氢氧化镍钴生产工艺中碱基活化控制技术的研发及应用

Study and application of alkali activation controlling technology in the production process of nickel and cobalt hydroxide

红土镍矿湿法冶金产出中间产品氢氧化镍钴(MHP),氢氧化钠沉淀镍钴工艺简单,设备投资小,生产成本低,但存在产物细小、含水率高、可溶性杂质含量高、沉降及过滤性能差等问题。中国恩菲针对此问题研发了碱基活化控制技术,该技术利用沉淀后溶液中的镁对氢氧化钠进行转化,使得液态碱转变为难溶碱,并在转碱过程中实现沉淀颗粒的活性控制,从而降低氢氧根释放速度,降低碱过饱和度,为沉淀颗粒生长机制创造了先决条件。整套技术包括转碱技术、活性生长技术以及联合控制方法,已应用于瑞木镍钴项目,经过长期生产实践探索及调试,目前运行高效稳定,经济效果明显。

The intermediate product nickel and cobalt hydroxide produced by laterite nickel ore hydrometallurgy.The precipitation of nickel and cobalt by sodium hydroxid has the advantages of simple process,small equipment investment and low production cost. However,there are problems such as fine crystals,high water content,high content of soluble impurities,poor sedimentation and filtration performance. ENFI has developed the alkali activation controlling technology to solve this problem. This technology uses magnesium in the solution after precipitation to convert sodium hydroxide,so that the liquid alkali is converted into a solid alkali,and the activity of the precipitated particles can be realized during the alkali transfer process,thereby reducing the release rate of hydroxide radicals and reducing alkali supersaturation,creating a prerequisite for the growth mechanism of precipitated particles.The whole set of technologies,including alkali conversion technology,active growth technology and smart controlling methods,has been applied to Ramu Nickel Cobalt Project. After long term production practice exploration and debugging,the current operation is efficient and stable,and the economic effect is obvious.