PROCESS OF PRODUCING SULFURIC ACID FROM WASTE ACID AND IRON SULFATE

摘要

The present invention relates to a process of producing sulfuric acid from waste sulfuric acid, which contains iron sulfate and has become available as a result of a solubilizing treatment of TiO2-containing materials with sulfuric acid, in which process ferrous sulfate having a high content of water of crystallization is transformed to ferrous sulfate having a low content of water of crystallization and the latter is filtered off as solids, the sulfuric acid concentration of the aqueous filtrate is increased by an evaporation of water, a partial stream of the filtrate of increased concentration is added to the waste sulfuric acid, and sulfuric acid is recovered from the solid iron sulfate which has been filtered off and has a low content of water of crystallization. It is an object of the invention to enable an economical and ecologically satisfactory processing of the waste acid and of the solid ferrous sulfate.