Development Of Glass-Ceramic Made By Low-silicon Iron Tailings

Tailings is a kind of solid waste. Because the characteristic of tailings is large amount, many kinds and complicate quality, the rate of only 7% in china. Tailings has been a important source of pollution, and it does a large harm to environment. Iron tailings is a mostly kind of tailings, and only used in the fields of low technique poor-profit. As far as low-silicon iron tailings is concered, they has not the fundamental elements and mineral that can be utilized, so it is not utilized mostly.Glass-ceramic, with lots of excellent characteristics, is new inorganic metalloid material and environmental material of 21st century. At present, iron tailings to manufacture glass-ceramic is limited to the high-silicon (SiO2>70%) ones. The project of glass-ceramic made of low-silicon iron tailings not only recycle wastes, but also improve the material's technique and value, which creates a new method of low-silicon iron tailings' multipurpose at the same time. Apparent environmental, social and economical benefits can be gotten.We succeeded in developping glass-ceramic which has 60% low-silicon iron tailings of Chengchao iron mine of WISCO by sintering. Designing the capital composition of glass, selecting proper nucleating agents and confirming glass-ceramic process program of low-silicon iron tailings on the base of analysis low-silicon iron tailings composition. To get the advance and reasoning of process program, we expound the crystal construction and technology ability parameters by the advanced test approach. We give the properest nucleating agent and processing parameters of glass-ceramic with low-silicon iron tailings by profound exploring and plenties of experiments.Experiments show that Fe2O3 of low-silicon iron tailings can'teffectively crystallize the whole glass. TiO2 and Cr2O3 are effectively crystallization of low-silicon iron tailings, but quantities require much. The effective crystallization of the whole glass is better when the TiO2 and Cr2O3 is composite nucleating agent - the optimal quantity of TiO2 is 2wt%, Cr2O3 is 1 wt%. The optimal parameters for the fusion of the glass is the mixture was whole put in at 1100℃, then heated to 1450℃, holding for 2h. Quadrature analysis is adopted to research the optimal parameters for the heat treatment of the glass. Results show that the glass should be heated to 800℃, holding for 2h, then heated to 1140"C, holding for 3h.And what's more, the factors which have effect on the low-silicon iron tailings'color and reason of bladder are studied and analysized. By use of SEM and PLM we give preliminary research of crystallization mechanism of low-silicon iron tailings.