Extraction mechanism of sulfuric acid from copper leaching solution of hydrometallurgical process
In view of the high content of free sulfuric acid in the copper leaching solution in hydrometallurgical process,neutralization treatment is required before copper extraction,which not only consumes large alkaline reagents and high operating cost,but also causes metal ion loss.In this paper,a solvent extraction process for sulfuric acid recovery was proposed and the mass transfer mechanism of the selective extraction process of trioctylamine(TOA)-n-octanol system was studied.The results showed that the third phase would be produced by hydration during TOA extraction of sulfuric acid.After adding n-octanol,the third phase can be avoided due to the formation of hydrophobic complexation((R3NH)2(A)0.3(H2O)1.7SO4).Under the conditions that the organic phase composition was 45%TOA+10%n-octanol+45%260#solvent oil,the ratio of O∶A(ratio of organic phase to aqueous phase)was 1∶1,the temperature was 25℃,the oscillation speed was 200r/min and the reaction time was 10min,the single-stage extraction rate of sulfuric acid reached 90.21%and the three-stage countercurrent extraction rate can achieve more than 99%.The extraction rates of Cu2+,Fe2+and Zn2+were less than 2.7%,2.2%and 2.3%,respectively.The extraction process was an exothermic reaction and the calculated ∆H of the extraction reaction was-14.9kJ/mol.
国家科技期刊平台
NSTL
万方数据
