甲醛-硫酸亚铁协同还原浸出低品位氧化锰矿

在硫酸介质中以甲醛-硫酸亚铁为还原剂协同还原软锰矿,考察了甲醛-硫酸亚铁摩尔比、温度、反应时间、转速、硫酸浓度等因素对锰、铝的浸出率及溶液中铁和有机残留甲酸的影响.采用单因素实验获得较佳的还原工艺条件,采用HPLC测定溶液中的甲酸.结果表明,在固定转速为200 r/min、液固比为8 ml/g时,最佳反应条件为:甲醛-硫酸亚铁摩尔比1∶3(甲醛1.5 mol)、浸出时间3 h、硫酸浓度3 mol/L、温度90℃.在该条件下重复实验,锰的平均浸出率为93.51%,铝的平均浸出率为33.08%,铁的浓度为23.07 mol/L,甲酸浓度为0.001 g/L.

Synergistic reductive leaching of manganese from low-grade oxide manganese ore with formaldehyde and ferrous sulfate

Effects of concentration of sulfuric acid, mole ratio of reducing agent, reaction time, leaching temperature and liquid-solid ratio as well as stirring rate on the extraction ratio of manganese and aluminum, concentrations of iron and organic residue in the leaching solution were studied by using formaldehyde and ferrous sulfate as reductants in sulfuric acid medium.Technological parameters were obtained from a single factor experiment.Organic residue of leaching solution was analyzed by HPLC.The results showed that the optimum conditions are as follows: H2SO4 is 3mol/L, CH2O / FeSO4 mole ratio is 3 (formaldehyde1 is 5mol), reaction time is 3 h, temperature is 90 ℃ fixed liquid-solid ratio is 8 ml/g and stirring rate is 200 r/min.The average leaching ratio is 93.51% for Mn, 33.08% for aluminum, concentration of iron is 23.07 mg/mL, concentration of formic acid is 0.001g/L from the repeated experiments under the optimum conditions.