Technological basis of processing skarn copper-gold-bearing ores of the Kyrgyz Republic

Introduction. The paper studies the matters of processing of skarn copper-gold ores from a deposit in the Kyrgyz Republic. Materials and methods. As a study task, the authors performed an analysis of the material composition, including micro- and macroscopic types of analyses are presented. Results. Textural-structural analysis and mineralogical characteristics of the main ore minerals is detailed. The characteristic features of the material composition of the studied types of ores are highlighted and described. The reagent suite for processing of skarn ores has been established by means of additional feed of weakly selective depressants (Na2SiO3) and effective flotation reagents to the process, the introduction of which can significantly improve the concentrate quality. The study direction is also supplemented by the consideration and introduction of the process of mechanical activation into the process flow diagram as a reserve in increasing the grade of metals in the concentrate through the mechanical liberation of minerals by ultrafine grinding. The forms of metal loss with concentrating tailings, which are represented by wollastonite, garnet (andradite) and pyroxenes, clay-micaceous minerals, feldspars, and talc are determined. Discussion. The main losses of sulphide copper are associated with the presence of intergrowths of copper minerals with barren minerals in the samples. When evaluating copper minerals in tailings, copper is present in sulphide minerals – 79.2% and 20.8% rel. belongs to the oxide minerals. Conclusion. The paper summarizes the results of the study with the developed closed flotation flowsheet for the processing of copper-gold skarn ores, which makes it possible to obtain the flotation concentrate with grade of Cu – 25.01%, Au – 55.02g/t, Ag – 401g/t, with recovery into concentrate of Cu – 84.65%, Au – 87.94%, Ag – 89.44%. Concentrate output 2.33%. The implementation of the proposed flowsheet will ensure the achievement of planned production performance in the processing of skarn ores. Resume. At the end of the study work, the authors issued recommendations on adjusting the reagent suite with the inclusion of the weakly selective depressant – liquid glass (Na2SiO3), introducing the process of attritioning the feed of the cleaning operation (ultrafine regrinding) and considering the regularity of the phase composition of the copper minerals of skarn ore from the copper grade, providing the initial grade of copper at 0.9-1.0% in the processed ore by blending the ore feed ore to the concentrator. Suggestions for practical application and direction for future research. The materials of the paper can be useful for mining and processing enterprises when processing skarn copper-gold ores.