| 摘要 |
The invention relates to a process for the purification of wet-processed phosphoric acid with the aid of organic solvents which are immiscible or only partially miscible with water, the sulfate ions being removed by addition of barium compounds. The purification is carried out in an n-stage extraction installation, where n is equal to or greater than 5. The barium compound is added to the phosphoric acid to be purified, and the resulting mixture is fed to the top of the extraction installation, in which the organic solvent phase is dispersed in the aqueous phase. The sulfuric acid is led in counter-current fashion to the phosphoric acid by adding it to one of the stages n=4 to at most n-1. |
