| 摘要 |
PURPOSE:To recover a soda ash-base refining agent from slag at a high rate of recovery and a low cost by subjecting the slag discharged in the form of a slurry to solid-liq. separation and adding sodium sesquicarbonate to the resulting soln. contg. Na under specified conditions so as to crystallize soda ash. CONSTITUTION:Slag produced by the pretreatment of molten pig iron with a soda ash-base refining agent is discharged in the form of a slurry with a vacuum suction type wet slag discharger. Solid matter is removed from the slurry to obtain a soln. contg. Na, sodium sesquicarbonate is added to the soln. at >=about 30 deg.C in 0.45-0.51 Z value (molar ratio of CO2/Na), and they are mixed to crystallize soda ash. This crystallized soda ash is separated by filtration or other method and recovered. A small amount of sodium sesquicarbonate may be added to the soda ash in a drying stage so as to increase the Z value of the resulting crystals to 0.5-0.61. |
