PREPARATION OF REFRACTORY MATERIALS FROM ASBESTOS TAILINGS

摘要

A process for producing especially high temperature refractory materials fromasbestos tailings, or from calcined productsproduced from asbestos tailings. The process comprises grinding the asbestostailings, or the calcined product, to a suitable particle size; mixing the ground particles with magnesium oxide or a magnesium oxideprecursor, and heating the mixture to a temperatureof at least 1200 °C for a suitable length of time to form a largeproportion of forsterite in the resulting product. The amountof magnesium oxide or precursor should preferably be such that the MgO:SiO2ratio in the starting materials is at least 1.2,which usually requires an amount in the range of 10 to 25 % by weight, basedon the weight of the asbestos tailings. More-over,the particle size of the asbestos tailings or calcined product shouldpreferably be in the range of -1.7 mm ~ 0.1 mm.The resulting refractory product has a fusion point above about 1660 °Cand can be used in contact with molten steel or thelike, particularly when mixed with a bridging agent such as graphite.