复合还原剂浸出低品位软锰矿

Leaching of low-grade pyrolusite with a compound reductant

以甲醛和葡萄糖为复合还原剂,在硫酸溶液中浸出低品位软锰矿。用高效液相色谱对浸出液中甲酸的质量浓度做定量分析。考察了还原剂各自的用量及反应时间、总浸出时间、浸出温度、硫酸的体积分数、搅拌速率及液固比对浸出率和甲酸质量浓度的影响。确定最佳工艺条件:甲醛和葡萄糖分别为理论量(质量分数)的90%和60%,二者反应时间比为1∶2,总浸出时间为3 h,浸出温度为90℃,硫酸的体积分数为18%,搅拌速率为300 r/min,液固比为12 m L/g。在此条件下,锰的浸出率为94.68%,甲酸的质量浓度为1.86 mg/m L。

In sulfuric acid medium,the leaching of low-grade pyrolusite was investigated with formaldehyde and glucose as compound reductant.Mass concentration of formic acid in the leaching solution was quantitatively analyzed by high performance liquid chromatography（HPLC）.Effects of dosages of reductants and their reaction times,the whole leaching time,leaching temperature,volume fraction of sulfuric acid,stirring rate,and liquid-solid ratio on the extraction ratio and mass concentration of formic acid were studied.The optimal conditions were determined as 90% and 60% theoretical amounts（mass fraction） of formaldehyde and glucose respectively,their reaction time ratio of 1 ∶2,the whole leaching time of 3 h,temperature of 90 ℃,volume fraction of sulfuric acid of 18%,stirring rate of 300 r/min,and liquid-solid ratio of 12 m L/g.Under these conditions leaching efficiency of manganese was 94.68% together with 1.86 mg/m L（mass concentration） of the formic acid