Abstract Being a green and mild acid along with remarkably high solubility for several base metals, ascorbic acid has been used as both leaching agent and reducing agent for the recovery of metals from primary and secondary sources. In the present investigation, ascorbic acid was tested as reducing agent in the presence of sulfuric acid for the leaching of manganese from low grade ferruginous manganese ore. The optimization of the leaching conditions has been comprehensively investigated with respect to H2SO4 concentration, temperature, pulp density, ascorbic acid dosage and agitation speed. Quantitative leaching of manganese was observed under the following optimized conditions: 1 M H2SO4 concentration, 0.070 M ascorbic acid concentration, 70 g/L pulp density, 60 °C leaching temperature, 800 rpm stirring rate and 300 min of reaction time. The leaching kinetic of manganese was evaluated based on the shrinking core model and further validated by SEM and XRD analysis of manganese ores before and after leaching. After further purification of the leach solution, a high purity of 99.95% α-Mn2O3 have been synthesized. The present process therefore deals with achieving the effective recovery of value added product from low grade ferruginous manganese ore.

中文翻译：

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以抗坏血酸为还原剂从含铁锰矿中回收锰

摘要 作为一种绿色温和的酸，对多种贱金属具有极高的溶解度，抗坏血酸已被用作浸出剂和还原剂，用于从一次和二次来源中回收金属。在本研究中，抗坏血酸作为还原剂在硫酸存在下被测试用于从低品位铁质锰矿中浸出锰。从H2SO4浓度、温度、矿浆密度、抗坏血酸用量和搅拌速度等方面对浸出条件的优化进行了综合研究。在以下优化条件下观察到锰的定量浸出：1 M H2SO4 浓度、0.070 M 抗坏血酸浓度、70 g/L 矿浆密度、60 °C 浸出温度、800 rpm 搅拌速率和300 min 反应时间。基于收缩核模型评估锰的浸出动力学，并通过浸出前后锰矿石的SEM和XRD分析进一步验证。浸出液进一步提纯后，合成了99.95%的高纯度α-Mn2O3。因此，本方法涉及实现从低品位铁锰矿中有效回收增值产品。