Preparation Of Lightweight Refractories Of Forsterite

In the paper, a new process which made use of forsterite ore full in China to produce lightweight rfractories used in moderate and high temperature was studied. A lightweight rfractory of forsterite with bulk density below 1.2g/cm3 was prepared from the forsterite ore in Shanluo City Shaanxi Province with oil coke and carbon black as pore-forming materials. The effects of binding materials, firing system, the kinds, addition and partical size of the pore-forming materials on the properties of the samples were discussed. The microstructure and physical properties of the samples was analyzed with the help of microscope, XRD etc.Effects of firing system on properties of the samples were researched and the suitable firing system is as follow:open door heating rate of 1℃/min before 700℃,holding for 3h at 700℃,and then close door heating rate of 3℃/min to the holding temperatures.The best sintering temperature is 1300℃holding for 3h.Among the chosen binding materials, MgCl2g·6H2O was the better for the forming processes of forsterite lightweight rfractory.The influences of the pore-forming material and its addition as well as the partical size on the properties of the samples were studied. The properties of the samples are better when the addition of oil coke with particle sizes minus 74μm was 40%.Through the study the optimized technique was available with 3% addition of MgCl2·6H2O as binding material and 40% addition of the oil coke with particle sizes minus 74μm sintered at 1300℃for 3h. The lightweight rfractory of the forsterite had been prepared according to the route with 1.15g/cm3 bulk density and 3.58MPa compressive strength.The linear shrinkage of the rfractories are less than 1% reheated at 1300℃×6h and bellow 3% at 1350℃×6h.