The potash deposit in Bethune, Canada contains the mineral potassium (26% potassium chloride content). Mining method is solution mining, in which minerals are dissolved with water. The mineral-rich solution called brine is then extracted from the ground and the minerals are recovered.
In solution mining, freshwater is brought into solvent (salt) rock through a drill hole, therefore creating chambers, or caverns, filled with a water-salt solution. In a subsequent step, the saturated brine is brought to the surface through an additional pipeline.
During the primary mining process, the cavern expands to create an ideal form for commencing secondary mining.
Secondary mining uses exclusively saturated NaCl solution to selectively dissolve residual KCl from existing caverns.
While primary mining is more energy intensive and requires hot water to dissolve the ore, secondary mining utilizes a brine loop set up between the cooling pond and secondary mining caverns, where sodium chloride-saturated brine is injected into the ground. When it comes into contact with a high-grade potash ore, it dissolves potassium chloride and redeposits sodium chloride back underground. The brine that comes out goes through a cooling pond, and as it cools, potassium chloride crystallizes and recoveries with dredges back to our process plant.
To develop production caverns, a number of wells are drilled from surface using directional drilling and spaced ........
