Acid recovery from waste sulfuric acid by diffusion dialysis

In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in the paper. The mass transfer dialysis coefficient of sulfuric acid of the membrane AFX is measured, the effect of the flowrate of the feed and ratio of feed to water is investigated, and the two kinds of membrane (AFX and S203) are compared. The results show that diffusion dialysis process can separate the metal cation from sulfuric acid effectively, but it is difficult to separate non-cation impurities as As− and F−. The contrast tests of the two membranes show that the dialysis mass transfer coefficient of the membrane AFX is larger, while capacity of the removing impurities of membrane S203 is somewhat better.