Increasing gold leaching efficiency with change of solution rheological properties

Abstract

Purpose. Increasing the efficiency of gold heap leaching by changing the solution rheological properties due to its mechanical activation. Semi-industrial tests were carried out to verify the results of laboratory work. Methodology. First, semi-industrial tests were carried out without activation of the solution (basic technology), and then the solution activation was applied. The ore amount in the stockpile was 600 kg; the gold content in the ore is 1.12 g/t. At the same time, the concentration of cyanide was 400 ppm. The activation degree was from 3 to 8 minutes, the leaching time was 2, 4, 6 hours, the solution temperature varied from 13 to 30 degrees. Findings. According to the results of semi-industrial tests, the dependence of gold content, pH value, and residual concentration of the reagent on the leaching time was obtained using both proposed technology and the basic one. Comparison of the semi-industrial test results related to the basic technology and proposed one (with the solution activation) showed that the maximum gold content in the productive solution with the basic technology is 1.83 mg/l, and with the activation of the solution it is 2.10 mg/l. Hence, there is an increase in the gold content by 14.7% with the solution activation Originality. Dependence of gold content in productive solution, pH value, and residual concentration of the reagent in solution on the degree of its activation has been obtained. Practical value. The optimum degree of the treatment solution activation during gold heap leaching is determined, which is from 5 minutes to 7 minutes depending on the leaching time, which increases the gold content in the solution by 14.7%.