Study on the Properties of Titanium Gypsum

Titanium gypsum,which is a byproduct in titanium dioxide production by sulfuric acid method,causes environmental contamination during accumulation.Investigations on the properties and characters of titanium gypsum have important guiding significance on proper selection of recycle and utilization methods of titanium gypsum.The Phase component,anhydration temperature and time,and coagulation features of titanium gypsum were studied in this paper.It is shown that titanium gypsum is composed of calcium sulfate dihydrate as main phase and small quantity of dolomite.The feasible temperature and time for anhydration of the crystal water in titanium gypsum should be controlled at about 200℃ and 50 min,respectively.With addition of citric acid as retarder and calcination temperature increased from 120 to 200℃,the coagulation time of titanium gypsum can be decreased from 1 800 to 1 000 s,which satisfies the time requirement for pouring.