Study On Synthesis Of Chrysotile Asbestos Tailing Glass-ceramics And Materials Mineralogy

In this paper, the glass-ceramics were produced with the chrysotileasbestos tailing from Shannan Mine and the lime stone, quartz sand fromJiangyou as the main raw materials, supplemented by s mall amounts ofche mical additives. CaO-MgO-SiO₂ternary system was choosed, andtthe main crystal phase were gehlenite and diopside. The mineralogicalcharacteristics of the raw materials, the chemical composition of theparent glass, the deter mination of the heat treatment, the impact of heattreatment on microstructure and properties of glass-ceramic, and themineralogical characteristics of the glass-ceramics we produced werestudied with the method of combining theoretical and experimental.The results show that: the chrysotile asbestos tailing was mainlythe fibrous mineral, and the main chemical composition were MgO andSiO₂, but also contained a s mall a mount of Al₂O₃, Fe₃O₄, CaO and so on.The main mineral composition of the chrysotile asbestos tailing waschrysotile, but also contained a little lizardite, brucite and magnetite.The limestone and quartz sand sa mples had high purity, and the maincomponent of the m were CaCO₃and SiO₂. The glass-ceramics wereprepared with chrysotile asbestos tailing, limestone, and quartz sand asthe main raw material, and adding a small amount of Al₂O₃, Na₂CO₃,H₃BO₃and CaF2. The method of producing the glass-ceramics sampleswas sintering. And the main crystal phase of the glass-cera mics weproduced were gehlenite and diopside. Five different formulas of theparent glass were choosed, and the weigthing content of the chrysotileasbestos tailing was from18.59%to58.04%. With the improvement ofthe nucleation temperature and crystallization temperature, the maincrystal phase of the glass-ceramic sa mples in the same fo rmula weregehlenite and diopside, and they did not change. But the intensity of themain crystalline phase of the diffraction peaks increased gradually,which indicated that the content of the crystal phase of the glass-ceramics gradually increased with the temperature increased. Theimpact on the crystalling phase of the glass-ceramics of heattreatment-time was the sa me as the impact of the heattreatment-temperature. With the rise of the heat treatment parameters,the density and the line shrinkage of the glass-cera mics sa mples weproduced were first increased, and then decreased. And theglass-ceramic sampl es had the highest content of the crystal phase andthe microcrystalline phase structure was the most dense when theparent glass was nucleated at850℃for120min, and then sintered at1050℃for120min. When the temperature up to1100℃, it resulted in"dilution" effecting. The X-ray diffraction data of the glass-ceramicswith different formulations was analyzed and the crystal cellparameters were calculated. The density of the glass-ceramics sampleswe produced at the opti mized heat treat ment conditions was from2.09g/c m3to2.77g/cm3, and the water absorption was less than0.08%,and the maxi mu m flexural strength loss rate under acid and alkalicondition was0.03%to0.13%, and less than0.01%. At last, the effectof on the properties of the glass-ceramics produced from chrysotileasbestos tailing wer primarily discussed.