Institute of Mineral Resources (Tashkent, Republic of Uzbekistan)

Khamidullayev B. N., Head of Department, PhD in Engineering Sciences, baxrom_0786@mail.ru
Nurmukhamedov I. S., Head of Laboratory, nurmuhamedov85@list.ru
Usmonov A. S., Intern Researcher, abrorusmonov102490@gmail.com
Samandarova Sh. Yu., Junior Researcher, Sshoxida90@gmail.com

This article presents the findings from a detailed analysis of the material composition of a refractory gold-bearing ore sample. The research focused on chemical, mineralogical, grain size distribution, and phase analysis methods, with special emphasis on the content of gold and silver. The sample for the study was obtained from a deposit in Uzbekistan. Both thin and polished sections were prepared for examination. A full chemical analysis of an average sample revealed that the ore consisted primarily of the following components by weight percentage: 60.76 % of SiO₂, 16.45 % of Al₂O₃, and 6.94 % of total Fe₂O₃. The content of the primary valuable elements in the ore was also established at 1.33 g/t for gold and 1.48 g/t for silver. The assay analysis of the sample indicated a gold content of 1.24 g/t and a silver content of less than 5 g/t, corroborating the results obtained in the chemical analysis stage. The grain size distribution analysis of the ore sample, crushed to a size class of –3+0 mm, revealed a notable increase in gold concentration within finer size fractions, where gold content ranged from 2.43 to 2.54 g/t in the finest classes. Mineralogical studies have identified the main ore minerals as native gold, pyrite, pyrrhotite, arsenopyrite, argentite, chalcopyrite, sphalerite, galena, and fahlore, with minor occurrences of bornite, wolframite, and antimonite. Pyrite was found to be the primary carrier of gold, followed by arsenopyrite. Given the refractory nature of the ore, it has been established that further processing would require fine grinding to achieve at least 90% passing the –0.074 mm class. Flotation is recommended as a viable processing method, with the potential for separate concentration of carbon and sulfide fractions. These concentrates can undergo pyrometallurgical treatment prior to sorption cyanidation, thereby improving the recovery of gold.

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