Mining rare earth minerals lead to a negative impact on the environment and the land.
It can also endanger habitats and their livelihoods through water contamination and the destruction of farmland.
Some of the water pollutions caused by mining are Acid Mine Drainage, Heavy Metal Contamination & Leaching, Processing Chemicals Pollution, and Erosion and Sedimentation.
The waste of this minerals mine infiltrates the groundwater through the surface, creating the change of the water body pH, affecting the self-purification ability of the water body, and causing intense pollution damage to the surrounding rivers and farmland.
AMFS uses MF membranes that are well constructed for dewatering slurries such as titanium dioxide and calcium carbonate. Teflon MF membranes are the most potent of all the membrane varieties; they can withstand temperatures of 130°C and handle constant pH levels of 0-14.
TYPES OF WATER POLLUTION FROM MINING
There are four main types of mining impacts on water quality.
Acid Mine Drainage
Acid Rock Drainage (ARD) is a natural process whereby sulphuric acid is produced when sulphides in rocks are exposed to air and water. Acid Mine Drainage (AMD) is essentially the same process, greatly magnified. When large quantities of rock containing sulphide minerals are excavated from an open pit or opened up in an underground mine, it reacts with water and oxygen to create sulphuric acid. When the water reaches a certain level of acidity, a naturally occurring type of bacteria called Thiobacillus ferroxidans may kick in, accelerating the oxidation and acidification processes, leaching even more trace metals from the wastes. The acid will leach from the rock as long as its source rock is exposed to air and water and until the sulphides are leached out – a process that can last hundreds, even thousands of years. Acid is carried off the minesite by rainwater or surface drainage and deposited into nearby streams, rivers, lakes and groundwater. AMD severely degrades water quality, and can kill aquatic life and make water virtually unusable.
Heavy Metal Contamination & Leaching
Heavy metal pollution is caused when such metals as arsenic, cobalt, copper, cadmium, lead, silver and zinc contained in excavated rock or exposed in an underground mine come in contact with water. Metals are leached out and carried downstream as water washes over the rock surface. Although metals can become mobile in neutral pH conditions, leaching is particularly accelerated in the low pH conditions such as are created by Acid Mine Drainage.
Processing Chemicals Pollution
This kind of pollution occurs when chemical agents (such as cyanide or sulphuric acid used by mining companies to separate the target mineral from the ore) spill, leak, or leach from the mine site into nearby water bodies. These chemicals can be highly toxic to humans and wildlife.
Erosion and Sedimentation
Mineral development disturbs soil and rock in the course of constructing and maintaining roads, open pits, and waste impoundments. In the absence of adequate prevention and control strategies, erosion of the exposed earth may carry substantial amounts of sediment into streams, rivers and lakes. Excessive sediment can clog riverbeds and smother watershed vegetation, wildlife habitat and aquatic organisms.