Telianov V. Dry mixes on the basis complex binding of phosphogypsum

Object of research: neutralization processes of water-soluble compounds of phosphorus and fluorine; processes of firing and hydration of binders on the basis of phosphogypsum. The aim of the thesis: the development of dry building mixes on the basis of modified binder obtained from phosphogypsum. Methods: commonly used standard methods of theoretical and experimental studies of basic properties of raw materials, binders and dry mixes. Chemical and X-ray diffraction analysis methods were used to determine chemical and mineralogical composition of the raw materials and dry mixes. Physical and mechanical properties of the mixes and their raw components were investigated with standard methods according to current regulations on certified equipment. Determination of the relationship between basic properties of the mix and technological factors was based on experimental studies, using methods of experimental design. Theoretical and practical results: dry neutralization of phosphogypsum allows using it without any additional expenditure for preparing of raw materials, simplifying of technological process of firing, creating of nonwaste production and improving of the environment ecology. Technology of production of composite binder and methods of its modification with nanoparticles (taurit) with redispersive powders and additives that slow hardening (KD "PGASA"), for production of binders with the characteristics: W/S = 0.50, compressive and bend strength - 6.9 and 3.5 MPa, respectively, and bulk density - 860 kg/m3, working life is more than 30 minutes; phosphogypsum disposal for manufacturing of complex binders and dry building mixes reduces territory of dumps; the developed compositions of dry building mixes on the obtained binder. Scientific novelty: for the first time method of dry neutralization of phosphate and fluoride impurities of phosphogypsum activated with a mix of silica and calcium carbonate is used, at which water-soluble compounds of phosphorus and fluorine are converted into insoluble or poorly soluble; optimal regimes of firing of phosphogypsum with maximum quantity of hemihydrates of low-temperature binders are established; theoretical propositions of modifications of complex binders based on phosphogypsum nanomaterials and redispersive powders got further development, due to their highly developed surface adding them allows activating of the processes of hydration and forming a structure with improved mechanical characteristics; theoretically determined and experimentally confirmed field of rational compositions of dry building mixes on the basis of the obtained complex binder from phosphogypsum. The degree of implementation: technological regulations of manufacture of gypsum binder based on secondary products of chemical industry and materials on their basis, which establish procedures and methods of manufacturing processes of products by the proposed technology, are developed, manufacturing inspection of a research batch of the binder on a plaster mix in the "Budindustria, LTD". Scope of use: production of interior dry building mixes.