A two-stage thermal upgrading process for nickeliferous limonitic laterite ores

Sulphide ore deposits are becoming increasingly less viable as a source of nickel, driving recent interest in the development of nickel laterite deposits. The difficulties with the current methods of nickel metal production from these oxide ores arise mainly from the inability to produce a concentrate analogous to that obtained in the flotation of sulphide ores, resulting in high production costs. In this work, a two-stage reduction and thermal growth process is proposed for the treatment of the nickeliferous limonitic laterite ores to produce a ferronickel product, recoverable by magnetic separation. An initial reduction roast of the ore with 6% coal and 4% sulphur additions at 600°C for 1?h, followed by particle growth for 1?h at 1000°C, produced a ferronickel concentrate with a nickel grade of 4% and a nickel recovery of 93·2%. The impact of particle growth temperature and retention time at temperature on the ferronickel particle size was also studied. For the control conditions, typical ferronickel particles produced were 10–20?μm in size. The particle size did not significantly change at temperatures higher than 1200°C or for retention times beyond 60?min.     

Leaching characteristics of nickeliferous pyrrhotite tailings from the Sudbury,Ontario area

Mineralogical characterisation showed the deportment of Ni to be similar in the Vale and Glencore tailings, with 60% of the total Ni locked in pyrrhotite, and the balance 40% associated with pentlandite. Nickel leaching was correlated with the dissolution extents of pyrrhotite and pentlandite as functions of four leaching regimes: ‘anoxic acid’ (with and without pH control), ‘oxic acid’ (oxygen sparging), ‘oxic acid’ (air sparging), and ‘oxic ferric’ (air sparging). The results showed that the maximum Ni dissolution was obtained during the pH controlled oxic acid leach with oxygen sparging at pH 1.5, while the anoxic acid leach at pH 1.5 resulted in minimum Ni dissolution (10–15%) from pyrrhotite. An overall Ni mass balance showed that pyrrhotite and pentlandite dissolve simultaneously in the presence of Fe(III) and oxygen, in contrast to the preferential dissolution of pyrrhotite in the absence of Fe(III). Elemental sulphur yield increased with increasing temperature, but no observable trend could be linked to ferric or ferrous ion concentration.     

Recovery of nickel and copper from high-grade matte at Impala Platinum by the Sherritt process

High-grade nickel-copper matte is treated at Impala Platinum to produce nickel briquettes and copper cathodes. The remaining residue is separately treated for the recovery of platinum group metals. The major portion of the nickel values is preferentially extracted in a first stage acid oxidation leach. The resulting nickel solution contains little or no dissolved copper. After adjustment with recycled ammonium sulphate and ammonia, this solution is reduced directly with hydrogen under pressure, to produce a nickel powder product which is subsequently briquetted and sold as such. Second stage acid oxidation leach is carried out on the first stage leach residue to extract substantially all of the copper values as well as the residual nickel values. Copper is recovered from the solution in an electrowinning step and the spent electrolyte containing copper, nickel and sulphuric acid is recycled to the first stage leach. The second stage residue is further leached under acid conditions to provide a final residue rich in platinum group metals. This residue constitutes the feed to the Impala platinum metals refinery.     

锰硅合金炉渣中锰回收率的影响因素

根据电炉冶炼锰硅合金的实际生产经验,分析了锰硅合金生产过程中影响锰硅合金炉渣含锰量的主要因素。同时指出,只要把这些主要因素控制在合适的范围内,就可降低渣中的含锰量,提高锰的回收率。     

Recovery of nickel from Orimulsion fly ash by iminodiacetic acid chelating resin

Macroporous resins containing imminodiacetic acid (IDA) groups (Lewatit TP-207, Purolite S-930 and Amberlite IRC-748) were studied under dynamic conditions for uptake of nickel ions from the sulphate solution at pH 4 deriving from preliminary acid leaching of Orimulsion fly ash and subsequent vanadium recovery and impurities removal stages. The effects of temperature and ionic medium on the Ni adsorption were investigated.     

The mineralogy of pyrrhotite from Sudbury CCN and Phoenix nickel ores and its effect on flotation performance

Abstract

The non‐stoichiometric sulphide pyrrhotite (Fe_1?xS), common to many nickel ores, occurs in a variety of crystallographic forms and compositions. In order to manipulate its performance in nickel processing operations either to target the recovery or rejection or pyrrhotite, one needs an understanding of pyrrhotite mineralogy, reactivity and the effect this may have on its flotation performance. In this study, a non‐magnetic Fe₉S₁₀ pyrrhotite from Sudbury CCN in Canada and a magnetic Fe₇S₈ pyrrhotite from Phoenix in Botswana were selected to explore the relationship between mineralogy, reactivity and microflotation. Non‐magnetic Sudbury pyrrhotite was less reactive in terms of its oxygen uptake and showed the best collectorless flotation recovery. Magnetic Phoenix pyrrhotite was more reactive and showed poor collectorless flotation, which was significantly improved with the addition of xanthate and copper activation. These differences in reactivity and flotation performance are interpreted to be a result of the pyrrhotite mineralogy, the implications of which may aid in the manipulation of flotation performance.

La pyrrhotine sulfureuse non stoechiométrique (Fe_1?xS), commune à plusieurs minerais de nickel, se retrouve sous une variété de formes cristallographiques et de compositions. Afin de manipuler son rendement lors des opérations de traitement du nickel, soit afin de viser la récupération ou bien la rejection de la pyrrhotine, on a besoin de comprendre la minéralogie de la pyrrhotine, sa réactivité et leur effet sur le rendement de sa flottation. Dans cette étude, on a choisi une pyrrhotine non magnétique, Fe₉S₁₀, de Sudbury CCN au Canada et une pyrrhotine magnétique, Fe₇S₈, de Phoenix au Botswana, pour explorer la relation entre la minéralogie, la réactivité et la microflottation. La pyrrhotine non magnétique de Sudbury était moins réactive par rapport à son absorption d'oxygène et a montré la meilleure récupération par flottation sans collecteur. La pyrrhotine magnétique de Phoenix était plus réactive et a montré une mauvaise flottation sans collecteur, que l'on a améliorée significativement avec l'addition de xanthate et l'activation au cuivre. Ces différences de réactivité et de rendement de la flottation sont interprétées comme étant un résultat de la minéralogie de la pyrrhotine, dont les implications peuvent aider à manipuler le rendement de la flottation.     

Dynamic modelling of an industrial copper solvent extraction process

The dynamic behaviour of an industrial copper solvent extraction mixer–settler cascade is modelled to develop an advanced process control system. First, the process is introduced and the dynamical models are formulated. The testing environment is described and the successful results presented. Only industrially measured variables are required and plant-specific McCabe-Thiele diagrams are utilized to predict copper concentrations. The results with constant and adapted parameters are compared and the importance of parameter adaptation is discussed. Testing the simulator with adapted parameters over a period of 1 month of industrial operating data gave data that followed the real process measurements closely. In the future, the mechanistic models will be used for control system development and testing. The model can be used on all copper solvent extraction plants by modifying the flow configuration and adapting parameters.     

Recovery of cobalt, nickel, and copper from sea nodules by their extraction with alkylphosphines

The paper describes a process for the recovery of pure Co(II), Ni(II), and Cu(II) from a hydrochloric acid solution of polymetallic sea nodules. An overnight contact of the nodule powder with 4 M HCl almost quantitatively leaches these metal ions. From the leachate, Co(II) and Cu(II) were recovered by their extraction with Cyanex 923 and Ni(II) by extraction with Cyanex 301. Co(II) and Cu(II) are partitioned in the organic phase as H₂CoCl₄·2 Cyanex 923 and CuCl₂·2 Cyanex 923, whereas Ni(II) is extracted in the form of NiR₂ (HR=Cyanex 301). A solution of 0.001 M H₂SO₄ is used for the stripping of Co(II) and Cu(II) and 5% NH₄Cl in 75% NH₃ for Ni(II). Both extractants are found to be stable toward prolonged contact with HCl and show negligible loss in their extraction capacity even after recycling them for 20 cycles. The partition data have been utilized in developing conditions for the separation of Co(II), Ni(II), and Cu(II) mutually and from other metal ions, namely Ti(IV), Al(III), Fe(III), Mn(II), and Zn(II). The procedure of separation thus developed has been extended for the recovery of around 90% Co(II), Ni(II), and Cu(II) from sea nodules. The purity of the metal ions thus obtained is around 99%.     

钒钛磁铁矿深度直接还原熔分提铁

以热力学分析为基础,采用直接还原熔分工艺对国外某钒钛磁铁矿进行了研究.利用 Factsage 软件计算了不同添加剂配比下的渣相四元相图,并进行直接还原试验,研究了 SiO2和 CaO 加入量对还原反应的影响以及CaF2的加入量对铁品位和回收率的影响.结果表明：在还原温度1380℃,还原时间30 min,SiO2的质量分数为7.0％,CaO的质量分数为3.5％,CaF2的质量分数为1.4％,煤粉加入质量分数为17.4％的实验条件下,还原后金属相中铁品位在95.0％以上,铁回收率97.0％以上.     

浅析高冰镍氯气浸出制取镍电解初液

氯气浸出工艺是当前世界上先进的高镍锍精炼工艺之一,在镍的回收率、生产率、产品质量及工作环境等方面具有较突出的优势.氯化湿法冶金由于具有高反应速率、高浸出率、以及灵活的金属提取工艺组合等优点,成为一项重要的湿法冶金新技术,以往制备镍电解初液的工艺都采用硫酸常压选择性浸出-加压浸出工艺,这样的工艺具有浸出效率低、工艺设备复杂、流程长、作业强度高、生产成本高等缺点.为了解决这些不利的因素,现在学者都在探索氯化浸出工艺替代硫酸选择性浸出工艺.本文就氯气浸出生产镍电解初液的工艺原理、试验过程、试验结果及其优点进行了充分的阐述.     

Application of deep learning in iron ore sintering process:a review

In the wake of the era of big data,the techniques of deep learning have become an essential research direction in the machine learning field and are beginning to be applied in the steel industry.The sintering process is an extremely complex industrial scene.As the main process of the blast furnace ironmaking industry,it has great economic value and envi-ronmental protection significance for iron and steel enterprises.It is also one of the fields where deep learning is still in the exploration stage.In order to explore the application prospects of deep learning techniques in iron ore sintering,a comprehensive summary and conclusion of deep learning models for intelligent sintering were presented after reviewing the sintering process and deep learning models in a large number of research literatures.Firstly,the mechanisms and characteristics of parameters in sintering processes were introduced and analysed in detail,and then,the development of iron ore sintering simulation techniques was introduced.Secondly,deep learning techniques were introduced,including commonly used models of deep learning and their applications.Thirdly,the current status of applications of various types of deep learning models in sintering processes was elaborated in detail from the aspects of prediction,controlling,and optimisation of key parameters.Generally speaking,deep learning models that could be more effectively implemented in more situations of the sintering and even steel industry chain will promote the intelligent development of the metallurgical industry.     

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.     

硫酸铵焙烧红土镍矿工艺优化

本文采用硫酸铵焙烧-水浸工艺,将红土镍矿与硫酸铵混合焙烧,研究了焙烧温度、焙烧时间、物料配比和矿粉粒度对镍、镁、铝和铁提取率的影响.采用正交实验优化工艺条件,得到影响焙烧效果的各因素顺序为:物料配比、焙烧时间、焙烧温度、矿粉粒度.优化工艺条件为:焙烧温度450℃,焙烧时间120min,物料配比2∶1,矿粉粒度小于80μm,镍、镁和铝提取率大于98%,铁提取率大于94%.研究了焙烧过程镍、镁、铝和铁与硫酸铵反应过程的动力学.镍、镁、铝和铁的反应速率均符合未反应收缩核模型,表观活化能分别为19.93 k J·mol^-1、18.96 k J·mol^-1、17.86 k J·mol^-1和20.83 k J·mol^-1.     

Kinetics of leaching selenium from Ni-Mo ore smelter dust using sodium chlorate in a mixture of hydrochloric and sulfuric acids

The kinetics of leaching selenium from Ni-Mo ore smelter dust in H₂SO₄-HCl-H₂O system was investigated. The effects including leaching temperature and time, particle size of the smelting dust, stirring speed, acid concentration and the coefficient β (the molar ratio of sodium chlorate to selenium in the smelter dust) on leaching of selenium were studied. The results indicated that the leaching of selenium increased sharply with the increase of temperature. The leaching of selenium reached 98% at 95 °C and stirring speed of 350 rpm for 150 min with the particle size of − 0.15 mm, initial [H⁺] concentration of 8 mol/L, the solid/liquid ratio of 1:5 g/mL and the coefficient β of 3.33. The leaching process was controlled by the surface chemical reaction and the kinetics of leaching selenium from Ni-Mo ore smelter dust followed the model of “shrinking core”. The apparent activation energy of leaching selenium was determined to be 44.4 kJ/mol, which was consistent with the values of activation energy reported for the surface chemical reaction control. The kinetics equation of leaching selenium from Ni-Mo ore smelter dust was expressed as , which coincided with the experimental results.     

Numerical simulation of copper recovery from converter slags by the utilisation of spent potlining (SPL) from aluminium electrolytic cells

An innovative method was devised to improve copper recovery and operational efficiency of the Cu converter slag-cleaning furnace, by utilising both carbon and fluoride values of an otherwise environmental hazardous material (i.e. spent potlining (SPL)) produced from the aluminium industry. Results based on numerical modelling show that 90% Cu recovery could be achieved by adding as little as 3–4?wt-% of SPL to the molten converter slag. The fluorides and sodium-containing compounds in the SPL reduced the slag viscosity, resulting in a much faster settling rate of matte droplets. In this process, the SPL could be detoxified by destroying the cyanides to form harmless N₂ gas, and inertising the fluorides in a much diluted form in the ferro-silicate slag, ensuring a safe disposal to the environment.     

大型转炉煤气干,湿法净化与回收方案探讨

介绍了转炉烟气净化与煤气回收系统干，湿两法工流程。着重对２３０ｔ转炉干，湿法方案进行了技术经济比较，说蜉采用干法净化的优点。     

以焙烧—湿法工艺从含金废料中回收金

针对紫金矿业集团黄金冶炼厂产出的含金废粒,进行了焙烧－湿法回收金的工艺研究。含金废料经焙烧去除炭质和有机物后,经氰化浸出、炭吸附回收金,金回收率可达90％以上,该工艺成本低,易实施,可获得良好的经济效益。     

Recovery of nickel and cobalt from laterite leach solutions using direct solvent extraction: Part 1 — selection of a synergistic SX system

The separation of nickel and cobalt from impurities such as manganese, magnesium and calcium using solvent extraction with Versatic 10 was largely improved by the addition of a synergistic reagent LIX63 (an α-hydroxyoxime) or 4PC (a pyridine carboxylate ester). With the organic systems containing Versatic 10 alone, the separation factors of nickel and cobalt over manganese were 6 and 15 respectively. When 4PC was added to the system, these increased to 147 and 1870 respectively, and with LIX63, they were even higher at 534 and 7720 respectively. This indicates that the synergistic solvent extraction (SSX) system with Versatic 10 and LIX63 performed very well and better than that with Versatic 10 and 4PC.The SSX system consisting of 0.5 M Versatic 10, 0.45 M LIX63 and 1.0 M TBP in Shellsol D70 performed the best among the systems tested containing LIX63. After a single contact, the extraction of Ni and Co was 99.6% and 96.9%, respectively. Only 6 mg/L Mn, 8 mg/L Mg and 1 mg/L Ca were found in the loaded organic solution. The manganese scrub efficiency was 97.7% at pH 5.3, resulting in a scrubbed organic solution containing only 0.8 mg/L Mn. Over 99% nickel, cobalt and manganese were stripped at pH 2.0, indicating easy stripping of these metals.The SSX system consisting of 0.5 M Versatic 10 and 1.0 M 4PC in Shellsol D70 performed the best among the systems tested containing 4PC. After a single contact, the extraction of Ni and Co was 99.4% and 89.4%, respectively. Some 200 mg/L Mn, 10 mg/L Mg and 48 mg/L Ca were found in the loaded organic solution. The manganese could not be scrubbed at the tested pH range of 5.4-6.0. Very fast Ni and fast Co stripping kinetics were observed, however, the Mn stripping kinetics were very slow. After 2 min of stripping, only 1.22% Mn was stripped.It is concluded that the SSX system containing 0.5 M Versatic 10, 0.45 M LIX63 and 1.0 M TBP performed much better than the SSX system containing 0.5 M Versatic 10 and 1.0 M 4PC in terms of both manganese and calcium behaviour in extraction, scrubbing and stripping.     

应用控轧控冷工艺开发低碳贝氏体高强度钢板

设计了强度级别为６８５ＭＰａ的工程机械用低碳高强度焊接用钢，利用Ｇｌｅｅｂｌｅ热模拟实验机研究了实验钢奥氏体高温变形行为、应变诱发析出行为和连续冷却相变行为。在此基础上利用实验轧机研究了轧制和冷却工艺参数对实验钢力学性能和显微组织的影响。结果表明，实验钢通过适当的控制轧制和控制冷却可以得到以细小的贝氏体为主的显微组织，达到强度和韧性的良好匹配。