In order to appreciate what a dust suppressant is one would first need to understand what dust is in the first place. By definition dust is classified as fine, dry matter which consists of pollen, soil, minerals and many other particulates present in the environment. The mere fact that dust can take different forms means that it is made up of varying chemical constituents which makes its suppression interesting based on the chemistries of both the dust particle and the dust suppressant. Effectiveness of a dust suppressant is governed by the chemistry of interaction between the dust particle and the dust suppressant. Amongst the many industries that generate dust is the mining industry which can be traced back to mining processes such as extraction, storage, transportation, construction and processing. The onus is on the mining companies to monitor, control and maintain dust emissions at every stage of the mining processes. It is pivotal then for a dust suppressant to conform with environmental safety and health requirements of workers onsite. In addition, the use of a dust suppressant improves equipment service life, increases the visibility aspect which arises from dust generation and increases the productivity of mineral production without hinderances in operations. Critically in both live and dead stockpiles a dust suppressant can reduce the risk of self-ignition which could lead to potential hazards such as explosions. The article combines the importance of understanding what a dust suppressant is with the types of dust suppressants available for use and completes the discussion with the Global Road Technology approach to dust suppression.
Drivers of growth
The demand for dust suppressants in the global mining space has increased and it has become more necessary than ever to utilize dust suppressants owing to more deliberations and lobbying for clean energy and worker safety and health. On a global scale, spanning across continents using dust suppressants the most, it is envisaged that the Asia-Pacific region will dominate the mining dust suppressants arena. This is attributed to robust economies such as China, India and Australia. Growth in use of dust suppressants is potentially on the rise as well as a result of stringent measures through legislation which have started adopting policies which protect the workers through imposing costly fines and revoking of licenses to mining companies that are found to be non-complaint. As “Industry 4.0” takes its mark in mining, the mining sector has become more aware of the need for dust suppressants with implementation of developed control systems and use of the mining internet of Things in smart technologies ,the growth of mining dust suppressants is expected to skyrocket.
Economic factors
Economically the drivers for dust suppressants has been increase in investments, more mining prospecting and exploratory projects have also created extended markets for dust suppressants. Incentives for health and safety through decrease in exposure to dust particles, flexibility of choice in targeted applications of dust suppressants, reduction in use of water which is very scarce, and finite are some of other main influences propelling dust suppressants in the mining industry. The challenges faced with use of dust suppressants include elevated cost of maintaining dust control equipment, below par growth in mining activities in global powerhouses such as Europe and the lack of stricter policies in some countries. Concerns about the environmental footprint of some dust suppressants such as bitumen emulsions also creates reluctance towards post life degradation and risk of hazardous materials which normally is vague and without mention of food-grade and water based ingredients it is difficult to associate dust suppression products with earth stewardship and environmental protections. The lack of maximizing water efficiency and minimization of water output also makes use of some dust suppressants unattractive hence their use is often avoided from a sustainability point of view.
Are environmental regulations, health and safety concerns or potential profit loss a concern right now?
Water, water, everywhere…
The oldest form of dust suppressant is actually water which traditionally relied on the using the right type of spray equipment and feeding the water to the spray nozzle at high pressure. Using coal mining as an example, the ineffectiveness of water as dust suppressant for dust generated from coal has been found to be related to the surface chemistry which depends solely on the hydrophobicity of coal relative to the hydrophilicity of water. Preference for use of a combination of water and a surface active agent which lowers the energy needed for miscibility between a hydrophobic and hydrophilic system can be achieved through addition of a surfactant which makes water work through superactivation. The advantage of using surfactants in water is that they vastly improve the binding properties of the dust suppressant especially with dust particles such as coal without the need for over watering which can affect the calorific value of coal owing to the porous nature of coal. Some schools of thought also present the function of a dust suppressant through attracting moisture from the surrounding air, which in turn holds the dust, or by adhering particles together. The former principle is evident in hygroscopic salts (whilst liquid polymers and refined synthetic fluids harness the second principle.
Engineering holistic solutions
GRT‘s approach to dust control and the use of dust suppressants fits within the holistic view of managing dust for their clients. Ensuring hardware is just as important as implementing the right chemistries. Addressing staff behaviour is just as important as ensuring application rates are correct. In haul mine roads, dust suppressants are used procedurally with different parts employed to achieve dust suppression. Pre-wetting brings the unsealed road material to near optimum content which helps in blading to remove ruts, corrugations, potholes and loose unbound gravel. This also reduces the surface tension, allowing for maximum penetration of the dust suppressant ultimately ensuring uniform application of the dust suppressant over the whole treated area. In the event liquid products are utilized, the amount of water used for prewetting should be reduced compared to the amount used for the application of soil products in order to avoid exceeding an optimum moisture level. Seasonally, the best time to apply dust suppressants is in early spring when moisture content of the road surface is high and there are different methods of applications. Dust suppressants are usually applied topically, with mix-in procedures more effective although lower application rates and shorter preparation time for topical applications tends to be more popular. Factors such as ease of application, durability, cost, and disruptions to mining operations should be considered when choosing dust suppressants. Overall, Global Road Technology dust suppressant technologies tackle all the different scenarios from pit to port including stages such as stockpiling, mine haul roads, underground coal mining, resource sectors, transportation, and conveyor belt transfer points.
Your feedback is important to us. If you enjoyed reading this Global Road Technology industry update and found it informative, please let us know by leaving a REVIEW.
REFERENCES
Deshpande, A.K. 1961. Physico-Chemical Studies on Dusts: Dust Suppression By Water Sprays. PhD Thesis from the University of Glasgow.
Edvardsson, K. 2010. Evaluation of Dust Suppressants for Gravel Roads: Methods Development and Efficiency Studies. PhD Thesis from the Royal Institute of Technology.
