MANUFACTURING METHOD OF TITANIUM DIOXIDE, CALCIUM SULFATE AND IRON OXIDE FROM WASTE ACID GENERATED IN MANUFACTURING PROCESS OF TITANIUM DIOXIDE

摘要

PROBLEM TO BE SOLVED: To provide a method for recovering useful substances contained in a waste acid that is generated from a manufacturing process of titanium dioxide by a sulfate method and capable of more reducing a substance to be wasted after recovering of the useful substances. SOLUTION: The invention relates to a method for manufacturing titanium dioxide, calcium sulfate and iron oxide from a residue that is remained after separating and recovering calcium sulfate by neutralizing a waste acid that is generated from a manufacturing process of titanium dioxide by a sulfate method. The method includes (1) a step for obtaining titanium dioxide as a precipitate by adding an aqueous solution of hydrochloric acid to the residue, (2) a step for obtaining calcium sulfate as a precipitate by adding sulfuric acid to the solution after separation of the precipitate in the step (1), and (3) a step for obtaining iron oxide as a precipitate by adding an alkali to the solution after separation of the precipitate in the step (2). COPYRIGHT: (C)2008,JPO&INPIT