Chemistry institute named after V. I. Nikitin of the Academy of Sciences of the Republic of Tajikistan (Dushanbe, Republic of Tajikistan):

Zinchenko Z. A., Head of Laboratory, Doctor of Engineering Sciences, e-mail: mariya14@list.ru
Samikhov Sh. R., Leading Researcher, Candidate of Engineering Sciences

Researches of nitric asid leaching and chloride sublimation of gold and silver from Chore and Taror deposit concentrates (Tajikistan) were carried out in laboratory conditions. On the grounds of called on studies following optimum conditions are found nitric-acid opening concoction: the temperature – 800 °С, duration of process – 120 min., ratio of S:L = 1 : 5 and concentration of the nitric acid – 300-315 g/dm³. The gold is extracted on 93–95 % from acid leaching cakes to cyanic solution. As a result of acid treatment copper is extracted to solution on 80–96,8 %, that creates the premises for selective separation of copper from ore. On the grounds of called on studies principle technological scheme of the arsenic containing ore of deposits Chore and Taror preparation is offered, comprising of itself crushing, grinding of ore, flotation with receipt of the collective concentrate. The concentrate moves to autoclaveless nitric acid leaching with the following cyanidation of leaching cakes. In the event of Taror concentrate solution, received after acid leaching, can be directed to electrolysis for reception metallic copper. The copper concentrate, received on mineral processing plant of “Zeravshan” Joint Enterprises at preparation of little arsenic ore of current mining Taror deposit , as well as flotation concentrate, received in laboratory conditions from deposit Chore ore were subjected to the study of the chloride sublimation process. At the temperature 100 0С and duration 2 hours the recovery of gold to sublimation is 95,65–98 %, silver – 93,08–95,3, copper – 90,1 %. The calcines of chloride sublimation are satisfactory cyanidated with recovery of gold to solution, equal 75,3–90,5 %. On the basis of the research results it is recommended that principal technological scheme of processing of deposits Taror and Chore refractory gold ores, including flotation enrichment of ore, chloride sublimation of received concentrates with subsequent cyanidation of chloride sublimation calcines.

1. Zinchenko Z. A., Samikhov Sh. R. Zolotodobycha – Goldmining, 2009, No. 130, pp. 36–39.
2. Akhmedov Kh. A., Kunbazarov A. K. Gidrosulfatizatsiya zolotosoderzhashchikh sulfidno-myshyakovykh kontsentratov (Hydrosulfatization of gold-containing sulfide-arsenic concentrates). Materialy soveshchaniya po voprosam izucheniya endogennykh mestorozhdeniy Sredney Azii (Materials of meeting on problems of research of endogenous deposits of Central Asia). Tashkent : Central Asia Scientific-Research Institute of Geology and Mineral Raw Materials, 1975, pp. 78–80.
3. Zinchenko Z. A., Samikhov Sh. R. Gornyi Zhurnal – Mining Journal, 2006, No. 6, pp. 99–100.
4. Samikhov Sh. R., Zinchenko Z. A. Zolotodobycha – Goldmining, 2011, No. 149, pp. 10–14.