Industrial mining processes that extract precious metals, copper, uranium, and other compounds from ore through a number of chemical reactions are called heap leaching. Heap leaching essentially allows for the absorption of specific minerals and then re-separate them after their division from other earth materials.

Heap leach mining is different to on site mining in that it utilises a liner to hold ore then adds the chemicals via drip systems to it. With on-site mining such pads aren’t there and pull pregnant solution up to obtain the minerals. This method is just a little bit more eco-friendly, yet both environmentalists and health experts perceive this approach as negative. This negative feedback has influenced the acceptance of this technique and many discussions regarding rehabilitation than perpetuation of these types of mines have taken place. In the 1970’s the popularity of this approach and method was significantly high. Today this method remains to be a profit-earning endeavour for several mining corporations across world-wide.

The process has ancient roots – one of the more traditional techniques for the manufacture of iron sulphate was to heap up iron pyrite and collect the leachate from the heap, which was then boiled with iron to produce iron.

LA15The leach cycle process:

The rock that extracted from the mine is typically crushed into small lumps and heaped on an impermeable plastic and/or clay lined leach pad where it can be irrigated with a leach solution to liquefy the treasured metals. Though sprinklers are occasionally used for irrigation, more frequently operations use drip irrigation to diminish evaporation, offer more uniform distribution of the leach solution, and evade damaging the exposed mineral. The solution then percolates through the heap and leaches both the target and other minerals. This process is called the

Source