天然石膏制备烧石膏晶须试验研究OA

Based on the current situation that natural gypsum is abundant in China but the added value of the pro-ducts is low,according to the theory of dissolution and recrystallization,the high added value calcined gypsum whisker preparation experiment was conducted using natural gypsum as raw material and nitric acid as an additive,using the atmospheric acidification method.The effects of solid-liquid ratio,concentration of nitric acid,and reaction tempera-ture on the phase and microstructure of the obtained products were investigated.The research results indicate that the mass fraction of gypsum whiskers in the sample increases with the increase of nitric acid concentration and reaction temperature,and the fraction of whiskers in the sample shows the trend of first increasing and then decreasing with the increase of solid-liquid ratio;The phase of the sample obtained under optimized conditions is mainly calcined gypsum,with the very small amount of gypsum and anhydrite phases.The length of the whiskers in the sample is 509～650 μm,and the length-diameter ratio is 43～62.The research results can provide reference for the high-value utilization of natural gypsum.