Wind Erosion and Stockpile Product Loss: Quantifying the Revenue You’re Losing to the Wind
Every tonne of iron ore, coal or bulk mineral on a stockpile represents an investment — the cost of mining it, processing it, transporting it by truck or conveyor to the stockpile, and storing it until it is loaded for rail, ship or customer delivery. That investment is denominated in diesel, electricity, wear on equipment, operator hours and capital allocation. The product sitting on the stockpile has already consumed those resources. Its value is realised only when it reaches the customer.
Wind erosion removes product from the stockpile before it can be sold. The fine fraction — the particles most susceptible to wind entrainment — is stripped from the surface and dispersed as dust. That dust becomes a compliance problem (particulate matter at the site boundary), a community problem (visible dust plumes, deposition on neighbouring properties), and a health problem (respirable crystalline silica for iron ore; coal dust for thermal and metallurgical coal). But before it becomes any of those things, it is a revenue problem: saleable product that was paid for, processed and delivered to the stockpile has been lost to the atmosphere.
This article quantifies the product loss from stockpile wind erosion across iron ore, coal and bulk mineral operations, explains the mechanisms that drive it, and covers the polymer veneering technology that eliminates it — protecting product value, regulatory compliance and air quality simultaneously.
The Physics: How Wind Strips Product from a Stockpile
Wind erosion from stockpiles occurs through three mechanisms that operate simultaneously.
Suspension. The finest particles (typically below 100 μm) are lifted directly into the air stream when wind velocity exceeds their threshold friction velocity. These particles can be transported kilometres from the stockpile and remain airborne for hours. They constitute the PM10 and PM2.5 fractions that trigger ambient air quality monitoring exceedances and pose the greatest health risk. They also represent the highest-value fraction of many ores — the fines that contribute to product specification compliance.
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Saltation. Medium-sized particles (100–500 μm) bounce along the stockpile surface in a hopping motion, propelled by wind. Each impact dislodges additional fine particles from the surface, creating a cascading erosion effect. Saltation is the primary driver of surface degradation on unprotected stockpiles.
Surface creep. Larger particles (500–2,000 μm) roll or slide along the surface under wind pressure and from the impact of saltating particles. While these particles may not leave the stockpile, they contribute to surface instability and expose the finer material beneath to further erosion.
Research published in Aerosol and Air Quality Research confirms that approximately 50% of the global mineral dust aerosol originates from industrial and agricultural sources, with stockpiles identified as a significant contributor. Wind tunnel testing of coal stockpile materials demonstrated that untreated coal lost approximately 6.1% of surface mass within 30 minutes at a wind speed of 14 m/s. Polymer-treated samples showed essentially zero erosion under identical conditions. The propensity of material to emit dust depends on particle size distribution, specific gravity, moisture content, storage conditions and abrasion forces — with coal and coke showing the highest emission rates among common bulk commodities.
Quantifying the Loss: What Wind Erosion Costs in Tonnes and Revenue
Illustrative annual product loss from stockpile wind erosion
| Commodity | Annual Throughput | Loss Rate (Conservative 3%) | Tonnes Lost | Revenue Impact |
| Iron ore (single Pilbara operation) | 80 Mt/year | 3% | 2,400,000 t | ~US$240M @ US$100/t |
| Iron ore (Port Hedland precinct) | 560 Mt/year | 3% | 16,800,000 t | ~US$1.68B @ US$100/t |
| Thermal coal (export terminal) | 30 Mt/year | 5% | 1,500,000 t | ~US$195M @ US$130/t |
| Met coal (mine stockpile) | 10 Mt/year | 5% | 500,000 t | ~US$115M @ US$230/t |
| Bauxite (port stockyard) | 20 Mt/year | 3% | 600,000 t | ~US$30M @ US$50/t |
These figures use the conservative end of the published 3–15% loss range. At the higher end — applicable to fine-grained materials in high-wind environments without suppression — the losses multiply by a factor of three to five. The actual loss rate at any individual stockyard depends on material properties, stockpile geometry, wind exposure, residence time and the dust control measures in place.
The critical observation is that product loss from wind erosion is not an environmental cost or a compliance cost — it is a revenue cost. Every tonne blown off the stockpile is a tonne that was mined, processed and delivered to storage at full operating cost but generates zero revenue. The cost of the polymer veneering that prevents this loss is a fraction of a cent per tonne treated, applied to product worth US$50–$230 per tonne. There are few investments in the mining supply chain with a comparable return.
Coal-Specific Challenges: Hydrophobicity, BTU Degradation and Combustion Risk
Coal stockpiles present three additional challenges beyond volumetric product loss.
Hydrophobic surface. Coal particles are inherently hydrophobic. Water sprayed onto a coal stockpile surface beads and runs off rather than wetting and binding the particles. Industry research confirms that coal’s water-repellent surface behaviour ‘necessitates continuous spraying to sustain dust suppression’ — a strategy that consumes enormous volumes of water without providing durable protection. The finest coal particles, which are the most susceptible to wind entrainment, are the most hydrophobic and the most resistant to water-based suppression.
BTU degradation. Stored coal undergoes oxidation — a chemical reaction between the coal surface and atmospheric oxygen that progressively degrades the energy content (BTU or calorific value) of the product. Published data indicates that BTU loss can reach up to 26% over a 12-month storage period for reactive coals. Wind erosion accelerates this process by continuously exposing fresh coal surfaces to atmospheric oxygen and by removing the oxidised surface layer that would otherwise slow further oxidation. A polymer veneer that seals the surface reduces both wind erosion and oxygen ingress, protecting both the volume and the energy content of stored coal.
Spontaneous combustion risk. Self-heating through low-temperature oxidation is a well-documented hazard in coal stockpile management. Wind exposure increases airflow through the stockpile, providing the oxygen that sustains oxidation. Uncontrolled oxidation can lead to spontaneous combustion, destroying product and creating a significant safety hazard. Surface veneering reduces airflow into the stockpile surface, complementing other combustion management measures such as compaction, height limits and temperature monitoring.
Iron Ore Challenges: Fines Loss, Specification Compliance and Pilbara Wind Exposure
Iron ore product specifications are measured to fractions of a percent for iron content, alumina, silica, phosphorus and moisture. The fine fraction of iron ore — the particles most susceptible to wind erosion — is not waste material. In many Pilbara operations, iron ore fines are a premium product with specifications that buyers pay a premium price for. When that fine fraction is blown off the stockpile, the operation loses saleable product and the remaining stockpile’s particle size distribution shifts coarser than specification.
The Pilbara’s wind regime makes this challenge particularly acute. Sustained winds exceeding 20 km/h are common, with gusts regularly exceeding 60 km/h during cyclone season and seasonal wind events. Port Hedland — through which over 560 million tonnes of iron ore is exported annually — has invested hundreds of millions of dollars in wind fences, real-time air quality management systems and dust control infrastructure specifically to manage stockpile wind erosion at the port and at mine stockyards feeding the rail system.
For operations where wind fences and water sprays provide the primary defence, polymer veneering offers a complementary surface protection layer that works directly on the stockpile surface itself — the last line of defence between the product and the wind.
Polymer Veneering: Protecting the Surface Without Affecting the Product
GRT: Ore-Loc is a polymer-based liquid veneering solution engineered specifically for bulk commodity stockpiles. Applied to the stockpile surface using water trucks, spray bar systems or bespoke gantry/cannon arrangements, the polymer fuses fine particles on the exposed surface into a thin, bonded, erosion-resistant crust. This crust withstands wind velocities that would strip unprotected surfaces, preventing both dust emissions and product loss during the storage period.
The engineering requirements for a stockpile veneer are demanding. The product must form a crust that is strong enough to resist wind erosion but thin enough to represent a negligible fraction of the total stockpile volume. It must not alter the chemical composition, particle size distribution, moisture content or quality specification of the commodity. It must persist through multiple wind events without requiring continuous reapplication. And it must not interfere with normal reclamation operations — the front-end loader or reclaimer must be able to break through the crust and recover the product without difficulty.
Ore-Loc meets these requirements. The veneer is a surface treatment, not a bulk treatment. It bonds the outermost layer of particles into a wind-resistant crust while the product beneath remains untreated and unaffected. When the stockpile is reclaimed, the treated surface layer is mixed into the bulk product at a ratio that has no measurable impact on product quality. For iron ore operations where the difference between meeting and missing a specification is measured in fractions of a percent of iron, alumina or silica, this assurance of quality neutrality is essential.
Wind tunnel research demonstrates the performance differential. Untreated coal lost approximately 6.1% of surface mass in 30 minutes at 14 m/s wind speed. Polymer-treated samples showed essentially zero erosion under identical conditions. In rain simulation tests, polymer-treated surfaces retained their entire crust while water-only treated surfaces lost nearly half their mass. The durability of the polymer veneer through both wind and rain events provides the multi-event protection that water sprays cannot.
Application Methods: From Water Truck to Automated Gantry
Ore-Loc application can be scaled to match the operational context.
Water truck spray. The simplest method: Ore-Loc is diluted and loaded into a standard water truck, which sprays the stockpile surface from ground level or from an elevated position. Suited to mine-site stockpiles, ROM pads and smaller port stockyards where the stockpile geometry permits truck access.
Cannon or mist fan application. For larger stockpiles where truck access to the surface is impractical, truck-mounted or trailer-mounted cannons project the product over distances of 50–100 metres, covering stockpile faces and crests from ground level. This method is common at port stockyards where vehicle access to the stockpile surface is restricted.
Spray bar and gantry systems. For high-throughput operations with automated stacking and reclaiming, spray bar systems can be integrated into the stacker or positioned at fixed points along the stockyard. Product is applied to the stockpile surface as it is built, providing protection from the moment material is placed. Rail wagon veneering uses similar gantry-mounted spray bars positioned above the rail load-out, applying Ore-Loc to the surface of each wagon as it passes underneath.
For all application methods, GRT: Activate can be added to the spray systems at conveyor transfer points, stackers and reclaimers to suppress dust during active material handling operations. Activate modifies the spray water properties to capture the fine hydrophobic particles — particularly coal dust — that plain water misses. The two products work complementarily: Ore-Loc protects the static stockpile surface between handling events, and Activate controls dust during the dynamic operations that build and reclaim the pile.
The ROI: Fractions of a Cent to Protect Dollars of Product
The economics of stockpile veneering are among the most compelling in mining. The product cost is measured in fractions of a cent per tonne of material protected. The product it protects is worth US$50–$230 per tonne depending on the commodity. Even at the conservative 3% loss rate, a veneering programme that reduces wind erosion by 90% on a 30 Mt/year coal terminal recovers approximately 1,350,000 tonnes of product per year — worth approximately US$175 million at current thermal coal prices.
The cost of the veneering programme — product, application, equipment and labour — represents a fraction of one percent of the recovered revenue. The return on investment is measured in multiples of hundreds, not percentages of single digits.
Beyond product retention, the veneering programme simultaneously delivers compliance benefits (reduced PM10 at the boundary), community benefits (reduced visible dust), health benefits (reduced respirable dust exposure for stockyard workers), and operational benefits (reduced clean-up of deposited material on roads, infrastructure and neighbouring facilities). These are additional returns on the same investment, not separate programmes requiring separate budget.
Every Tonne on the Stockpile Is Revenue Waiting to Be Realised — or Lost
The product on your stockpile has already cost you everything it takes to mine, process and deliver it. The only remaining step is to get it to the customer. Wind erosion removes product from that equation before the revenue is realised. The loss is real, quantifiable and, in most cases, preventable.
GRT: Ore-Loc polymer veneering protects the stockpile surface between handling events without affecting product quality. GRT: Activate controls dust during active stacking and reclamation. Together, they provide a complete stockpile dust management system that retains product, satisfies regulators, protects communities and delivers a return on investment that few other operational expenditures can match.
For stockyard managers, supply chain managers and commercial managers responsible for the product that sits between the processing plant and the customer, the question is direct: what is the wind costing you? And what would it be worth to stop it?
Sources and References
Aerosol & Air Quality Research: Kung et al. (2024) — Techniques for Suppressing Mineral Dust Aerosol from Raw Material Stockpiles: A Review
ResearchGate / Springer: Wind Tunnel Study of Iron Ore Dust Emissions from Stockpile and Train Wagons (2024–2025)
Taylor & Francis: Research on the Infiltration Law and Enhancing Application of Dust Suppressants in Powder Materials (2025)
IntechOpen: Fugitive Dust Emissions from Coal, Iron Ore and Hydrated Alumina Stockpiles — Port of Koper wind tunnel data
WeatherSolve Structures: Wind Fences for Industrial Ports — 3–15% product loss from unprotected stockpiles
Investing News Network: Iron Ore Price Forecast 2026 — US$93–$108/t range 2025–2026
BHP: Pilbara Air Quality Program — $300M investment, wind fences, AQMS
Pilbara Ports Authority: Dust Management at Port of Port Hedland
GRT: GRT: Ore-Loc — polymer veneering for stockpiles
