Material composition and diagnostic leaching tests of gold mine tailings dump (taror deposit, Tajikistan).

Tajikistan possesses large reserves of dump tailings characterized by a high gold content. The formation of these dump tailings is associated with the low cost of gold in the past, since rich ores with a gold content above 6–8 g/t were more often involved in processing. At recovery of ≈ 70–75%, tailings with a gold content below 1.8 g/t were disposed of. The paper studies the material composition and carries out an assessment of the degree of refractoriness of the studied dump tailings to leaching. It was established that the main components of tailings are SiO2 and Al2O3. The dump tailings contain 2.4 g/t of gold and 7 g/t of silver. In terms of material composition, the sample of the dump tailings belongs to a readily cyanidable type. Gold finely disseminated in acid-soluble minerals represents 6–6.5%, while minerals insoluble in acids and quartz contain 15% of gold. In addition, the tailing sample contains gold encapsulated in minerals soluble in sulfuric acid. In terms of gold form, the dump tailings are classified as medium refractory to leaching processes. The diagnostic leaching test results for gold showed that the use of thiourea as a lixivant in the further development of the leaching process is promising. Gold recovery by thiourea leaching was 78%. [ABSTRACT FROM AUTHOR]