Arsenic in Gold Processing

Abstract

The processing of gold bearing sulphide minerals which contain arsenopyrite and other complex arsenic sulphide minerals results in arsenic containing emissions and effluents which must be given careful consideration in relation to clean air and clean water standards. The sources of arsenic and the various process options for treating arsenical gold ores and concentrates are briefly reviewed

The problem relating to the removal of arsenic from gaseous emissions from roasting processes is considered

Residues from aqueous processing contain a variety of arsenical materials which have not been characterised, and the long-term stability of these is suspect

The use of lime to stabilise aqueous residues as cither calcium arsenate or calcium arsenite has been shown to be inadequate for long term disposal since both compounds are converted into calcium carbonate due to the influence of carbon dioxide in the atmosphere

Ferric ion solutions have been used to precipitate ferric arsenate or to form ferric hydroxide which binds the arsenic for short term disposal. The long term stability of these ferric materials is poor, but could lead to the acceptance of a slow release option rather than complete containment of residues.     

Recent Trends in the Processing of Enargite Concentrates

The copper industry is witnessing great interest in the development and utilization of copper-arsenic deposits. While most plants tend to use traditional processing technologies, the depletion of conventional copper ores has created competition for designing and implementing new process alternatives for the treatment of copper-arsenic ores containing minerals such as enargite, luzonite, and tennantite. Nevertheless, the downstream processing of high-arsenic copper concentrates represents a significant metallurgical challenge in terms of both arsenic separation and also its stabilization in an environmentally benign form that fulfills the current and future environmental policies. Smelters are subject to penalties on high arsenic-bearing copper concentrates. While reductive roasting can drive-off the arsenic from enargite concentrates to an acceptable level suitable for smelting (<0.5 wt.%), this option has generally been viewed as unacceptable due to environmental conflicts and the lack of a market for arsenic trioxide. The lack of a suitable pyrometallurgical option has led to several proposed hydrometallurgical treatments of enargite concentrates. Hydrometallurgical options include either selective arsenic dissolution to produce a clean copper concentrate or collective leaching of copper and arsenic. Both options with various conditions and lixiviants are discussed and evaluated. In this review, alkaline sulfide leach (ASL), sulfate- and chloride-based leach systems, high temperature pressure oxidation (HTPOX), sodium hypochlorite leach, bio-leach/oxidation, nitrogen species catalyzed pressure oxidation, Cominco Engineering Services Limited, Intec, HydroCopper? and Fluobor® processes are outlined. Pyrometallurgical process strategies have also been briefly reviewed. Among all processing options, ASL, HTPOX, Fluobor® and reductive roasting processes are given special attention with specific flowsheets for enargite concentrates discussed.     

X射线荧光光谱在矿石分析中的应用评介—总论

矿石因其种类繁多、成分复杂和元素含量差异悬殊而成为地质分析的一大难题。作者收集各类矿石分析方法文献726篇,在此基础上主要以列表方式按黑色金属、有色金属、稀有稀土稀散金属、能源矿产和非金属矿石5大类介绍了X射线荧光光谱(XRF)分析在数十种矿石中应用的文献概况,从分析方法研究的基础条件和各类矿石分析方法类型、特点和文献量等进行了介绍和评介,也依据XRF分析仪器及技术的发展和目前在我国矿石分析中的应用现状提出了XRF在各类矿石分析中更广泛应用的发展建议。其中的黑色金属矿石包括铁矿石、锰矿石、铬铁矿及钛铁矿石和钒钛磁铁矿石,涉及文献177篇;有色金属矿石包括铝土矿石、钴镍铜铅锌矿石、钨钼矿石、锡锑铋汞矿石和多金属矿石,涉及文献186篇;稀有稀土稀散金属矿石包括稀土、铌钽、锆石和稀散金属矿石,涉及文献67篇;能源矿产包括煤、煤灰、石盐和油页岩,涉及文献40篇;非金属矿石包括碳酸盐类、磷酸盐类、硫化矿及硫酸盐类、氟化物矿石、镁及硅镁酸盐类、硅及硅铝酸盐类、岩盐卤水类和宝玉石9类非金属矿石,涉及文献257篇。作为矿石分析总论旨在以文献为基础框架展现XRF分析技术在我国各类矿石分析应用的基本概况,给读者一个全貌。而对XRF在各矿种矿石分析中应用的更具体评介将陆续发表,XRF在铁矿石、铬铁矿石和铜矿石分析中的应用评介已于2019年刊于《冶金分析》。     

X射线荧光光谱在矿石分析中的应用评介—总论

矿石因其种类繁多、成分复杂和元素含量差异悬殊而成为地质分析的一大难题。作者收集各类矿石分析方法文献726篇,在此基础上主要以列表方式按黑色金属、有色金属、稀有稀土稀散金属、能源矿产和非金属矿石5大类介绍了X射线荧光光谱(XRF)分析在数十种矿石中应用的文献概况,从分析方法研究的基础条件和各类矿石分析方法类型、特点和文献量等进行了介绍和评介,也依据XRF分析仪器及技术的发展和目前在我国矿石分析中的应用现状提出了XRF在各类矿石分析中更广泛应用的发展建议。其中的黑色金属矿石包括铁矿石、锰矿石、铬铁矿及钛铁矿石和钒钛磁铁矿石,涉及文献177篇;有色金属矿石包括铝土矿石、钴镍铜铅锌矿石、钨钼矿石、锡锑铋汞矿石和多金属矿石,涉及文献186篇;稀有稀土稀散金属矿石包括稀土、铌钽、锆石和稀散金属矿石,涉及文献67篇;能源矿产包括煤、煤灰、石盐和油页岩,涉及文献40篇;非金属矿石包括碳酸盐类、磷酸盐类、硫化矿及硫酸盐类、氟化物矿石、镁及硅镁酸盐类、硅及硅铝酸盐类、岩盐卤水类和宝玉石9类非金属矿石,涉及文献257篇。作为矿石分析总论旨在以文献为基础框架展现XRF分析技术在我国各类矿石分析应用的基本概况,给读者一个全貌。而对XRF在各矿种矿石分析中应用的更具体评介将陆续发表,XRF在铁矿石、铬铁矿石和铜矿石分析中的应用评介已于2019年刊于《冶金分析》。     

Editor's Introduction

This paper reviews the state of the art in processing and extraction of ocean floor manganese nodules. It briefly reviews the mining sites where the abundant rich nodules occur and also discusses the metal distribution in nodules in view of economical processing and extraction of these metal values.

The paper discloses in a detailed manner the physical and chemical characteristics of nodules, including porosity, surface area, water content and the effect of temperature on crystal structure of major constituents of nodules.

In the extraction aspect of nodules, the paper reviews two different extraction schemes revealed in the literature, namely hydrometallurgical treatment and pyrometallurgical treatment. The hydrometallurgical treatments include acid leaching, ammonia leaching, leaching with reducing agents and leaching after high temperature pre-treatments such as in sulfating rousting, while the pyrometallurgical processes include smelting, chlorination-vaporization and segregation. The paper also covers metal recovery processes from leach liquor.

An economic survey of processing nodules has been made in terms of problems associated with metal-marketing, and impact of metal production from nodules on mineral industries.     

Tin and zinc separation from tin,zinc bearing complex iron ores by selective reduction process

Abstract

Tin, zinc bearing complex iron ores are typically intractable and have not been efficiently utilised in China. In this investigation, the process mineralogy of the tin, zinc bearing iron ores and reduction behaviours of iron, tin and zinc oxides by CO were investigated. A selective reduction roasting process was initially developed to separate tin and zinc from the complex iron ores. Under optimum conditions, most of the tin and zinc were effectively removed from the iron ore pellets, and the roasted pellets could be used as high quality ironmaking burdens for large scale blast furnaces.     

Coordination Chemistry in Mineral Processing

Abstract

In mineral processing industry, achieving an optimal extraction of valuable mineral components is an extremely important goal. The processes of leaching, solvent extraction and flotation are major methods of processing minerals under aqueous conditions in which coordination chemistry may play an important role, and in facilitating the realization of this goal. The success of some of these processes is ascribed to the ability of the chemical reagents to form stable coordination complexes with metal ions in the aqueous solution or on the surfaces of the mineral lattice. Leaching processes which involve complex formation usually result in increased dissolution of mineral values in aqueous solution, and may include cyanide, basic and chloride leaching. In solvent extraction, the extractant and masking reagents react with metal ions to form principally coordination complexes, which are either selectively extracted into the organic phase or retained in the aqueous raffinate. This is the basis underlying the concentration and purification of metal values by this process. Flotation processes, which employ collectors and depressants whose interactions with metal ions in aqueous solution lead to complex formation through coordinate bonding are believed to be more efficient than other analogous processes. In an effort to contribute to the understanding of the chemistry of these processes, the authors have attempted to review the role of coordination chemistry in mineral processing by flotation, leaching and solvent extraction.     

1997年湖南有色金属选矿回顾

本文从选矿工艺、选矿药剂与设备、选矿理论、选厂管理等方面对湖南有色金属选矿进行了1997年工作回顾，并对今后的发展进行展望。     

Molybdenum Metallurgy Review: Hydrometallurgical Routes to Recovery of Molybdenum from Ores and Mineral Raw Materials

With the vigorously growing demand of the steel industry, oil and gas industry, corrosion resistance alloys, cast iron, and catalyst industries, high-grade molybdenum ores are being exhausted gradually in the world. Thus, much attention have been drawn to the recovery of molybdenum from low-grade molybdenum ores in recent years. With the increasingly stringent environmental requirements, the shortcomings due to SO₂ emission in the roasting process of traditional technology becomes obvious. This review outlines metallurgical processes for molybdenum production from various resources, particularly focusing on recent developments in direct hydrometallurgical and recovery processes to identify potential sources of molybdenum products and by-products such as uranium which can be economically produced.

Several methods have been extensively reviewed for molybdenum separation and purification from solution which are potentially applicable to leach solutions of molybdenum ores and raw materials. The main methods include solvent extraction, ion exchange, membrane-based separation, and precipitation. Solvent extraction is highly selective for recovery of molybdenum and the most promising method recommended for future research and development. Membrane-based separation is the next preferred method for selective extraction of molybdenum, purification of molybdenum solutions, or co-recovery of other valuable metals. Ion exchange offers useful means for purification and/or co-recovery of other base metal impurities, although the scale of application of ion exchange in the industry is limited.     

铝土矿选矿脱硅的研究现状及进展

论述了我国铝土矿资源状况与特点,指出了铝土矿选矿脱硅的重要性,并从化学选矿脱硅和物理选矿脱硅两方面介绍了铝土矿选矿脱硅的研究现状与进展,在此基础上指出了铝土矿选矿脱硅的研究方向.     

2010年云南冶金年评

依据2010年云南冶金科技工作者发表的文献资料,对该年度云南黑色金属冶金、有色金属冶金、半金属及稀有金属和贵金属冶金生产、科研及技术开发进行了评述。     

Roasting in extractive metallurgy a thermodynamic and kinetic review

Abstract

Selected papers are reviewed in both the ferrous and nonferrous fields of extractive metallurgy, to il1ustrate recent developments in the theory and practice of roasting. Attention is confined primarily to solid-gas and liquid-gas systems, which are considered from both their thermodynamic and kinetic aspects.

The thermodynamics section of this review includes studies of sulphide mineral vapourization, matte oxidation, selective sulphation roasting and the chlorination of sulphides. The use of various thermodynamic diagrams is illustrated. The kinetics section includes rate studies on oxidation, reduction, sulphation and chlorination processes and discussions of some of the proposed mechanisms and rate-controlling steps which are common to many of these processes.

Newer developments in chemical transport, plasmas and computer models are mentioned.

Résumé

Pour souligner les plus récents développements théoriques et pratiques ayant trait aux procédés de grillage, une revue bibliographique a été effectué tant dans le domaine de la métallurgie extractive des ferreux que des non-ferreux. Elle porte d'abord et avant tout sur les aspects concernant la thermodynamique et la cinétique des systémes solide-gaz et liquides-gaz. Dans la partie thermodynamique de cette revue, sont relevées des études ayant trait à la volatilisation de minerais sulfurés, l'oxydation des mattes, le grillage sulfatant selectif et la chlorination des sulfures. L'utilisation de divers diagrammes pour faire la corrélation des données thermodynamiques y est illustrée. Les aspects de la cinétique qui ont été retenus portent sur l'étude du taux des processus d'oxydation, de réduction, de sulfatation et de chlorination et sur la discussion de certains mécanismes et de certaines étapes communes à ces processus et susceptibles d'influehcer le taux global de réaction.     

1998年云南金属材料与加工年评

根据１９９８年所发表的论文，从黑色金属材料、有色金属材料、稀贵金属材料和陶瓷材料等方面对云南省金属材料研究情况进行评述，反映了各类新材料的最新研究与发展趋势     

2004年云南金属材料与加工年评

以云南材料工作者在国内刊物上所发表的科研论文为主要依据，对2004年云南金属材料与加工进行评述，内容包括黑色金属、有色金属、稀贵金属和陶瓷材料等。参考文献150篇。     

Review of the hydrometallurgy of chalcopyrite concentrates

Abstract

A critical appraisal has been made of methods that have been proposed for the hydro metallurgical treatment of chalcopyrite concentrates. Those methods in which the primary breakdown of chalcopyrite is effected by leachants are discussed. Methods in which leaching is preceded by pyrometal-lurgical decomposition of the mineral include selective sulphation and nonoxidizing treatments in which the ratios of copper, iron and sulphur are changed. No process has yet been found that can replace conventional pyrometallurgical processing, although several have reached the pilot plant stage. The incentives for devising an economic hydrometallurgical process for extracting copper from sulphide ores are the avoidance of air pollution and the possibility of recovering iron, elemental sulphur and other nonferrous metals.

Résumé

Une appréciation critique a été faite des méthodes proposees pour le traitement hydrométallurgique des concentrés de chalcopyrite. Les méthodes par lesquelles la deécomposition originale de la chalcopyrite est affectée par les lixiviants, sont décrites. Les méthodes selon lesquelles la lixiviation est précédée par la décomposition pyrométa1lurgique du minerai comprennent la sulphatation sélective et les traitements non-oxydants dans lesquels les concentrations relatives de cuivre, fer et souffre sont changées. Aucun procédé pouvant remplacer les procédés pyrométallurgiques conventionnels n'a encore été trouvé, bien que plusieurs soient parvenus au stade de l'exploitation sur pilote. L'intérêt d'un procédé hydrométallurgique économique, pour l'extraction du cuivre, à partir des minerais de souffre, serait la non-pollution de l'air et la possibilité de récupération du fer, du souffre élémentaire et des autres métaux non-ferreux.     

Refractoriness of Certain Gold OrestoCyanidation: Probable Causes and Possible Solutions

Cyanidation has established itself as the main process for extracting gold from ores in this century. However, many ores exhibit refractoriness to the conventional cyanida-tion process. The main cause of the refractoriness is generally the presence of carbon, tellurium, and sulfides, particularly those of antimony, arsenic, and iron. The problem is usually solved by either modifying the cyanidation conditions or providing an oxidation pretreatmerrt

This paper presents results from studies that help in understanding the causes of refractoriness of various gold ores. This is followed by a discussion of many processes that have been developed to solve the problem such as intensive cyanidation, pressure cyanidation, carbon-in-leach cyanidation. and prctreatment processes such as roasting, chemical oxidation, autoclave oxidation, and bacterial oxidation.     

金矿非氰化浸金研究进展

随着易处理金矿石资源枯竭,含砷、含碳、高硫、超细颗粒金矿石已成为金矿开采的重点,这些难处理金矿通过常规氰化浸金等方法浸出效果差,由于氰化物有剧毒,会危害人体健康,并严重污染生态环境。非氰化法浸金因具有环保、浸出速率快、效率高等优点受到了广泛关注。在综述了硫代硫酸盐法、甘氨酸法、卤素法、石硫合剂法、碘化焙烧工艺、硫脲浸出法和非水溶液浸金7种非氰浸金方法的浸金原理及其在难处理金矿方面的最新研究进展的基础上,讨论了非氰浸金方法存在的浸出剂昂贵、浸出液中金回收困难、浸出体系复杂、浸出剂性质不稳定及消耗量大等问题,并对非氰浸金技术的发展方向进行了展望。      

Design,Capital and Operating Costs of Mineral Processing Plants

This paper reviews important aspects of the design of mineral processing plants, emphasizing the different factors which seem to be most important today, when labour and energy represent a high proportion of total costs. Such items as autogenous and semi-autogenous grinding, two-stage classification, large flotation cells, pressure filtration, etc., are discussed. Recent examples of flotation plants are described

Capital cost evaluation is briefly surveyed, as well as generally accepted procedures; relationships with flowsheeting and mill design are specially pointed out

Distribution of operating costs is reported on the basis of processes and elements, and a few examples are fully detailed.     

The Role of Solids Characterisation Techniques in the Evaluation of Ammonia Leaching Behaviour of Complex Sulphides

This paper presents the state of art of some experimental techniques that are useful for identification of the various mineral phases of raw materials, leach residues and for determination of reaction mechanisms for the oxidative ammonia leaching of sulphide minerals and Cu-Zn-Pb bulk concentrates. Techniques discussed include microscopy, X-ray diffraction (XRD), thermal analysis (TA), surface area measurements, chemical phase analysis and electrochemical measurements. These provide supportive evidence in studies on leaching of multimineral sulphides. Under the experimental conditions used, a multidisciplinary approach ensures elimination of various uncertainties and provides better analysis of kinetic data. This is discussed in the light of raw material characteristics, experimental variables, solution analysis, nature of products formed, etc. Uncertainties usually associated with the analysis of kinetics data are also briefly discussed. Lean grade complex sulphide ores are chosen for a case study because they have assumed a worldwide significance as potential future resources of both nonferrous and precious metals.     

长坑金矿选矿工艺试验研究

长坑金矿矿石属于以黄铁矿为载体的次显微结构难选难浸金矿石。对该矿矿石进行了浮选、催化预氧化-氰化、焙烧氧化-氰化、碱浸预氧化-氰化等工艺试验研究,为选矿工艺方案的确定指明了方向。