高磷硅锰合金还原脱磷实验研究

Experimental research on the dephosphorization of high phosphorus Si-Mn alloy

在硅钼炉中,1400℃的条件下,利用硅钙合金、稀土硅、铝基脱磷剂等对高磷硅锰合金进行还原脱磷实验研究.脱磷实验采用CaO-CaF2（质量比为25∶75）为覆盖渣,渣金比为0.2∶1.采用ICP光谱仪检测脱磷后合金中的磷含量,X射线衍射检测渣样物相成分,着重分析了不同脱磷剂及其用量对高磷硅锰合金还原脱磷的影响.结果表明：随脱磷剂用量的增加,硅锰合金脱磷率呈上升的趋势.其中,铝基脱磷剂脱磷效果最好,当其质量分数达到8%时,合金中磷的质量分数可降至0.21%,符合国标要求（≤0.25%）,脱磷率达78%;硅钙合金次之,当其质量分数达到10%时,脱磷率为47%;稀土硅的脱磷效果最差,当其质量分数达10%时,脱磷率仅22%.铝基脱磷剂为本实验条件下的最佳脱磷剂.

There are abundant manganese mineral resources in Chengkou and Xiushang County,Chongqing City,as well as a phosphorus content that is over the national standard;thus,the mass percent of phosphorous in Si-Mn alloys produced from manganese ores is over 1%.This can easily result in ＂cold brittleness＂and reduce the steel quality when the alloys are used for deoxidation and alloying in steelmaking.Therefore,it is important to research on the dephosphorization of Si-Mn alloy.Dephosphorization of a highphosphorus Si-Mn alloy was studied under dephosphorizing agents of Si-Ca alloy,rare earth silicon,and Al-based dephosphorizer in a silicon molybdenum furnace of 1400 ℃.In the experiment,CaO-CaF2（mass ratio of 25∶75） was used as a covering slag,and the ratio of slag-metal is 0.2∶1.The phosphorous content in the Si-Mn alloy after dephosphorizatoin was detected by an inductively coupled plasma（ICP） spectrometer,and the phase composition of the slag was analyzed by X-ray diffractometry（XRD）.The effects of different dephosphorizing agents and their dephosphorization rates were analyzed.The results show that the dephosphorization rate increases with dephosphorizer content.For Al-based dephosphorizer,the dephosphorization effect is optimum at 8% dephosphorizer content,whereby the phosphorus content in the Si-Mn alloy is reduced to 0.21%,which meets the national standard（≤0.25%）,and the dephosphorization rate reaches 78%.The efficiency of Si-Ca alloy is lower;the dephosphorization rate is 47% even when the alloy content reaches 10%.The effect of rare earth silicon is the least;the dephosphorization rate is 22% when the content reaches 10%.Thus,the Al-based dephosphorizer is the best dephosphorization agent under the present experimental conditions.