Mineralogical features and optimization of combined beneficiation flowsheets for refractory gold-bearing ores of the Pakrut deposit (Central Tajikistan)

Kh.I. Kholov; Sh.R. Juraqulov; Sh.R. Samihzoda; H.A. Mahmudov

doi:10.31643/2027/6445.26

Authors

Kh.I. Kholov V.I. Nikitin Institute of Chemistry NAST
Sh.R. Juraqulov Institute of Geology, Earthquake-Resistant Construction and Seismology of the NAST
Sh.R. Samihzoda V.I. Nikitin Institute of Chemistry NAST
H.A. Mahmudov Mining Metallurgical Institute of Tajikistan

DOI:

https://doi.org/10.31643/2027/6445.26

Keywords:

Pakrut deposit, refractory ores, gold, pyrite, arsenopyrite, cyanidation, flotation, gravity separation, mineralogy, beneficiation.

Abstract

Against the backdrop of depleted rich deposits and the increasing proportion of refractory gold-bearing ores, improving their processing methods has become an urgent task. This work presents the results of a comprehensive study of gold-bearing ores from the Pakrut deposit, located in Central Tajikistan's Zeravshan–Gissar zone. Mineralogical analysis established that the principal gold carriers are pyrite and arsenopyrite, with the metal predominantly localized as fine inclusions and fracture-related accumulations. A notable fraction of gold occurs as free particles (17.03%); however, the dominant share is fracture-bound (62.41%) and is predominantly associated with arsenopyrite. This distribution explains the limited efficiency of single-stage treatment and substantiates the need for combined unlocking and recovery routes. Physicochemical studies confirmed the ores' refractory nature, attributed to the fine dissemination of gold within the sulfide matrix, combined with high hardness and abrasiveness. At the laboratory scale, various beneficiation flowsheets were tested, including direct cyanidation; flotation combined with additional leaching of tailings; and variants incorporating gravity separation. A comparative analysis showed that the highest gold recovery rate (92.23%) was achieved by the flowsheet involving cyanidation, followed by tailings leaching and flotation. Although direct cyanidation also demonstrated a high recovery rate (90.05%), it was less effective. The flotation–cyanidation and gravity–flotation schemes yielded comparatively lower performance. The obtained data confirm the effectiveness of an integrated approach to processing the refractory ores from the Pakrut deposit. Optimizing the beneficiation flowsheet enables a significant increase in precious metal recovery, reduces technological losses, and minimizes environmental risks associated with the accumulation of arsenic-bearing waste.

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Author Biographies

Kh.I. Kholov, V.I. Nikitin Institute of Chemistry NAST

Cand. Sc. (Tech.), Senior Researcher at the Laboratory of Ore Processing, V.I. Nikitin Institute of Chemistry, National Academy of Sciences of Tajikistan; Senior Lecturer of the Department of Chemical Technology and Ecology at the Tajik State Pedagogical University named after S. Aini, 734063, Dushanbe, Aini St., 299/2, Republic of Tajikistan. ORCID ID: https://orcid.org/0000-0002-8202-5919

Sh.R. Juraqulov, Institute of Geology, Earthquake-Resistant Construction and Seismology of the NAST

Senior Researcher, Institute of Geology, Earthquake-Resistant Construction and Seismology, National Academy of Sciences of Tajikistan; 734063, Republic of Tajikistan, Dushanbe, Ayni St., 299/2. ORCID ID: https://orcid.org/0009-0001-1255-8541

Sh.R. Samihzoda, V.I. Nikitin Institute of Chemistry NAST

Dr. Sc. (Tech.), Chief Researcher at the Laboratory of Ore Processing, V.I. Nikitin Institute of Chemistry, National Academy of Sciences of Tajikistan, 734063, Dushanbe, Aini St., 299/2, Republic of Tajikistan. ORCID ID: https://orcid.org/0009-0002-7454-7343

H.A. Mahmudov, Mining Metallurgical Institute of Tajikistan

Cand. Sc. (Tech.), Dean of the Faculty of Mining, Mining and Metallurgical Institute of Tajikistan, 735730, Buston, Mayakovski St. 6, Republic of Tajikistan. ORCID ID: https://orcid.org/0009-0005-8428-5334

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