水热法溶出高铁铝土矿过程中含铁矿物的相变行为  

Transformation behavior of iron in process of dissolving high-iron bauxite by hydrothermal method

作　　者：贺永飞 王一雍[1] 万兴元 宁哲[1] HE Yong-fei;WANG Yi-yong;WAN Xing-yuan;NING Zhe(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China)

机构地区：[1]辽宁科技大学材料冶金学院,辽宁114051

出　　处：《中国有色金属学报》2021年第2期461-469,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51674141)。

摘　　要：以淀粉作为还原剂,在一水硬铝石水热溶出的过程中同步还原氧化铁,采用热力学计算和实验研究氧化铁在碱性溶液中的水热还原行为。热力学计算结果表明:在适当的氧化还原条件下,Fe_2O_3可以转化为Fe_3O_4。Fe_2O_3将溶于碱性水溶液中形成Fe O_2~-;在温度大于373K的碱性水溶液中,Fe O_2~-部分会转化为Fe(OH)_4~-。淀粉在碱性水热条件下通过降解,释放醛基形成强还原体系,将Fe~(3+)还原成Fe~(2+),Fe~(3+)进一步与Fe~(2+)反应生成Fe_3O_4,该过程中温度和碱浓度对Fe_2O_3的水热还原有很大影响。当处理温度为260℃、碱浓度为210 g/L、时间为60 min、石灰与淀粉的用量分别为干矿石的7%和10%、磁性分离强度为0.08 T时,此时铝溶出率为98.57%,铁还原率为98.41%,磁选率为97.0%以上,FeT品位为73.5%。The starch is used as a reducing agent to simultaneously reduce the iron oxide during the hydrothermal dissolution of the diaspore.The hydrothermal reduction behavior of iron oxide in alkaline solution were investigated by the thermodynamic calculation and experiments,the thermodynamic calculations show that Fe2O3 can be converted to Fe3O4 under appropriate redox conditions.Fe2O3 will dissolve in an alkaline aqueous solution to form FeO2-,and part of the FeO2-moiety will be converted to Fe(OH)4-in an alkaline aqueous solution at temperature higher than 373 K.The starch is degraded under alkaline hydrothermal conditions,releasing an aldehyde group to form a strong reduction system and reducing Fe3+to Fe2+,and Fe3+further reacts with Fe2+to form Fe3O4.The temperature and alkali concentration in this process have a great influence on the hydrothermal reduction of Fe2O3.The experimental results show that,when the treatment temperature is 260℃,the alkali concentration is 210 g/L,the time is 60 min,the amount of lime and starch is 7%and 10%of dry ore,respectively,and the magnetic separation strength is 0.08 T.The aluminum dissolution rate is 98.57%,the iron reduction rate is 98.41%,the magnetic separation rate is 97.0%or more,and the TFe grade is 73.5%.

关 键 词：一水硬铝石 赤铁矿 淀粉 磁铁矿 溶出 还原 

分 类 号：TF111.3[冶金工程—冶金物理化学]