Process and apparatus for extraction of metal values from metal bearing ores

A process for extracting metal values from an ore bearing a desired metal, which comprises the following steps:

• (a) milling an ore containing the desired metal in the presence of water from at least one first pipeline to produce an ore containing slurry;
• (b) adding a lixiviant to the slurry;
• (c) dissolving the desired metal in the lixiviant to thereby leach the desired metal from the slurry;
• (d) absorbing the dissolved metal from the lixiviant with activated carbon particles in a carbon-in-pulp absorption section;
• (e) separating the carbon particles from the slurry;
• (f) recovering the desired metal from the carbon particles;
• (g) wherein the slurry is conveyed along second pipelines, some of which can be fitted with pumps to each succeeding step of the process;
• and
• wherein the improvement comprises introducing, prior to step (f), and after the formation of the ore-containing slurry in step (a), a gaseous agent, capable of promoting recovery of the metal values from the ore, into at least one of the second pipelines or the first pipeline said agent being introduced at a plurality of spaced apart points or zones of at least one of said first and second pipelines, provided that when at least one of the spaced apart points or zones is in a second pipeline between step (e) and step (c), or in a first pipeline from step (c) to step (a), then at least one further gaseous agent introduction point or zone is provided in one of said first or second pipelines slurry or process water which is positioned downstream after step (c).