The Study of Types of Spinel on Properties of Corundum-spinel Unburned Brick
|School||Wuhan University of Science and Technology|
|Course||Materials Physical Chemistry,|
|Keywords||Magnesium aluminum spinel situ pre-synthetic light burned corrosion|
Corundum-spinel refractories are the main ladle lining refractories in ferrous metallurgy.People have different ideas to the ways of introduction of spinel and the varieties of spinel toproperties of corundum-spinel unburned bricks. In this paper, the differences of corrosionresistance and penetration resistance to ladle slag of commercial spinel raw material andsynthetic light burning spinel are studied. And after they are introduced into corundum-spinelunburned brick, we study the differences of properties of corundum-spinel unburned brick, theresults show that：(1)With the Al2O3content increasing in the spinel raw materials, the spinel shows bettercorrosion resistance to slag, but lower penetration resistance to slag, except for the penetrationresistance of S90is more weakened than S78. And the erosion resistance of spinel materials tolow C/S slag is better, but the penetration resistance of spinel materials to high C/S slag isbetter.(2)With increasing the synthetic temperature of light burning spinel, the grain size ofspinel grows, the reaction rate of spinel and slag reduces, so the corrosion resistance of lightburning spinel to slag is enhanced.(3)When situ spinel fines are introduced into corundum-spinel unburned bricks, becauseof the expansion effect from spinel reaction, the structure of that series of samples is not dense,and larger apparent porosity, lower bulk density, lower cold crush strength and cold bendingstrength, lower HMOR. The sample, into which the S67pre-synthetic spinel is introduced, hasa higher linear rate of change after heat treatment, lower bulk density, lower cold crushstrength and cold bending strength, worse penetration resistance to slag, better thermal shockresistance. On the contrary, the S90pre-synthetic spinel is introduced, the sample has lowerlinear rate of change, higher bulk density, higher cold crush strength and cold bending strength,better corrosion resistance to slag, worse thermal shock resistance. Colligating variousproperties of sample, when the S70pre-synthetic spinel fine is introduced into sample, theproperties of corundum-spinel unburned bricks are better basically.(4)The different types of light burned spinel fines are introduced into corundum-spinelunburned bricks. In the sample, in which light burned spinel fines was synthesized in the sametemperature, with the Al2O3content increasing in the light burned spinel, linear rate of changegradually decreases, low coefficient expansion. When the Al2O3content of light burned spinelis same, with the synthesis temperature of light burned spinel increases, the linear rate ofchange of sample is not obvious in change, but bulk density increases, cold crush strength andcold bending strength become higher, HMOR increases, corrosion and penetration resistanceto slag become better. Colligating various properties of sample, when the synthesis temperature of light burned spinel fine at1600℃and the Al2O3content in light burned spinelis about75%, the properties of corundum-spinel unburned bricks are better basically.(5)Compared with the sample, which pre-synthetic S67spinel fine is introduced into,because of the secondary spinel reaction and high activity of light burned spinel, the sample,which there are light burned LS68spinel fines in, has higher expansion rate at1400℃, lowercompressive strength, lower HMOR, worse corrosion resistance to slag, but better thermalshock resistance, better penetration resistance to slag.