The calcium sulfate dihydrate whisker was prepared with hydrothermal method. The raw material calcium sulfate was made with chemical wastewater containing sulfuric acid root ion and calcium salt. The dispersant and crystal promoter was cetyl sodium sulfate and magnesium chloride, respectively. The solution p H was adjusted by sulfuric acid. In this paper, the effect of reaction temperature and cooling speed on the product quality of calcium sulfate dihydrate whisker was discussed. The length-diameter of cal...