摘要
分析了Al,Si,C热还原制备FeV50合金的热力学可行性及铝热还原过程渣金钒铝平衡,采用分期梯度配铝的方式,考察了原料配比、反应温度、加料制度和多期配铝系数对渣中TV含量及合金成分的影响。通过不同还原剂热还原的热力学分析表明:1500 K时,常压条件下碳热还原过程优先生成VC,只有当体系真空度高于76.8 Pa才能得到稳定钒基合金产品;硅热反应仅适用于高价钒氧化物的还原,配加CaO有利于反应的进行以及钒氧化物的还原效率;铝热还原V_2O_5和V_2O_3的单位反应热分别为368.4和221.0 k J·mol^(-1),基本能够满足密闭系统维持自发反应的热量需求。铝热还原渣金热力学平衡分析结果表明FeV50渣中TV含量随合金Al含量的升高而降低,当合金Al含量为2.0%时,渣中理论TV含量为0.27%;若要使渣中理论TV含量降低到0.15%,合金Al含量需达18.8%以上。基于此,采用"梯度配铝"工艺试验,在三期加料制度4-3-1,配铝系数1.30-1.00-0.30,原料配比3∶1,体系温度1850℃的条件下,渣中平均TV含量由均匀配铝的1.85%降低到0.69%,合金Al含量从1.6%降低到0.4%。
The possibility of different thermal reduction reactions and the alloy-slag equilibrium of valuable vanadium oxides transferred into melting alloy were analyzed for the preparation of FeV50. ＂Gradient distribution of Al addition＂ process was carried out, and the effects of raw material ratio, reaction temperature, feeding method and Al distribution coefficient on TV content in slag and al- loy compositions were investigated. The thermodynamics results of thermal reduction showed that carbon-thermal reduction generated VC preferentially under normal pressure, and the stable vanadium-based alloy could be prepared when the system vacuity was higher than 76.8 Pa at 1500 K. The silicon-thermal reaction was only suitable for the reduction of V2O5 , CaO addition had the promoting effect on the reaction and the reduction efficiency of vanadium oxides. The reaction enthalpy of V2 O5 and V2O3 by aluminum-thermal reduc- tion was 368.4 and 221 kJ·mo1-1 respectively, which could meet the heat requirements of the closed system to maintain spontaneous reaction. The alloy-slag thermodynamic equilibrium analysis showed that the TV content in slag increased with the increase of A1 in alloy. When the Al content reached 2.0% , the theoretical TV content in slag could be decreased to about 0.27%. To reduce the theoretical TV content to 0.15%, the A1 content in alloy should be increased to above 18.8%. Through ＂gradient distribution of Al addition＂ experiments, the average TV content in slag was reduced from 1.85% to 0.69% , and the A1 content in FeV50 alloy was decreased from 1.6% to 0.4% with feeding method of 4-3-1, aluminum coefficient of 1.30-1.00-0.30, vanadium oxides ratio of 3：1 and reaction temperature of 1850 ℃.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2017年第11期1279-1284,共6页
Chinese Journal of Rare Metals
基金
国家重点基础研究发展(973)计划项目(2012CB724202)资助
关键词
梯度配铝
FeV50合金
渣金平衡
热还原
gradient distribution of Al addition
FeV50 alloy
alloy-slag equilibrium
thermal reduction
