Patent ID: 7935295

Claim:
A method of leaching at least one core comprising a soluble part and an insoluble part with a leaching fluid, the method comprising: providing a linear multi-stage, multi-tank arrangement in which two or more dip tanks are arranged with a volume of leaching fluid in each dip tank in which a core can be dipped; and adjusting parameters comprising concentration, volume and temperature of the leaching fluid in each dip tank with an adjustment means such that at least one parameter differs between at least two of the two or more dip tanks, wherein the adjustment means comprises a pre-adjustment tank that calibrates the leaching fluid to a known leaching efficiency so that a desired rate of leach erosion of the soluble part of each core is consistent or specifically varied over the number of cores received, each dip tank of the linear multi-stage, multi-tank arrangement having a tap supply connected directly to the pre-adjustment tank.