DOC《基于 CaO-SiO2-FeO-Na2O-Al2O3渣系的中高磷铁水脱磷实验...》

基于 CaO-SiO2-FeO-Na2O-Al2O3渣系的中高磷铁水脱磷实验研究 轩心宇*,施哲,漆鑫,蔡加武 (昆明理工大学冶金与能源工程学院,昆明650093) 摘要:结合现有铁矿含P高的实际情况,采用CaO-SiO2-FeO -Na2O-Al2O3渣系对中高P铁水进行脱P的实验研究.

研究结果表明:脱磷渣系的碱度值ω(CaO)/ω(SiO2)为4时,在相同实验条件下,分别用Al2O

3、Na2O、和Al2O3与Na2O的混合物代替常规的CaF2时均可达到更高的脱磷效果;

造渣剂分两次加入的脱P效果比一次性加入的更好.当渣系中使用4%(Al2O3)+2%(Na2O)的复合熔剂,分两次加入时,铁水的终点脱磷率可达到96%. 关键词:高磷铁水;

铁水预处理;

钙系脱磷剂;

脱磷 Study of Dephosphorization of High-Phosphorus Hot Metal in CaO-SiO2-FeO-Na2O-Al2O3 Slag System Xuan Xinyu, Shi Zhe, Qi Xin, Cai Jiawu (Faculty of Metallurgical and Energy Engineering of Kunming University of Science and Technology,Kunming 650093,China) Abstract: According to the actual situation of the high-phosphorus iron ore, the present paper studies the dephosphorization of high-phosphorus hot metal by using CaO-SiO2-FeO-Na2O-Al2O3 slag system. The results show that,under the same experimental conditions, when basicity of ω(CaO)/ω(SiO2) was 4, the effects of dephosphorization using Al2O

3、Na2O and the mixture of Al2O3 and Na2O were better than that of using CaF2.The effects of dephosphorization with twice-joining slags were better than the effects of once-joining. When the composite flux with4% (Al2O3) and 2% (Na2O) was used, and was added twice, the dephosphorization rate reached 96%. Keywords: high-phosphorus hot metal;

pretreatment of hot metal;

calcium base dephosphorizing flux;

dephosphorization 近年来铁矿石价格逐年上涨,供需矛盾突出,国内钢铁企业迫于成本压力,纷纷开始寻求开发利用国内的中高P铁矿石资源.中高磷铁矿的铁品位比目前使用的铁矿石低,所得铁水杂质含量相对较高,特别是其中的磷,含量很高,对铁水品质危害极大.该铁水若要达到后续炼钢要求必须进行铁水预处理脱P.因此对高磷铁水的脱磷研究显得尤为迫切.对铁水预处理脱磷工艺来说,要取得良好脱磷效果的一个关键环节就是找到高效脱磷剂.从前人[1]的研究结果可知,中高磷铁水在高碱度、高氧化性下更有利于脱磷,但碱度过高会影响炉渣的流动性,因此通常会加入助熔剂CaF2来进行改善.但在实际生产中,CaF2会对铁水罐有不同程度的侵蚀,且其价格贵、成本高,还会降低脱磷渣的枸溶率[2],影响炉渣的回收利用. 为解决上述问题,本研究针对中高磷铁水,对传统的CaO- SiO2-FeO- CaF2脱磷渣系进行改造,旨在不用氟化物作助熔剂的情况下提高脱磷率.为保证化渣速度,以Na2O 和Al2O3代替CaF2,研究高氧化性 CaO基脱磷渣对高磷铁水脱磷的影响. 1.实验 预先测定了脱磷渣剂的熔点,得到渣系中Al2O3或Na2O均在6%左右时,其熔化温度可降至1200℃以下. 1.1实验设备 本实验采用如图1所示的管式电阻炉,内用高纯A12O3炉管作保护管,其内径为70mm,外径为90 mm;

用内径为50mm的MgO坩埚作为实验坩埚,外套石墨坩埚作为保护坩埚,其内径为60mm,高为110 mm.反应管上端有开口用于取样和加脱磷熔剂.管内温度由PID 温度仪来控制,精度为±3℃. 图.1实验装置示意图 Fig.1. Schematic diagram of experimental facilities 1-通闸;

2-氮气瓶;

3-进料器;

4-炉盖;

5-控制柜;