No abstract

The results of using as a fluxing component in ceramic mixes flotation tailings of tungsten -molybdenum ores from the Kaitashskoe mine are presented. Flotation tailings used in ceramic-tile mixes lower the production costs of the finished products, decrease the firing temperature, make it possible to salvage the mining wastes, and yield articles with the required technical properties.Work on using the tailings from the Kaitashskoe mine as raw material in the production of ceramic tiles has been performed at the Tashkent Scientific -Technical Institute of Chemical Technology. Flotation tailings which are formed as a result of the processing of tungsten -molybdenum ore take up hundreds of hectares of useful land and amount to 1.20´10 7 tons. The yearly average amount of tailings dumped since 1976 is 1.10´10 5 tons.The chemical composition of the flotation tailings is as follows (% 2 ): 41.other. This is a finely disperse, sand-like, dark-gray material with plasticity 6.7. Carbonates are present in the tailings; this has been confirmed by mineralogical analysis. The main rock-forming minerals are kaolinite (21.77%), calcite (36.40%), hydromica (3.68%), and hematite (15.80%); the remainder consists of SiO 2 and other impurities.Differential thermal analysis of the flotation tailings shows that the free and physically bound water evaporates in the temperature range 20 -250°C and water is also partially released from hydromicas as a result of their degradation. The exothermal effect at 430°C corresponds to the removal of water of crystallization and burnup of organic impurities, and the exothermal effect at 580°C corresponds to the removal of water of crystallization and partial destruction of the crystal lattice of kaolinite. The endothermal effect at 846°C is due to the polymorphic transformations of quartz. The exothermal effect peaking at 980°C is accompanied by the appearance of new phases of anortite and hematite. Most of the structural water is removed at temperatures 800 -1000°C.These flotation tailings are low-melting; their refractoriness is 1130 -1160°C.The kaolin -chamotte -Kaitashskoe tungsten -molybdenum ore (KTMO) flotation tailings system was studied to determine the optimal mix and the physical-mechanical properties of the samples. The effect of the grain composition of the neutral additives and the firing temperature regime on the technological properties of the mixes and their sintering temperature was investigated.The samples were calcined for 5 h in a silit furnace at temperatures 850 -1050°C with soaking time 1 h at the maximum temperature.The mixes for the plastic molding were prepared by dry mixing of angren clay powder with neutral additives followed by the addition of water up to the molding moisture content.The samples were formed from mixes by introducing into the mixes 4 -5% chamotte from angren clay with maximum grain size 1 and 2 mm. When KTMO flotation tailings are added to the mixes, the molding moisture content of the mix decreases from 16.8 -18.0 to 14.5 -16.0% and the shrinkage in ai...

which possesses high heat and chemical resistance, are presented. The interrelation of the physical-chemical properties and the phase composition and structure of the coatings with different content of the flotation tailings introduced are investigated.