Research On Color Slag Glass-Ceramic Preparing By Utilizing Pyrite Tailing Kaolin Mined From South Of Sichuan

The pyrite reserves in south of Sichuan are the primacy in China. The exploit history of pyrite is long, but there are several problems existed in pyrite mining, such as no multipurpose utilization, only pyrite has been separated as product, and other minerals wasted, which resulted in serious environmental pollution and low profit, one of the key solution is multipurpose utilizing the tailing kaolin.Glass-ceramic is a kind of building material with high capabilities, low cost and high additive value. Utilizing the tailing kaolin in glass-ceramic producing can increase production profit, and solve the serious environmental pollution problem; it is fit our country's sustainable development strategy.The research is aimed at utilizing the gangue kaolin to produce color glass-ceramic, probing suitable technique for preparing colorful glass-ceramic with excellent capabilities, finding the role of high TiO2 content in glass-ceramic, and increasing the ratio of treated gangue kaolin included in burden.No slag has been used in glass-ceramic industrialization manufacture, the main hinders are the high coloring impurity content included in slag, which remained in glass-ceramic product and brought variable color to it, and the unsteady manufacturing technique. Considering the composition characteristics of the pyrite gangue kaolin, a calcining-double hydrochloride acid leaching technique has been used to extract iron and part of aluminum from the gangue kaolin, producing a solid with stable high Si and low Fe contents, which can satisfy the request to raw material asked by glass-ceramic preparing. Its content of Fe2O3 is as low as 0.2% or so, this will reduce the unwanted influence of iron to glass-ceramic, and benefit the producing of slag glass-ceramics with different colors and main crystalline phases.By analyzing phase diagram of glass, determining wanted crystal phase of glass-ceramic, a lot of experiments have been done to choose suitable germination agent, adjust the composition of kaolin, and define thermal treatment regulation. As the result, colored slag glass-ceramics with diopside main crystalline phase have been prepared in laboratory, the dosage of treated gangue kaolin is over 46 percent.The study indicates that utilizing pyrite tailing kaolin in glass-ceramic production is feasible. TiO2 existed in the slag can be used as the main germination agent, by incorporating with a little amount of ZrO2, P2O5 and CaF2, compound germination agents related to diopsideand wollastonite crystalline phases were constituted. The research also prove that the germination mechanism of TiO2 is first promoting phase-separating in glass, then producing rutile crystals to induce heterogeneous nucleation. The influence of TiO2 to the crystalline phase composition is big, it can deviate glass composition to high Al2O3 region, which provide a important leading function for designing glass-ceramic dosage when using high TiO2 content raw material. TiO2 has toner's function and greatly influenced glass color, so glass-ceramic color is decided by the combining of stains and TiO2.The technology of color slag glass-ceramics using Sichuan pyrite tailing kaolin has been defined by the research, it has a guide role for utilizing other high Fe2O3, TiO2 content raw material in slag glass-ceramic producing.