METHOD OF PRODUCING GYPSUM AND METHOD OF PRODUCING CEMENT COMPOSITION

摘要

The present invention relates to a method for producing gypsum and a method for producing a cement composition. The method for producing gypsum comprises a step (A) of precipitating gypsum by adding a calcium source into waste sulfuric acid having a heavy metal, wherein when the gypsum is precipitated by adding the calcium source into the waste sulfuric acid, pH of the waste sulfuric acid is less than or equal to 3.0 in the step (A). The method for producing a cement composition comprises the following steps of: producing the gypsum by the method for producing gypsum; and producing a cement composition using the gypsum produced by the step of producing the gypsum.