Separation by Leaching
In a mineral processing plant when mechanical methods of separation cannot secure optimal metal value of an ore, leaching is an alternative, either as a complement or as an overall process. Most of the leaching process is feed preparation by crushing, grinding and in some cases pre-concentration and roasting. The separation is normally done by creating retention time for the chemicals to penetrate the feed. The waste and heap leaching operations are typically low in investment but high in cost of chemicals. Recovery is normally low (below 60%). The agitation methods (con current or counter current) are high in investment but are paid back in higher recovery. Leaching by size In leaching there is always an optimum in the relation feed size versus recovery. This balance between cost for size reduction and value recovery is important to establish for high value ores, see below. Leachants Leaching of Metals Below find the flow sheets for classical leac...