Extraction of titanium (IV) from acidic media by 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester

The extraction of titanium(IV) from sulphate, chloride and nitrate solutions has been investigated using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (EHEHPA) in kerosene. The kinetics of extraction was slow, requiring 60 min for the complete extraction of titanium and was improved with the increase of the extractant concentration in the organic phase. When the acid concentration in the aqueous feed phase was varied from 0.5 M to 4 M, the distribution ratios of titanium showed minimal values at 1-2 M acid. The effect of the initial concentration of titanium on extraction was found to be negligible, indicating the presence of mononuclear species in the aqueous phase. The stripping of titanium was studied using H2SO4, H2SO4+H2O2 and Na2CO3. The kinetics of the stripping was very slow when sulphuric acid was used, but was improved with complex forming stripping agents (H2SO4+H2O2 and Na2CO3). The extraction and stripping of titanium were 100% using an aqueous nitrate medium and sodium carbonate strip. Hence, results generated would be applicable to separate titanium from secondary sources such as fly ash originated from incinerators of Municipal Solid Waste.