从红土镍矿中提取镍的技术研究现状及展望

随着世界上硫化镍矿资源日趋枯竭.开发利用红土镍矿是未来镍业发展的方向.本文介绍的红土镍矿处理工艺有火法工艺和湿法工艺,其中火法工艺和湿法工艺中的氨浸法、高压酸浸法存在明显缺点,而常压酸浸法有工艺简单、能耗低、操作易于控制、投资少等优点,将会有很好的发展前景.     

常压酸浸从废旧镍基合金中浸出镍钴

以氯酸钠为氧化剂,采用常压氧化酸浸工艺从废旧镍基合金中浸出镍、钴,钨、钼、钽等稀贵元素富集在浸出渣中。结果表明,在下述最佳条件下,镍、钴的浸出率均可达到99%以上:粒度0.075~0.100mm、硫酸浓度4.5mol/L、液固比8∶1、氯酸钠用量2.0g(占合金废料的2%)、反应时间2.5h、反应温度(85±3)℃。     

酸浸法从含镍蛇纹石中提取镍的研究

某地蛇纹石矿中镍主要以类质同象存在于硅酸盐矿物内,且粒度很细,不能用物理方法予以富集。为此,采用硫酸浸出工艺,镍浸出率为85.7%,浸出贵液经净化沉镍,可得含镍41.24%的Ni(OH)2镍精矿,沉镍收率88.6%,综合收率达75.93%。     

红土镍矿高压酸浸小型试验与研究

本小型试验采用高压酸浸技术处理典型的近赤道低品位湿型红土镍矿,研究镍、钴、铝、铁浸出率与温度、酸矿比、搅拌转速、浸出时间、入釜矿浆浓度之间的关系,然后应用技术经济分析的手段对筛选后的试验结果再进一步分析,探索出红土镍矿高压酸浸最佳工艺条件.     

从红土镍矿酸浸渣中回收铁矿物的试验研究

本文针对某红土镍矿酸浸渣中铁矿物含量较高,铁矿物粒度较细、含铁矿物以赤褐铁矿为主的特点采用焙烧磁选的选矿方法加以处理。指出对红土镍矿酸浸渣的处理,可以综合利用矿产资源,减少其对环境的污染有着重要的现实意义。     

“干型”红土镍矿氧压酸浸研究

对传统高压酸浸(HPAL)工艺进行改进,在反应初始充入一定量的氧气,在较低温度下浸出澳大利亚"干型"红土镍矿。研究了硫酸用量、浸出温度、浸出时间、初始氧分压对镍、钴、铁浸出率及游离酸含量的影响。结果表明,在220℃、硫酸用量25 mL、反应初始充入0.5 MPa氧气反应2 h的条件下,镍、钴浸出率分别为99.83%、90.44%,与250℃不充入氧气时的镍、钴浸出率大致相当。     

氧化酸浸法从非对称电容电池中提取镍、钴和稀土

非对称电容电池兼具氢镍电池能量密度和非对称超级电容器功率密度的优势,具有广阔应用前景,从废弃非对称电容电池回收金属不仅是环境保护的需求,更是资源再生利用的需要。以H2O2为氧化剂从非对称电容电极负极材料中用氧化酸浸法提取镍、钴和稀土。研究了硫酸浸出过程中镍钴的浸出机制,发现当p H小于6.5时,Ni2+和Co2+具有较高的溶解度,且钴优先于镍浸出;同时研究了氧化剂用量、浸出温度、硫酸浓度、液固比和浸出时间等因素对非对称电容电极负极材料氧化酸浸过程中有价金属镍、钴和稀土浸出率的影响。结果表明,Ni,Co浸出率随温度升高而增加,在353 K时,浸出率均达到最大值,Ce则在常温下浸出效果较好;Ni,Co和Ce浸出率随氧化剂用量、硫酸浓度、液固比和浸出时间的增加而增大。最适宜的工艺条件为:硫酸浓度190 g·L-1,液固比为9∶1,H2O2用量8 ml,353 K温度下浸出20 min,流动水冷却到293 K,搅拌浸出90 min,Ni,Co和稀土的浸出率分别达99.4%,99.7%和96.5%。并提出了"硫酸钠回收稀土-苛碱回收镍钴"的后续分离净化流程,能有望应用于非对称电容电极负极材料及类似物料中有价金属的提取与分离的工业生产。     

高压酸浸法从镍红土矿中回收镍钴

采用高压酸浸法从Ramu镍红土矿中回收镍钴。详细介绍了矿浆处理、高压酸浸、循环浸出及矿浆中和、CCD逆流洗涤、中和除铁铝、氢氧化镍钴沉淀、深海填埋工艺(DSTP)等流程,并分析了工艺出现的问题及改进措施。全流程镍回收率～96%,钴回收率～94%。     

镍精矿加压酸浸新工艺研究

研究了金川镍精矿加压一步全浸镍、钴、铜新工艺,浸出液中和除铜后萃取分离镍钴,镍、钴、铜的浸出率可分别达到99.5%、98%和98%以上。该工艺与硫酸选择性浸出相比具有金属浸出率高、分离彻底、易分别回收等优点。     

硫化镍精矿常压浸出研究

本文研究了温度、通氧速率、pH值、硫酸浓度等条件对硫化镍精矿常压浸出的影响,发现在80℃→85℃之间,镍浸出率随温度的升高而迅速增加,通氧条件下,镍浸出率差值的变化与通氧速率存在数学关系:y=8.271x0.3003,pH值为2.1~2.2时,镍浸出率最高,且镍浸出率随硫酸用量和铜离子的增加而升高。     

硫酸常压强化浸出红土镍矿新工艺研究

采用常压强化浸出红土镍矿,镍、钴浸出率可以提高到95%以上,且无废酸处理。浸出液进行两段除铁、铝得到铁渣;控制较高pH沉淀镍、锰获得纯净的硫酸镁溶液,再经浓缩、结晶、脱水制取无水硫酸镁。采用硫磺作还原剂,在真空回转窑内800℃常压热分解无水硫酸镁得到二氧化硫和活性氧化镁,二氧化硫制酸后用于浸出红土镍矿,一部分活性氧化镁作除铁铝和沉镍锰的中和剂,另一部分外销。     

常压盐酸浸出红土镍矿的研究

为有效提取红土矿中镍钴资源,研究了常压盐酸浸出工艺提取红土矿中的镍钴。结果表明,矿料粒度为-0.15 mm,初始酸浓度8 mol/L,浸出温度353 K,固液比S/L=1:4,搅拌速度300 r/min,反应时间2 h,镍、钴、锰、铁、镁的浸出率分别达到93.94%、60.5%、94%、56%9、4%。     

某难处理铀矿石加压酸浸试验研究

某难处理铀矿石采用常规酸法搅拌工艺浸出时,酸耗高,浸出液后处理难度大。采用加压酸浸工艺,酸耗可降低约30%,浸出液余酸质量浓度降至2~4g/L,无需再处理即可满足下一处理工序的要求。     

腐植土层镍红土矿常压硫酸浸出

对采用常压硫酸浸出工艺处理镍红土矿沉积物中的腐植土矿层进行了研究.本工艺包括浸出腐植土矿料、中和浸出矿浆和从母液中沉镍.为了确定试验条件,进行了一系列试验.试验结果表明,根据腐植土矿样的镍沉淀物的定量分析,镍的总回收率可达80%以上.本研究中最简单最经济的沉镍方式是使用石灰作为沉淀剂.也可采用一些别的沉镍方法,以使沉镍产物满足市场需要.     

Pressure Acid Leaching of Nickel Laterites: A Review

Abstract

A review of the literature over the past 30 years on the processing of nickel laterites by high temperature acid leaching has been carried out to provide a better understanding of the mineralogy, leaching process chemistry and effect of operating conditions on nickel recovery, residue properties and scaling. Particular attention is paid to the leaching experience of the commercial Moa Bay plant and to the recently reported testwork and flowsheets associated with the three Western Australia lalerite plants that will be operating in 1999.

It is shown that laterites can vary significantly in their mineralogy according to location, climate and depth, and that the main host minerals for nickel and cobalt can be either goethite (iron oxide) or nontronite (clay) or manganese oxides. The mechanism of leaching involves acid dissolution of the host mineral lattice followed by hydrolysis and precipitation (transformation) of a variety of insoluble oxides and sulphates of iron, aluminium and silica under the high temperature conditions. Optimum leaching conditions and final liquor composition varies according to the ore mineralogy. More fundamental studies have demonstrated that the rate of leaching and character of the residue is dependent upon the level of Mg, Mn and Cr in the ore, the Eh of the slurry and salinity of the process water.

A number of studies are reviewed on the chemistry and precipitation of iron, aluminium, magnesium and silica to understand how the process conditions affect the solubility of the species and the nature of the scale which they form. Early work at Moa Bay indicates that the incorporation of chromium into alunite scale also affects the incorporation of silica and nickel and the settling of the residues. Various types of scale have been identified during different stages of leaching and possible means of minimising scale are discussed.

The clay-rich nickel laterites in Western Australia differ from Moa Bay laterite in mineralogy and have comparatively high silica and low chromium content. Since no commercial plant has previously processed such ores or used saline process water, there is little published in this area. It is therefore recommended that further research be carried out on understanding the process chemistry and species equilibrium from various ore types under autoclave conditions.     

常压硫酸焙烧法提取镍磷铁中的镍

采用硫酸化焙烧再水浸的方法从钙镁磷肥的副产物镍磷铁中提取镍,重点研究了提镍过程中相关因素对镍浸出率的影响。结果表明,在酸料比0.5、焙烧温度300℃、焙烧时间3h、水浸液固比7∶1、水浸温度70℃、水浸时间2.5h的条件下,浸出效果最好,浸出液中镍浸出率达到73.43%。