1.Beneficiation, crushing, grind into powder of 325 mesh or less; 2.Mixing powder, water and disperser,and beating,make it into 4500-6000mesh; 3.The ultra fine slurry was dried and beat,then calcinated, adding 1-3% white agents of the total weight when calcinated, White agents is made by coal, sodium sulfate and sodium chloride, by weight 10:0.3:0.2 …