The aim of this work was to investigate the leaching of chalcopyrite concentrate in hydrochloric acid with hydrogen peroxide as a strong oxidizing agent. The effects of the leaching variables on ...metal extraction, such as stirring speed, solid-to-liquid ratio, temperature and HCl and H2O2 concentrations, were studied. The maximum final copper extraction of 33% was attained with 3.0 mol/L H2O2 in 0.5 mol/L HCl at room temperature after 180 min of the reaction. The results showed that the copper extraction was increased in the first 60 min of reaction, after which it essentially ceased due to the fast catalytic decomposition of hydrogen peroxide. Further, solid-to-liquid ratio affected the copper extraction significantly and the highest copper extraction was obtained in the most dilute suspension (i.e., S/L ratio of 1:100). The dissolution process was described by the first order kinetics equation. The apparent activation energy of 19.6 kJ/mol suggested that the dissolution process was under diffusion control. The reaction orders for HCl and H2O2 were established to be 0.30 and 0.53, respectively. The results of the XRD and SEM/EDS analysis of the leaching residue indicated the generation of the elemental sulphur on mineral surfaces which tended to inhibit the leaching rate.
Research on chalcopyrite leaching represents a great challenge, given its importance as one of the most abundant copper minerals and its significant role in global copper extraction. This study aimed ...to evaluate the effects of different parameters on chalcopyrite leaching by hydrogen peroxide as a strong oxidizing reagent in sulfuric acid solution. A series of leaching tests were carried out to investigate the effect of the solid/liquid ratio, stirring speed, temperature, oxidant and acid concentrations, and lixiviant dosing method on copper extraction from chalcopyrite concentrate. The catalytic decomposition of hydrogen peroxide occurred in the investigated leaching system, as reflected in the obtained metal extraction values. Copper extraction was increased in the first 60 min of the reaction, after which it essentially ceased. The maximum final copper extraction of 64.5% was attained with 3.0 mol/L H2O2 in 3.0 mol/L H2SO4 at a temperature of 40 °C after 120 min of reaction. Due to the catalytic decomposition of hydrogen peroxide in the examined leaching system, the leaching experiment was performed with the periodic addition of lixiviant at specific time intervals as well. The dissolution process was described by the first-order kinetics equation with an apparent activation energy of ~39 kJ/mol. Finally, XRD and SEM-EDS analyses were used to characterize the leached residue, and the results showed that the formation of elemental sulfur on the chalcopyrite surface affected the dissolution process.
New approach to the reclamation of the old flotation tailings in Bor [Serbia] Dozic, S., Univerzitet u Beogradu, Beograd (Serbia). Sumarski fakultet; Djukic, M., Univerzitet u Beogradu, Beograd (Serbia). Sumarski fakultet; Bogdanovic, G., Tehnicki fakultet u Boru, Bor (Serbia) ...
Glasnik Sumarskog fakulteta - Univerzitet u Beogradu (1987),
(2010)
101
Journal Article
Recenzirano
Odprti dostop
This paper presents the results of the experiment which was realised by the biological reclamation of the tailings area in the vinicity of the town Bor (Serbia). Several variants of meliorated ...substrates were used to grow several forest woody plants and some grass species. The substrate was made of fertile soil, mixture of soil and sterile waste in the ratio 1:1, and pure sterile waste. The woody plant species that were planted are: Robiania pseudoacacia, Castanea sativa, Platanus acerifolia, Quercus robur, Prunus avium, Fraxinus exelsior, Picea abies and Acer pseudoplatanus. Altogether 650 plants were planted in the sample plot. This analysis show that it is possible to grow several woody species on the sterile substrate on the waste of the Bor copper mine. The best results achieved by the species that were planted in the fertilie soil layer and on the mixture of fertile soil and sterile waste. Among the woody species Robinia pseudoacacia, Fraxinus exelsior, and Acer pseudoplatanus attained the best survival percent, growth and physiological vitality. The poorest were Picea abies, Prunus avium and Quercus robur. Maintenance of woody plants on the planted area in the first years of the their development is very important for plant survival because of the unfavourable environmental impacts, especially poor soil , air pollution, and extreme climate conditions.
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