| 摘要 |
PURPOSE:To reduce the contents of Si and S in pig iron simultaneously by blowing basic materials such as limestone and dolomite together with pulverized coal through a blast tuyere into a blast furnace. CONSTITUTION:Pulverized coal is blown from a raw material hopper 4 into a blast furnace 1 through the blowing nozzle 11 of a blast tuyere 3 via an intermediate tank 5, a pressure feed tank 6 and a transport pipe 10. At the same time, basic materials such as limestone, dolomite, or their calcined matters or hydroxide of calcium and magnesium which are ground to about the same grain sizes as those of the pulverized coal are blown into the furnace 1 through the nozzle 11 of the tuyere 3 via a hopper 7, an intermediate tank 8, a pressure feed tank 9 and the pipe 10. The rate of blowing of additive materials such as limestone is set at about 5-50kg per ton of pig iron while the ordinary rate of pulverized coal is about 30-150kg. Thereby, the additive materials are blown simply by modifying a part of a blowing installation. |
