Study On The Synthesis Of Lightweight Forsterite Refractories With Iron Tailings

Along with the short of mineral resource, more and more people realized that it has great significance both in economy and environmental protection field to make full use of tailings. In the paper, the lightweight forsterite refractories is synthesized by using high-silicon iron tailings from An Shan with certain proportion of active magnesia, which base on the abundant magnesium resource in Liao Ning province, at the same time, the property of the forsterite is studied. The results are as follows:Through the analysis of small sample's appearance and metallography, the proper recipes of raw material which is 60% active magnesia and 40% iron tailings in weight in the synthesis process is found, and the proper sinter temperature is 1450°C.A quota of chamotte and appropriate water are used to manufacture the qualified brick in which phosphoric acid or Na₂SiO₃ is used as cementing agent, during the processing, reasonable mix processing, placement and molding methods are applied. Moreover through seemly drying and sintering process, dehiscence phenomenon does not appear any more in the brick, and its intensity is eligible too. The methods including XRD, SEM, EDAX have been used to analyze the sintered sample, the results are as follows : the principal constituents of the product are forsterite and some periclase, moreover it also has a little magnesium ferrite, fayalite as well as other impurities.Lightweight forsterite refractories can be manufactured with adding a quota combustible substance to adjust the pore rate in which phosphoric acid is used as cementing agent. When the density of the product is 1.1g/cm³, the pressure resistant of the brick is 4.8MPa, and the refractoriness is over 1700°C , and its thermal conductivity(0.47W/m·K) is obviously lower than the same type brick, such as lightweight argillaceous brick, lightweight high-aluminum brick and lightweight silicon brick, so it can be used as heat insulation material.