锰硅合金沉淀脱磷工艺制度的优化

OPTIMIZATION OF TECHNICS ON PRECIPITATION AND DEPHOPHORIZATION FOR FERROMANGANESE-SILICON

选用钙系脱磷剂、CaO-CaF_2渣,对锰硅铁合金进行沉淀脱磷,着重研究脱磷剂加入量和锰硅铁合金中硅含量增量对脱磷效果的影响。结果表明:当脱磷剂加入量由2.5%增加到7.5%时,脱磷效果增加5.56%,而合金中硅含量由19%增加到25%时,脱磷效果将至少增加23.22%,说明锰硅合金中硅含量增加对脱磷效果的作用远大于单一增加脱磷剂的作用。合金熔体中硅含量的增加降低了氧势,同时提高了磷的活度,这将有助于脱磷剂中的钙以Ca_2P_3而非CaO形式进入渣中;此外,采用沉淀脱磷工艺的锰硅合金熔体中碳含量也有明显下降,有利于中、低碳锰铁生产中碳含量的控制。

The precipitation dephosphorization on ferromanganese-silicon was studied in this work with calcium dephospho- rizing agent and the slag of CaO-CaF2. It is focused on the relationship between adding the content of dephosphorizing agent and the effect of silicon content of ferromanganese-silicon. The experimental results show that when the amount of dephos- phorizing agents increasing from 2.5% to 7.5%, the largest dephosphorizing ratio only increase 5.56%. However, the silicon content in the ferromanganese-silicon increased from 19% to 25% by adding silicon ferroalloy, the dephosphorization effect obviously increased and the ratio of dephosphorization at least was 23.22% in this scale experiment. It explained that the dephosphorization effect of adding the silicon content of fcrromanganese-silicon was better than single adding the content of dephosphorization agent. Increasing the silicon content of alloy melt can decrease the oxygen potential and increase the phosphor activity, It＇s helpful for the calcium in dehosphorization to go into the slag by Ca2P3 instead of CaO. In addition, the carbon in ferromanganese-silicon melt has dropped significantly by using technics on precipitation dephosphorization for ferromanganese-silicon. It＇s favorable to control the carbon content during the medium and low carbon ferromanganese production.