摘要
为了实现钒钛磁铁矿的低温冶炼,以NaOH为碱熔剂,采用煤基直接还原技术,研究了钒钛磁铁矿直接还原—熔分工艺。主要考察了Na/Si对钒钛磁铁矿团块金属化率及熔分效果的影响,并通过XRD分析得出了Na/Si对金属化团块及熔渣物相组成的影响。采用Factsage热力学软件对不同Na/Si下Na2O-SiO2-TiO2-Al2O3-CaO五元相的渣系熔点进行了计算。结果表明:Na/Si越高,渣系熔点越低。NaOH可有效改善钒钛磁铁矿的直接还原和熔分效果。随着团块Na/Si的升高,团块金属化率随之升高,但升高的幅度逐渐减小。当Na/Si=5.0、直接还原温度为1150℃、C/O=1.4、直接还原时间为30 min时,团块金属化率就达到了93.17%。随着Na/Si升高,渣铁分离越彻底,当Na/Si>4.0时,熔分所得粒铁表面平整度较好,熔分钛渣中无小尺寸粒铁分散。以NaOH处理钒钛磁铁矿金属化团块所得熔分渣中钛、硅、铝大多以钠酸盐形式存在,NaOH可以有效的降低钒钛磁铁矿的还原熔分难度,在1460℃实现熔分,促进渣铁分离。
In order to realize the smelting of V-Ti magnetite concentrate at lower temperature,the direct reduction-smelting separation process was studied by coal-based direct reduction technique with NaOH as the alkali fusion agent.Effects of NaOH addition on metallization rate and smelting separation of V-Ti magnetite concentrate were investigated and the phase compositions of the metallized pellets and slag were observed by XRD.The melting points of slags of Na2O-SiO2-TiO2-Al2O3-CaO with different Na/Si ratios were calculated by Factsage software.The results show that a higher Na/Si ratio corresponds to a lower melting point of the slag.NaOH can improve the direct reduction and smelting separation performance of V-Ti magnetite concentrate significantly.With increase in Na/Si ratio,the metallization ratio of pellets increases,but the increase amplitude decreases gradually.At a temperature of 1150℃for 30 min,Na/Si=5.0 and C/O=1.4,the metallization rate of metallized pellet can reach 93.17%.When Na/Si>4.0,the granalated iron obtained by melting indicates that the flatness is good,and there is no small-sized gramular iron dispersed in the molten titaniam slag.Titanium,aluminum and silicon in the slag obtained by the method mainly exist as sodium salts.The addition of NaOH can realize smelting separation at lower temperatures and promote the separation between slag and metal.
作者
侯耀斌
洪陆阔
孙彩娇
艾立群
Hou Yaobin;Hong Lukuo;Sun Caijiao;Ai Liqun(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,Hebei,China)
出处
《钢铁钒钛》
CAS
北大核心
2020年第2期6-13,共8页
Iron Steel Vanadium Titanium
基金
河北省钢铁联合研究基金(E2018209284)
河北省钢铁联合研究基金(E2019209160)
河北省教育厅科技基础研究项目(JQN2019007)。
关键词
钒钛磁铁精矿
直接还原
碱熔
熔分
粒铁
V-Ti magnetite concentrate
direct reduction
alkali fusion
smelting separation
iron grain
