Methods for obtaining a composite gypsum binder based on Samarkand and Bukhara stucco

Abstract

The article analyzes the study of the production of gypsum binders using the filler of the Bekabad metallurgical slag with a chemical additive superplasticizer GLENIUM 27S. The analysis of the results obtained showed that the general regularities of changes in the properties of gypsum compositions, regardless of the type of binder based on which they were obtained, are preserved: with a constant amount of slag, the water demand and setting time of the binder, regardless of the specific surface area of the additive, practically do not change. In this case, with an increase in the specific surface area of the used slag, an increase in the strength of the gypsum stone is observed.The possibility of regulating the physical and mechanical properties of a gypsum binder with the help of a filler and additives that regulate both the process of crystallization and hardening is shown. Also shown is a comparison of the production of gypsum binder in different ways.As a result of studying the properties of binders showed the following: the water demand of the composition is 5% lower, the setting time practically does not change, and the strength of the gypsum stone increases by 0.5 times. If, to increase the strength of gypsum stone by 11%, it is necessary to introduce slag with a specific surface area of 500 m2 / kg in the composition of Samarkand gypsum. When using Bukhara gypsum, it is sufficient to grind it to a specific surface area of 150 m2 / kg. This will reduce the energy consumption for grinding the additive.In the course of comparing the preparation of gypsum compositions by various methods, it was shown that the simplest from the point of view of the production technology is the third method, which makes it possible to exclude the operations of preliminary grinding of the components. And the strength and density of gypsum stone based on the composite gypsum binder obtained by the third method increases by 13.4 and 10.3%, respectively. Also, the regularities of changes in the properties of binders, depending on the method of their production, including the order of introduction of a mineral additive and a superplasticizer, have been established, served as the basis for the development of a technological scheme for the production of a composite gypsum binder.