采用废糖蜜作还原剂,在硫酸介质中直接浸出低品位软锰矿,通过正交实验和单因素实验,考察了反应温度、反应时间、硫酸浓度和废糖蜜浓度等因素的影响,并对浸出机理进行了初步的探讨.实验结果表明,通过控制浸出工艺条件,可获得较高的Mn浸出率和较低的Fe,A1浸出率.由于废糖蜜中胶体等物质的存在,Mn浸出率高于相同条件下用纯糖作还原剂的结果,但Fe和A1的浸出率不受影响.相关的浸出影响因素优化为:H2SO42.35mol/L,废糖蜜75g/L,反应时间2h,反应温度90℃.在此条件下,Mn浸出率达到96.7%,而Fe为34.4%,A1仅为25.5%.
Manganese leaching fi'om a low-grade pyrolusite was investigated using cane molasses as reducing agent in sulfuric acid medium. Orthogonal and single-factor experiments were employed to examine the influences of concentrations of cane molasses and sulfuric acid, leaching temperature as well as reaction time on the leaching rates of Mn, Fe and A1. And the mechanism of leaching process was also studied. The results showed that high manganese recovery rate with low Fe and A1 leaching rates was obtained by analyzing the dissolution of Mn, Fe and A1 during the leaching process. The presence of colloidal materials in the cane molasses helped the higher leaching rate of manganese than that obtained by only using pure sucrose and glucose, which had no affection on the dissolution of Fe and A1. The optimal leaching conditions were obtained as 2.35 moFL H2SO4 and 75 g/L cane molasses for 2 h at 90 ℃. The leaching rate bv this way was 96.7% for Mn. whereas 25.5% for A1 and 34.4% for Fe.