CAJ | 학술논문

在铝土矿拜耳法溶出的同时使赤铁矿转化为磁铁矿对高铁铝土矿的经济高效利用至关重要。在热力学计算的基础上，实验研究氧化铁在碱溶液中的水热还原行为。热力学计算结果表明：在适当的氧化还原电位条件下，氧化铁在碱性溶液体系中可转化为磁铁矿。实验结果表明：铁粉与氧化铁粉或者铁粉与水在碱性水溶液中反应形成四氧化三铁，反应转化率均随温度和碱浓度的升高而显著升高，这说明四氧化三铁的形成过程可能经历铁粉和氧化铁粉溶解分别形成含铁离子Fe(OH)3?和Fe(OH)4?，Fe(OH)3?和Fe(OH)4?进一步反应生成四氧化三铁两个过程。同时，铝酸根对氧化铁在碱溶液中的水热还原没有显著影响，在其拜耳法溶出过程中一水硬铝石中的铁矿物可以转化为磁铁矿。
재려토광배이법용출적동시사적철광전화위자철광대고철려토광적경제고효이용지관중요。재열역학계산적기출상，실험연구양화철재감용액중적수열환원행위。열역학계산결과표명：재괄당적양화환원전위조건하，양화철재감성용액체계중가전화위자철광。실험결과표명：철분여양화철분혹자철분여수재감성수용액중반응형성사양화삼철，반응전화솔균수온도화감농도적승고이현저승고，저설명사양화삼철적형성과정가능경력철분화양화철분용해분별형성함철리자Fe(OH)3?화Fe(OH)4?，Fe(OH)3?화Fe(OH)4?진일보반응생성사양화삼철량개과정。동시，려산근대양화철재감용액중적수열환원몰유현저영향，재기배이법용출과정중일수경려석중적철광물가이전화위자철광。
Digesting aluminum-bearing minerals and converting ferric oxide to magnetite simultaneously in Bayer digestion process is crucially important to deal with high-iron diasporic bauxite economically for alumina production. The reaction behaviors of hydrothermal reduction of ferric oxide in alkali solution were studied by both thermodynamic calculation and experimental investigation. The thermodynamic calculation indicates that Fe3O4 can be formed by the conversion of Fe2O3 at proper redox potentials in alkaline solution. The experimental results show that the formation ratio of Fe3O4 either through the reaction of Fe and Fe2O3 or through the reaction of Fe and H2O in alkaline aqueous solution increases remarkably with raising the temperature and alkali concentration, suggesting that Fe(OH)3? and Fe(OH)4? form by dissolving Fe and Fe2O3, respectively, in alkaline aqueous solution and further react to form Fe3O4. Moreover, aluminate ions have little influence on the hydrothermal reduction of Fe2O3 in alkaline aqueous solution, and converting iron minerals to magnetite can be realized in the Bayer digestion process of diasporic bauxite.