Abstract: Water-leached residue of limonitic laterite was obtained after Na2CO3-roasting, and its atmospheric leaching behavior was investigated. Thermodynamic calculation was performed to evaluate possible reactions in the leaching process. Hydrochloric acid was chosen as the leaching agent after comparing atmospheric leaching behaviors of elements of the residue in sulfuric and hydrochloric acid, as well as consideration of the treatment options of the leaching liquid and residue. Atmospheric acid leaching experiments were carried out to investigate the effects of mass ratio of acid to residue, mass ratio of liquid to solid, leaching temperature and time on the leaching of water-leached residue of laterite after alkali-roasting. 99.2%(w) Ni, 99.5%(w) Co and 97.8%(w) Fe were leached out at the optimum leaching conditions of mass ratio of acid to residue 1.25, mass ratio of liquid to solid 4, 80℃ and 3 h.

Key words: limonitic laterite, atmospheric acid leaching, hydrochloric acid, sulfuric acid, nickel, cobalt, iron

摘要： 采用Na2CO3焙烧-水洗方法处理褐铁型红土镍矿，并对预处理后的原料(碱浸渣)进行常压酸浸工艺研究. 通过热力学计算判断酸浸过程中可能发生的反应及趋势大小，考察各元素在硫酸和盐酸常压浸出中的行为，并结合浸出渣的XRD图谱，分析浸出过程中的反应，综合考虑浸出液及废渣处理等因素，选定盐酸为常压浸出剂. 实验研究了酸渣比、液固比、浸出温度和时间对各元素浸出规律的影响，确定优化酸浸条件为：酸渣质量比1.25，液固质量比4，浸出温度80℃，保温时间3 h，此时Ni, Co和Fe的浸出率分别达99.2%, 99.5%, 97.8%(w).

关键词: 褐铁型红土镍矿, 常压酸浸, 盐酸, 硫酸, 镍, 钴, 铁