PRODUCTION OF SINTERED LIME HAVING HIGH DENSITY AND HYDRATING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To obtain sintered lime useful as an intermediate material of a lime refractory material by washing, pulverizing and sintering limestone containing impurities of less than specified ratios at a specified temperature, hydrating and drying the sintered lumps, mixing a specified amount of a transition metal oxide in the obtained lumps while crushing, palletizing the mixture and sintering palletized mixture. SOLUTION: Limestone containing 2% impurities is washed, while the impurities mingled from the outside are removed if necessary and the washed limestone is pulverized into the pieces having =25 mm particle size, which then are sintered at 1,000 to 1,150 deg.C. The sintered lumps are hydrated, which then are dried. The dried lumps are crushed. Such an additive is mixed by 1 to 4 wt.%, as is a transition metal oxide capable of forming low melting point compounds and/or a rare earth metal oxide capable of forming solid solution. The obtained mixture is palletized under =1,000 kg/cm2, the obtained pellets are sintered at 1,500 to 1,650 deg.C for 2-4 hours and the sinters are naturally cooled. The sintered lime preferably has 3.05 to 3.23 g/cc bulk density and 47 to 155 m particle size.