Optimization of Parameters for the Production of Gypsum Binders Based on Gypsum-Containing Waste

Gypsum-containing wastes are a promising source of raw materials for the production of gypsum binders. However, they have specific features that require the development of alternative approaches and technological regimes in order to ensure the high quality of the final product. The purpose of the article was to study the influence of moisture content of gypsum-bearing waste and firing temperature on the specific surface of the gypsum binder, as well as the compressive strength and average density of gypsum paste based on it. The gypsum-bearing material was citrogypsum. It is a waste product of the biochemical synthesis of citric acid. The experiment was carried out using the method of mathematical planning. Burning of citrogypsum was carried out in a laboratory oven according to a given temperature regime. Using the statistical computer processing of experimental data, regression equations were obtained; graphic dependence as nomograms are constructed; the influence of variable factors on the controlled parameters was assessed. It has been established that the optimal, from the standpoint of energy consumption, is the binder burning at a temperature of 150 ℃ and the lowest possible raw material moisture content of 5%. Increasing the burning temperature above 150 ℃ is not economically workable and adversely affects the compressive strength of the gypsum stone, as well.