One technique for recovering uranium, copper, and gold is heap leaching. For each heap, operations typically take two to six months, with a 50–80% recovery rate. Copper oxide and sulphide copper ores can be leached, and copper and gold oxide can be recovered at a faster rate.
On the mine’s highest “lift,” leach solution is applied. It forms a chemical bond with the mineral as it slowly seeps through the layers, creating a “pregnant” solution. Through capillary action, the solution descends to the leach pile’s bottom. After passing through a geo-membrane liner, it enters temporary holding ponds before entering a “tank house” for refining and extraction.
A crucial step in the leaching process is installing the appropriate irrigation system in the mines, which has a significant impact on the uniformity and permeability of percolation across the pad. Because it regulates the percolation throughout the pad, the flow rate and oxygen ratio during the leaching process are crucial for the ore.
A common drip irrigation setup on a leach pad is seen in this video. Individual cells are supplied with the leaching solution via a lay-flat pipe. Installing a pressure regulator after the hose connection ensures that the emitters run at precisely the right pressure, which determines the appropriate rate of solution application. A pre-arranged distance between the drip lines and the lay flat hose is used. A predetermined distance between the emitters and the lines is maintained when emitters are placed in drip lines to apply the solution. A leach pad, for instance, could normally have spacing of 24″ by 24″. The optimal application rate for a certain ore is always the determining factor when it comes to spacing.
