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。      

印尼某红土镍矿常压浸出实验研究

以印尼某地红土镍矿为原料,考察了浸出时间、浸出温度、硫酸浓度、液固比等因素对硫酸常压浸出镍、铁的影响。结果表明,硫酸浸出红土镍矿的适宜工艺参数为: 初始硫酸浓度300 g/L、液固比6∶1、搅拌速度300 r/min、浸出温度85 ℃、浸出时间240 min,此优化条件下红土镍矿中Ni浸出率97%,Fe浸出率83%。对浸出渣进行XRD、SEM分析表明,红土镍矿晶型较稳定,浸出后形貌无较大变化; 浸出渣主要成分为铁氧化物、硅氧化物和铁酸镍、铁酸镁。     

红土镍矿酸浸渣硫酸铵焙烧-超声分散-离心分离提纯增白效果与机理

红土镍矿酸浸渣作为提镍废渣,存量大、白度低、重金属含量高。 为实现它在相关领域的 回收应用及高值开发,本文通过研究红土镍矿酸浸渣原矿、提纯增白样品和尾渣的化学成分、物 相、微观形貌、孔结构以及焙烧过程中的气相,并通过同步热分析与红外-质谱(TG-FTIR-MS)联 用系统,以及XRD、SEM、EDS等手段对提纯增白机理进行了分析。 提纯增白机理为:预先煅烧去 除有机杂质并将铁、铝、铬等离子氧化,二段焙烧将金属氧化物通过一系列反应转化为NH4(Al、 Fe、Cr)(SO4)2,并在超声波作用下溶于水中经洗涤去除,未参与反应的六方硫镍矿和砷化锗镉还 有部分石英经离心沉淀去除。 试验结果:红土镍矿酸浸渣白度由56% 提升到84% 、含铁量由 0.92% 下降到0.2% 、比表面积由84m2/g提升到96m2/g、回收率达到47% 以上。     

红土镍矿酸浸渣硫酸铵焙烧—超声分散—离心分离增白工艺研究

红土镍矿酸浸渣的存量大、白度低、重金属含量高,严重制约了在相关领域的回收应用,提纯增白是高效综合利用这种固废资源的一个亟待解决的技术问题。采用两段煅烧——直接煅烧后再加硫酸铵焙烧的工艺,使其白度得到较大提升后,再采用超声波分散浸出—离心提纯工艺去除影响酸浸渣白度的杂质。对样品白度、化学成分、矿物成分、颗粒形貌和孔结构进行了表征。结果表明:最优的增白工艺为,500℃预先煅烧1 h,添加200%镍渣质量的硫酸铵焙烧2 h,超声分散浸出8 min,在离心分离因数为4的条件下离心1 min。最终实现红土镍矿酸浸渣的白度由56%提升到84%,含铁量由0.92%下降到0.20%,比表面积由84 m2/g提升到96 m2/g,回收率达到47%以上。得到的红土镍矿酸浸渣纯度和白度显著提升,粒度减小以及孔结构特性得到优化,高值开发应用前景广阔。      

硝酸常压浸出红土镍矿特性及镍浸出动力学

采用ICP和XRD分析手段研究了某红土镍矿的元素及物相组成。采用硝酸常压浸出该红土镍矿。通过单因素条件实验和综合实验探究了硝酸浓度、固液比、搅拌转速、浸出时间、浸出温度在常压条件下对红土镍矿中Ni、Co、Fe和Mg浸出的影响,并求解了镍的浸出动力学。结果表明,该红土镍矿为硅镁型,在硝酸浓度5mol/L、固液比(g/mL)为1:12、搅拌转速250r/min、浸出时间150min、浸出温度85℃的条件下,Ni、Co、Fe和Mg的浸出率最佳,分别为98.75%、91.66%、81.45%、94.21%。镍的浸出过程符合收缩核模型,反应活化能为38.804kJ/mol,反应过程受化学反应和内扩散混合控制。     

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。     

印尼某低品位红土镍矿的热解性能

为提高红土镍矿火法冶炼工艺技术指标,对印尼某低品位红土镍矿进行了热解性能分析。结果表明：该红土镍矿属于典型的低品位过渡层红土镍矿,主要组成矿物为利蛇纹石、针铁矿、石英、铁蛇纹石、叶蛇纹石和高岭石,镍主要赋存于蛇纹石、橄榄石等硅酸盐类矿物中,部分以氧化镍形式赋存于针铁矿中。红土镍矿热解分析结果表明：在86 ℃时有1次失重过程,形成1个吸热峰,有H2O溢出,对应自由水的脱除;在268 ℃时有1次失重过程,形成1个吸热峰,有H₂O溢出,对应针铁矿的脱羟基过程;在589 ℃时发生失重,形成1个吸热峰,有H₂O溢出,对应高岭石、利蛇纹石的脱羟基反应;在816 ℃时有1个放热峰,而红土镍矿质量没有变化,对应利蛇纹石热解产生无定型的硅酸盐重结晶后产生镁橄榄石（Mg₂SiO₄）及顽火辉石（MgSiO₃）的过程;在1 126 ℃时有1次失重过程,有CO₂溢出,由白云石分解产生。试验结果对红土镍矿火法工艺的改进有指导作用。     

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。     

复合钠盐法处理印尼某红土镍矿研究

针对印尼某红土镍矿的组成及结构特点,运用还原焙烧—浸出—磁选法综合利用红土镍矿。在配料中使用添加剂硫酸钠和碳酸钠改善还原焙烧性能,并考察了硫酸钠和碳酸钠配比(S/C)、配煤量、焙烧温度以及焙烧时间对镍铁精矿中镍品位以及镍回收率的影响。结果表明,当红土矿、硫酸钠、碳酸钠和煤的质量比为100∶14∶8∶8,焙烧温度为1 200℃以及焙烧时间为80 min时,可以得到品位为4.59%,镍收率为88.58%的镍铁精矿。该工艺流程能够高效富集红土镍矿中的Ni、Fe、Al等有价金属元素,实现了红土镍矿资源的高效综合利用。     

氢氧化钠浓度对水热法合成介孔材料的影响

以F68(聚氧乙烯-聚氧丙烯-聚氧乙烯)为模板剂,铝酸钠和水玻璃为铝源和硅源,按物质的量比为1∶120∶1233,采用水热法合成介孔材料.通过X射线衍射仪(XRD)、比表面积测定仪(N2吸附/脱附)、扫描电镜(SEM)对样品进行表征分析,研究了氢氧化钠浓度对水热法合成介孔材料的孔径、比表面积、孔容和形貌的影响.结果表明:氢氧化钠浓度增大,合成的介孔材料比表面积和孔容增大,孔径分布逐渐均匀.氢氧化钠浓度为11 mol/L时合成的介孔材料性能最佳,此时比表面积为165.42 m2/g,平均孔径23.03 nm,孔容0.85 cm3/g.     

Calcination of low-grade laterite for concentration of Ni by magnetic separation

With the continuous depletion of high-grade nickel ores such as millerite and niccolite, nickeliferous laterites have become the major source for the production of nickel metal. However, only 42% of the world’s production of nickel comes from laterites, since the concentration of Ni is relatively low (ca. 2 wt.%). In addition, other metals, such as magnesium, iron and silicon can be found in laterite, which make the concentration of nickel even more difficult.In this study, a low-grade nickeliferous laterite ore was first calcinated and then processed by using a wet magnetic separator in order to recover nickel. Since, the ore contains both Ni and Fe, the calcination of laterite is effective in altering the crystalline structure of Fe species and therefore its magnetic properties, which in turn enable the selective concentration of nickel by magnetic separation that is an easy and environmentally-friendly technique. The experimental results have indicated the importance of carefully controlling: (1) the calcination temperature; (2) the pulp density and (3) applied magnetic field strength. The main finding of this work was that magnetic separation is effective in recovering 48% of nickel from laterite, increasing the Ni grade in the recovered product from 1.5% to 2.9%, when prior to the separation the ore was calcinated at 500 °C for 1 h.     

海泡石提纯改性及在内墙涂覆材料中的应用研究

针对湘潭海泡石原矿进行了提纯和改性处理,去除海泡石内部的石英、方解石等脉石矿物,以疏通其孔道结构,比表面积提升至156.9 m2/g,大幅增强吸附性能。利用改性海泡石制备内墙涂覆材料将显著提高涂料涂层对室内装修建材释放的甲醛等有害气体分子的吸附和固化效果和对室内空气环境湿度的调节性能,充分发挥海泡石涂料产品的功能性。研究了海泡石提纯改性工艺及其在内墙涂覆材料中的应用,验证了涂料样品对甲醛的吸附性,拓展了海泡石高附加值材料化应用的范畴。     

工业固废和难处理矿石氯化处理综述

工业固废和难处理矿物作为金属资源的附载体,正在日益受到全世界的关注,高效提取其中的金属资源,对于固废的减量化或某些金属的战略安全具有重要意义。本文主要以氰化尾渣、硫酸烧渣、红土镍矿、磁性废料、钛渣、钒渣等工业废物和难处理矿石为关注对象,从氯化技术处理的角度进行总结综述。对于某些含高价值金属(如Au、Ag等)的固废或难处理矿物而言,氯化技术有着更大的优势。     

The effect of sodium sulphate on the hydrogen reduction process of nickel laterite ore

A series of nickel laterite ores with different calculated amounts of anhydrous sodium sulphate were prepared by physical blending or sodium sulphate solution impregnation. The reduction of the prepared nickel laterite ore by H₂ was carried out in a fluidised-bed reactor with provisions for temperature and agitation control, and the magnetic separation of the reduced ore was performed using a Davis tube magnetic separator. The mineralogical properties of the raw laterite ore, reduced ore and magnetic concentrate were characterised using ICP, TG–DSC, N₂ adsorption, X-ray diffraction and optical microscopy. The catalytic activity of sodium sulphate was also studied by using Hydrogen temperature-programed reduction. The experimental results indicate that Na₂SO₄ could overcome the kinetic problems faced by the laterite ore and that it exhibited noticeable catalytic activity only if the temperature reached at least 750 °C. This high temperature accelerated the crystal phase transition of the silicate minerals and increased the utilisation of H₂. In comparing the results from the two different methods for adding Na₂SO₄, the nickel content and recovery of the magnetic concentrate were increased by using the impregnation method rather than the physical blending method and the increasing amount of sodium sulphate assisted in the further beneficiation of nickel. The partial pressure of H₂ and the reducing time also affected the reduction process of the iron oxides. The results of the microscopic study indicated that the formation of a Fe–S solid solution, which was derived from the SO₂ sulphide reduction of FeO, was conducive to mass transfer and accelerated the coalescence of metallic ferronickel particles. For the nickel laterite ore, under the synergistic effect of sodium sulphate and hydrogen, a nickel content and nickel recovery of 6.38% and 91.07% were obtained, respectively, with high product selectivity.     

The effects of mineralogy on the biological leaching of nickel laterite ores

The amenability of limonite ore, the iron rich nickel laterite phase, was observed to be less than saprolite, the silicate rich phase, when subjected to biological leaching with heterotrophic microorganisms. To understand this difference, controlled leaching of the various nickel laterite minerals was conducted using citric acid to mimic the chemical action of the organisms and subsequent characterisation of the leached residues. The raw ore and the leached mineral residues were examined using high-resolution synchrotron based X-ray diffraction and optical microscopy. The possible contribution of electrosorption and solid porosity was also considered. The results suggest that although electrosorption contributes to nickel and cobalt losses, it is the structural changes induced by the acid in the minerals which effects the recovery of the metals. Citric acid was found to dehydroxylate saprolite minerals resulting in an unstable nickel oxide and thus making it susceptible to acid attack. This behaviour was not observed in the limonite ore, which was found to be poorly leached by citric acid.     

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。     

红土镍矿冶金工艺现状及前景分析

本文简要介绍了镍资源的性质特点及现状,分析了红土镍矿回转窑-电炉还原熔炼、还原焙烧－磁选、还原硫化熔炼３种火法工艺以及常压酸浸、高压酸浸等湿法工艺的优势与短板,并指出生物浸出在红土镍矿处理中的应用,探讨了未来红土镍矿冶金工艺的改进发展,指出红土镍矿湿法冶金将在今后扮演重要地位。