海砂矿与红土镍矿还原生产钒钛镍铬合金试验

Test on production of V-Ti-Ni-Cr alloy by reduction of sea placer and laterite nickel ore

通过研究东南亚地区廉价含钒钛海砂矿和含镍铬红土镍矿的复合配矿、冷固结球团制备及直接还原工艺,解决直接还原法生产高强度耐腐蚀钢筋用钒钛镍铬合金关键技术难点,实现低成本生产高强度耐腐蚀钢筋,在一定程度上缓解中国资源短缺问题。对多种原料配比、碱度及还原制度下金属化率和钒钛镍铬合金成分进行分析,结果表明,在C∶O=1.5、配矿碱度R=1.2、1300~1350℃温度下还原30 min,球团的金属化率达到90%以上;R=1.2与R=0.8的金属化率相比,R=1.2的金属化率略高;相同条件下,当温度提高到1550℃时,能够完全实现渣铁分离,获得形貌完整的粒铁;海砂矿∶红土镍矿=70∶30或50∶50、R=1.2、1450℃温度下还原和熔分45 min产出的含钒钛镍铬合金成分为w(Ni)=0.53%~1.24%,w(Cr)=0.30%~0.52%,w(V)=0.35%~0.24%,w(Ti)=0.28%,适用于低成本生产高强度的耐腐蚀钢筋。

By studying the compound ore blending,cold consolidation pellets production and direct reduction process of low-cost V-Ti sea placer and Ni-Cr laterite nickel ore in Southeast Asia,the key technical difficulties in the production of V-Ti-Ni-Cr alloy by direct reduction method were solved,and the low-cost production of high-strength corrosion-resistant steel bar was realized,which could alleviate the shortage of resources in China to some extent.The metallization rate and the composition of V-Ti-Ni-Cr alloy under various raw material ratio,basicity and reduction system were analyzed.The results showed that,the metallization rate of pellet was over 90%when reduced at C∶O=1.5,ore basicity R=1.2,the temperature was 1300-1350℃for 30 min;the metallization rate of R=1.2 was slightly higher than that of R=0.8;under the same conditions,the separation of slag and iron could be completely realized when the temperature was raised to 1550℃,and the granular iron with complete morphology was obtained;alloy mass fractions of Ni 0.53%-1.24%,Cr 0.30%-0.52%,V 0.35%-0.24%,Ti 0.28%were obtained by reduction and melting separation at the ratio of sea placer to laterite nickel was 70∶30 or 50∶50,R=1.2,the temperature was 1450℃for 45 min,and that was suitable for producing high-strength corrosion-resistant steel bar at low cost.