TWI849370B

Disclosed is a method for reducing the content of sulfur in calcium fluoride sludge, including the following steps: mixing the calcium fluoride sludge having particle size below 1000[mu]m with calcium sulfate, and performing desulfurization treatment at 800 DEG C to 1200 DEG C for more than 20 minutes, wherein the calcium fluoride sludge contains calcium fluoride and calcium sulfide, and when the total amount of the calcium fluoride sludge is 100wt%, the content of the calcium fluoride is above 75wt% and less than 100wt%, and a mole ratio of the calcium sulfide to the calcium sulfate is 1:0.5 to 1:2. Through mutual arrangement of the particle size of the calcium fluoride sludge, the temperature and time of the desulfurization treatment, and the mole ratio of the calcium sulfide and the calcium sulfate, the content of the calcium sulfide in the calcium fluoride sludge can be reduced, and also the remained calcium sulfate can be reduced. Therefore, by adopting the method for reducing the content of sulfur in th