Preparation Of Glass-ceramics

Glass-ceramics material which is composed of uniform distribution glass phase and minicrystal phase, can be prepared by the parent glass via controlling the behavior of crystallization. As a kind of new inorganic material, it has many super properties such as higher mechanical strength, good grinded , corrosion ,weathering heat resistant capacity, and adjusted expansion coefficient. So, it has been used in various fields widely as a functional and structural materials.With the development of industry, a great deal of wasters which were deposited by different industries, has caused the problem of polluting on environment and wasting the nature resources. Generally, the main composition of industrial wastes are CaO, MgO, Al₂O₃, SiO₂ and a few other components, which make it be a potential raw material for the preparation of glass-ceramic.In this paper, the Ni-slag and fly ash, which come from Jinchuan company and Xigu electric power plant in Gansu respectively, were used as major raw materials for the preparation of glass-ceramic. The main crystal phase is pyroxene which is designed in the system of glass-ceramic is CaO- SiO₂- MgO- Al₂O₃.Basing on the theoretical analysis and experiment , we discussed the effects of the composion of glass , different batches, and the heat treatment parameter on the comprehensive properties of slag glass-ceramic.Applying theoretical arithmetic and experiment adjustment, the composion of glass-ceramic was confirmed and the quadrature analysis was adopted to research the relations of composion and properties. The experiences have proved the best batch : slag 34%, fly ash 28%, Si-Fe 14%, fluorite 5%, sodium carbonate 4%, calcium carbonate 10%, composite nucleating agent TiO₂+ZrO (4% ) .On the base of original glass which was prepared according to the best batch, a single heat treatment schedule was applied during the process of the glass converted to glass ceramics according to the result of DTA. At the same time, we discussed the effects of heat treatment schedule on the glass-ceramic properties, then the best parameters of the heat treatment on glass were decided. As the result showed the crystal temperature play a more important role in the effects on properties, compared the other factor;and the best parameters of heat treatment was730℃ and heat preservation was 1.5hours.By a series of properties' tests, the result showed that it is feasible to prepare glass-ceramic utilizing Ni-slag and fly ash which was more than 60%.Theglass-ceramic has great social and economical beneficence because of well performance.