Alumina prodn. from waste aluminium processing solns. - by reacting pickling and anodising waste solns. and filtering

摘要

Waste basic solns. from the NaOH pickling of Al and waste acidic solns. from the H2SO4 anodising of Al are reacted together in proportion such that all the Al in the solns. is converted to hydrated alumina. The product is subjected to filtering and water washing to obtain the hydrated alumina. A valuable by-product is obtd. and the residual soln. is a very dilute Na2SO4 soln. which can be disposed of.