ON THE INFLUENCE OF CHEMICAL-MINERALOGICAL COMPOSITION AND STRUCTURE OF BLAST-FURNACE SLAGS ON PHYSICAL AND MECHANICAL PROPERTIES OF ARTIFICIAL STONE DURING HARD FIRING
The paper considers the influence of characteristics of chemical-mineralogical composition and structure of blast furnace slags on the formation of physical and mechanical properties of artificial stone during hard firing. The research has been carried out into blast slags different in composition and structure. Phase, chemical and mineralogical compositions of 11 blast-furnace slags obtained from various metallurgical companies in Russia have been determined. It has been revealed that full crystal, non-crystalline, vitrophyric and aphanitic blast-furnace slags prevail. On the basis of chemical classification, low base, basic and acid blast-furnace slags have been studied. Experimental research into the impact of silicate mineral additives on the process of artificial stone formation during hard firing has been carried out. Over 1,000 laboratory samples have been studied. Statistical processing of experimental data has been carried out with the calculation of the magnitude of the general variance and confidence intervals using the results of current measurements. The regularities of the structural-phase transformations in the system akermanit-gelenite for blast furnace slags have been revealed. It has been found out that during strength synthesis of artificial stone in the process of hard firing the structure and properties of the material are directly dependent on the conditions of primary processing of blast-furnace slags with a practically identical qualitative phase composition formed under the equilibrium conditions of hard firing. The introduction of sodium silicate and aluminosilicate mineral additives extends the sintering interval, is able to smooth the abrupt changes in the properties of materials. As a result of experimental analysis it has been revealed that the temperature and sintering interval of the materials under study with increased content of alkaline earth oxides (CaO, MgO) depends not only on the total content of the latter in the raw mix, but also on the phase state of their compounds, as well as on the type of structure of slag component. New data have been obtained on the relationship between the chemical and mineralogical composition, slag structure, type of additive and firing temperature of artificial stone based on blast furnace slag, which are to provide scientific support for the production of multifunctional materials, products and structures on the slag base.