Selective Leaching of Manganese Nodules Using Sulfur Dioxide as a Reductant

以氨水为溶剂，二氧化硫为还原剂，实现了锰结核中镍、钴、铜的选择性萃取。随着浸出温度的升高，选择性浸出能力增强。当结核在溶液中使用较低浓度的铵离子浸出时，锰和铁也在较低浓度的二氧化硫下被大量提取。选择性萃取的适宜性取决于溶液的pH值，并估算了pH= 6时的极限值。以氨溶液为溶剂，在浸出残渣中检测到亚硫酸氢氧化铵锰，在碳酸铵溶液浸出中检测到碳酸锰。用二氧化硫作还原剂，在氨水和碳酸铵混合溶液中浸出结核时，碳酸铵浓度越高，锰的浸出率越低，氨水浓度越高，铁的浸出率越低，在最佳条件下，金属组分的浸出率分别为：铜99%、镍98%、钴95%、锰含量为3%，铁含量为1%。这种浸出方法对锰结核的处理是有效的，因为有价值金属的浸出率高，选择性好。

The selective extraction of nickel, cobalt and copper from manganese nodules was achieved by using ammoniacal solution as a solvent and using sulfur dioxide as a reductant. The selective extractability was a pronounced with raising leaching temperature. When the nodules were leached in the solution using lower concentrations of ammonium ion, manganese and iron were also extracted considerably at lower concentrations of sulfur dioxide. The suitableness of selective extraction was decided by pH of the solution, and the limit value was estimated at pH=6.Manganese ammonium sulfite hydroxide was detected as a leaching residue using ammonia solution as a solvent, and manganese carbonate was detected at the ammonium carbonate solution leaching. When the nodules were leached in the mixed solution of ammonia and ammonium carbonate using sulfur dioxide as as a reductant, the extraction of manganese was lower using higher concentrations of ammonium carbonate, and that of iron was lower using higher concentrations of ammonia water.The extraction percentages of metallic components under optimum conditions were 99% for copper, 98% for nickel, 95% for cobalt, 3% for manganese and 1% for iron, respectively. This method of leaching may be effective for the treatment of manganese nodules because there are high extraction of valuabl emetals and good selective extractability.