Study On Chloride Absorption Property Of Hydrotalcite In Desulfurization Gypsum System

Desulfurization gypsum(DSG),as a typical kind of synthetic gypsum,contains different impurities compared to natural gypsum.The chloride is one of the important impurities in DSG,which leads some negative effects for plasterboard.Hydrotalcite becomes the key chloride adsorbent due to its particular layer structure and physical properties.Nowadays,Hydrotalcite has been successfully applied in Cement-Concrete field,but it is still blank in Gypsum field at home and abroad.This study confirms the chloride mainly impacts the paper-core bond performance of plasterboard.Meanwhile,it is also validated that Hydrotalcite can absorb chloride in gypsum slurry according to the Langmuir formula,and the absorption efficiency is around 30%.Based on those results,2 candidates are selected and tried to optimize their absorption performance by changing calcination temperature and duration time.It is found that the chloride absorption performance of Hydrotalcite is increasing with the increment of calcination temperature and duration time.On the other hand,the chloride absorption performance of Hydrotalcite is also enhanced with the increment of environment temperature and absorption time.At last the study establishes a cost-benefit model by using Design of Experiment(DoE).The tendency chart of variable cost vs chloride concentration in gypsum is made through fitting formulation from Minitab software.Alcamizer 1-C is the most cost-efficient product that been selected,and it also doesn’t impact on both processing parameters and performances of plasterboard according to the results of a serious of quality check.