Mining and Metals
Mining and Metals
Industrial waste from various sectors is becoming increasingly pestilent which requires immediate attention. Due to expansion of metal and mining sector in remote areas it is highly challenging to control the metal laden wastewater stream from polluting the surrounding. WCES takes up the gauntlet to provide effective solution for the treatment of waste gush from the industry.
Effluent Produced in Mining Sites
The principal waste water from mines and metal industry are impregnated with rock particles. Rainfall washing the area exposed and the process of gradation and rock washing involved in extraction create this. The sewage is produced in large quantities which by the process of density gradients where the metals and wastewater are separated. This separated water contains fine particulate hematite and surfactants and hydraulic oils.
Pollutants and their Effect
The minerals are the main contaminants present in native rock during formation and are washed with discharge during crushing and mining extraction. Unwanted metals like zinc and others like arsenic are most common contaminants.
Extraction in gold and silver mines release slime which has fine particulates. These fine particles are difficult to remove by physical process of filtration. The economically valuable copper and gold extraction involves fine grinding of rocks and the leftover undesired piece of rock is called tailing. The tailing has sulphide type ores which forms sulphuric acid upon exposure to air and water. This occurs when they are present in large amounts. The resulting acid mine drainage poses real threat to environment if disposed of untreated. They are the main cause for degrading and depleting ground water and surface water resources.
For effective treatment at first pH of contaminant is adjusted. This is done by lime or by adding other chemicals like calcium silicate or carbonate neutralization where the pH is brought down drastically. Then air is introduced for metals to form insoluble precipitates. Adding coagulants and flocculants help the solid particles to form lump which settles down during sedimentation.
The water exiting from sedimentation is finely filtered for separation of minute particles. Sludge treatment of the sediment aids in extraction of metals.
The constructed wetland is the cost effective procedure used for sedimentation and the highly reactive sediment should be kept submerged permanently under water.
WCES with its vast knowledge and experience are equipped with conservative and updated Hi-tech solutions for the management of acid mine sewage which is highly toxic and can even render the surroundings uninhabitable.