Manufacture of aluminium salts of controlled whiteness

摘要

A process for the manufacture of an aluminium salt-crystalline amorphous or in soln. in a liquor or appropriate solvent, is claimed. This is generally obtd. by acid or alkaline attack of a natural or synthetic Al cpd., which comprises steps of dissolution and/or mixing, and/or precipitation, and/or crystallisation and/or separation and/or milling of the prods.. During at least one stage - one or several colour additives are contacted with the prod. to correct the whiteness characteristics over all the visible range of the spectrum on a permanent basis.