| Sulfide mineral ore reserves are widely distributed throughout China. In our country, the main mineral found in the concentrate of sulfide ore is pyrite, with other useful metals such as lead, zinc and copper. The possibility to comprehensively recover lead, zinc and copper from sulfide concentrate will be not only an important benefit for the economy, but also for material recycling technology. According to the characteristics and structure of sulfide ore, the treatment of non-ferrous mineral namely lead, zinc and copper is considering being quite difficult. The processing of lead, zinc and copper is affected by the decreasing of the reserves. Therefore, the implementation of a comprehensive process for an efficient extraction of these minerals became a major field of interest for non-ferrous metal industries.The sulfide concentrate sample used during this investigation was obtained from a non-ferrous metal company in the province of Hunan. The grade of Pb, Zn and Cu in the sample is 1.01%,1.15% and 0.1%, respectively. Considering to the structure, characteristic, and isomorphism of the ore, three techniques were applied for the treatment of lead, zinc and copper. There are namely, bulk flotation, flotation separation and hydrometallurgy.Bulk flotation of lead, zinc and copper was achieved when the optimum experiment conditions as follows:sodium hydroxide 300 g/t, SN-9# 400 g/t, butyl xanthate 400 g/t, ammonium butyl aerofloat 150 g/t, grinding fineness 85%-0.074 mm, flotation time 30 min, pulp density is 30%; Under the bulk flotation optimum conditions, the concentrate yield was 17.6%, lead, zinc and copper, recovery efficiency were 85.3%,82.4%,86.5%, respectively. From the results, it can be noted that Pb, Zn and Cu were highly concentrated. In the meantime, the separation of these sulfides from the gangue would effectively prepared lead, zinc and copper for further separation test.From the results of lead, zinc and copper flotation separation test, it is ascertained that zinc was inhibited and lead-copper floated. When the particle size is 80% of -0.045 mm, butyl xanthate 40 g/t, flotation time 8 min, zinc can be effectively separated from lead and copper. It is found that lead and copper are intimately in isomorphism, so it is difficult to achieve the separation of these two minerals by flotation process.Hydrometallurgical treatment of lead, zinc and copper showed that the optimum conditions of the pretreatment should keep to be:roasting temperature 800 C, roasting time 4h, and the residue obtained from the roasting process is around 61.3%. The leaching step was carried out under the optimum conditions of:sulfuric acid 50% (g/g), leaching time 10h, stirring speed 600 r/min, liquid to solid ratio 3 mL/g, temperature 90 C, for 98.6% Zn and 97.2% Cu extractions. The optimum conditions established for the precipitation experiment were:temperature 30 C, stirring speed 300r/min, reaction time 40 min, nZn/nCu=2.0, for a precipitation rate of 97.5% for Cu. From this result, it can be concluded that hydrometallurgy should be considered as an effective technology for separation of lead, zinc and copper from mixed concentrate of sulfide mineral. |
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