Prospects of recovery system for valuable metals by mechanochemical milling with an intensive ball converge mill

为了建立工业废渣中有价稀有金属的回收系统，采用强化球磨机对几种含稀有金属的材料进行了机械化学研磨，并研究了机械化学处理后的粉末在酸性溶液中的溶解行为。铟氧化物呢？在低盐酸和硝酸浓度2.5 mol/dm3和2 mol/dm3溶解条件下（30 min，室温），锡氧化物（ITO）玻璃的洗脱率达到80%以上。MC处理时间20min。对于钕基和钐基永磁体，MC处理后的颗粒直径与（Nd, Sm）在硝酸溶液中的洗脱速率之间的关系尚不清楚，但MC处理后的粉末（Nd, Sm）在密集会聚磨和行星球磨机中的洗脱速率不同。钕基永磁体在5.0 mol/dm3以上的硝酸洗脱条件下，MC粉中有价金属的洗脱率（24 h，室温）达到80%以上；钐基永磁体在0.5 mol/dm3以上的硝酸洗脱条件下，MC粉中有价金属的洗脱率达到80%以上。由于未进行MC处理的大块样品中有价金属的洗脱率小于40%，因此强力球磨机械化学研磨工艺是回收工业废渣中稀有元素的有效方法。

In order to develop a recovery system for valuable rare metals from industrial wastes in unheated treatment, mechanochemical(MC) grinding process by an intensive ball “converge” mill were performed for several materials containing rare metals, and dissolution behaviors of MC treated powders in acid solution were examined. For indium oxides ? tin oxides (ITO) glass, high rate of elution over 80 % was attained in dissolution conditions (30 min, ambient temperature) at low 2.5 mol/dm3 of hydrochloric and nitric acids and at 2 ? 20 min of MC treatment time. For neodium based and samarium based permanent magnets, relationship between the particle diameter by MC treatments and the rate of elution of (Nd, Sm) into nitric acid solutions was not clearly found, although the elution rate of (Nd, Sm) for MC treated powders with an intensive converge mill was different from with a planetary ball mill. The rate of valuable metal elution (24 h, ambient temperature) over 80 % from MC grinded poders was obtained in elution conditions over 5.0 mol/dm3 of nitric acid concentration for neodium based permanent magnets, and was obtained over 0.5 mol/dm3 of nitric acid concentration for samarium based permanent magnets. As the rate of valuable metal elution was less than 40 % for bulk samples which was not MC treated, mechanochemical grinding process with an intensive ball converge mill was effective for recovery of rare elements from industrial wastes.