Study On Preparation Of Aerated Gypsum Material By Chemical Method

ABSTRACT:As one of the superior physical properties of building materials, a-high-strength gypsum is widely used. It mainly comes from desulfurization gypsum as the industrial by-product gypsum. In recent years, in order to further improve the comprehensive utilization efficiency a-high-strength gypsum, aerated method is usually adopted, which can improve the heat insulation, heat preservation, light, etc. In this paper, chemical gas is used, that is calcium carbonate reacts with aluminum sulfate carbon dioxide, to the preparation of aerated gypsum block, and the microstructure of aerated gypsum products was characterized, the influence of related factors were explored, obtained the optimal production process. The main results are as follows:(1) Using calcium carbonate and aluminum sulfate in the process of preparation of aerated gypsum material adding way, slurry mixing time and intensity has a great influence on the performance of gypsum products, through the experiment to determine the best process is:the first will be dry mixing solid powder, then add water to wet mix, to obtain the required slurry, then stirring after30seconds, in the mold shape.(2) By means of XRD, SEM and other means of gypsum products of hydration products and microstructure were analyzed and characterized. Studied the various influence factors such as ratio of material, the experimental results show that the water ratio of0.80to0.80, pulp temperature of25to35℃, aluminum sulfate, calcium carbonate content of4.50%-4.50%dosage is7.50%8.75%, stable foam agent is7.50%-2.00%, retarder is0.050%-0.075%, within the scope of naphthalene series water reducing agent is1%o of gypsum block performance is good.(3) Orthogonal experiment method was used to study the various materials for the size of the influence of gypsum products, and through the orthogonal experiment analysis of the poor, and the optimized conditions for six indexes separately, to determine the optimal solution for:water is expected to more than81%,4.5%calcium carbonate, aluminum sulfate7.5%, stable foam agent2.0%,33℃temperature, naphthalene series water reducing agent1‰,0.75‰retarder.