Leaching behavior of metals from a limonitic nickel laterite using a sulfation–roasting–leaching process

The leaching behavior of metals from a limonitic laterite was investigated using a sulfation–roasting–leaching process for the recovery of nickel and cobalt. The ore was mixed with water and concentrated sulfuric acid followed by roasting and finally leaching with water. Various parameters were studied including the amount of acid added, roasting temperature and time, sample particle size, addition of Na₂SO₄ and solid/liquid ratio in leaching process. More than 88% Ni, 93% Co and < 4% Fe are extracted under the determined conditions. Simultaneously, about 90% Mn and Cu, 70% Mg, 45% Al, 25% Zn, 4% Cr and Ca are extracted respectively. The pH of the leach solution is about 2. The leaching efficiency is independent of sample particle size due to decomposition of ferric sulfate formed during roasting. The roasted mass was characterized by various physico-chemical techniques such as DSC/TGA, XRD and SEM. This process provides a simple and effective way for the extraction of nickel and cobalt from laterite ore.     

微波辅助硫酸浸出红土镍矿的研究

以红土镍矿为原料,研究了微波辅助硫酸浸出镍钴的工艺条件。考察了硫酸浓度、微波功率、微波温度、辐射时间、液固体积质量比对镍钴浸出率的影响。结果表明,在硫酸浓度3.0mol/L、微波功率700 W、微波温度90℃、辐射时间2.5 h、液固体积质量比4:1的最佳工艺条件下,镍浸出率达91%,钴浸出率65%以上。     

Comparative leaching of minerals by sulphuric acid in a Chinese ferruginous nickel laterite ore

The Yuanjiang nickel laterite ore containing mainly maghemite, goethite and lizardite was leached by sulphuric acid at atmospheric pressure and the residues were characterized using X-ray diffraction and scanning electron microscopy/X-ray energy dispersive spectroscopy. The relationship was discussed between the extraction of nickel, cobalt, iron, magnesium, aluminum, and the dissolution behaviour of the laterite minerals; as well as the extent of congruency of nickel, cobalt and iron extraction. The results show that the solubility of the laterite minerals in sulphuric acid decreases in the following order: lizardite > goethite > maghemite > magnetite ≈ hematite > chromite ≈ ringwoodite. Lizardite dissolved rapidly in 0.6 mol/L sulphuric acid at 60 °C whilst goethite dissolved completely in 2.5 mol/L sulphuric acid at 80 °C. The dissolution of the primary mineral maghemite was slow, but increased with increasing acid concentration and leaching temperature. Magnetite dissolved more slowly than maghemite; and hematite was only dissolved in > 6.2 mol/L sulphuric acid at 105 °C. Chromite and ringwoodite were not dissolved. The leaching behaviour of the laterite minerals may be explained by the bond strength differences of Me–O and the substitution of metal cations in the mineral structure.     

红土镍矿加压浸出工艺残积型红土镍矿中和试验研究

残积型红土镍矿是一种重要的红土镍矿,镁元素含量较高(10％～27％),在红土镍矿加压浸出项目中,通常用来中和加压浸出的矿浆,矿浆中硫酸浓度通常为30 ～ 50 g/L.但残积矿用量对镍、钴浸出率有较大影响,为了更好地利用残积型红土镍矿,本文进行了常规浸出试验和还原浸出试验.试验结果表明:随着残积矿用量的增加(液固比降低...     

Pressure acid leaching of arid-region nickel laterite ore: Part I: effect of water quality

The effect of water salinity on the reactions occurring during pressure acid leaching of an arid-region laterite ore, using hypersaline water, seawater, sub-potable water and tap water, is examined. Particular emphasis is placed on the mineralogy of the residue and its implications with regard to residue volume/mass, overall acid consumption and nickel extraction. Analysis of a pressure acid leach residue by electron microprobe indicates that the residual nickel is present in phases that contain silicon and varying concentrations of aluminium, but are deficient in sulphur. Incomplete extraction of nickel from the ore may not be attributed to any one mineral phase.     

Pressure acid leaching of a Chinese laterite ore containing mainly maghemite and magnetite

The high pressure acid extraction of nickel and cobalt from a Chinese laterite containing mainly maghemite and magnetite was studied. X-ray diffraction (XRD) and scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM/EDS) were employed to characterize the residues. The factors influencing the dissolution of maghemite and magnetite, nickel and cobalt extractions and iron precipitation were investigated. The results show that after 75 min at 270 °C with an acid/ore ratio of 0.55, maghemite and magnetite completely dissolved, liberating 98% Ni and 88% Co into the leach liquor. EDS analysis reveals that some nickel may be associated with the amorphous silica and/or basic ferric sulfate, resulting in a minor loss of nickel. The presence of a cobalt-containing phase in the residues, believed to be ringwoodite, is mainly responsible for the incomplete extraction of cobalt. Both maghemite and magnetite dissolved gradually with the increase in temperature from 200 to 270 °C. Maghemite dissolved more slowly than magnetite at 270 °C which also produced ferrous sulfate in the leach liquor and increased the total iron extraction. Increasing temperature and/or agitation accelerated the hydrolysis of ferric sulfate. The leaching of maghemite and magnetite corresponds to a dissolution-precipitation mechanism. In both high and low acidic environments, the precipitation of ferric sulfate proceeds through the initial formation of basic ferric sulfate and its conversion to hematite. The extent of conversion depends largely upon residual acidity and reaction time.     

拜耳法赤泥对红土镍矿还原性能的影响

利用真空电弧炉高温还原熔炼工艺,结合金属回收率、还原产物微观组织和元素分布分析,研究了拜耳法赤泥对红土镍矿还原性能的影响。结果表明:添加拜耳法赤泥能够提高红土镍矿高温还原熔炼时渣的碱度,有利于渣铁分离,提高铁镍元素的回收率,从而减少其他熔剂的添加量;同时,拜耳法赤泥中的钛元素也随铁、镍元素一起被还原,进入到铁镍合金中,丰富了铁镍合金的元素组成,镍、铬元素均匀分布在铁相中,而钛元素聚集成不规则大颗粒析出。     

红土镍矿微波水热法浸提镍钴

采用微波水热盐酸浸出方法对腐泥土型红土镍矿提取镍钴进行了研究,详细探讨了焙烧预处理、微波水热浸出温度和浸出时间对镍钴浸出率的影响.对于300℃焙烧预处理后的红土镍矿,微波水热温度为50℃,浸出时间为1 h时,镍的浸出率高达93.65%,钴的浸出率为87.86%.红土镍矿的微波水热浸出体系与普通水热浸出体系相比,镍和钴的浸出效果更好.研究表明,扩散过程是镍、钴浸出过程的主要限制环节.     

碱度对腐泥土型红土镍矿烧结行为的影响

 为了研究腐泥土型红土镍矿在焙烧过程中物相转变及固结机制问题,通过微型烧结试验和三角锥法软熔特性试验,对原矿和焙烧后的团块进行了化学成分、X射线衍射(XRD)和软熔特性分析,并通过添加熔剂CaO改变团块碱度,结合冶金相图进行了分析。研究结果表明,自然碱度的红土镍矿经高温焙烧后主要由尖晶石(MgFe2O4)、镁橄榄石((Mg,Fe)2SiO4)和顽火辉石(MgSiO3)构成。随着碱度从0.5上升到2.0,顽火辉石相继转变为低熔点的透辉石(CaMgSi2O6)和高熔点的镁黄长石(Ca2MgSi2O7)以及镁蔷薇辉石(Ca3MgSi2O8)。红土镍矿的软熔温度也随碱度的提高先降低后升高,在碱度为1.0时达到最低点。结合冶金相图分析得知,通过改变碱度可以显著增加红土镍矿烧结过程液相量,红土镍矿烧结理想的黏结相为透辉石。     

铁矾土和萤石对冶炼成渣特性影响的试验室研究

为了考察铁矾土和萤石在转炉冶炼过程中对成渣的影响,在中试工厂50kg真空感应炉上进行了12炉次的模拟冶炼试验。在冶炼过程中分别取渣样进行岩相观察和钢样成分分析,结果表明,在冶炼过程中,吨钢加入1.2kg的萤石或铁矾土助熔剂时,二者的化渣效果基本相当;与铁矾土相比,萤石的化渣速度较快。在同等吹炼条件下,铁矾土与萤石通过助熔化渣而使渣的脱磷能力基本相当。     

Pressure acid leaching of arid-region nickel laterite ore: Part II. Effect of ore type

A comparison of the leach chemistry and residue mineralogy has been carried out on the pressure acid leaching of nontronite, limonite and saprolite ores, using hypersaline water. Results are also compared with a typical arid-region laterite feed from Bulong, which consists of a blend of these ore types. Particular emphasis is placed on the influence of ore type on liquor analysis of iron, aluminium and magnesium, residue mineralogy and nickel extraction. Microprobe evidence is presented that incomplete nickel extraction results from the presence of unreacted minor phases present in the original ore, or from the presence of nickel in the amorphous silica, in apparent association with magnesium.     

云南红土型金矿浅析

云南近年来相继发现了一批红土型金矿床（点）,成为金矿找矿工作的主攻目标之一。新构造运动期是云南红土型金矿的重要成矿期。由于地壳快速抬升,云南红土型金矿表现出对基岩含金性依赖性强、风化剖面较薄、成熟度偏低和发育不全等特点,红土化成矿作用长期保持在初－中期阶段。金矿物成色多大于８５０,呈显微－次显微状镶于褐铁矿中。矿石组构依风化程度不同分为三组。     

Effect of mechanical activation on the leaching kinetics of pyrrhotite

BET, SEM, and particle size analysis was used for studying the changes in surface and bulk properties of mechanically activated pyrrhotite in a vibrating mill. The results showed that mechanical activation increased microstructure defects and specific surface area of pyrrhotite, and decreased powder particle size. And the formation of aggregates was very obvious. The influence of mechanical activation on leaching kinetics of pyrrhotite by FeCl₃–HCl solutions was investigated. When pyrrhotite was mechanically activated for 10 min, 20 min and 40 min, the apparent activation energy decreased from 133 kJ/mol to 33, 26 and 25 kJ/mol, respectively. Compared with the non-mechanical activation method, mechanical activation greatly improved the activity of pyrrhotite and decreased the apparent activation energy, so that the reaction speed was accelerated remarkably.     

低品位红土镍矿焙烧-碱浸过程中硅的转化

针对目前红土镍矿碱法处理过程中存在的问题提出工艺改进,研究低品位红土镍矿焙烧活化-碱浸过程中含硅矿物的转化。考察了焙烧温度对红土镍矿活性的影响,探索了红土镍矿经焙烧后碱浸过程中温度、时间、搅拌强度、液固比以及碱初始质量浓度对硅转化的影响。结果表明,红土镍矿经650 °C焙烧2 h后,活性得到明显提高,红土镍矿经焙烧后采用初始质量浓度为60 g/L的碱溶液,在搅拌速度为400 r/min、浸出温度为140 °C、液固比为5∶1的条件下浸出120 min,硅的转化率可达89.42%。     

红土镍矿冶金综述

随着社会工业的快速发展,镍的消耗不断增加,含镍品位较高的硫化镍矿也日益枯竭,有效开发和利用红土镍矿受到越来越多国家的重视。文章主要分析了红土镍矿资源的矿物特点及其国内外的开发现状,详细介绍世界冶金工业中处理红土镍矿的生产工艺及其优缺点。通过分析红土镍矿提取镍的工艺技术近况,指出了未来的发展方向,并重点对湿法和火法工艺未来的发展趋势进行预测。     

红土矿还原焙砂常压酸浸液用SO2/O2氧化除铁的研究

在实验室条件下采用SO2和O2混合气体为氧化剂,开展了从预还原焙烧红土矿常压酸浸液中氧化、除铁的研究.模拟浸出液中Fe2+的质量浓度为10.2 g/L,实验温度分别为60、70、80和90℃.氧化后的Fe(Ⅲ)基本以针铁矿的形式沉淀除去,沉淀过程中加入碱式碳酸镁为中和剂以维持溶液pH值恒定.氧化、沉淀除铁的pH值控制范围为1.7至3.2.实验结果表明,SO2和O2混合气体可加速Fe2+的氧化,且SO2的优化配比取决于混合气体的流量.在优化配比情况下,混合气体中SO2的利用率在97%左右.SO2含量超过最优配比时,过量的SO2则会被溶液中的Fe3+氧化.除铁沉淀渣中的镍含量(质量分数)不超过0.05%,镍仅有少量损失于除铁渣中.     

红土镍矿火法冶炼工艺现状

叙述了红土镍矿资源状况,介绍了回转窑预还原—电炉（RKEF）工艺、NST（Nickel smeltingTechnology）工艺、Vanyukov工艺、江山工艺、转底炉工艺等红土镍矿冶炼工艺的特点和应用现状.对于红土镍矿冶炼工艺存在的能耗高、固废排放量大的共性问题,提出可直接利用热熔渣生产微晶玻璃、铸石或矿物棉等建筑材料.     

Dehydrating and sintering of Philippine nickel laterite

Abstract

Dehydrating of nickel laterite is necessary when high magnesium laterite ores are treated by pyrometallurgical means. In this work, the Philippine nickel laterite was dehydrated and sintered simultaneously in a laboratory scale sintering apparatus. The original nickel laterite was characterised using thermogravimetric (TG) analysis, differential thermal analysis (DTA) and X‐ray diffraction (XRD) experiments. The measurements indicate that chlorite (Fe,Mg,Al)₃(Si,Al)₂O₅(OH)₄ and serpentine Mg₂₁Si₂O₂₈(OH)₃₄H₂O are the primary phases, while FeO(OH) and (Fe,Mg,)₃Si₄O₁₀(OH)₂ are the minor phases in Philippine nickel laterite. The laterite contains free water, water of crystallisation and hydroxyl group; these can be removed in that order during the heating. The temperature range for the removal of free water is 25–140°C, for water of crystallisation it is 200–480°C, and for hydroxyl group it is 500–800°C. Sintering experiments with various coal additions show that sintering time, sintering product ratio, mass loss and the temperatures of off‐gas and burden increase with increasing coal addition. The sintered samples were analysed using XRD, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results demonstrate that olivine (Mg,Fe)₂SiO₄ and spinel MgFe₂O₄ are the main bonding phases during the sintering.

La déshydratation de la latérite de nickel est nécessaire lorsque des minerais de latérite à haute teneur en magnésium sont traités par méthodes pyrométallurgiques. Dans ce travail, on a déshydraté et fritté simultanément la latérite de nickel des Philippines dans un appareil de frittage à l’échelle du laboratoire. On a caractérisé la latérite de nickel originale en utilisant des expériences de thermogravimétrie (TG), d’analyses thermiques différentielles (DTA) et de diffraction des rayons X. Les mesures indiquent que le chlorite (Fe,Mg,Al)₃(Si,Al)₂O₅(OH)₄ et la serpentine Mg₂₁Si₂O₂₈(OH)₃₄H₂O sont les phases primaires alors que FeO(OH) et (Fe,Mg)₃Si₄O₁₀(OH)₂sont les phases mineures de la latérite de nickel des Philippines. La latérite contient de l’eau libre, de l’eau de cristallisation et le groupe hydroxyle; on peut les enlever dans cet ordre lors du chauffage. La gamme de température pour l’enlèvement de l’eau libre est de ～25 à 140°C, elle est de ～200 à 480°C pour l’eau de cristallisation et de ～500 à 800°C pour le groupe hydroxyle. Les expériences de frittage, avec additions variées de charbon, montrent que le temps de frittage, le ratio du produit de frittage, la perte de masse et les températures du gaz de dégagement et du lit de fusion, augmentent avec une augmentation d’addition de charbon. On a analysé les échantillons frittés en utilisant la XRD, la microscopie à balayage d’électrons (SEM) et la spectroscopie à dispersion d’énergie (EDS). Les résultats démontrent que l’olivine (Mg,Fe)₂SiO₄ et le spinelle MgFe₂O₄ sont les principales phases de liaison lors du frittage.     

Reducibility of nickeliferous limonitic laterite ore from Central Anatolia

Limonitic nickel laterite from Sivrihisar reserve in Turkey was reduced at 700–1100°C by the addition of 5·74, 8·61 and 11·48 wt-% coal under an argon atmosphere. The run-of-mine ore and the reduced samples were studied using X-ray diffraction. The metallisation of Fe was found to be limited up to 900°C, but increased rapidly at higher temperatures. The metallisation of Ni and Co increased when the temperature was increased from 700 to 800°C, almost levelled off up to 900°C and then increased up to 1100°C. The results also showed that increased coal additions did not affect Fe metallisation up to 900°C. At 1000°C the metallisation of Fe became slightly better, but its effect was more pronounced at 1100°C. The increased coal addition affected the nickel reduction equally at all temperatures, while it had no effect on the metallisation of Co.

La réserve de nickel limnétique en Turquie a été réduit à 700-1100 ° C par l'addition de 5.74, 8.61 and 11.48 wt-% de charbon sous atmosphère d'argon. Le minerai et les échantillons réduits ont été étudiés par DRX. La métallisation de Fe a été jugée limitée à 900 ° C, mais elle a augmenté rapidement à des températures plus élevées. La métallisation de Ni et Co a augmenté lorsque la température a été augmentée de 700 à 800 ° C, presque stabilisé jusqu'à 900 ° C puis 1100 ° C. Les résultats ont également montré que l'augmentation des ajouts de charbon n'a pas affecté Fe métallisation jusqu'à 900° C. A 1000 ° C, la métallisation de Fe s'est un peu ameliorée, mais son effet était plus prononcé à 1100 ° C. L'augmentation du taux de charbon a affecté une constante réduction de nickel à toutes les températures, alors qu'il n'a eu aucun effet sur la métallisation de Co.     

含镍、铬复合氧化球团的制备工艺

 利用廉价的低品位铬铁矿精矿以及红土镍矿制备含镍、铬复合球团,用于高炉生产含镍和铬不锈钢母液,对于保障不锈钢产业的可持续发展具有重要意义。系统研究含镍、铬球团制备工艺,探究红土镍矿配比、铬铁矿配比以及添加剂对球团强度的影响。结果表明,当混合料配比为45%红土镍矿+15%铬铁矿+40%铁精矿时,添加7.7%添加剂的混合料经高压辊磨预处理后可制备出合格生球,在预热1 000 ℃+12 min,焙烧(1 220～1 250 ℃)+12 min的条件下可获得抗压强度大于2 500N/个的成品球团,可用于高炉生产铁、镍和铬三元不锈钢母液。