水钴矿中选择性提取铜和钴的新工艺

针对某水钴矿的特点,采取还原酸浸旋流电积新工艺选择性提取其中的铜和钴。系统考察初始硫酸浓度、温度、时间、Na2SO3用量、液固比等因素的影响,确定浸出最佳条件如下:初始硫酸浓度为75g/L,Na2SO3用量为7%,液固比L/S=4 mg/L,温度为70℃,时间为0.5 h。对浸出液进行了旋流电积提取铜和钴的探索实验研究,得到纯度分别为99.95%、99.97%的电积铜、钴产品,铜、钴的直收率分别达到98.23%和94.54%。     

镍红土矿高压酸浸过程的金属元素浸出行为

以镍、钴的提取为目的,研究褐铁矿型镍红土矿高压酸浸过程中各金属元素的浸出行为,探讨硫酸加入量、浸出温度、浸出时间及液固比对各金属元素浸出率的影响.实验结果表明,在优化条件下Ni、Co、Mn和Mg的浸出率分别达到97%、96%、93%和95%以上,则Fe的浸出率小于1%.对高压浸出渣的分析表明,渣中的铁和硫主要分别以赤铁...     

Extraction of valuable metals from low-grade nickeliferous laterite ore by reduction roasting-ammonia leaching method

Nickel and cobalt were extracted from low-grade nickeliferous laterite ore using a reduction roasting-ammonia leaching method. The reduction roasting-ammonia leaching experimental tests were chiefly introduced, by which fine coal was used as a reductant. The results show that the optimum process conditions are confirmed as follows: in reduction roasting process, the mass fraction of reductant in the ore is 10%, roasting time is 120 min, roasting temperature is 1 023–1 073 K; in ammonia leaching process, the liquid-to-solid ratio is 4:1(mL/g), leaching temperature is 313 K, leaching time is 120 min, and concentration ratio of NH₃ to CO₂ is 90 g/L:60 g/L. Under the optimum conditions, leaching efficiencies of nickel and cobalt are 86.25% and 60.84%, respectively. Therefore, nickel and cobalt can be effectively reclaimed, and the leaching agent can be also recycled at room temperature and normal pressure.     

红土镍矿常压盐酸浸出工艺及其动力学研究

采用盐酸在常压下浸出红土镍矿, 考察了矿石粒度、酸料比、反应温度、反应时间、固液比、氯离子浓度对镍、钴、锰等金属浸出率的影响, 得到了该实验下的优化条件为:矿石粒度为0.125～0.15 mm、酸料比为3∶1、反应温度80 ℃、反应时间1 h、固液比为1∶4、不外加氯化盐。在优化条件下的浸出结果表明, 各金属的浸出率分别为Ni 86.9%、Co 67.8%, Fe 86.5%、Mn 80.1%、Mg 58.5%、Cr 72.6%。对不同反应温度下的镍、铁的浸出率-时间曲线进行拟合, 结果表明该浸出过程不符合广泛采用的收缩核模型, 而用Avrami方程拟合则很好地符合其线性关系。浸出过程中镍、铁的活化能分别为72.125 kJ/mol和88.566 kJ/mol。     

采用旋流电积技术从电镀污泥中回收铜和镍

以电镀废水处理过程中产出的电镀污泥为研究对象,采用旋流电积技术从电镀污泥中选择性回收铜和镍,并研究旋流电积过程中Cu2+和Ni2+以及杂质离子的电积行为.结果表明:旋流电积技术可以从高杂质含量的低铜浸出液中直接生产电积铜,产品质量达到GB/T467-1997中Cu-CATH-2牌号标准阴极铜的要求,铜直收率达到99%以上;铜电积后液经除铬后,仍采用该技术从低镍溶液中直接生产电积镍,化学成分达到GB/T6516-1997中Ni9990牌号电积镍的要求,镍直收率达到93%以上.与传统电积技术相比,旋流电积技术具有选择性强、电流效率高和产品质量好等优点.