高磷鲕状赤铁矿还原焙烧中脱磷剂CaCO_(3)作用影响因素研究  

Study on Influencing Factors of Dephosphorization Agent CaCO_(3)in Reduction Roasting of High Phosphorus Oolitic Hematite

作　　者：连宵宵 孙体昌[1] 寇珏[1] 郭晓霜 LIAN Xiaoxiao;SUN Tichang;KOU Jue;GUO Xiaoshuang(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083

出　　处：《金属矿山》2023年第3期120-126,共7页Metal Mine

基　　金：“十四五”国家重点研发计划项目(编号:2021YFC2902404)。

摘　　要：为揭示褐煤用量和焙烧温度对CaCO_(3)作用效果的影响机制,以褐煤为还原剂、CaCO_(3)为脱磷剂对国外某高磷鲕状赤铁矿进行了直接还原焙烧试验。热力学计算、X射线衍射(XRD)和扫描电镜(SEM-EDS)分析表明,Ca-CO_(3)的作用效果是其分解的CaO和CO_(2)共同作用的效果总和。CaO的主要作用是促进铁矿物中的磷生成磷灰石并抑制磷灰石的还原,减少铁橄榄石和铁尖晶石的生成;CO_(2)可促进煤的气化反应,加快铁氧化物的还原。而褐煤用量和焙烧温度会影响CaO的反应程度,进而影响CaCO_(3)的作用效果。由于低褐煤用量和高焙烧温度时焙烧过程的熔融程度高,可促进CaO的固相反应,因此CaCO_(3)的作用效果好。试验研究发现,在CaCO_(3)用量28%、褐煤用量20%、焙烧温度1200℃时,得到的直接还原铁产品的脱磷率高达92%。In order to reveal the influence mechanism of lignite dosage and roasting temperature on the effect of CaCO_(3),the direct reduction-magnetic separation tests were carried out for a foreign high-phosphorus oolitic hematite with lignite and CaCO_(3)as reductant and dephosphorization agents,respectively.Thermodynamic calculations,XRD and SEM-EDS analysis showed that the effect of CaCO_(3)was the synergism of CO_(2)and CaO generated by the decomposition of CaCO_(3).The main role of CaO is to promote the formation of apatite from the part of the phosphorus in the iron mineral,which is in the form of Fe3PO7,and inhibit the reduction of apatite and the formation of iron olivine and iron spinel.CO_(2)can promote the gasification of coal and accelerate the reduction of iron oxides.The lignite dosage and the roasting temperature affect the degree of response of CaO,which in turn will affect the effect of CaCO_(3).Due to the high degree of melting in the roasting process at low lignite calculations or high roasting temperature,the solid phase reaction of CaO can be promoted,so the effect of CaCO_(3)is good.Experimental studies have found that the direct reduction roasting effect was good at roasting temperature of 1200°C,the lignite dosage of 20%and CaCO_(3)dosage of 28%,in which the dephosphorization rate was as high as 92%.

关 键 词：高磷鲕状赤铁矿 碳酸钙 褐煤用量 焙烧温度 脱磷效果 

分 类 号：TD925[矿业工程—选矿]