Effects of Various Factors on the Rate of Desulfurization of Molten Pig Iron with Solid Lime.

Abstract

Effects of various factors on the rate of desulfurization of molten pig iron with solid lime were studied with the following results:
1) Desulfurization hardly proceeded in the oxidizing atmosphere consisting of argon and carbon dioxide or carbon monoxide and carbon dioxide.
2) The desulfurization reaction of molten Fe-C-S alloy in a neutral or a reducing atmosphere was found to be of the 1st order with respect to the sulfur content of iron at the very beginning of the reaction.
3) The rate of desulfurization in the atmosphere of Ar was equal to that in CO. The rate in town gas was 3 times as much as others.
4) Contact surface between lime and molten iron has remarkable effects on the rate of desulfurization. To attain effective desulfurization the lime should be finely pulverized and large contact surface relative to the mass of iron should be given.
5) The rate of desulfurization increased with increasing temperature. The relationship of the rate to temperature could be expressed with the so-called Arrhenius' equation.
6) The rate of desulfurization was increased with increasing Si content of iron. In case when iron contained silicon, the reaction was found not to be of the 1st order. The effect of Si content was increased as the reaction proceeds.