FREMGANGSMAADE TIL FREMSTILLING AF ET BASISK ALUMINIUMSULFAT

The present invention relates to a method for preparing a basic aluminium sulphate of the general formula A (OHx) (SO4)y (H2O)z n where n is an integer x is 0.75 - 1.5; y is 0.7 - 1.07; x+2y is 3; and z is 1.5-4; whereat z is 4 when the product is in solid form, and z is 4 when the product is in the form of an aqueous solution. The compound produces positively charged complexes having charge-neutralizing properties in systems containing suspended or colloidal, negatively charged particles. When carrying out the method an aluminium sulphate is reacted with a compound from the group CaO, Ca(OH)2, BaO, Ba(OH)2, SrO and Sr(OH)2 to form the above compound. The sulphate formed is then separated.