Selective sulphidation of a nickeliferous lateritic ore

The processing of nickeliferous laterites to produce nickel metal is both complex and energy intensive. Since most laterites are found in less developed regions, the capital costs for the infrastructure can exceed those for the process itself. The low temperature sulphidation of lateritic ores to produce an intermediate nickel concentrate, for further processing, offers a number of potential advantages, such as lower energy consumption and a relatively simple flowsheet. In this research, the sulphidation of a nickeliferous lateritic ore was investigated between the temperatures of 450-1000 °C and sulphur additions of between 25 and 900 kg of sulphur per tonne of ore. The experiments showed that the nickel oxide can be selectively sulphidized to a nickel-iron sulphide. It was found that both the grade and the sulphidation degree largely depended upon the temperature and the sulphur additions, with temperatures above 550 °C exhibiting the highest recoveries and grades. A DTA/TGA with mass spectrometer was used to further elucidate the nature of the phase transformations that occur upon heating of the ore in the presence of sulphur.     

α → γ → β-phase transformation of spodumene with hybrid microwave and conventional furnaces

Spodumene is the most important lithium containing hard rock mineral. In order to extract lithium from spodumene concentrate by leaching, the crystal structure of spodumene must be converted from the natural monoclinic α-form to the tetragonal β-form. The technical possibilities to generate the heat to the conversion process of spodumene concentrate via microwaves were studied. The heat treatment experiments were carried out with a domestic microwave furnace (700 W) with silicon carbide susceptor and with the conventional resistance heated furnace as a reference. In the microwave furnace the phase transformation of spodumene began after 110 s of heating and samples were converted almost completely to β-spodumene after 170 s. Partial melting of gangue minerals was observed in samples after 170 s of heating. Heating in microwave furnace for 170 s corresponded with the heating of approximately 480–600 s at temperature of 1100 °C in the conventional furnace. In addition to α- and β-forms an intermediate phase, hexagonal γ-spodumene, was identified from samples heated with both furnaces. The conversion of spodumene samples was verified with X-ray diffraction (XRD) and with field emission scanning electron microscope (FESEM).     

Reducing the greenhouse gas footprint of primary metal production: Where should the focus be?

The mineral processing and metal production sector is endeavouring to identify opportunities to improve the sustainability of its operations and reduce its greenhouse gas footprint, with improved energy efficiency receiving increased attention. However, if truly sustainable outcomes are to be obtained it is essential that a life cycle approach be adopted in evaluating these opportunities. In this paper, life cycle assessment methodology is used to indicate where in the metal production life cycle this focus on energy efficiency should be and to evaluate a number of potential opportunities for reducing the greenhouse gas footprint of primary metal production.Results from life cycle assessments of the main primary metal production processes, together with current and predicted global metal production rates, ore grades and grind or liberation size, have been used in a broad analysis to indicate that endeavours to improve the energy efficiency of primary metal production should focus mainly on the metal extraction stage, particularly for steel and aluminium. Declining ore grades and more complex ore bodies anticipated in the future can be expected to significantly increase the energy required for comminution of the main metal ores and will present opportunities for improving the energy efficiency of primary metal production. However, these opportunities will still be appreciably less than potential energy efficiency improvements in the extraction stage for these metals.     

Influence of mineralogy and ore texture on pentlandite flotation at the Nkomati nickel mine,South Africa

The influence of ore mineralogy and ore texture on flotation response was studied for 29 samples from the main mineralised zone at Pit 3 of the Nkomati Ni mine, through laboratory scale flotation testing, laboratory assay, and mineral liberation analyser examination of the ore and the concentrates. The individual sample flotation responses vary widely in terms of Ni grade, and cumulative Ni recovery. It is demonstrated that this is a complex function of ore mineralogy and ore texture. Chalcopyrite is the first sulphide to float, followed by pentlandite and finally pyrrhotite, in ore samples with dominant chalcopyrite, or where pentlandite, pyrrhotite and chalcopyrite occur in equal abundance. However in samples with a high ratio of pyrrhotite to pentlandite and chalcopyrite, pyrrhotite floats earlier than expected, reports to concentrate over the entire flotation period, and depress and extend the flotation of pentlandite over the flotation interval with no clear peak of Ni recovery during flotation. Primary silicates (e.g. olivine and pyroxene) and alteration-related minerals (talc, tremolite and chlorite) are naturally floating, and hence affect the flotation of pentlandite in a similar manner to that of pyrrhotite. The most problematic ore at Nkomati in terms of Ni recovery is characterised by fine disseminated and fine bleb- or net-texture sulphides, contain abundant olivine, pyroxene, amphibole, talc and tremolite, and include abundant metamorphism-related country rock xenoliths (with calc-silicate minerals such as diopside and tremolite).     

选矿专家系统

系统介绍了专家系统在选矿各个领域中的应用，根据国内外的经验和作者的研究工作，论述了选矿专家系统的应用前景和发展趋势。     

中国磷矿石选矿工艺研究现状

磷矿是具有战略意义的非金属矿,具有不可替代性、不可再生性。我国磷矿资源丰富,但易选的沉积变质磷灰岩少,难选的磷块岩储量多。根据磷矿石的矿物学性质、矿床成因,将磷矿石分为岩浆岩型磷灰石、沉积变质岩型磷灰岩、沉积岩型磷块岩。岩浆岩型磷灰石的选矿方法有浮选法、磁浮联合工艺流程;沉积变质岩型磷灰岩中磷矿物嵌布粒度较粗,可浮性较好,采用直接浮选法、擦洗脱泥—浮选联合流程等工艺;沉积型磷块岩宜采用浮选法、重选法、重—浮联合流程、磁—浮联合流程、擦洗脱泥—浮选联合流程以及焙烧—消化工艺。针对我国磷矿石大部分为中低品位矿石、结晶微细、隐晶质、可选性差的特点,提出了浮选法与其他选矿方法的联合使用是处理此类难选矿石的主要方向。     

微波技术在选矿中的应用

介绍了微波加热的原理和所具有的即时性、整体性、选择性、高效性、无污染等特性,从碎矿、磨矿、浮选、磁选、浸出、矿石预处理等方面对微波技术在选矿中的应用情况进行了综述,指出微波技术在选矿领域中的应用有着广阔前景。     

第27届国际矿物加工大会论文题录

<正>第27届国际矿物加工大会于2014年10月20日至24日在智利首都圣地亚哥举行。来自世界50多个国家1000多名代表参加了这次盛会。大会宣读论文共9篇、分会重点宣读论文16篇、分会宣读论文325篇和墙报论文168篇。本次大会确定第28届国际矿物加工大会于2016年在加拿大魁北克市会议中心举行,第29届国际矿物加工大会于     

超声波技术在选矿中的应用

对超声波在选矿测试(如粒度分析、物位测量、流量检测和浓度检测)、矿物选别、化学浸出、矿石破碎等方面的应用进行了详细介绍，并阐述了超声波技术在这些方面得以应用的基本原理，指出超声波技术是一种很有发展前景的技术。     

2008年中国选矿年评

纵观2008年国内选矿科研和生产实践的进展,在矿石准备、有色金属选矿、黑色金属选矿、非金属选矿、微生物技术在选矿中的应用、选矿药剂、选矿设备、尾矿处理及环保等方面均进行了丰富的研究工作。工作的重点主要集中在提高选别指标方面,特别是在铜、铅、锌等难选矿石的分选及铁矿石的提质降杂方面。此外,在微生物选矿、尾矿资源的综合利用等方面的研究也日趋深入;而在选矿基础理论方面的研究及选矿新设备的研发方面则显薄弱,有待于进一步加强。     

选矿厂过程控制的现状及发展前景

对选矿厂过程控制的现状及发展进行了阐述,同时对选矿厂过程控制存在的问题及发展前景提出了自己的观点。     

基于数据挖掘的选矿模型

运用数据挖掘技术建立了用于矿山技术指标优化系统中的子系统——选矿模型，阐述了运用数据挖掘技术建立选矿模型的技术思路和基本步骤，并通过工程实例进一步说明了建立该模型的过程，为矿山优化系统建模提供一个新的思路。     

高压辊磨机在矿物加工领域的应用

结合国内外一些典型的工业实例,从金刚石矿粉碎、铁矿石加工、有色和贵金属矿石粉碎3方面综述了高压辊磨机在矿物加工领域的应用进展和现状,并分析了高压辊磨机在矿物加工领域的发展趋势。     

Silver loss during the oxidative refining of silver-copper alloys

The high temperature oxidative refining of molten silver-copper alloys is accompanied by silver losses to the slag. Typically, borosilicate slags are utilized as a flux and air or oxygen is injected into the molten alloy. The majority of the copper can be selectively oxidized to copper oxide, but some silver is also lost to the slag. In this research, the mechanism of silver loss has been investigated. Firstly, TGA and DTA studies of molten silver-copper alloys were performed, in order to elucidate the oxidation processes occurring at the gas-metal interface in the bubble. Secondly, the silver losses to the slag in the high temperature refining tests were quantified. Thirdly, the slag was characterized using XRD and the morphology of the silver in the slag was examined. Fourthly, a pseudo-equilibrium model of the refining process was developed and this was utilized to suggest methods for minimizing the silver loss to the slag. Finally, possible methods for recovering the silver from the slag are discussed.     

矿物材料及矿物材料学

本文在总结前人研究成果的基础上，提出了矿物材料和矿物材料学的定义，论述了矿物材料的分类方法和矿物材料学的研究任务，并简述了我国非金属矿物材料学的研究概况。     

褐铁矿选矿研究现状与思考

随着我国钢铁工业的迅速发展,品位高且易选的铁矿石资源濒临枯竭,合理开发利用复杂难选铁矿石资源对缓解我国铁矿石供求矛盾,促进我国钢铁工业发展具有重要现实意义。近年来研究开发的褐铁矿选矿技术主要包括:重选、磁选等单一流程和选择性絮凝浮选等联合流程。这些研究结果表明,目前尚未形成成熟有效的褐铁矿选矿技术。为此,针对褐铁矿资源特点,对褐铁矿资源进行较系统的分类,研究开发特定类型褐铁矿资源的有效选矿技术,可能是逐步解决褐铁矿选矿难题的有效途径。     

Dynamic modelling of copper solvent extraction mixer–settler units

The copper Leaching, Solvent Extraction and Electrowinning circuit (LX–SX–EW) is one of the most effective processes for extracting copper from low grade ores. This work focuses on the liquid–liquid extraction SX sub-process, since many difficult to handle operational problems within LX–SX–EW circuits are related to SX malfunction. Controlling these problems better can reduce operational costs and increase recovery and copper production. Realistic dynamic simulation is a standard tool nowadays to design and assess more effective control strategies. In this work we present a general dynamic model for SX mixer–settlers, and applied it to two different units, one located in an extraction stage and the other in a stripping stage of a copper plant. The model includes a non-trivial settler hydrodynamics represented by a set of nonlinear differential equations for both mixer and settler units. The mixer is modelled as a continuous stirred tank reactor and the settler as a hydrodynamic circuit combining series and parallel connections of continuous stirred tank and plug flow reactors. The model was calibrated with industrial plant data, resulting in realistic simulations of outlet copper concentrations. Using the proposed model, we obtained better fitting than that achieved with simpler settler models that include only a time delay. The model fitting parameters provide sufficient flexibility to accurately reproduce the dynamics of different units in industrial plants.     

再谈高压辊磨机在矿物加工领域的应用

从高压辊磨机在矿石碎磨工艺流程中的地位及所起的作用角度综述此设备在矿物加工领域的应用现状和潜力,展望未来的发展前景及面临的挑战。     

2010年中国选矿年评

2010年,我国选矿工作者以合理开采矿产资源、突出综合利用、走矿业循环之路为根本出发点,在选矿工艺、选矿药剂、选矿设备、矿产资源的微生物处理技术以及尾矿处理与处置等方面进行了大量的试验研究工作,尤其在提高碎磨效率、优化选矿工艺流程、复杂难选矿石的分选工艺、新型浮选药剂的研制与应用、尾矿综合利用等方面取得了较为丰富的研究成果。存在的不足是关于浮选药剂作用机理的研究仍欠深入,关于新型选矿设备的研究也明显偏少。     

2009年中国选矿年评

2009年,中国的选矿科研和生产实践主要围绕节能降耗和矿石的清洁高效生产展开,在选矿工艺、选矿药剂、选矿设备、资源微生物技术、尾矿处理及环境保护等诸多方面进行了系统的研究工作,尤其是在复杂难选矿石的分选、新型浮选药剂和磁选设备的研制等方面取得了一大批新成果,与此同时,研究方法还呈现出多样化的特点。此外,针对微生物浸矿和尾矿资源综合回收利用的研究也愈发得到重视,而关于选矿基础理论及工程层面的系统研究则较为欠缺,有待于进一步加强。