Abstract: Fe-rich red mud was treated by wet method using alkaline medium, dealkalization process of the red mud and enrichment process of Fe2O3 were carried out simultaneously. The effects of reaction temperature, reaction time, initial concentration of sodium oxide, initial caustic ratio and ratio of liquid to solid on the final slag composition and phase were investigated. The optimal conditions were obtained as follows: reaction temperature 250℃, reaction time 30 min, initial concentration of sodium oxide 530 g/L, initial caustic ratio 15 and ratio of liquid to solid 6 mL/g. Under the optimal conditions, Fe2O3 content in the final slag was increased to 46.27% from 33.56%, Na2O content decreased to 0.87% from 4.99%. The main phases in the red mud were converted from sodalite and andradite to a single phase of andradite.

Key words: Fe-rich red mud, sodium-silicon residue, iron oxide, alkaline solution, separation

摘要： 采用碱介质湿法处理高铁赤泥，脱除赤泥中钠硅渣并使其中的氧化铁在渣相中富集. 考察了反应温度、反应时间、初始溶液Na2O浓度、苛性比(Na2O与Al2O3的摩尔比)及液固比等对终渣化学组成及物相的影响. 结果表明，在250℃、初始溶液Na2O浓度530 g/L、苛性比15、液固比6 mL/g、反应30 min的条件下，赤泥终渣Fe2O3含量由33.56%提高到46.27%，Na2O含量由4.99%降至0.87%. 经碱介质处理后赤泥的主要物相由方钠石和钙铁榴石转化为较单一物相钙铁榴石.

关键词: 高铁赤泥, 钠硅渣, 氧化铁, 碱溶液, 分离