Determination of the relative leaching kinetics of Cu, Rh, Ru and Ir during the sulphuric acid pressure leaching of leach residue derived from Ni-Cu converter matte enriched in platinum group metals

Hydrometallurgical process routes are typically used for separation of platinum group metals (PGMs) from base metals in Ni-Cu converter matte. Nickel dissolution is primarily achieved in the first stage leach (high pressure or atmospheric leaching, or a combination of the two), which is followed by second stage high pressure sulphuric acid/oxygen leaching to dissolve copper and the remaining nickel. PGMs are recovered from the leaching residue, and their dissolution must hence be limited. The leaching of base metals in the first stage has been characterised, but there is a limited understanding of the behaviour of metals, and more specifically PGMs, in the second stage pressure leach. This research presents the results of laboratory work performed to investigate the kinetics of leaching in the second stage pressure leach. The influence of key operating parameters such as the temperature, pressure, and initial acid concentration on PGM dissolution was investigated.     

Selective leaching of penalty elements from copper concentrates: A review

Custom copper smelters impose substantial financial penalties for the presence of deleterious impurity elements in copper concentrates and can outright reject concentrates which contain impurity elements in concentrations that exceed specified values. Hence, there is strong motivation to remove penalised impurity elements from copper concentrates at the mine site before shipping to custom smelters. A number of leach systems have been developed for the selective extraction of penalty elements from copper concentrates, including: alkaline sulphide leaching (ASL); hypochlorite leaching; dilute sulphuric acid leaching with aluminium sulphate; and combined pressure oxidation (POX) leaching with copper precipitation leaching. This paper reviews these four systems with emphasis on the leaching behaviour of penalty elements. ASL has previously been employed in industry for the selective extraction of As and Sb from tetrahedrite-rich copper concentrates. Sodium sulphide solution leaches As, Sb, and Hg from a large range of minerals, however, does not leach arsenopyrite, a mineral which often contains a significant portion of the total As in copper concentrates. Hypochlorite leaching extracts As associated with enargite minerals. This leach system benefits from superior rates of As extraction when compared with ASL, and for this reason, has gained recent interest within the research community. Two major issues have been identified with hypochlorite leaching of copper concentrates. These are poor reagent selectivity towards As-bearing minerals and high levels of hypochlorite consumption. Unless these two issues are resolved it is unlikely that hypochlorite leaching will be employed in commercial processes. Dilute sulphuric acid leaching with aluminium sulphate is used to extract F associated with fluorite. This leach system also extracts F associated with apatite and chlorite. Laboratory-scale experiments and extensive operating experience have indicated that fluorite can be substantially leached from copper concentrates without addition of aluminium sulphate provided that the concentration of sulphuric acid in the leach solution is sufficiently high (at least 40 g L⁻¹). POX/copper precipitation leach systems have potential to extract a large number of penalty elements from copper sulphide concentrates while simultaneously upgrading the concentration of copper in the concentrate. Two patented POX/copper precipitation leach processes have been specifically developed for the deportment of penalty elements. These two processes are reviewed in detail.     

我国镍冶金的发展与工艺技术进步

我国的镍冶金生产近３０年来取得了巨大的发展，工艺技术的进步尤为突出。本文重点论述了我国镍冶金现有的电炉、闪速炉熔炼低冰镍－转炉吹炼高冰镍－铜镍磨浮分离－硫化镍阳极电解；高冰镍两段逆流硫酸选择性浸出－黑镍沉钴－电积；二次镍精矿制粒－沸腾焙烧生产氧化镍等工艺流程。同时，介绍了我国自行研究开发的高冰镍氯化精炼；焙烧－氨浸－氢还原；镍精矿微波脱硫－热等离子体熔炼高冰镍；大洋多金属结核常压氨浸和硫酸选择性浸出回收镍等有价金属的新工艺新技术。     

从铅冰铜中高效选择性提取铜的工艺研究

采用高温高压纯氧氧化法选择性提取铅冰铜中铜, 研究了硫酸用量、浸出温度、反应时间、液固比、氧气压力、搅拌速度以及分散剂木质素用量对铜浸出率的影响及对浸出液中铁含量的影响。铅冰铜经氧压浸出后进行液固分离, 铅冰铜中的铜进入液相中, 绝大部分铁以赤铁矿的形式与铅、银、金等有价金属一起进入渣相中; 浸出后的硫酸铜溶液经调酸后直接进行旋流电解可得到合格的阴极铜产品, 浸出渣返回铅冶炼系统综合回收铅、银、金等有价元素。高温氧压浸出铅冰铜, 铜浸出率可达93.5%, 阴极铜产品质量达到99.975%, 有效实现了铅冰铜中铜的选择性提取。     

低冰镍加压酸浸工艺研究

本文研究了低冰镍湿法冶炼工艺流程,详细进行了低冰镍加压酸浸-萃取脱铜-中和除铁-中和沉镍的工艺研究。在优化试验条件下,加压浸出镍、铜的浸出率分别为91.56%,99.08%。浸出液经萃取脱铜-中和除铁-中和沉镍工艺使有价金属分别得到回收富集。     

铅冰铜氧压浸出铜锌试验研究

为有效回收铅冰铜和烟灰中的铜铅锌资源,采用浮选试验和硫酸氧压浸出方法,探讨了回收铜、锌的可行性。研究表明:浮选分离铅冰铜中铜铅较为困难,而铅冰铜单独氧压浸出和铅冰铜与烟灰混合浸出均能取得较好的铜锌浸出效果,且混合处理指标更优。适宜条件下,铅冰铜单独浸出时,铜、锌浸出率达到88.25%和95.46%;铅冰铜与烟灰混合浸出时,铜、锌浸出率达到94.40%和99.65%。浸出液多次循环浸出,铜锌浸出率都能维持在83%以上,浸出液循环后溶液中铜锌浓度能满足后续工序要求。     

Extraction of copper, nickel and cobalt from the leach liquor of manganese-bearing sea nodules using LIX 984N and ACORGA M5640

This paper describes a method, using sulfuric acid and activated charcoal for leaching Polymetallic sea nodules. Resulting leach solutions were examined for the extraction of copper, nickel and cobalt using LIX 984N and ACORGA M5640 in kerosene. After the removal of manganese and iron impurities from the leach liquor, copper and nickel were co-extracted leaving cobalt in the raffinate. The selective stripping of nickel and copper produces solutions rich in these metals, while regenerating the solvent for reuse.     

新型还原剂与海洋锰结核还原浸出的研究

采用一种还原剂BR与锰结核发生反应, 再用硫酸浸取有价金属离子。研究了锰结核与还原剂之配料比、还原剂的细度对还原效果的影响, 考察了还原过程中温度和物相的变化;并探讨出合适的浸出液pH 值, 浸取温度, 浸取时间等浸取条件。结果表明锰结核与还原剂配料比为4∶1 , 还原剂的细度为-0.125 mm, 浸出液pH 值为2.2 , 无外热浸出35 min, 锰、铜、钴、镍的浸出率分别达到98.20%、99.88%、99 .91%、99 .95%、铁的浸出率为18.23%。     

镍精矿氯化精炼过程的热力学分析

以金川公司高冰镍缓冷磨浮所产的镍精矿成分为基础,计算了25℃、100℃和125℃镍精矿中镍矿物、铜矿物、铁和钴矿物氯化反应的标准自由能变化,镍矿物浸出的平衡电位低于铜矿物．计算了用金川公司一次会金交换沉铜过程各化学反应的标准自由能变化和部分反应的平衡电位,推导出沉铜经液铜浓度与控制电位之间的关系式,并作图．溶液中氯离子浓度对交换沉铜过程影响不明显,合金交换沉铜,可以深度脱除浸出液中的铜,满足净化和电积的要求．     

Complex treatment of mining and metallurgical wastes for recovery of base metals

A complex process for the recovery of copper and zinc from mining and metallurgical wastes has been investigated and proposed. It includes sulfuric acid leaching of old pyrite flotation tailings to produce ferric containing leach solution; followed by ferric leaching of copper converter slag flotation tailings with the leach solution. A sample of old pyrite flotation tailings from the concentrator containing 0.36% of copper and 0.23% of zinc was leached with 10% sulfuric acid in the column. Recovery of copper and zinc reached 47.1% and 47.2%, respectively. The pregnant leach solutions contained 15.9 g/L of ferric iron. The subsequent ferric leaching of copper converter slag flotation tailings containing 0.53% copper and 2.77% zinc with the pregnant leach solution was conducted. The effects of various process parameters on the leaching dynamics of metals under batch conditions were investigated. Under the best conditions (temperature 70 °C, pulp density 30%, ferric iron concentration 15.9 g/L, initial pH of the pulp 0) the recovery of copper and zinc reached 79.6% and 43.7%, respectively. It was concluded that acid leaching of base metals from old pyrite flotation tailings with pregnant leach solution for the ferric leaching of copper converter slag flotation tailings is a prospective and promising technique for the complex treatment of mining and metallurgical wastes.     

Comprehensive processing of low grade sulphidic molybdenum ores

Low-grade sulphidic molybdenum ores were treated by using a combined processing route for a comprehensive recovery of molybdenum, copper, and other minor elements. As the first step, oxidation roasting was used to convert most of sulphides into metal oxides, during which 85–90% of sulphur was removed. Then both water and dilute sulphuric acid leaching of the roast were tested, in order to remove silica, iron and other impurities from the roast. Both copper and molybdenum were recovered one after another from the filtrates via cementation by iron powder under controlled temperature and pH conditions. Recovery for both elements was in all cases over 99%. Reasonable separation efficiency for copper and molybdenum was achieved from the water leach solutions. The leached cakes were dissolved in ammonia to recover the molybdenum by crystallisation as ammonium-dimolybdate. The proposed roasting, leaching and separation steps give a feasible alternative for a comprehensive processing of low grade molybdenum ores.     

水淬焙烧渣中金铂钯的氯化浸出

为了回收水淬焙烧渣中的贵金属,本文提出了氯酸钠溶液、硫酸和氯化钠混合溶液从冰铜水淬渣中浸出金、铂、钯的方法,并对不同的影响因素进行了优化。 系统研究了固液比、硫酸浓度、氯化钠浓度、氯酸钠浓度、温度、粒度和浸出时间等主要参数, 结果表明铂浸出的动力学限制条件为,浸出液中氯离子浓度,而金钯动力学浸出限制条件为浸出液的氧化性。在氯酸钠自身歧化反应限制下,无法兼顾较高的氧化性以及较高的氯酸钠浓度,所以利用氯酸钠一次性浸出金铂钯难度较大。酸钠溶液,硫酸,氯化钠混合浸出冰铜水淬渣中金铂钯的优化的工艺参数为硫酸浓度为0.5M,氯化钠浓度为10%,在初始ORP值为1062(mv),在上述条件下金铂钯的浸出率分别为100%,78.56%,100%。     

关于阜康铜渣冶炼工艺的研究和选择

我国独立开发的镍精炼新工艺已在新疆实际应用。经阜康冶炼厂选择性浸出提取后,金属化高冰镍原料中大量铜及贵金属进入了铜渣。在完成了阜康铜渣吹炼粗铜的试验研究任务之后,北京矿冶研究总院又制订了铜渣"焙烧—浸出—电解"方案,并进行了验证试验。证实了该工艺具有铜回收率高、浸出液较为纯净可直接电解、镍能综合回收、浸出渣率低和贵金属富集比高等特点。结合公司和阜康实际,最终推荐了焙烧、浸出方案。该方案已被新疆有关部门采纳,于1999年建成了国内能力最大的采用溶液电积工艺生产电解铜的车间(5000t电解铜/a),投产后经济效益显著。     

某高砷银铜精矿的利用研究

根据某高砷银铜精矿的物质组成 ,分析了对该精矿利用的技术方案 ,简述了对这一精矿进行的低温焙烧、化学除砷、氨浸萃取提铜和氨浸渣浸银等试验研究以及取得的技术指标     

高铜铅冰铜氧压浸出

为回收含铜44.7%的高铜铅冰铜中的有价金属, 进行了氧压酸浸实验研究。考察了初始硫酸浓度、氧压、时间、温度、液固比和木质素用量对浸出效果的影响, 结果表明, 氧压酸浸高铜铅冰铜的适宜工艺条件为: 浸出温度140 ℃、氧分压0.5 MPa、浸出时间4 h、液固比7∶1、初始硫酸浓度180 g/L, 该条件下Cu、As、Fe、Sb、Pb浸出率分别为99.57%、12.24%、86.33%、85.73%、38.10%, 实现了铜的高效浸出。浸出渣主要成分为PbSO₄, 实现了铅冰铜中铜与铅的分离。木质素用量对铅冰铜中有价金属的浸出效果影响较小。     

Dissolution behaviour of a Turkish lateritic nickel ore

The atmospheric pressure sulphuric acid leaching characteristics of Adatepe (Eski?ehir, Turkey) laterite ore that has recently been put into operation was investigated. The effects of sulphuric acid concentration (5-95%), temperature (20-95 °C) and time (30-240 min) on leaching were determined by nickel, iron and arsenic analyses. The amounts of Ni, Fe and As in solution were observed to increase with increase of temperature from 20 °C to 70 °C for sulphuric acid concentrations between 5% and 95%. Further increase of temperature to 95 °C showed that the dissolution of Ni, Fe and As were increased until 60% sulphuric acid concentration and over 60% a decrease in the dissolution percentages was observed due to the probable formation of nickel and silicon containing ferric sulphate type compounds that cause nickel loss from the leach solution. Experimental results showed that maximum nickel dissolution of 99.2% at 95 °C could be reached in 120 min of leaching time for a sulphuric acid concentration of 60%. The congruency of Ni dissolution with respect to Fe was found to be congruent over about 25% Ni and 15% Fe dissolution values. XRD analyses on the residues obtained after leaching showed that it was not required to dissolve all goethite phase to reach maximum dissolution of nickel contained in the sample. An activation energy of 30.36 kJ/mole was determined for Ni dissolution showing that leaching is controlled by external diffusion and chemical reactions.     

硫化镍加压浸出研究进展与应用

硫化镍是镍冶炼的重要原料,加压浸出技术在硫化镍冶炼中占有重要地位。本文对硫化镍加压浸出研究及应用进行了简单的介绍。根据反应体系的不同,镍加压浸出分为酸性加压浸出和氨性加压浸出两大类,工业生产中氨性加压浸出应用较少,以酸性加压浸出为主。硫化镍加压浸出处理原料灵活多样,主要包括硫化镍精矿、镍锍、镍钴硫化物等。另外,其在镍冶炼渣、低品位复杂物料处理方面也有一定的研究应用。加压浸出工艺灵活,综合回收率高,可同时生产镍、钴、铜、铂族金属等多种产品,主产品即可为硫酸镍,也可为电镍或镍粉,产品质量高,环境污染小,具有一定的市场竞争力。     

Use of lignosulfonate for elemental sulfur biooxidation and copper leaching

The surface-active properties of lignosulfonate, a solid by-product from the sulfite papermaking industry, were investigated in several aspects of a proposed Barrick copper heap leaching process where sulfur is added to the heap to be oxidized in-situ to produce acid. In this copper heap leaching process, lignosulfonate could affect sulfur milling, sulfur biooxidation, acid consumption, copper recovery, and solvent extraction of the copper pregnant leach solution.In milling, lignosulfonate was shown to reduce the measured Bond work index of sulfur in a batch mill, but not in a continuous mill. In biooxidation, lignosulfonate increased the growth rate of sulfur-oxidizing microorganisms, but the faster rate was not sustained during the whole biooxidation period. Lignosulfonate accelerated the kinetics of sulfur biooxidation in certain leach environments. In copper leaching, lignosulfonate did not have negative effects on copper recovery, acid consumption, or leach kinetics, but neither did it improve the kinetics of copper recovery. In solvent extraction, the separation of the organic and aqueous phases was rapid and clean if lignosulfonate was previously in contact with the copper ore or the sulfur particles. Based on these various outcomes, lignosulfonate did not have a negative impact on the copper heap leaching process tested, but does not constitute an essential additive to the process.     

从铋渣中回收铜铋实验研究

采用硫酸和盐酸两段浸出, 使铋渣中的铜和铋与其他有价金属分离, 再经旋流电解提取浸出液中的铜和铋, 从而回收铋渣中的铜和铋。实验结果表明, 硫酸浸出铜工序中, 在硫酸用量为理论量的3倍、双氧水用量为原料的40%、液固比5∶1、浸出温度70～80 ℃、浸出时间2 h条件下, 铜浸出率达91%; 浸铜后的渣用盐酸浸出铋, 在盐酸用量为理论量的2～3倍、液固比5∶1、浸出温度70～80 ℃、浸出时间2 h条件下, 铋浸出率达98%。对含铜浸出液和含铋浸出液进行旋流电解, 得到含铜99.95%的阴极铜及含铋96.78%的粗铋, 且铜回收率达99.0%, 铋回收率达98.0%。     

高镁低品位铜镍矿氧压硫酸浸出液综合回收研究

针对高镁低品位铜镍矿氧压硫酸浸出液特点,提出“Lix984萃取提铜-MgO中和黄钠铁矾法沉淀除铁-MgO中和沉镍”综合回收工艺。结果表明,采用Lix984可选择性萃取99.79%的铜,其他金属离子基本不萃取,经模拟工业贫铜电解液反萃,铜反萃率达98.13%,得到富铜电解液,可电积制备金属铜; 萃铜余液通过MgO中和黄钠铁矾法沉淀除铁,铁沉淀率达99.20%,镍损失率仅0.60%; 沉铁后液通过MgO中和沉淀回收镍,镍沉淀率为99.91%,并得到镍含量24.13%的氢氧化镍粗产品; 沉镍后的高浓度硫酸镁沉淀后液,可用于回收镁。