Method for deeply extracting calcium sulfate from phosphorus ore acid hydrolysis liquid

The invention relates to a method for deeply extracting calcium sulfate from phosphorus ore acid hydrolysis liquid, and belongs to the technical field of chemical production. The method comprises the following steps: (1) acid hydrolysis; (2) acid hydrolysis liquid purification; and (3) calcium removal and crystal transformation. The calcium removal purification comprises two crystallization processes, calcium sulfate hemi-hydrate is generated by primary crystallization, and secondary crystallization is to add a seed crystal into a primary crystallization reaction solution to prepare calcium sulfate dihydrate. According to the method, the optimal conditions in each process are controlled by adopting a mode of flocculating and then crystallizing twice, so that the production process is effectively shortened, the requirement on the content of the used raw material (phosphorus ores) is relatively low, the application range is wide, and the method is not limited by the quality of the phosphorus ores. The produced