硅还原钨酸钙固相反应实验研究  

Experimental Study on Solid-Phase Reduction Reaction of Calcium Tungstate by Silicon

作　　者：刘吉刚[1] 李正邦[1] 刘彦华[2] 杨海森[1] 梁林宝 

机构地区：[1]钢铁研究总院冶金工艺研究所,北京100081 [2]北京能泰环保产业集团公司,北京100124 [3]江阴市长兴钒氮新材料有限公司,江阴214400

出　　处：《特殊钢》2013年第1期9-12,共4页Special Steel

摘　　要：为研究CaWO_4与Si在直接合金化炼钢过程中的低温固相反应过程,采用差示热分析仪在10℃/min恒速升温条件下对CaWO_4与Si粉末混合物进行热分析实验,通过高温炉恒温实验对CaWO_4与Si球团在1400℃恒温30 min的反应生成物及反应率进行分析,结合熔点测试实验分析了球团在升温过程中的物理变化行为。实验结果表明,CaWO_4与Si在1400℃以下所发生的还原反应为全固相反应,反应生成物为W、WSi_2、W_5 Si_3、Ca3(Si_3O_9)、SiO_2,CaWO_4球团在1400℃30 min的反应率达到93.41%,固相反应过程中CaO不能促进反应的进行;CaWO_4与Si 1400℃以下恒速升温条件下表观反应符合Avarami-Erofeev方程,反应机理为随机形核和随后生长,表观反应动力学表达式为dα/dt=11.68e^(-51.75×10^3/RT)·4(1-α)[-ln(1-α)]^(3/4)。In order to study the solid-phase reduction process of CaWO4 and Si at low temperature during steelmaking process by direct alloying, the thermo-analysis experiments on CaWO4 and Si powder mixture have been carried out by using differential thermal analyzer with constant heating rate 10 ℃/min, the reaction products and reaction ratio of CaWO4 and Si pellets at 1 400 ℃ for 30 min are analyzed by high temperature furnace constant temperature test and combined with melting point measure test the behavior of physical change of pellets in heating process is analyzed. Experimental results show that the reduction reactions of CaW04 and Si occurred at less than 1 400℃ are all solid-phase reaction, the products of reaction are W, WSi2 , W5 Si3 , Ca3 （ Si3 09 ） and SiO2 , the reduction ratio of CaWO4 pellets at 1 400 ℃ for 30 min is up to 93.41%, and during solid-phase reaction process the CaO could not increase the reaction rate; with condition of constant heating rate at less than 1 400℃, the apparent reaction of CaWO4 and Si conforms to Avarami-Erofeev equation, the mech- anism of reaction is random nucleation and subsequent growth, and the apparent reaction dynamical equation is da/dt=11.68e-51.75×103/RT·4（1-a）[-ln（1-a）]3/4.

关 键 词：钨酸钙 硅还原 固相反应 热分析 动力学 

分 类 号：TF701[冶金工程—钢铁冶金]