Ore leaching tests using the percolation method. This method allows to create conditions that are as appropriate as possible to the industrial process. Samples weighing from 50 kg are subjected to preliminary tests in columns, which are loaded into columns for leaching from organic glass with a height of 2.5 m and an internal diameter of 150-200 mm.
The ore mixture with a known mass is loaded into the leaching column, after which a low intensity leaching solution is fed. The solution percolates through ore mass and enters the container from which it is taken on a daily basis. The volume of the solution entering the container is measured and analyzed for the content of precious metals, pH level, and cyanide concentration. These determinations are performed for each batch of the collected pregnant solution. The leaching procedure continues until the contents in the pregnant solution are stabilized at low concentrations.
When complete recovery is achieved or the subsequent leaching process is not practical, the loaded ore is washed and then removed from the column and dried. After drying, the material is analyzed for the residual concentration of precious metals, or dispersed into fractions to determine the contents of the desired elements.
The results of process tests using the method of percolation in columns provide further clarification of information about the possible degree of metal recovery and the need for reagents in conditions as close as possible to production.
After receiving the analysis data, the degree of recovery is calculated by comparing the volumes and contents in the source material, accumulated pregnant solutions and spent ore.