Abstract
Sulfide copper concentrate from domestic ore deposit (Bor, Serbia) was subjected to oxidation in the air atmosphere due to a better understanding of reaction mechanism and oxidation of various sulfides present in the copper concentrate at elevated temperatures. Results of the initial sample characterization showed that concentrate is chalcopyrite–enargite-tennantite type, with an increased arsenic content. Characterization of the oxidation products showed the presence of sulfates, oxysulfates, and oxides. Based on predominance area diagrams for Me-S-O systems (Me = Cu, Fe, As) combined with thermal analysis results, the reaction mechanism of the oxidation process was proposed. The reactions which occur in the temperature range 25 – 1000 °C indicate that sulfides are unstable in the oxidative conditions. Sulfides from the initial sample decomposed into binary copper and iron sulfides and volatile arsenic oxides at lower temperatures. Further heating led to oxidation of sulfides into iron oxides and copper sulfates and oxysulfates. At higher temperatures sulfates and oxysulfates decomposed into oxides. Kinetic analysis of the oxidation process was done using Ozawa’s method in the non-isothermal conditions. The values for activation energies showed that the reactions are chemically controlled and the temperature is the most influential parameter on the reaction rates.
Highlights
Copper ores in the world’s exploiting deposits are being continually depleted, getting more complex, and grades of the valuable elements are constantly declining
Characterization of minerals present in the initial sample showed that concentrate consisted of binary copper-iron sulfide chalcopyrite (CuFeS2), as well as copper-arsenic sulfides, enargite (Cu3AsS4) and tennantite (Cu12As4S13)
The XRD analysis results showed that arsenic present in the initial sample as enargite and tennantite volatilized fully since it was not detected in the oxidation products at higher temperatures
Summary
Copper ores in the world’s exploiting deposits are being continually depleted, getting more complex, and grades of the valuable elements are constantly declining. Sulfide copper ores are closely associated with minerals like enargite, Cu3AsS4 or tennantite Cu12As4S13, which contain a significant amount of copper and precious metals. These arsenic sources can end up to wastewaters upon mineral processing, causing various environmental problems. Partial oxidation of copper concentrate containing sulfide minerals is carried out in order to reduce the sulfur content to the amount desirable for the smelting process and further, obtaining richer copper matte. As a contribution to a better knowledge of the Cu-Me-S-O system (Me = Fe, As) and its behavior during oxidation at elevated temperatures, the results of thermal decomposition of sulfide copper concentrate samples from domestic ore deposit (Bor, Serbia) are presented in this paper. Kinetic analysis of the concentrate oxidation was done using Ozawa’s method of non-isothermal kinetics under heating rates 5, 10, 15, and 20 °C min-1 within the heating range 25 – 1000 °C
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
