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.     

Investigation of Copper Recovery from a New Copper Deposit (Nussir) in Northern Norway

ABSTRACT

Norway has seen an upsurge of interest in exploiting its mineral deposits during the last decade. One of the major areas of interest is a huge copper deposit, operated by Nussir ASA located in the Repparfjord tectonic window in the Caledonides of west Finnmark. Nussir ASA is evaluating the Nussir and Ulveryggen mineral resources that contain copper sulfides with a small amount of gold and silver bearing minerals. The performance of flotation operations is generally evaluated on the basis of degree of liberation of minerals or the surface interactions between the collector and mineral. Firstly, size-by-size mineralogical characterization of the flotation feed and cumulative final product using Zeiss automated mineralogy techniques (Mineralogic) revealed that mineral liberation heavily influenced the flotation behavior of the ore. Furthermore, in order to assess the role of pH, collector concentration and flotation time, bench scale flotation experiments were performed. The metallurgical results were maximum between pH 6 and 8 and at collector concentration 6 × 10^?5 M. A correlation is established using the zeta potential and Hallimond flotation tests to assess the role of operating parameters in flotation. The distinctive role of process mineralogy and flotation chemical influence for copper mineral flotation of Nussir ore is presented in this article.     

Processing Techniques for Difficult-to-treat Ores by Combining Chemical Metallurgy and Mineral Processing

This paper is concerned with a review of published literature on the processing of difficult-to-treat ferrous and nonferrous ores that have very fine liberation size and have constituent minerals with similar properties for which the conventional mineral processing techniques are ineffective. By altering mineralogy either pyrometallurgically or hydrometallurgically, the low cost methods of mineral processing could be applied on ores which are complex and refractory in character.

It briefly reviews methods such as magnetizing roasting and direct reduction for ferrous ores and discusses the pyrometallurgical pre-treatments on nonferrous ores, such as sulfidizing roasting, roast-flotation, segregation process and matte separation process, and hydrometallurigcal pre-treatments to extract valuable metal values by applying leach-precipitation-flotation method, and ion flotation.

Application of a combination of chemical metallurgy and mineral processing methods to solid waste materials, in particular, steel plant wastes, nonferrous slags, smelter flue dusts and anode slimes have also been briefly discussed.     

CHEMISTRY AND OPTIMAL CONDITIONS FOR COPPER MINERALS FLOTATION: THEORY AND PRACTICE

Reliable information on the surface state of sulphide copper minerals and regularities of sulphidization and flotation of oxidized copper minerals, the composition of sorption layer on the mineral surface forming during its interaction with xanthate or dixanthogen, and the influence of collector forms sorption on the copper minerals floatability and on the optimal conditions for these minerals flotation and depression has been obtained at present. The determined physicochemical models in the form of quantitative equations have been derived for the optimal conditions of flotation and depression of copper minerals under changing pH value and of sodium sulphide, lime, cyanide, zinc–cyanide complexes additions. The equations derived were proven in the laboratory and industrial scale and can be used both in automatic control systems at plants and for improvement of technological processes of selective flotation of copper containing ores.     

陕西某微细粒浸染型金矿选矿试验研究

微细粒浸染型金矿床往往富含砷、汞、锑、碳等难处理矿物,其中细粒金常赋存于黄铁矿等硫化矿物中,属于难处理矿石。陕西省某金矿床金矿物粒径非常细小,主要为次显微金,通过传统浮选方法难以获得高品位的金精矿产品,为有效提取细粒金矿石,开展了工艺矿物学及选矿试验研究。工艺矿物学研究表明,矿床主要载金矿物为黄铁矿,在-0.074 mm占60％的细度条件下,黄铁矿的解离度达93.48％,自然金以次显微金及晶格金存在,属于微细粒浸染型难处理矿石。综合对比选矿试验结果表明,该金矿宜采用“研磨-焙烧-研磨-氰化”的流程方案,首先将原矿磨细到-0.075 mm占80%,然后在650 ℃的温度下焙烧2 h,再将焙烧矿磨细到-0.075 mm占95%,在NaCN用量为4 kg/t、氰化时间为36 h的条件下,金浸出率可达73.36%。该试验方案适合微细浸染型金矿石的浮选,选矿效果较为理想。     

Physico-Chemical Modeling of Flotation Systems

Abstract

The methodology of physical-chemical modeling of flotation systems is considered and effectiveness of its application for fundamental investigations in flotation is shown. Using iron sulphides as the example, reliable information has been received on the surface state of iron sulphides, optimal conditions for their activation with copper salts and deactivation with cyanide and sulphide ions, the composition of sorption layer on the mineral surface forming during its interaction with xanthate or dixanthogen, the influence of collector forms sorption on the iron sulphides notability and on the optimal conditions of these minerals flotation.

From a single position the determined physico-chemical models in the form of quantitative equations have been derived for the optimal conditions of flotation and depression of iron sulphides under changing pH value and of the sodium sulphide, cyanide or lime addition. The equations derived were proven in the laboratory and industrial scale and can be used in automatic control systems at the plants as well as for improvement of technological processes of selective flotation of iron sulphides containing ores or coals.     

Effect of a Water Soluble Fraction Derived from Mycobacterium phlei on the Surface Characteristics and Flotation of Apatite and Dolomite

Abstract

When Mycobacterium phlei is subjected to sonication, a solid and a water soluble fraction are obtained. The water soluble material is highly surface-active and adsorbs onto both dolomite and apatite. In both cases the mineral becomes more hydrophobic with the effect being greater on dolomite than on apatite. The change in surface characteristics of the minerals was monitored by contact angle, zeta potential and micro flotation experimentation. The data obtained were compared to results obtained when whole cells of M.phlei were used in place of the soluble fraction. Implications on the effect of the addition of both M.phlei and its soluble fraction on the flotation separation of the two minerals are discussed.     

硅石选矿提纯工艺研究现状

作为高纯石英粉生产原料的天然高品级水晶日趋匮乏，研究用硅石矿物替代天然水晶生产高纯石英原料迫在眉睫。本文综述了国内外硅石矿物原料替代天然水晶生产高纯石英砂的研究现状；系统总结了擦洗、磁选、浮选、酸浸的常规方法和非常规方法以及去除包裹体的选矿提纯工艺的研究和进展；提出了我国硅石矿物选矿提纯工艺研究的发展方向和制约其发展速度的主要因素。     

从超细粒高铅锌氰化尾渣中浮选回收有价金属的试验研究

从超细粒氰化尾渣中回收有价元素是浮选中的难题,目前采用的方法主要是先加入氧化剂预处理脱氰,再加入捕收剂浮选。然而,该工艺存在药剂成本高、氰化物无法循环使用及矿物表面二次氧化等问题。以山东某高铅锌氰化尾渣为研究对象,在不脱氰的条件下,以氰化贫液为浮选用水,通过浮选试验和闭路试验等方法研究氰化尾渣的浮选回收效果。试验结果表明,在不脱氰的条件下,可浮选回收铅锌,铅精矿铅品位为56.61%,回收率为89.04%;锌精矿锌品位为32.6%,回收率为74.5%。SEM显微镜研究表明,铅精矿中铜矿物表面包裹一层小颗粒方铅矿,改变了黄铜矿界面性质,使得铜矿物表面特性趋于方铅矿界面性质,导致铜矿物大部分进入铅精矿中。     

金属离子对矿物浮选行为影响的研究进展

在矿物浮选过程中,由于矿物的粉碎溶解、药剂的添加、回水的循环利用等原因,矿浆中难免会存在一些金属离子,这些金属离子往往会对矿物的浮选行为产生重要影响.在对相关文献分析和总结的基础上,概述了金属离子对氧化物矿物、硫化物矿物、硅酸盐矿物浮选和分离的影响.金属离子在不同pH条件下会形成络合物或沉淀,通过消耗捕收剂,抑制捕收剂分解来抑制矿物浮选,矿浆中离子浓度增大到一定程度也会抑制矿物浮选,单种离子不同组分或不同离子组合对浮选效果有较大影响.      

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.     

Flotation behavior and electronic simulations of rare earth minerals in the presence of dolomite supernatant using sodium oleate collector

Common rare earth (RE) minerals, such as bastnasite and monazite, may be formed in deposits associated with carbonate gangue, such as calcite and dolomite. Sodium oleate is a widely used collector for the flotation of both RE and gangue minerals, which might, therefore, be an inefficient process due to the lack of selectivity of this collector. Since these minerals are also sparingly soluble in solution, they could release their constituent ions into the solution, which could affect the floatability of other minerals. In this study, the interactions of sodium oleate with bastn(a|¨)site and monazite in the presence of dissolved dolomite species have been investigated. Micro flotation tests were carried out to explore the effects of these dissolved species on the floatability of the RE minerals. Zeta potential measurements and XPS characterization were carried out to understand how the species affect the collector adsorption. To complement these characterizations, density functional theory (DFT) simulations were conducted to investigate the collector-mineral and collector-adsorbed species (on the mineral surface) interactions.The results show that collector-dolomite interaction energy is greater than that of collector-adsorbed species, but lower than collector-monazite interaction energy, explaining the decrease in the minerals’recovery upon exposure to the dissolved mineral species. It is also shown that oleate ions (OI~-) have the strongest interaction with the minerals compared to other oleate species such as acid soap (HOI_2~-) and oleate dimer (Ol_2~(2-)). The behavior (strength and selectivity) of sodium oleate towards RE minerals and dolomite, as compared to other RE mineral collectors (such as aromatic hydroxamate), is attributed mainly to the collector's and the minerals'structure. The long hydrocarbon chain of sodium oleate which imparts hydrophobic characteristic to the minerals, makes it stronger collector than benzohydroxamate.Moreover, sodium oleate (with linear structure), unlike the aromatic hydroxamate, can approach the mineral easier due to lesser steric hindrance effect and higher reactivity of O involved in the interaction,making it less selective. In addition, it can interact easily with dolomite due to the presence of more exposed active sites than RE minerals.     

某银金矿选矿工艺研究

某银金矿矿石中有用金属甚多 ,相互关系密切 ,银主要以类质同像状态分散赋存在各种硫化矿物及铁矾类、氧化锰矿物中 ,用常规选矿方法难以选别 ,对该矿石的选别工艺流程作了研究 ,认为氧化焙烧—氯化焙烧—氰化工艺流程较适合该矿矿石性质 ,获得的指标最好。     

铅离子对苯乙烯膦酸浮选锡石的活化作用

通过单矿物浮选试验揭示了Pb2+对苯乙烯膦酸（SPA）浮选锡石效果的影响规律,在此基础上,利用接触角测定、Zeta电位检测、红外光谱分析和浮选溶液化学研究了苯乙烯膦酸浮选锡石体系中Pb2+的活化作用机理.单矿物试验结果表明:在矿浆pH为2.0~8.0的区间内Pb2+对锡石的浮选具有明显的活化作用,矿浆pH为4.0时锡石的回收率最高,达到93.78%,与不存在Pb2+的情况相比提高了5.33%.Zeta电位检测、红外光谱分析和浮选溶液化学结果表明:苯乙烯膦酸主要化学吸附于锡石表面,使锡石表面的Zeta电位负移,Pb2+的作用促进了苯乙烯膦酸的吸附,进一步降低了锡石表面的Zeta电位;Pb2+可以与锡石表面的Sn4+发生置换,PbOH+能够与锡石表面的Sn-OH发生相互作用形成以Sn-O-Pb+形式存在的络合物,这些作用增加了锡石表面的活性位点数量,使得苯乙烯膦酸在锡石表面的吸附量增多,导致了锡石的活化.      

The Aqueous and Surface Chemistry of Activation in the Flotation of Sulphide Minerals—A Review. Part I: An Electrochemical Model

The activation of sulphide minerals by heavy metal ions in acidic pH solutions has been reviewed from an electrochemical point of view. It is shown that the well-documented ion-exchange model is oversimplified. Surface oxidation of the mineral and reduction of the activator metal ions occur during the activation processes. Activation in an oxygen-deficient system leads to the formation of a sulphur-rich surface and results in activation-induced flotation. The overall process of activation is controlled by a mixed-potential mechanism.     

改性油酸浮选性能研究

为适应钢铁工业节能减排的发展趋势,铁矿石的"提铁降硅"已经成为选矿界的重要研究课题。针对油酸选择性差和捕收能力弱的缺点,开展油酸改性研究,是阴离子反浮选对铁矿石进行"提铁降硅"研究内容之一。试验对油酸、改性油酸进行了单矿物可浮性试验、人工混合矿物浮选分离试验、铁矿石浮选分离试验以及流程试验。铁矿石试验结果表明,改性油酸YS-1的捕收效果最好、YS-2次之,油酸最差。文中讨论了在铁矿石反浮选过程中,油酸作为捕收剂与矿物的作用机理。     

The role of iron and its compounds in processes of enrichment of sulfide ores of non-ferrous and noble metals

On the basis of the analysis of the literature data and the data of our investigations, the role of iron and products of its oxidation in sulfide pulps is shown. The technological factors are noted, such as the pH value of the medium, concentration of modifiers, mineral composition, and points and the order of batching flotation reagents; which affect the redox processes with the participation of iron and the characteristics of separation of sulfide minerals during flotation.     

高锰酸钾强化海藻酸钠抑制闪锌矿浮选的作用及机理

通过浮选试验、X射线光电子能谱（XPS）分析和吸附量测试分析,研究了高锰酸钾和海藻酸钠对黄铜矿、方铅矿和闪锌矿三种硫化矿物浮选的影响,考察了高锰酸钾强化海藻酸钠抑制闪锌矿浮选的作用机理。浮选试验结果表明,单独使用高锰酸钾或海藻酸钠均无法实现对闪锌矿的选择性抑制。同时添加适量高锰酸钾和海藻酸钠对闪锌矿具有选择性的协同抑制作用,而对黄铜矿和方铅矿浮选的影响较小。XPS分析结果表明,海藻酸钠与闪锌矿表面氧化产生的氧化锌、氢氧化锌或硫酸锌等氧化物发生化学吸附,而不与未氧化的闪锌矿表面发生吸附。吸附量测试结果表明,高锰酸钾对闪锌矿的预先氧化作用显著增加了海藻酸钠在闪锌矿表面的吸附量,因此高锰酸钾可以强化海藻酸钠对闪锌矿的抑制作用。      

离心重选—浮选脱硫工艺回收细粒级钨锡矿物的试验研究

为有效回收广西某细泥中的钨锡矿物,开展了离心重选—浮选脱硫工艺试验研究.细泥中WO3、Sn含量分别为0.52％和0.31％,其中钨主要为黑钨矿和白钨矿,分别占47.69％和39.42％;锡主要以锡石形式存在,占比为75.48％,其次为硫化物中的锡,占比为17.42％.细泥中-0.03 mm粒级产率为61.36％,其WO...     

Influence of mineral compositions and their modification on the selection flowchart and collectors of selective flotation of ores of nonferrous metals

The influence of the mineral composition of sulfides and their modifications on the selection of flowcharts for the selective flotation of ores of nonferrous metals is considered. It is shown that the oxidation conditions of collectors with the formation of a new form of the collector participating in the formation of sorption layers on the surface play a significant role in the mechanism of the interaction of the collector with minerals. Practical investigations showed that the application of combinations of compositions of various collectors allow us to increase their collection and selective properties and improve the efficiency of the flotation separation of minerals. It is revealed that the structure of the adsorption layer with the use of the composition of the collectors in the flotation (one of them is the xanthate) is determined by the ratio of components and sequence of their dosing. These results allowed us to change the flowcharts of flotation of the ores of the Tarnier, Gai, and other deposits with the recovery of modifications of pyrite and sphalerite relative to the stages of the flotation process.