Phase transformation and electrical resistivity of reduced ilmenite concentrate carbon-containing pellets
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摘要: 以石墨粉为还原剂,研究钛精矿内配碳球团还原过程中的物相转变规律和还原产物的电阻率。结果表明,钛精矿内配碳球团的还原过程先后主要经历铁氧化物的还原和钛氧化物的还原两个过程,且提高还原温度、延长还原时间和增加石墨配比均有利于钛氧化物还原程度的加深;在还原时间为60 min,石墨配比为33.6%的条件下,还原温度由900 ℃提高到1550 ℃时,还原产物物相随温度升高的转变过程为:FeTiO3→Fe+TiO2→Fe+TinO2n−1(n≈1,2,3,4)→Fe+TiC。还原产物电阻率测试结果表明,还原温度和石墨配比对还原产物电阻率影响较大,还原时间影响较小;在石墨配比为33.6%,还原温度1300 ℃,还原时间为45 min的条件下,还原产物的电阻率的值为2.67×10−2 Ω·cm。Abstract: Using the graphite powder as a reducing agent, the phase transformation and electrical resistivity of the reduced products during the reduction process of carbon-containing ilmenite concentrate pellets were studied. The XRD analysis results indicate that the reduction process of carbon-containing ilmenite concentrate pellets mainly undergoes two processes: the reduction of iron oxide and the reduction of titanium oxide. Increasing the reduction temperature, prolonging the reduction time, and increasing the graphite ratio are all beneficial in deepening the reduction degree of titanium oxide. With a reduction time of 60 min and a graphite ratio of 33.6%, the phase transformation process of the reduction products with increased reduction temperature from 900 ℃ to 1550 ℃ was as follows: FeTiO3→Fe+TiO2→Fe+TinO2n−1(n≈1,2,3,4)→Fe+TiC. The electrical resistivity test results of the reduction products show that the reduction temperature and graphite ratio have a significant impact on the electrical resistivity of the reduced products, while the reduction time has a small impact. Under the conditions of graphite ratio of 33.6%, reduction temperature of 1300 ℃, and reduction time of 45 min, the electrical resistivity of the reduced product was 2.67 × 10−2 Ω·cm.
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表 1 钛精矿的主要化学成分
Table 1. Main chemical composition of ilmenite concentrate
% TiO2 FeO CaO MgO SiO2 Al2O3 P2O5 SO3 K2O Cr2O3 MnO 46.70 42.03 0.59 5.13 2.26 1.00 0.10 0.65 0.03 0.15 0.77 -
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