Synthesis of nickel ferrite precursors from low grade nickel matte

Fine nickel ferrite precursors NiFe2（C204）3·6H2O were obtained via co-precipitation method with low grade nickel matte as the raw material. Thermodynamic analysis of NiClz-FeC12-（NH4）2C204-H20 system for precipitation identified that the theoretical optimum co-precipitation pH value is 2, and C2O2 has strong complexation with Ni2＋ and Fe2＋ ions. Based on these theoretical considerations, the effects of parameters on the precipitation rates and precursors size were investigated systematically. The results show that the optimum co-precipitation conditions are pH=2, temperature 45 ℃, 1.2 times theoretical amount of （NH4）2C204 dosage and 3% PEG400 addition. Under these conditions, the precipitation rates of Ni2＋ and Fe2＋ are both over 99.8%, with the precursors size of 1-2 urn. Furthermore, X-ray diffraction （XRD） and thermogravimetry-differential thermal analysis （TG-DTA） demonstrate that the precursors are single-phase solid solution, wherein the nickel/iron atoms are replaced by the iron/nickel atoms reciprocally.

Extraction of valuable metals from low nickel matte by calcified roasting-acid leaching process

A calcified roasting-acid leaching process was developed as a highly effective method for the extraction of valuable metals from low nickel matte in the presence of CaO additive. The influences of process parameters on the metal extraction were studied, including the roasting temperature, roasting time, addition of CaO, H2SO4 concentration and liquid-solid ratio. Under the optimum condition, 94.2% of Ni, 98.1% of Cu, 92.2% of Co and 89.3% of Fe were recovered. Additionally, 99.6% of Fe was removed from the leachate as goethite by a subsequent goethite iron precipitation process. The behavior and mechanism of CaO additive in the roasting process was clarified. The role of CaO is to prevent the formation of nonferrous metal ferrite phases by a preferential reaction with Fe2O3 during the roasting process. The metal oxides(Cu O and NixCu1-xO) remained stable during high-temperature roasting and were subsequently efficiently leached using a sulfuric acid solution.

Efficient and selective recovery of Ni, Cu, and Co from low-nickel matte via a hydrometallurgical process

Low-nickel matte was intensively characterized, and Ni, Cu, and Co were determined to exist mainly as (Fe,Ni)9S8and FeNi3, Cu5FeS4, and (Fe,Ni)9S8and Fe3O4(in isomorphic form), respectively. The efficient and selective extraction of Ni, Cu, and Co from the low-nickel matte in an (NH4)2S2O8/NH3·H2O solution system was studied. The effects of (NH4)2S2O8and NH3·H2O concentrations, leaching time, and leaching temperature on the metal extraction efficiency were systematically investigated. During the oxidative ammonia leaching process, the metal extraction efficiencies of Ni 81.07%, Cu 93.81%, and Co 71.74% were obtained under the optimal conditions. The relatively low leaching efficiency of Ni was mainly ascribed to NiFe alloy deactivation in ammonia solution. By introducing an acid pre-leaching process into the oxidative ammonia leaching process, we achieved the high extraction efficiencies of 98.03%, 99.13%, and 85.60% for the valuable metals Ni, Cu, and Co, respectively, from the low-nickel matte. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

ANINTELLIGENT DECISION SUPPORTSYSTEM（IDSS） ONTHEPROCESSOFNICKELMATTESMELTER

This paper describes the structure and function of the intelligent decision support system (IDSS) on the process of nickel matte smelter. The knowledge and model base system based on fuzzy-decision rules ale specially suggested. The IDSS possesses the self-learning and adaptive properties, andhas been used for managing and analyzing the production information, optimizing the composition of the charge mixture, and deciding the optimal operational conditions. Electric energy consumption has been reduced remarkably and the yield of nickel has been increased.

FUZZY ADAPTIVE CONTROL MODEL FOR PROCESS IN NICKEL MATTE SMELTING FURNACE

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Experiment Research on the Enrichment of Precious Metals from Nickel-copper-iron Matte

According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals at home and abroad, this paper put forward the process route of enrichment of precious metals and selectively leaching of base metals from the nickel-copper-iron matte by sulfuric acid and sodium hypochlorite. The effects of particle size, leaching temperature, leaching time, amount of sulfuric acid and sodium hypochlorite on the leaching rate of nickel, cobalt, copper and iron are mainly discussed. The results show that raw material particle size has significantly effects on the leaching rate of base metals, high leaching rate of base metals and enrichment of precious metals are obtained with the suitable particle size. Through the experiments, the reasonable experiment parameters and conditions were determined as fellows: particle size of-200 to +250 mesh, leaching temperature 95℃ , leaching time 5 h, sulfuric acid concentration 30%, adding amount of sodium hypochlorite 3 times of matte weight. Under these experiment parameters and conditions, the leaching rate of nickel, cobalt, copper and iron were 97.39%, 96.24%, 98.30% and 99.01%, respectively. The content of nickel, cobalt, copper, iron in the leaching residues was 8.15%, 0.23%, 1.40% and 0.24%, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching residues was 247 g/t, 521 g/t, 112 g/t, 494 g/t and 24 g/t, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching solution was <0.0005 g/L, 0.0023 g/L, 0.0007 g/L, <0.0005 g/L and 0.00017 g/L, respectively. This process has advantages as follows: a small investment, simple technology, high enrichment efficiency.

Electrolysis of Converter Matte in Molten CaCl₂-NaCl

The electrolytic production of nickel-copper alloy by electrochemical reduction of converter matte in molten salt has been investigated. The sintered solid porous pellets of Ni3S2, Cu2S and converter matte were electrolyzed at a voltage of 3.0 V in molten CaCl2-NaCl under the protection of argon gas at 700℃, respectively. The electro-reduction processes were investigated and the products were characterized. The results show that the molten salt electro-reduction process can be used to produce nickel, copper and nickel-copper alloy directly from Ni3S2, Cu2S and converter matte precursors in molten CaCl2-NaCl, respectively. CaS would be formed as the intermediate compound during the electro-reduction process, and then the formed CaS can be gradually decomposed and removed with the increase of the electrolysis time. The experimental results show that the molten salt electro-reduction process has the potential to be used for the reduction of sulfide minerals in molten CaCl2-NaCl.

高冰镍浸出渣还原浸出工艺研究

以湿法冶炼高冰镍过程中产生的高冰镍浸出渣为研究对象,采用二氧化硫对高冰镍渣加压还原浸出,考察了初始硫酸浓度、液固比、通气方式、浸出温度和浸出时间对高冰镍渣还原浸出过程铜、铁行为的影响;对还原浸出液采用置换沉淀和冷冻结晶的方法,对还原浸出中铜和铁进行分离回收。结果表明:在初始硫酸浓度100 g/L、液固比6 mL/g、反应时间3 h、反应温度90℃、二氧化硫分压0.15 MPa的条件下,铁和铜的浸出率分别为99.35%、77.46%,浸出液中铁几乎全部为亚铁离子;在硫酸含量20~30 g/L、温度70℃、铁粉加入量5.7 g/L、反应时间40 min的条件下,对还原浸出液进行置换沉铜,沉铜率达到了99.70%,渣含铜为67.91%。在温度—10℃、保温时间20~30 min、初始硫酸浓度100 g/L的条件下,对沉铜后液进行冷冻结晶制备硫酸亚铁,铁沉淀率达到了72.6%,七水硫酸亚铁纯度达到了92.93%。

缓冷条件对高镍锍铜镍浮选分离的影响

由于金川镍原料成分的变化,造成高镍锍含铜升高,打破了磨浮系统的平衡状态,导致铜精矿和镍精矿金属互含较高。浮选产品的质量优劣取决于镍矿物和铜矿物晶体的大小和镶嵌关系,而晶体的大小和镶嵌关系又受保温缓冷条件的影响,因此,有必要探究保温缓冷条件对高镍锍浮选行为的影响规律。试验研究表明,在高镍锍物相结晶的温度区间内,适当延长缓冷时间,可改善辉铜矿和锍镍矿的浮选分离效果。在适宜的缓冷控温条件下,1次浮选可获得Cu品位53.9%、Cu回收率86.1%的铜精矿,Ni品位66.2%、Ni回收率81.5%的镍精矿,与原样品浮选相比,指标得到显著改善。机理研究表明,控温缓冷后的样品中辉铜矿晶粒尺寸和磨矿单体解离度增大是取得较好浮选效果的根本原因。

保温缓冷条件对金川集团镍冶炼厂高镍锍结晶性能的影响

高镍锍在分选过程中存在铜镍矿物结晶粒度小,金属互含高等难题。金川集团镍冶炼厂为了改善铜、镍分选效果,提高产品质量,开展了高镍锍保温缓冷试验,并通过TG-DSC测试、粒径统计、MLA以及SEM检测,分析了缓冷条件对高镍锍结晶性能的影响。研究结果表明,辉铜矿的生长情况影响高镍锍中辉铜矿和锍镍矿互含情况,在最佳缓冷条下可得到晶粒粒度+74μm占比98%以上的辉铜矿晶体;SEM检测表明,最佳缓冷样品中辉铜矿区域Ni含量0.3%,硫镍矿Cu含量2.6%;MLA检测表明,最佳缓冷条件下,样品中辉铜矿和锍镍矿的单体解离度分别为93.97%和86.58%,与现场样品相比,控温缓冷后样品的性能得到了显著改善。

多金属硫基镍资源加压浸出

多金属硫基镍资源富含镍、钴、铜,以及金、银、铂、钯等贵金属,其综合回收价值显著。加压浸出技术能有效促进这些金属离子溶解于溶液中,为后续的分离提纯创造条件,对镍冶金领域具有重大应用价值。深入研究多金属硫基镍资源加压浸出的冶金机理及多金属迁移路径,对于提升金属回收率、优化物料平衡及促进技术革新至关重要。依托赞比亚某硫化镍精矿、云南某高镍锍及新疆某硫基镍渣的加压浸出的工业实例,剖析了在加压浸出过程中镍、钴、铜、铁,以及金、银、铂、钯等贵金属的溶出特性和反应原理,探讨了基于加压浸出的多组份分离提取工艺方案,旨在为加压浸出工艺的设计优化提供数据支持与理论指导,推动多金属硫基镍资源高效、清洁、可持续综合利用。

Enhancement of the nickel converter slag-cleaning operation with the addition of spent potlining

The slag cleaning(or matte settling) process was experimentally investigated at 1573 K using a fayalitic nickel converter slag containing spinel and matte/alloy particles.The addition of various amounts of spent potlining(SPL) was studied in terms of its influence on matte settling and the overall metal recoveries.The slags produced were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and wet chemical analysis using inductively coupled plasma optical emission spectrometry.The presence of solid spinel particles in the molten slag hindered coalescence and settling of matte/alloy droplets.Matte settling was effectively promoted with the addition of as little as 2 wt% SPL because of the reduction of spinel by the carbonaceous component of the SPL.The reduced viscosity of the molten slag in the presence of SPL also contributed to the accelerated matte settling.Greater metal recoveries were achieved with larger amounts of added SPL.Fast reduction of the molten slag at 1573 K promoted the formation of highly dispersed metal particles/clusters via accelerated nucleation in the molten slag,which increased the overall slag viscosity.This increase in viscosity,when combined with rapid gas evolution from accelerated reduction reactions,led to slag foaming.

红土镍矿侧吹还原造锍熔炼试验研究

基于新能源汽车的快速发展以及三元动力电池的高镍化发展对镍原料需求旺盛的大背景,提出红土镍矿侧吹造锍熔炼生产低镍锍工艺的研究。本文对石膏的热分解行为进行了系统的热力学研究,分析碳硫比、反应温度对CaS转化率的影响,进行石膏选择性还原硫化红土镍矿基础试验,并在此基础上进行富氧侧吹硫化红土镍矿扩大试验,总结石膏选择性还原硫化红土镍矿和富氧侧吹硫化红土镍矿的反应机制。结果表明,脱硫石膏短流程直接还原硫化红土镍矿生产低镍锍工艺可行,该工艺采用工业固废脱硫石膏作为硫化剂,可全组分利用石膏渣中的Ca、S元素,达到“固废绿色循环、资源化利用”的目的,且镍回收率大于90%,钴回收率在87%以上,硫利用率大于75%,铁回收率低于60%,可满足红土镍矿镍、钴、铁的选择性还原硫化富集回收目的。

富氧侧吹熔池熔炼生产金属化镍阳极工艺研究

反射炉熔炼二次镍精矿生产镍阳极板工艺,存在燃料的热利用率低、燃料消耗量大,炉体耐火材料使用寿命短、阳极板脆弱易碎、残极率高,熔炼运行成本高、现场操作环境恶劣等问题。本文通过对富氧侧吹熔池熔炼二次镍精矿生产金属化镍阳极板的工艺研究,得到金属化镍锍产品(Ni+Cu≥76%,Fe<3%,S 16%~20%),最佳工艺参数为:在反应温度为1450~1600℃,富氧浓度65%~75%,连续进料速率为100 kg/h条件下,氧料比10~45 Nm^(3)/t,还原剂率为0.5%~1%。随着氧料比增加,镍锍的品位逐渐增加,且铁、硫含量逐渐降低,相应的熔渣含镍逐渐升高。富氧侧吹熔池熔炼生产金属化镍阳极板具备工艺可行性,实现二次镍精矿短流程的“熔化、除铁、降硫”的目的,可产出合格的金属化镍阳极板,明显提高镍阳极板成材率,大幅提高热利用率、提高生产效率和产能,并降低了生产成本。

四川某低品位难选铜镍硫化矿石选矿试验研究

四川某低品位难选铜镍硫化矿石含铜0.22%、镍0.47%,矿石中含铜、镍矿物工艺粒度细微,铜镍极难实现有效分离,故采取直接浮选方法获得铜镍混合精矿,并详细考察了磨矿细度、抑制剂、调整剂等影响因素。结果表明:在磨矿细度-74μm占70%,经一次粗选、两次扫选、三次精选浮选工艺流程,可获得产率5.88%、铜品位3.31%、镍品位5.92%、铜回收率86.60%、镍回收率73.84%的铜镍混合精矿,选矿试验指标较好。

低冰镍衍生的具有高结构稳定性和快速扩散动力学的钠离子掺杂层状LiNi1/3Co1/3Mn1/3O2正极

通过共沉淀法合成钠离子(Na^(+))掺杂的高稳定性Li_(1−x)NaxNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NCM-Na)正极材料。首先论证采用低冰镍提取镍作为合成材料镍源的可行性。其次,在化学试剂合成的NCM(Ni,Co,Mn)材料中预先引入最优含量的Na^(+),占据部分Li^(+)位点,实现具有更低Li^(+)/Ni^(2+)阳离子混排的稳定结构,从而提高其电化学性能。结果表明,当Na+掺杂量为1%(质量分数)(x=0.01)时,获得的NCM-Na正极材料在1C电流密度下,循环100次后容量保持率从76.84%提高至89.21%。特别是在5C大电流密度下,循环200次后,可逆放电比容量依然维持在110 mA·h·g^(-1)。这为杂原子掺杂耦合材料化冶金开发低成本、高性能锂离子电池三元LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)正极材料提供具有前景的策略。

Nickel leaching from low-grade nickel matte using aqueous ferric chloride solution

Nickel leaching from low-grade nickel matte(LGNM) using aqueous ferric chloride solution was studied.The influence of factors such as leaching temperature and concentration of ferric chloride on the nickel leaching ratio was investigated.The results show that increasing leaching temperature and concentration of ferric chloride increases the nickel leaching ratio.The overall nickel leaching process follows the unreacted shrinking core model,and the surface chemical reaction is the rate-controlling step.The activation energy and the reaction order of the nickel leaching process,controlled by the surface chemical reaction,were calculated to be 52.96 kJ mol^(-1)and 0.5,respectively.Therefore,the kinetics equation for the nickel leaching was found to be 1-(1-α)^(1/3)=7.18×10~4C^(0.5)exp[-52,960/(RT)]t.

镍锍试金-微波消解法联合测定汽车三元催化剂中铑

目前测定汽车尾气净化催化剂中铑含量采用国家标准中分光光度法,该方法分析时间长,试剂消耗大。本文采用试样经合适的镍锍试金法配料,铸模冷却后,锤镍扣并称重,然后将镍扣放入微波消解罐中,加入氢氟酸、王水经微波消解,再以电感耦合等离子体原子发射光谱仪测定铑含量,并对仪器参数及被测元素谱线的选择进行了讨论,通过条件试验确定溶样时间、镍扣质量以及对渣中铑含量进行补正。对试料中待测元素进行多次测定,对方法的检出限、精密度及加标回收率等进行了考察,方法相对标准偏差小于2%,回收率为98%~100%。该方法使用合适的样品前处理方法和仪器分析条件,实现了高效、快速、准确的测定汽车三元催化剂中铑。

低品位铜镍电镀污泥还原硫化熔炼低冰镍

通过热力学分析,揭示了铜镍电镀污泥还原硫化熔炼低冰镍过程中主要金属的物相演变规律,分析了还原硫化熔炼过程的主要影响因素。经热力学理论计算可知,电镀污泥铜和镍品位分别为6%和4%时,采用硫石膏作为硫化剂,硫实际用量为理论用量的2.0倍,熔炼气氛P(CO)/[P(CO)+P(CO_(2))]=50%,预期产出低冰镍的品位(Cu+Ni)为57.2%,渣中铜和镍品位均低于0.2%,铜和镍直收率分别可达99.89%和96.59%,固硫率77.20%。铜镍污泥高温硫化熔炼低冰镍工业应用结果表明,与常规湿法回收工艺相比,该工艺金属回收率更高,过程绿色低碳,具有显著的技术优势。

利用NH_(4)Cl焙烧-水浸工艺从低冰镍中提取金属并合成(Ni,Cu,Co)Fe_(2)O_(4)光催化剂

针对低冰Ni火法冶炼过程能耗高、Co损失大的问题,本文提出了NH_(4)Cl焙烧-水浸联合提取金属,再分离利用金属的工艺。通过正交试验,研究了NH_(4)Cl焙烧过程中不同因素对金属提取的影响,并确定了优化的工艺条件。结果表明,焙烧温度和NH_(4)Cl用量为主要的影响因素,最佳氯化条件为:低冰镍粒径<75μm,焙烧温度500℃,焙烧时间2.5 h,NH_(4)Cl用量250%,O_(2)流速20 mL/min。通过研究温度和时间对金属浸出的影响,确定了适宜的浸出条件为:温度90℃,时间2 h,这时Ni、Cu、Co和Fe的浸出率分别达到97.6%、96.2%、94.5%和29.2%。以浸出液为原料,以α-Fe_(2)O_(3)为载体与其他金属复合,合成了(Ni,Cu,Co)Fe_(2)O_(4)光催化剂。最佳制备条件确定为:沉淀温度25℃,Ni-Cu-Co与Fe的摩尔比1:3。制备的催化剂为40~60 nm的球形纳米颗粒,在120 min内对亚甲基蓝溶液的降解率可达99.8%。