Over the past few years, many dust suppression methods investigated as a means to curb emissions and dispersion of dust particles such as resins, kerosene, synthetic polymers and various combinations of magnesium chloride, brine, etc.
These methods provide limited suppression capabilities.
Some of them are ineffective or only temporarily effective all of them particularly polluting, and therefore are in limited use in various parts of the world. It found that, due to the new prohibitions, people use water as the preferred dust suppression method.
Thus, the most common and effective method, which we will focus on, is applying potable or treated water and/or water supplemented with magnesium chloride onto the soil substrate.However, over time, magnesium chloride also proved too caused soil pollution and, even worse, damage groundwater and aquifers, carried to great distances because of rainfall. Consequently, along with the emerging possibility of direct and indirect damages to human beings and the environment, indicated in various parts of the world, the use of magnesium chloride, which, as aforesaid, was previously considered most effective, was also restricted as far as possible.
Thus, the suppression efficacy decreased while water consumption increased significantly. Nevertheless, water usage was found to be effective but for a very short-term and therefore, requires constant application on the ground to prevent a significant decrease in suppression effectiveness, especially in dry areas and/or with relatively high wind speeds.
Reality shows that usage of this measure requires huge water quantities at an effective volume of 2.5 liters/m² every 2-3 hours (at an ambient temperature of 30-33 °C), consuming potable water whose sources are already dwindling in Israel and throughout the world. (in recent years, treated effluent water were also used).
Magnesium chloride usage produces several key problems affect the environment as well as the mine site itself, for example:
a) Magnesium chloride seeps into and pollutes groundwater and/or reaches as rain into rivers and streams, sweeping the pollution further over hundreds and thousands of miles, influencing nearby flora, fauna, towns, and villages that use them for sustenance.
b) Magnesium chloride and dust drifted and lifted to the atmosphere and inhaled by humans and animals cause respiratory illnesses in mild cases and serious illnesses in severe cases.
c) Throughout the mine life or its depletion and site closure, vast areas of contaminated soil continue to pollute the environment for many years, which requires the site/mine owner to incur high financial costs for cleaning and restoring the soil.
d) Since residue of corrosive magnesium chloride remains at the site, the work tools and metal structures and facilities affected by accelerated corrosion, productivity amortization because of fast wear and direct damages to employee health.
e) Extensive damage caused to agricultural crops over large distances and vast areas within the range of Aeolian drift, to the point of becoming unfit for use.
All the aforementioned have considerable financial implications in terms of public health, food, water, dust suppressants, fuel, manpower, accelerated amortization of tools and facilities, and expenses that grow over time even after the mine is closed.