water evaporates from the road surface (rapidly, in arid conditions), the polymer residue remains, forming the adhesive bonds that suppress dust for hours to days rather than the minutes that saline water alone provides.

The practical consequence is that a mine site using hypersaline bore water for dust suppression can achieve the same polymer-enhanced dust control performance as a site with fresh water. The salinity of the carrier water does not degrade the product performance because the binding mechanism is independent of the water chemistry. The site’s water supply — previously a limitation on dust control effectiveness — becomes simply the delivery vehicle for the polymer concentrate.

GRT7000 soil stabilisation can also be applied using saline water. When incorporated into the wearing course during road construction or rehabilitation, the polymer binds the road material into a structurally sound, dust-free, waterproof surface regardless of the salinity of the mixing water. For sites that have been constructing haul roads with saline water and experiencing accelerated deterioration from salt crystallisation and weakened base layers, GRT7000 provides a stabilisation pathway that works with the water available on site.

Regional Context: Pilbara, Goldfields and South Australia

Pilbara Iron Ore Operations

The Pilbara’s iron ore operations abstract approximately 550 GL of water per year, with around 250 GL used for ore processing, dust suppression and other operational purposes. Much of this water comes from below-water-table dewatering of aquifer systems that underlie the ore bodies. While Pilbara groundwater is generally less saline than the Goldfields (typically 500–10,000 mg/L TDS depending on the aquifer and location), salinity varies significantly between operations and between bores on the same site. Water management is under increasing strategic scrutiny, with CSIRO, GHD and the ICMM Water Stewardship Framework all advocating for reduced water consumption in dust suppression.

For Pilbara operations, polymer-dosed saline water reduces total water consumption for dust suppression by 50–90% compared to saline water alone. This is a water stewardship outcome as much as a dust control outcome — reducing the volume drawn from aquifer systems that may not be sustainably recharged under current abstraction rates.

Eastern Goldfields Gold Operations

The Eastern Goldfields presents the most extreme salinity challenge in Australian mining. Palaeochannel aquifers underlying the gold mining region contain hypersaline groundwater with TDS concentrations of 30,000–200,000+ mg/L — comparable to or exceeding seawater. Fresh water is essentially unavailable at many sites. Process water is recycled through thickeners and tailings systems, further concentrating salts.

For Goldfields operations, the choice of dust suppressant is constrained from the outset by water chemistry. Chloride-based products are redundant — the water already contains high chloride concentrations, and adding more chloride salt provides negligible additional hygroscopic benefit while compounding corrosion and salinisation risks. The only product categories that provide genuine additional dust suppression performance when dosed into hypersaline Goldfields water are polymers and, to a limited extent, bitumen emulsions (where emulsion stability in hypersaline water can be verified).

South Australian Operations

South Australian mining operations — including copper, gold, uranium and iron ore projects across the Gawler Craton, Stuart Shelf and Flinders Ranges — frequently rely on bore water with moderate to high salinity. The arid climate (annual evaporation exceeding 2,500 mm in most mining regions) means that saline water alone evaporates rapidly without leaving effective suppression. Operations in the Olympic Dam, Carrapateena and Prominent Hill corridors face the same combination of limited fresh water availability, elevated salinity and extreme evaporation that characterises the Pilbara and Goldfields.

Practical Implementation: Making Polymer Suppression Work with Your Water

1. Test your water. Before deploying any dust suppressant product, characterise your site’s water supply. At a minimum, measure TDS, pH, and the concentrations of the major ions (sodium, calcium, magnesium, potassium, chloride, sulphate, bicarbonate). This baseline determines the dosing rate and product selection.
2. Select a product formulated for saline water. Not all polymer emulsions tolerate high salinity. GRT’s products are specifically formulated and tested for compatibility with saline water supplies. Request the technical data for your site’s specific salinity range to confirm product suitability.
3. Install automated dosing. Consistent dosing is critical for performance, particularly in saline water where the margin between under-dosing (ineffective) and optimal dosing is site-specific. SMART Dosing Units installed at the standpipe or fill point meter the polymer concentrate into the water supply automatically every time the water truck fills, ensuring the correct dose regardless of which operator is on shift.
4. Adjust for seasonal variation. Salinity in bore water and pit dewatering water can vary seasonally (dilution after heavy rainfall events, concentration during dry periods). Periodic water testing and dosing adjustment ensures consistent performance year-round.
5. Monitor and measure. Track water truck operating hours, dust monitoring results and watering frequency before and after polymer introduction. The data demonstrates both the dust control improvement and the water consumption reduction — evidence that supports environmental reporting and water stewardship commitments.

Your Water Quality Is Not a Limitation — It Is an Opportunity

The perception that saline water limits dust control options is understandable but incorrect. Saline water limits hygroscopic dust control — the mechanism used by chloride salts and by saline water itself. It does not limit polymer-based dust control, where the binding mechanism is independent of the carrier water’s chemistry.

For mine sites in the Pilbara, the Goldfields, South Australia and any other region where fresh water is scarce and the available supply is saline or hypersaline, polymer dust suppression converts that water from a marginally effective dust control tool into a delivery vehicle for a proven, durable, non-corrosive and environmentally safe suppression technology. The water does its job — carrying the polymer to the road surface — and the polymer does its job — binding the dust permanently, regardless of what the water tastes like.

GRT: Haul-Loc and GRT7000 are formulated to work with the water your site actually has. SMART Dosing Units ensure consistent delivery regardless of operator or shift. And the documented 50–90% reduction in water consumption means you are not only controlling dust more effectively — you are using less of the water that your operation, your community and your environment depend on.

Sources and References

Mining Technology / GHD: Water Management in the Pilbara — 550 GL/yr abstraction, 250 GL operational use, CSIRO data

AWA / GHD: Mining and Water Management in the Pilbara: A New Way Forward

Springer / Mine Water and the Environment: Suitability of Saline Surface Water for Recharging Hypersaline Palaeochannel Aquifers, Eastern Goldfields WA

MDPI: Below Water Table Mining, Pit Lake Formation, and Management — Pilbara (October 2024)

ICMM: Water Stewardship Framework — catchment-based approach to water management in mining

GRT: Polymer vs Water: Mining Haul Road Dust Control (March 2026)

GRT: GRT: Haul-Loc — polymer dust suppressant, saline water compatible

GRT: GRT7000 — soil stabilisation

GRT: SMART Dosing Units

GRT: Dust Suppression Solutions

GRT: Dust Suppression Systems for a Safer Environment