Process for preparing potassium dichromate from a chromate-containing waste water, in particular from a vanadium production waste water

摘要

The waste water is first chemically freed from substances interfering with the preparation of potassium dichromate. The prepurified waste water is treated with amines. The chromate is eliminated from the waste water in the organic phase of a solvent extraction process. From this organic phase, the chromate is re-extracted with aqueous sodium hydroxide. In the re-extract the potassium dichromate is then formed by the addition of a potassium carrier and is removed from the residual mother liquor.