Table of Contents
Heap leaching of gold and other precious metals has revolutionized the precious metals industry, and has become a common milling technique. One heap leach milling process, the carbon loading and stripping mill, loads the metal on carbon (using activated charcoal or char), strips the metal from the char, and recovers the metal by electroplating. The system is simple and economic, particularly when applied to oxidized ores with relatively high gold content.
The Modular Station/Movable Column System
The system is modular: several loading and stripping stations (Figure 1) can be employed at various places on the property, as dictated by operational needs.
The Movable Char Column
For char control the column has two integral valves. The dump valve mounted on the bottom is used to dump the load of char. The stripping valve mounted 1.1 m (42 in) from the bottom is where the stripping solution overflows when removing the metal from the char. During stripping, a cover and insulated jacket are fitted to the column to retain heat needed for the stripping reaction.
The Loading Station
The loading station (Figure