| 摘要 |
A finely granular agent for desulphurising molten iron consists of 50 to 98% by weight of industrial-grade calcium carbide and 50 to 2% by weight of a dried coal containing at least 15% by weight of volatile constituents. The coal is intended to liberate the volatile constituents, at the temperature of the iron melt, within less than 60 seconds, preferably less than 40 seconds, and in doing so to evolve a volume of gas of at least 80 l(S.T.P.)/kg of coal. Suitable coals for preparing the agent are lignite, bright-burning (open-burning) coal, gas-flame coal and gas coal (bituminous coal). The agent is prepared by adding the dried coal to the calcium carbide, which may have been pre-crushed, and comminuting the mixture to a particle size of 90% 200 mu m. Using a carrier gas, the agent according to the invention is blown, in a fluidised form, into the iron melt, using the conveying gas in an amount of 3-30 l(S.T.P.)/kg of agent, at a conveying rate (feed rate) of 10 to 100 kg/min. |
