Experimental Study On CAS System Fly Ash Building Glass-ceramics

In recent years with the rapid development of our country industrialization, a lot of industrial waste has been produced, especially the fly ash. How to reuse, recycle fly ash has become one of the hot issues. From the view of components of fly ash which is composed mainly by Si, Al and Ca oxide, fly ash is exactly the main chemical elements of glass ceramic. So it is feasible to be used to prepare CAS glass-ceramic. Fly ash glass ceramic has many properties such as high strength and hardness, wear resistance, non-absorbent, antifouling anti-freeze and good chemical stability. It is widely used as a building interior wall, ground, mesa, the adornment of the pillar and exterior wall, and therefore become a modern construction replace natural granite, marble of green environmental protection adornment material, and gets more and more consumer's favor.In this paper, according to the process engineering of materials, from waste recycling and energy-saving angle, we produced glass ceramic. According to certain ratio of raw materials and the preparation technology of fly ash to making glass-ceramics samples, it is used by differential thermal analysis (DTA) and X-ray diffraction (XRD), scanning electron microscopy (SEM) technology and according to relevant standards for fly ash building glass ceramic performance to test. Through the different CaO/SiO2 of fly ash of glass-ceramics crystalling phase, microstructure, density, compressive strength, flexural strength, bibulous rate and corrosion resistant performance were analysed. Based on analysis to determine the crystal dynamics theory further Al2O3/SiO2 microlite glass to fly ash kinds of influence of performance; The step to prepare fly ash glass ceramic by sintering, and analysis of the holding time, binder dosage and moulding pressure for glass-ceramics influence; Finally prepare glass-ceramics samples and ceramic grain billet and related composite detection performance. The results show that, with the CaO/SiO2 and Al2O3/SiO2 increases, the main crystalling phase of the sample is always wollastonite. Its size of the crystal changes with heat treatment system varies; the compressive strength and flexural strength of the sample both showed the trend of that it first increases, then decreases; acidic resistance and alkali resistance changed little; one step sintering method of sintering fly ash glass ceramic is feasible, and the heat preservation time should be controlled as 3 hours, take sodium silicate binder mixing content is 15%, the molding pressure for 20 Mpa. Under this rule we can get good performance glass ceramic. Through the fire temperature and thermal expansion coefficient analysis, ceramic and glass ceramic can be composited; and the test shows that the performance of the compound such as compressive strength, flexural strength, bibulous rate, corrosion resistance and gloss was better than the other building decoration materials.