Abstract:

The enormous quantity impurity of iron(Ⅱ) in the liquids of sulfuric acid oxygen titanium, the intermediate during the production of titanium dioxide, was removed by solvent extraction. Iron(Ⅱ) in the sulfuric acid oxygen titanium liquid was firstly oxidized to iron(Ⅲ) that could be extracted by tri-n-butyl-phosphate(TBP) and kerosene mixture system. Various influencing factors on the extraction efficiency of iron(Ⅲ) were investigated, such as the category of oxidant and thinner, the TBP concentration in organic phase, the phase ratio of extraction, the addition of NaCl, the condition of reverse extraction as well as the reuse of the extracting agents. The result showed that a three-time extracting percentage of iron(Ⅲ) could reach 99% when the volume ratio of kerosene to TBP was 4∶6, the concentration of NaCl was 4 mol/L and the phase ratio(O/W) was 2∶1. The three-time reverse-extract percentage of iron(Ⅲ) reach to 100% when the phase ratio of reverse extraction was 1∶1. The extracting percentage of iron(Ⅲ) did not decline significantly even though TBP has been recycled for 5 times.

Key words: Sulfuric acid oxygen titanium, Iron Removal, Extracting, TBP