红土镍矿品质特点及检验方法探讨

本文介绍了红土镍矿资源特点,分析了红土镍矿主要品质评价指标.结合检验红土镍矿工作经验,对红土镍矿取制样方法和各品质项目的检验方法进行了探讨.提出了做好红土镍矿检验监管的对策和建议,为红土镍矿贸易和检验提供参考.     

红土镍矿冶炼现状及酸浸渣综合利用探讨

本文对红土镍矿的性质进行分析,指出红土镍矿的处理难点;对国内外红土镍矿冶炼现状进行论述,分析了火法、湿法以及火法与湿法相结合的处理红土镍矿工艺技术的优缺点及各工艺中冶炼渣的利用现状;重点探讨了对褐铁矿型红土镍矿高压酸浸工艺处理后的酸浸渣进一步处理利用的方法,以实现对铁的富集回收,达到提高红土镍矿综合利用价值的目的。     

红土镍矿冶金技术研究进展

如今世界经济迅猛发展,金属镍的需求量也在加速增长。人们主要从硫化镍矿和红土镍矿中提炼金属镍。然而硫化镍矿资源因大规模开发而不断减少,红土镍矿未来将成为镍的主要来源。因此研究红土镍矿的高效开发利用,是当今围绕镍资源研究的热点,对实际生产具有重要的现实意义。本文简要介绍了镍的应用、开发红土镍矿的意义、红土镍矿的矿物学特性、红土镍矿世界范围内的储量和分布,并且列举并分析了红土镍矿的各种冶炼工艺及其优点与不足,同时综述了有关红土镍矿研究的新方法,为红土镍矿高附加值综合利用研究提出思路。     

红土镍矿处理工艺研究现状

随着世界上硫化镍矿资源日趋枯竭以及未来镍需求量不断增长,红土镍矿将成为未来镍的主要来源,因此红土镍矿的有效处理以及高效利用对我国的经济建设有着极大的意义。红土镍矿由于其具有储量丰富、易开采、便于运输等特点,已成为研究开发的热点。本文主要从不同矿层的红土镍矿角度,介绍了当前不同红土镍矿冶炼方法和技术,概述了不同矿层的红土镍矿及其适用的冶炼工艺,分析了不同红土镍矿处理工艺的优势与不足,实现不同类型红土镍矿的综合利用。      

红土镍矿软熔性能及还原过程研究

基于煤基直接还原工艺, 采用灰熔点测定仪和相图分析对红土镍矿的软熔性能进行了研究, 结果表明: 随着CaO添加量的逐渐提高, 红土镍矿的熔化温度和流动温度呈现先降低后升高的趋势, 当CaO添加量为10%时, 红土镍矿的熔化温度和流动温度最低, 分别为1 315 ℃和1 335 ℃。结合扫描电子显微镜和能谱分析仪, 对不同温度下反应后的球团样品进行了分析, 研究了红土镍矿含碳球团的还原过程。     

红土镍矿资源现状及加工工艺综述

综合论述了世界红土镍矿的资源概况和利用现状,分析了我国对镍的需求情况,对红土镍矿的处理方法和目前有前景的加工工艺进行了较为详细的阐述和分析.     

印度尼西亚红土镍矿资源特点及未来开发趋势

近年来,随着红土镍矿开发工艺技术日益成熟及市场竞争压力的推动,印度尼西亚成为全球镍矿资源开发的重点地区,在对印度尼西亚红土镍矿资源特点及其开发历程进行分析回顾的基础上,结合目前市场情况提出了印度尼西亚红土镍矿的未来开发趋势。     

红土镍矿资源现状及其冶炼工艺的研究进展

随着硫化镍矿资源的逐渐减少,高效低成本地开发红土镍矿资源以满足逐渐增加的镍需求有着重要意义。介绍了世界红土镍矿资源现状和特点,并阐述了目前红土镍矿处理的火法工艺、湿法工艺以及其它工艺技术的研究现状及进展,同时分析了这些处理方法的优势与不足,指出了未来的发展方向,以期为低品位红土镍矿的开发提供参考。     

红土镍矿酸浸渣与硅藻土的吸放湿性能比较

通过干燥器法,对红土镍矿酸浸渣和硅藻土在三种湿度下的吸湿性能进行了研究,并比较了二者的放湿性能,对二者的粒度和孔结构进行了分析和比较。研究表明:红土镍矿酸浸渣的调湿性能优于硅藻土,其吸湿量、吸湿速率、放湿量、放湿速率等指标均超过了硅藻土;且红土镍矿酸浸渣的比表面积和粒度均大于硅藻土,结合调湿性能分析,红土镍矿酸浸渣适合作为一种优良的调湿材料。      

熔剂性红土镍矿球团的还原焙烧-弱磁选效果

回转窑直接还原红土镍矿存在所需温度高、对耐火材料要求苛刻、还原指标差等问题。为开发一种高效低成本的红土镍矿球团还原工艺,考察了以CaO为熔剂改变红土镍矿碱度对红土镍矿球团还原焙烧-弱磁选效果的影响。结果表明：自然碱度下,在还原温度为1 400 ℃、还原时间为60 min时,所得还原产品经磨矿-弱磁选,获得的磁性产品镍、铁品位分别仅3.8%和72.9%,回收率分别为17.8%和39.8%,磁性产品中含有较多的镁橄榄石和顽火辉石;随着红土镍矿碱度的增加,红土镍矿的软熔温度先降低后提高,碱度为1.0时,红土镍矿的软熔温度最低,比自然碱度时降低了100 ℃;碱度为1.0的红土镍矿球团在1 300 ℃下还原焙烧60 min后,经磨矿-弱磁选,获得的磁性产品镍、铁品位分别为8.7%和83.8%,回收率分别为85.6%和62.8%。XRD和扫描电镜分析结果表明：自然碱度的红土镍矿还原焙烧生成的Fe-Ni合金晶粒多在5 μm以下,并且分布比较分散,还原产品中夹杂有较多的杂质;添加CaO至碱度为1.0时,Fe-Ni合金晶粒可以长大到10~50 μm,还原产品中杂质较少,镍和铁得到了明显的富集。试验结果可以为红土镍矿球团还原焙烧-磁选制取镍铁新工艺提供理论基础。     

红土镍矿酸浸沉镍后液中镁资源化的研究进展

红土镍矿的加压酸浸、常压酸浸、堆浸工艺分别适用于褐铁矿型红土镍矿、过渡层和硅镁镍矿型红土镍矿,两种或两种以上的湿法联合处理工艺对矿石适用范围更广。在红土镍矿酸浸过程中,Mg和Ni、Co等同时被不同程度的浸出进入溶液,浸出液沉淀富集Ni、Co后产生大量的含镁废水。若不对其进行有价回收,不仅造成了资源的浪费,还会污染环境。本文综述了红土镍矿酸浸沉镍后液中Mg资源化工艺的研究进展及工业化情况,其中包括沉镍后液中Mn(II)的净化,并对今后的研究发展方向进行了展望,以期为红土镍矿中Mg的综合回收提供技术参考。     

氢化物发生-原子荧光光谱法测定红土镍矿中砷

提出了以硫脲-抗坏血酸作为还原掩蔽剂,氢化物发生-原子荧光光谱法(HG-AFS)直接测定红土镍矿中砷的方法。考察了测定的最佳条件、共存元素对测定的影响及方法的精密度和回收率。方法适用于红土镍矿中0.005%～0.1%砷的测定。     

Microwave carbothermic reduction roasting of a low grade nickeliferous silicate laterite ore

The known resources of nickel sulphide ores are quickly diminishing and in order to satisfy future nickel demands, nickel laterite deposits are being investigated as an alternative. Currently, expensive leaching and smelting processes are used to process the nickel laterite ores. The objective of the present research was to produce a high grade nickel concentrate via microwave carbothermic reduction roasting followed by magnetic separation. A thermodynamic model was developed for the roasting process in order to determine the optimum experimental conditions. The experimental variables investigated were: microwave energy and argon shrouding for the reduction tests and the magnetic field strength for the concentration stage. The behaviours of nickel and cobalt were studied in the reduction and magnetic separation processes. By optimizing the reducing and magnetic separation conditions, a high grade concentrate containing 9.2% nickel with a nickel recovery of 88.8% was achieved.     

Effect of sulfur on the mineral phases of laterite ores at high temperature reduction

Recovery of nickel and cobalt from nickel laterites processed according to the Caron process is hampered by reduction of iron in limonite ores and formation of fosterite in saprolite ores. The Caron process involves the reduction of the ores at temperatures between 700 and 800 °C followed by ammoniacal leaching. The presence of sulfur has been found to markedly improve the Ni and Co recoveries from laterite ores. In this study, limonite and saprolite laterite ores were reduced in the presence of an activator, in the form of elemental sulfur. The mineral phases resulting from the reduction, both in the presence and absence of sulfur were related to recoveries and selectivity obtained from laboratory reduction and leaching tests. The mineral phases were examined using X-ray diffraction with a synchrotron radiation source. The role of sulfur and the history of reduction in effecting the increase in recovery and selectivity of nickel and cobalt was investigated in this study.     

红土矿含碳球团还原富集镍铁的工艺研究

为了解决低品位红土镍矿的合理利用问题, 以活性炭粉为还原剂, 采用直接还原富集-磁选分离技术, 将矿石中的镍和铁直接还原制成金属镍和铁, 并通过磁选分离使其得到富集。研究确定了最佳工艺条件为: 配炭量4%、还原温度1 350 ℃、焙烧时间120 min。此条件下, 镍和铁的回收率分别为87.6%和95.3%。     

红土镍矿加压酸浸工艺进展

随着硫化镍矿资源的逐渐减少,高效且低成本的开发红土镍矿资源以满足逐渐增加的镍需求有着重要意义。据此,本文首先介绍了红土镍矿的矿物学特性及其加压酸浸工艺的反应机理,并从提高镍浸出率、降低酸耗角度概述了该工艺的影响因素;其次从工业应用角度介绍了该工艺的技术改进,着重介绍了加压酸浸—常压酸浸工艺(HPAL-AL)和非常规介质浸出工艺。     

Thermodynamic analysis of the carbothermic reduction roasting of a nickeliferous limonitic laterite ore

As the sulfide ore deposits become less economically viable as a source of nickel, increasing attention is being paid to the nickeliferous laterite ores. However, in contrast to the sulfide ores, these oxide ores cannot be as easily concentrated by current technologies. Consequently, considerable research effort is being directed at developing new techniques for beneficiating the nickeliferous laterites. The pyrometallurgical production of a high-grade ferronickel alloy using a low cost carbonaceous reductant at relatively low temperatures is particularly attractive. In the current research, a thermodynamic model has been developed to aid in the understanding of the carbothermic reduction roasting process as a potential upgrading method for the nickeliferous limonitic laterite ores. The effects of process parameters such as temperature and reductant to ore ratio on the grade of the ferronickel alloy produced and the nickel recovery in the alloy have been studied. The thermodynamic predictions are shown to be in general agreement with the experimental results currently available in the literature.     

Assessing the energy and greenhouse gas footprints of nickel laterite processing

The energy and greenhouse gas footprints of some of the various technologies that are used for processing nickel laterite ores have been assessed using life cycle assessment methodology based largely on publicly reported inventory data. The results of the study were used to identify opportunities to improve the energy and greenhouse gas impacts of the various processes and to examine how they might be affected under different future scenarios such as falling laterite ore grades and the possible imposition of a carbon tax. The opportunities identified included the use of biochar as a fuel and reductant, along with slag waste heat recovery in ferronickel smelting, and the use of the emerging bath smelting technology for ferronickel production instead of the rotary kiln/electric furnace process. As a significant amount of the life cycle-based greenhouse gas emissions from the hydrometallurgical acid leaching processes are generated by acid neutralisation with lime or limestone, there may be opportunities to reduce these emissions by utilising other neutralising agents or possibly by considering non-acid leaching systems. Improving the energy efficiency of the electrowinning stage used to recovery nickel metal from the leach liquor is another possible way in which the sustainability of hydrometallurgical production of nickel from laterite ores could be improved.     

Effect of saline stress on fungi metabolism and biological leaching of weathered saprolite ores

Biological leaching of nickel laterite ores is based on the use of heterotrophic microorganisms and their metabolic products to dissolve nickel and cobalt from oxide minerals. High salinity of water supplies and soils in the vicinity of nickel laterite ore bodies can be a major challenge in the application of bio-leaching process in situ. Salt stress can imbalance the osmotic potential in fungi cells generating a water deficit and the influx of sodium may lead to metabolic toxicity. The purpose of this study is to examine salt tolerance development of Aspergillus foetidus using gradual acclimatization technique to salt concentrations up to 2% and to assess the use halotolerant microorganisms in leaching weathered saprolite ores under saline conditions. It has been observed that salinity stress affects the growth but not the energy metabolism of the organism. Kinetic of metal leaching, nature of secondary reactions and metal dissolutions were also influenced by salt stress.