The semi-arid environment many mines find themselves in is not conducive to dust control – and consequently it has emerged as a major issue at many mines.

SKM atmospheric scientist Jon Harper told delegates at yesterday’s IIR Minehaul 2006 conference that with urban encroachment and increased community concerns companies needed to put in place dust management plans now.

“In 10 years time people are not going to put up with what they do now. Communities are a major issue in your operation and you need to get them on side from the start,” he said.

Hand-in-hand with rising community concerns has been increased regulatory control over dust control at minesites. Regulators have gone from making general statements to ordering detailed measures – and Harper believes licences will become stricter.

The emission of dust from unsealed roads on minesites represents a number of concerns: loss of surface material; a potential safety hazard through reduced visibility and damage to vehicles; reduced amenity as the particles settle out near the source; increased health impacts of employees and potential health impacts on the community; an impact on vegetation as the particles settle onto leaves, which decreases transpiration and increases heat absorption; and deterioration of the road with increased maintenance costs as the roads must be continually graded and re-surfaced.

“The main concerns of the regulators and the community are amenity, health and environmental. If fugitive particulate emissions are perceived to be significant then a mining facility may face increased regulatory requirements, more stringent environmental licence conditions and poor community relationships, which may potentially impact on the continuing operation of the mine,” Harper said in his paper.

Historically the solution has been to suppress dust with water, but in the current environment water conservation is also a significant issue. Harper proposed a number of dust reduction strategies in face of this.

He said firstly mines needed to have a dust management plan. This not only defined the way forward, but also helped show the community what the mine was actively doing about the perceived problem.

He also said one of the most powerful tools to reduce dust was education. “Managers and supervisors need to show a commitment to reducing emissions by including particulate emissions in meetings, weekly inspections and performance reviews. The workforce needs to be involved by reporting dusty roads, adjusting their speed accordingly and assisting in toolbox meetings on dust reduction strategies that can be trialled.”

A more physical measure is to seal roads where light vehicles frequent, guttering to stop vehicles from leaving the road, designated parking and limiting the number of roads used.

Where it is unfeasible to seal a road, it needs to be made sure the road is correctly constructed and maintained.

He also suggested trialling a number of suppression products – as there was no “one size fits all” formula. Products generally fall into four areas – water, chlorides, lignin sulphonates and polymers/microbiological binders.

“If all these strategies are incorporated into the daily operation of a facility then multiple benefits will be realised including reduced particulate emissions, lower maintenance costs of the vehicle fleet [light and heavy], increased safety, a decrease in water consumption and improved community relationship,” he said.