Abstract: Lactic acid was used to treat low grade pyrolusite for leaching of manganese. The effects of lactic acid amount, reaction time, leaching temperature and volume fraction of sulfuric acid on the leaching rate of manganese were examined by single-factor experiments. Response surface methodology was used to optimize the conditions of reductive leaching. The organic compounds in the reaction were detected by high performance liquid chromatography. The results show that when the pyrolusite ore is 10.0 g, the leaching rate of manganese reaches 93.99% under the optimal conditions of lactic acid 1.24 mL, reaction time 3.47 h, leaching temperature 90℃, volume fraction of sulfuric acid 12%, stirring speed 200 r/min and ratio of liquid to solid 10 mL/g. Acrylic acid, formic acid and acetic acid are generated in the oxidation of lactic acid. After the reduction leaching for 60 min, lactic acid reacts almost completely. During the reaction time of 210 min, the content of acrylic acid is not decreased obviously, but the content of formic acid and acetic acid increased slowly.

Key words: lactic acid, pyrolusite, manganese, leaching, reduction

摘要： 用乳酸还原浸出低品位软锰矿，采用单因素实验考察乳酸用量、反应时间、温度、硫酸用量等因素对锰浸出率的影响，用响应面法对反应条件进行了优化，用高效液相色谱测定了反应中的有机物，对还原浸出产物进行了研究. 结果表明，在锰矿粉加入量10.0 g、乳酸用量1.2 mL、反应时间3.47 h、温度90℃、硫酸用量12%、搅拌速率200 r/min、液固比10 mL/g条件下，锰的浸出率可达93.99%. 还原产物为丙烯酸、甲酸和乙酸；还原浸出60 min后乳酸反应基本完全，210 min内丙烯酸含量降低不明显，甲酸和乙酸含量缓慢增加.

关键词: 乳酸, 软锰矿, 锰, 浸出, 还原