Research Of Microtructure, Properties And Applications On Fused Forsterite

In recent years, our country is facing the grim situation of a shortage of magnesiteresources, and a large number of forsterite are not effectively utilized. Therefore, thecomprehensive utilization of natural forsterite is needed to be research. Fused forsterite is a newrefractory raw material, prepared by high-temperature melting reduction using the abandonedforsterite powders as raw material. Properties of fused forsterite may be better than natureforsterite and it would be a promising refractory raw material in future, because of its highpurity of forsterite and low content of Fe₂O₃. The present work aims to study the structure,properties and products of fused forsterite, and contains three parts as follows:Firstly, the basic performances of fused forsterite, which include chemical and mineralcomposition, and physical properties and the sintering of powder, are investigated and theresults indicate that: the content of Fe₂O₃was only o.4%; the mainly phase of fused forsteritewere forsterite（a=10.196, b=5.9814, c=4.7545） and clinoenstatite （a=9.601, b=8.817,c=5.174）, with a little of spinel and diopside; forsterite crystal was long column and growingdirectionally, developing fully, having less lattice defect, and its low-melting phase were mainlydistributed in the grain boundary, and it may be present solid solution at high temperature; thebulk density and refractoriness of fused forsterite was3.09g.cm^-3and1660℃，and containing0.48%carbon; the sintering experiment indicated that, the best temperature range of sinteringwas1450¹500℃.Secondly, the effects of process factors on fused forsterite products, which containingshaped products and castables, are investigated and the results indicate that:In the shaped products, magnesia can react with the low-melting phase to form forsterite,which can improve the high temperature properties but with larger expansion; zircon candecompose to form m-ZrO₂, which can improve the thermal shock resistance;In the castables, microsilica can improve the fluidity, react with magnesia and water toform MgO-SiO₂-H₂O network structure, and transform into low-melting phase to improve theproperty of sintering at high temperature; magnesia can improve the high temperatureproperties; the right amount of zircon can improve the thermal shock resistance significantly.Thirdly, the application to industry of fused forsterite products was investigated and theresults indicate that: fused forsterite saggar achieved remarkable results in the pusher kiln ofsynthesizing LiCoO₂, which shows that fused forsterite saggar would have a promisingapplication in industry in future.