Basic chromium aluminum sulfates and their preparation

摘要

The invention relates to basic chromium aluminum sulfates which are soluble in cold water and are of the general formula CrxAl2-x(OH)2y. (SO4)3-y.n H2O where x is from 0.1 to 1.9, y is from 0.01 to 2 and n is from 4 to 24, and a process for the preparation thereof. The process comprises reacting chromium (III)-containing waste sulfuric acid having a water content of 20-50% by weight with aluminum oxide and/or aluminum oxide hydroxide and/or aluminum hydroxide at a temperature of 100 DEG to 200 DEG C. The molten product is converted to droplet form and allowed to solidify in free fall.