Effect Factors And Key Technologies Of Desulfurization Gypsum Plaster Board

As a new green light panel，Gypsum board is widely used.This paper studied theeffects of process paramenters on the performance of gypsum and the optimumcalcination temperature and aging time was identified.Secondly，the effects of variousadditives and inorganic powder on on the performance of gypsum and gypsum boardwas studied，the optimum amount of water reducer，retarder，starch，fly ash and cementwas identified.On the basis of these studies，slurry process，multivesicular technologyand saturated lime water were proposed，wich can improve thestrength，water resistanceand the adhesive properties.The studies draw the following conclusions:(1) With the improvement of calcination temperature，strength of desulfurizationgypsum increased firstly and then decreased slightly， the bonding performanceimproved.when the calcination temperature is180℃，the performance of desulfurizationgypsum and the board is best.(2)When aging time is short，there is dihydrate gypsum because of uncompleteburning，so the setting time of calcined gypsum is short and the strength is low.Whenaging time is too long， some hemihydrate absorb moisture from the air and intodihydrate， so the physical performance of calcined gypsum decline wich has longsetting time and low strength. The aging time is5d，the performance is optimal.(3)Addition of citric acid can greatly improve the setting time of calcined gypsum,but with the increase of its dosage, the strength of desulfurization gypsum decreasedsignificantly; The addition of water reducer can increase the fluidity of calcinedgypsum, the strength increased firstly and then decreased.The water reduction effectreduction of naphthalene superplasticizer is is optimal; The incorporation of fly ash andcement can improve the damp fluidity，the strength and water absorption properties. (4)Slurry process can significantly improve the strength and adhesive property ofdesulfurization gypsum board， reduce the water absorption rate.Multivesiculartechnology solve the problem that gypsum board the density of gypsum board exceededthe standard caused of slurry process, but its flexural compressive strength decreased.So based on slurry process and multivesicular technology， saturated lime watertechnology can make up the reduction in streng. When the water gypsum ratio is0.6, airentraining agent content is0.5%, and calined gypsum is mixed by the saturated limewater,the gypsum board showed the good performances.