Preparation、Microstructure And Properties Of M₂s Light-Weight Insulation Material

With resources gradually deficient, light-weight heat insulating refractory become aresearch hotspot for its small bulk density, low thermal conductivity and excellent thermalinsulation effects. Forsterite is in widespread use in steel and iron industry and foundry industryas good high temperature resistance refractory. But due to its application of only coarsness in theindustry mentioned above, fine powder of forsterite is overstocked. In order to save energy andreduce consumption, this paper studies how to use fine powder of forsterite mentioned abve toprepare light-weight heat insulating refractory.This paper takes fine powder of forsterite, light sintering MgO, fused magnesia andmicrosilica as raw material to study the influence of processing parameters on the characteristicsof forsterite based light weight brick and to make correlative industrial test.Forsterite based light weight bricks could be made by foaming method. When sodiumhexametaphosphate was used as water reducing agent, its optimal addition was0.2wt%. Sodiumcitrate was used to disperse the agglomerates in the foam mud evenly as well as its best additionwas0.10wt%. When moderate MgCl₂aq was added, bulk density and green strength of thesamples showed a sensible rise. When the proportion of light sintering MgO and fused magnesiawas3:2（wt%）, the activity of light sintering MgO could be controlled efficiently andconsequently strength of the samples could be ensured. Microsilica could improve the plasticityof the foam mud strikingly and its optimal addition should be3wt%.Forsterite based light weight bricks could be made by inclusion of combustible materials.The samples sintered at1500℃for3h showed small reheating linear change and good thermalstability. Rice husk powder was used as pore-forming agent to reduce bulk density of productsand its best addition should be10wt%. Dextrin used as binder could improve the plasticity ofthe raw meal and form lots of small pores to reduce the bulk density of the products and itsoptimal addition was about3wt%.Using forsterite based light weight bricks made as preparation above to make industrial test,the result showed that the light weight bricks could take the place of high alumina refractorybricks of heavy weight applied to thermal insulating layer of ladles, for its stable performance,small reheating linear change and high intensity could reduce the temperature of barrel about30⁵0℃and was beneficial to conserve energy and reduce cost of ladles.