| 摘要 |
1,137,075. Purification of phosphoric acid. DOW CHEMICAL CO. 17 May, 1966 [21 May, 1965], No. 2195.5/66. Heading C1A. Aqueous phosphoric acid solution is treated for the removal of titanium and vanadium therefrom by extracting the solution with an organic solvent not soluble in water to more than 10 wt. per cent of the mixture, contacting the thus-obtained organic solution with an aqueous solution containing 0À2-30 wt. per cent of hydrogen peroxide to obtain an organic phase containing the phosphoric acid and an aqueous phase containing the titanium and vanadium, and separating these two phases. Aqueous phosphoric acid or sodium phosphate are recovered from the organic phase by washing it with water or sodium hydroxide solution respectively. The hydrogen peroxide is applied in a volume ratio of 1 : 10 to 1 : 50 in relation to the organic solution. The organic solvent may be a trialkyl phosphate, an aliphatic alcohol, cyclohexanol, methyloyolohexanol, methylcyclohexanone, an ester, an ether or an amide, and may optionally be admixed with a diluent such as toluene, " Varsol " (Registered Trade Mark), benzene, decane, xylene, kerosene or mesitylene. The process is especially suitable for the treatment of phosphoric acid obtained by treating phosphate rock or ore with HC1, H 2 SO 4 , or HNO 3 . |
