Research On Glass-Ceramic Preparing By Utilizing Tailing Of BISCO

Tailings are 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. The discarding of tailings brings about a series of social problem as well as environment pollution. Tailings used in the fields of low technique poor-profit. As far as tailings are concerned, they have not the fundamental elements and mineral that can be utilized, so they are no utilized mostly.Because of lots of excellent characteristics, Glass-ceramic is new inorganic metalloid material and environmental material of 21st century. At present, tailings to manufacture glass-ceramic is limited to others. The projects of glass-ceramic made of tailings not only recycles wastes, but also improves the materials technique content and added value, which creates a new method of tailings multipurpose at the same time. At the same time, the method improves the use of tailings and offers a new channel for the comprehensive utilization of tailings. Apparent environmental, social and economical benefits can be gotten.Based on tailings major raw materials, the thesis develops successfully glass-ceramic with adopting the sintered method as well as the melting method and the rate of comprehensive utilization can receive the percent of 70. The thesis designs fundamental ultimate composition of glass and chooses suitable temperature and defines glass-ceramic's technology. At one time, the test adopts the method of DTA, XRD, SEM, and EDS. The microcrystalline structure and the physical chemical properties are analyzed in order to get the preparation technology's progress and rationality. The method offers tech support and theory foundation. Finally, the paper defines optimum crystal nucleus and technological parameter.This paper has made the following conclusions through experiments, testing and results analysis.(1) Using 70% tailings as the main raw material, Glass-ceramics was prepared by melting and sintering. Glass-ceramics of the performance indicators: flexural strength 480MPa, water-resistance of 0.03%, Resistance to0.186g/m2?h.(2) With rare tailings introduce the increase tailings glass nuclear temperature and crystallization temperature lower and the precipitation pyroxene phase, increasing the tailings glass-ceramics chemical stability by DTA, XRD.(3) It results show that nucleation temperature has fallen and small grain size with CeO2, Nb2O5. (4) Rare tailings of BISCO containing nuclei in a large number of agents, can induce the nuclear non-homogeneous, which makes the glass produce large, Uniform distribution of nuclei. Moreover, due to the tailings containing niobium, rare earth and other trace elements, different nucleating agents have different characteristics, composite nucleating agent can be achieved double-alkali effect, the ion packing density, and promote nucleating agent in the vitreous dissolved, but the interface can be reduced, so as to reduce nuclear activation energy.(5) Appropriate heat treatment system enables effective basis glass and crystal nucleation, and then obtained a small uniform distribution of crystal glass-ceramic materials. Experimental design arrangements heat treatment programs, analysis, Rare tailings glass-ceramics for heat treatment process, glass annealing temperature of 700℃, holding for 2 hours. The best heat treatment schedule: The glass should be heated to the nuclear temperature at 300-350℃/h rate , holding for 2 hours; then heated at a rate of 3-4℃/min to crystallization temperature, holding for 1 hour. Then cooling with the stove.