| Segregation method for processing of gold-containing copper oxidized ores, secondary quartzites and residues of chalcopyrite concentrates Vaja Chagelishvili1; Rusudan Chagelishvili 2; Tsisana Gagnidze2; Nestan Gegia3; Ekaterine Ukleba3; 1RAFAEL AGLADZE INSTITUTE OF INORGANIC CHEMISTRY AND ELECTROCHEMISTRY, IVANE JAVAKHISHVILI TBILISI STATE UNIVERSITY, Tbilisi, Georgia; 2IVANE JAVAKHISHVILI TBILISI STATE UNIVERSITY, RAFAEL AGLADZE INSTITUTE OF INORGANIC CHEMISTRY AND ELECTROCHEMISTRY, Tbilisi, Georgia; 3ALEXANDER TVALCHRELIDZE CAUCASIAN INSTITUTE OF MINERAL RESOURCES, IVANE JAVAKHISHVILI TBILISI STATE UNIVERSITY, Tbilisi, Georgia; PAPER: 88/AdvancedMaterials/Regular (Oral) SCHEDULED: 14:00/Wed. 30 Nov. 2022/Saitong ABSTRACT: <p>In Georgia (Bolnisi region) along with major sulfide ores, containing colored and noble metals, there are low-quality, hard-enriched gold-containing copper oxidized ores and secondary quartzites, the interest in which is steadily growing. The segregation method is effective for the complex processing of this ores. The segregation method was discovered in the 1920s and found practical use 30 years later by the Anglo-American group as a "TORCO" process (Treatment Of Refractory Copper Ores). The segregation method has found application in countries: Peru, Mauritania, USA, Canada, South Africa, Kazakhstan, etc. This method ensures high quality and ecological safety of the extraction of non-ferrous and noble metals. The segregation method on the first stage implies high temperature (750-9000 C) burning of ores in neutral or weak-reduced area in the presence of coal and sodium chloride. Copper and noble metals obtained after the burning chlorides are reduced on the surface of carbon with hydrogen, which is formed by the interaction of water vapor with carbon. Metallic copper and noble metals particles are collected around the carbon. The second stage of processing is carried out by flotation enrichment of the segregation product. As a result of flotation, copper and noble metals are extracted together with coal in a concentrate, the content of which is much higher than in the conventional flotation concentrate. We have conducted work experience using the segregation method. The segregation roasting process was carried out in a tubular rotary kiln. Subsequently, there are conducted the flotation enrichment experiments of the product received after segregation roasting. Segregation roasting was used to extract gold, silver and residual copper from residues of hydro-metallurgical treatment of Madneuli (Bolnisi region) chalcopyrite concentrate. On the basis of technological research, the optimal parameters of segregation roasting of residues after their preliminary oxidative firing were determined: temperature 8500ะก, consumption of sodium chloride and coal respectively 1% and 1.5% by weight of residue, the duration of the process is 30-60 minutes. Under these conditions, from residues containing 1.1-1.3% copper, 38-40 g/t silver and 3.8 g/t gold, the flotation concentrate with a copper content of 8-9%, silver 232-300 g/t and gold 18-24g/t is obtained. The total recovery to the first and second flotation concentrates is 88-92% copper, 85-87% silver and 88.3-93% gold. A sharp improvement in the quality of the concentrate can be achieved by introducing the cleaning operation into the usual flotation mode (pulp pH 8-11, potassium butyl xanthate consumption 100 g/t and pine oil 50 g/t). The copper content in the first flotation concentrate increases to 42%, gold - 40g/t, silver - 1381g/t. Its yield is 2.3% by weight of the product of segregation roasting. Their extraction is about 80%, and the copper content in the flotation tailings is 0.16%. The results show that the process of segregation of the gold-containing copper oxidized ores and secondary quartzites has a positive effect on the process of further flotation enrichment of the segregation product. The degree of gold extraction in concentrate as a result of flotation of segregated product obtained by roasting of secondary quartzites (Au - 2 g/t, Cu - 0.021%) is 80%, and that of copper- 77%. Although concentrates with a gold content of 14-24 g/t have been obtained, studies are still ongoing to determine the optimal mode. Segregation was also carried out on copper oxide ore (Cu - 3.5%, Au - 0.5 g / t). The results of experiments conducted on both ores indicate the effectiveness of the segregation process in both cases. Currently, we are pointed on the determination of conditions for the optimal proceeding of the process.</p> |
