Technologist Team from UrbanMines has emphasized the study of copper extraction from smelter slag, which is subjected to sulphating. Sulphating of slag was performed by pyrite concentrate or flotation tailings at temperatures from 500 to 650°C, and the resulting calcine was leached with water. The results showed that maximum copper leaching (70-73%) is obtained from calcine, obtained by two-and three hour sulphating at 550 o C. The process is selective since only 3-5% of iron is leached. In addition to sulphating temperature, it was found that a great effect on copper leaching has the pyrite/flotation tailings: ratio. The best results were achieved by sulphating of 5.00 g slag with 2.00 g of pyrite or 3.00 g of tailings.
Smelting Copper through Additive
Blow air and heat it up to make iron and pyrite reach the oxidation level
2CuFeS2 + 3O2 → 2CuS + 2FeO + 2SO2
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Heat up calciate, quartz and pyrite to 1100℃
CuS + S（in pyrite） + O2 → Cu2S + SO2
Meanwhile as the cupric sulfide precipitates
CaCO3 + SiO2 → CaSiO3 + CO2
CaSiO3 + FeO + SiO2 → 2(Fe,Ca)SiO3
Thus generate iron oxide mixed with stove dregs and separate them
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Extract precipitating cupric sulfide and blow in air
Cu2S + O2 → 2Cu + SO2↑
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When necessary, perform further electrolyting with sulfuric acid and cupric sulfide solution
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Recycle gold, silver and platinum from the precipitated impure matter
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Store lead extracted from the ore in a place above the melting point
Copper with higher melting point will separate and float upward