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By Trevor Saldanha, Stephen Grano

A key uncertainty in flotation modelling is determining, a priori, the proportion of each mineral which will develop a certain rate constant for different feeds of variable liberation and hydrophobicity. First and foremost is the ability to predict the proportion of minerals that will not be recovered, even at very long flotation times, and which therefore report to the tailing stream as the non-floatable fraction (i.e., having a zero rate constant). Recent empirical evidence has shown there are at least two factors which contribute to heterogeneity in flotation rates and, in particular, the appearance of a non-floatable fraction - heterogeneity in the distribution of adsorbed collector amount on a particle-by-particle basis, even for the same liberated mineral in the same size fraction, and the existence of a critical contact angle below which the bubble-particle union is unstable. In this paper, inferred measures of the critical contact angle for liberated particles are compared with stability model calculations. This has demonstrated that the dependency of the critical contact angle with particle size and mineral specific gravity are explicable by bubble-particle stability considerations. This argument is further extended to the flotation behaviour of composite particles, as a function of liberation class, in which the wetting perimeter of the attached bubble on the composite particle surface is constrained by the presence of a surrounding hydrophilic domain for the case of simple binary composites. Reasons for the different flotation behaviour of composite particles having different textures, as noted in the literature, are also discussed in terms of the stability of the bubble-particle union.

Jan 1, 2014

By C. Eswaraiah

A drop weight tester (DWT) is designed and fabricated for the purpose of analyzing single particle impact breakage characteristics of different ores. The test results were evaluated through the breakage distributions of different size fractions at five different input energy levels. The breakage parameter, t10 (Narayanan, 1986) is used to represent the degree of size reduction, which is assumed to be representative of the breakage product size distribution obtained from single particle breakage. Representation of breakage distribution with this method consist one more breakage dependent parameter (a). To evaluate the impact breakage characteristic of different ores, a mathematical relationship was established to analyze the dependency of breakage parameters, t10 and a on specific input energy (EIS) or fracture energy (Tavares et al, 1998, Fandrich, 1998), specimen size (?) and Bond?s operating work index (WI0). Mathematical results developed gives adequate model for all ball mill modeling. It can be concluded that the drop weight test method is a useful and practical way of evaluating the impact strengths of various ores and results of which can be used in modeling mills.

Sep 1, 2012

By A. Wieniewski

The observed progress in technology of non-ferrous ores enrichment and condition of machines and equipment in the ores concentrators on the one hand have brought a possibility and on the other resulted in necessity for introduction of modernization actions. Positive results of investigations into influence of chemical modification of selected products of enrichment process on copper ores enrichment results gave possibility for implementation of chemical-flotation technologies of ores enrichment. The substantial development in flotation machines structure has contributed to modernization of flotation process resulting in increase of enrichment efficiency. The paper presents the idea and results of chemical modification of difficult in enrichment semi-products in the technology of copper ores enrichment and the results obtained after application of the modernised technology. The structure of large-volume flotation machines used in various stages of flotation and current situation in modernization of flotation process in copper ores concentrators are also described. The paper presents industrial-scale results of flotation after application of modified flotation reagents of collector group. Introduction of modifiers into the widely used xanthates resulted in increase of copper recovery in concentrate.

Jan 1, 2014

By J. R. Cui

The production of electric and electronic equipment (EEE) is one of the fastest growing areas. This development has resulted in an increase of waste electric and electronic equipment (WEEE). In view of the environmental problems involved in the management of WEEE, many counties and organizations have drafted national legislation to improve the reuse, recycling and other forms of recovery of such wastes so as to reduce disposal. Recycling of WEEE is an important subject not only from the point of waste treatment but also from the recovery of valuable materials. Consumer electronic equipment (brown goods), such as television sets (TV), radio sets, and video recorders, are most common. However, recent work on recycling of waste electric and electronic equipment (WEEE) primarily focused on personal computer and printed circuit boards scraps. Based on a detailed characterization study of consumer electronic scraps, recycling of TV scraps oriented to recovery of metals is highlighted by utilizing air table separation, eddy current separation, and optical (metal) sorting process. The result indicates that a high recovery of copper could be obtained by utilizing an effective gravity separation process. The separation results reveal that air table separation is an effective technology to recover metals from consumer electronic scraps. By using a DGS table, approximately 90% of non-ferrous metals were recovered in the heavy product with a purity of 40%. Printed circuit boards and cables in TV scrap cause metals loss due to the fact that metals in printed circuit boards and cables are not liberated from plastics and ceramic materials. The study shows that eddy current separation and optical (metal) sorting process provide alternatives for recovery of metals from shredded TV scraps.

Jan 1, 2014

By R. C. Miranda

This paper intends to demonstrate the applicability of tools for advanced process control and online particle size image analysis in crushing and autogenous grinding circuits. In a crushing plant, cameras are installed in the conveyor belts of the circuit products. The vision system continuously processes the acquired images and thus obtains the variation of the size distribution curve. From these measurements, the advanced control system can operate, for example, at the opening of the crusher, in order to keep the P80 in the desired range. In addition, through the power information and level of the crusher's chamber, it is possible to increase the capacity of the crushing circuit. If the crusher is not equipped with an automatic opening adjustment, a warning may be issued to the operator to provide this setting manually. In mineral processes that use autogenous and semi-autogenous grinding for fragmentation, obtaining online F80 through the vision system allows for manipulating the parameters of rotation speed and solids concentration, through which the amount of material at the critical particle size that is produced can be controlled. In addition, the noise produced in the mill can be measured and controlled. Thus, it is possible to prevent breaches and to optimise the mill capacity for grinding. Image analysis combined with an expert system that translates this information and acts to seek the most appropriate particle size distribution, brings greater stability to the process optimising the capacity of the equipment, which allows for significant gains in production.

Sep 1, 2012

By B. Rath

An effective process plan is an important part of maintaining consistent recoveries in mineral processing operations. Traditionally, Mineralogical studies are completed using chemical and metallurgical methods to monitor recovery and elemental distribution. The development of mineralogy and more efficient processes in mineral analysis techniques means that mineralogy is now more accessible as an efficient and comprehensive study tool. As operating costs increase and feed grades decrease it is important to maintain tight control of process and ensured maximum recovery is maintained at all times. Just a few days of losses in recovery caused by changes in ore type or processing conditions can have a large effect on total metal recovery and profit. Mineralogical audits can be used to minimize these losses by monitoring the fundamental behavior of feed ore on a regular basis. Smart use of mineralogical studies can develop mineralogical and ore type benchmarks in a detailed, which can be used in process control and monitoring. Geological ore types can be used to identify key mineralogical parameters that may be used in routine and cost effective analysis. Mineralogical systems ideally suited to this because of the depth of information on everything from modal mineralogy to locking/liberation characteristics and mineral associations. Mineralogical studies can equally be applied to specific unit operations within the process, which can allow more detailed information to be gathered on areas of the process that have been identified as critical. This will be especially effective for flotation or oxidation processes where process parameters can be very sensitive to small changes in mineralogy. This paper deals with the Ore Morphology, Ore Mineralogy, Gangue mineralogy, Photo micrographs under reflected, transmitted light and XRD studies Ore, Mineral studies of Sub grade Iron ore of Bacheli Complex, Bailadila Sector, India. Keywords: mineralogy, liberation, liberation studies, ore mineral, gangue mineral, morphology, jasper, ferruginous clay

Sep 1, 2012

By Hugo Barrientos

"The growing need to optimize the mining processes produces a need for users to have a simple, reliable, secure and cost-effective method to monitor the values of the variables measured in field. The solutions described in this paper, we will demonstrate how the implementation of Emerson Smart Wireless technology helps to optimize the leaching and electro winning processes. An effective monitoring of the variables involved in the operation of a heap leach, such as pressure, flow rate, pH, water level control and regulator valves can improve production and optimize the use of sulfuric acid, which results in a more effective management of resources and helps reducing input costs. Moreover, the constant monitoring of variables prevents the risk of landslides, reducing maintenance costs. In electro winning cells, the wireless solution measures variables such as pressure, flow rate, temperature and voltage provides a performance indicator for the entire operation, capable of detecting and predicting shorts, and monitoring the overall functioning of a cell or group of cells. As a result of the applications studied, users can monitor variables in real time, optimizing the use of resources, quickly detecting possible flaws in the process and reducing the risks in the operation. All these factors have a direct impact on company results."

Jan 1, 2014

By P. K. N. Raghavan

Bauxite is the principal source for the production of aluminum metal which has gained tremendous importance over the years due to its versatility as a metal capable of substituting almost all of the non-ferrous metals, non metals like wood, plastics, fibre glass, etc. and even steel in many applications. 90% of the high purity alumina needed for the production of this wonder metal in the world comes from bauxite. Even though alternate methods have been developed to produce alumina from non bauxite sources, owing to the high capital and operating costs involved, Bayer process still retains the superiority among all the methods by virtue of its simplicity and favourable economics. Bauxite continues to be the perfect ore for alumina production and its remarkable utilization makes it the most important non-ferrous ore. Most of the Alumina Refineries in the world process different types of bauxite and that too from varied sources. The technology employed in the Alumina Refineries depends on the Bauxite processed, with an ultimate view to produce alumina of required quality in the most efficient manner. Bureau of Indian Standards (BIS) and Indian Bureau of Mines (IBM) had from time to time put forward bauxite specifications for metallurgical and other applications. However, these are found no fully based on alumina technology, present developments and availability of different types of bauxite in the country. The aim of this paper is to provide scheme of metallurgical grading of Indian Bauxite based on the background of alumina processing technologies and availability of various types of bauxite in the country. Efforts are made here to evaluate beneficiation techniques for central Indian Bauxite from the point of view of alumina production. Keywords: bauxite beneficiation, digestion, alumina, gibbsite, bohemite, diaspore

Sep 1, 2012

By V. E. Vigdergauz

The work presented shows results of electrochemical study of pyrite hydrophobicity evaluated by air bubble induction time (IT) measurements. On the basis of measured IT?s an average thickness of the thin liquid film prior to its rupture has been evaluated, which confirms long-range character of the interactions between air bubbles and hydrophobic surfaces. Obtained data are discussed in the frame of recent studies of structures of solid-liquid interface based on molecular dynamics simulations and results of surface force measurements.

Jan 1, 2014

By Pamela Castillo, Marcia Muñoz, Rodrigo Luca, Brian Townley, Fernando López

In the present study we discuss the value of multi-element geochemistry as a tool for semi-quantitative to quantitative bulk mineral characterization in geological and geo-metallurgical modeling of porphyry copper type deposits, with an emphasis on hydrothermal alteration associations, types and intensities. In mine production of porphyry copper deposits much effort is placed on ore grade and geological modeling, applied for predictive mineral processing behavior, from blasting, grinding, leaching or flotation, down to waste disposal and environmental management. High confidence geological models are commonly based on geological mapping of drill core and surface/ underground exposures, combined with discrete mineral characterization (e.g., petrography, QEMSCAN®, spectroscopy, etc.). Unfortunately these are expensive and applied to limited numbers of samples, thus lacking sufficient representation and not suitable for geo-statistical modeling. In addition, geological mapping always presents uncertainty, based mostly on qualitative estimates. The combination of information usually provides geological models that are hard to combine with geo-metallurgical data, much less with mineral processing predictive behavior models. The advent of multi-element geochemistry, at low cost, has allowed employment of such tools massively, yet little use is given to the data, usually focused on elements of economic interest (main ore and credits) and elements of negative impact to concentrates and/or process. Geochemistry reflects the mineral composition of rocks, thus allowing characterization of lithology, alteration types and intensities, and mineralization. As examples of such applications we present generic classification techniques which were developed on various porphyry copper deposits of northern Chile, these based on multi-element geochemistry, allowing for semi-quantitative to quantitative high resolution modeling of key aspects of lithology, hydrothermal alteration and mineralization, and which may be cross-referenced to metallurgical test samples and by that, to geo-metallurgical properties of rocks and modeling. In addition, as data is quantitative and continuous, modelling of gangue can benefit from geo-statistical modeling.

Jan 1, 2018

By V. F. Bannikov, A. P. Kozlov

"The purpose of this study was to develop a theoretical and technology framework for designing new combined technologies for processing tailings containing non-ferrous and noble metals using dry separation. The main goals of the study were: identifying the distribution patterns of valuable components in various fractions in dry separation processes; examining the patterns identified for different types of non-ferrous and noble metal tailings; developing a theoretical and technology foundation for the development of innovative technologies for the efficient processing of tailings with minimal process water consumption. To examine the possibility of efficient recovery of valuable components from refractory tailings using dry separation, an experimental laboratory unit was designed and built, composed of novel or modified lab equipment: plasma unit for increasing the magnetic susceptibility of Fe - containing minerals; magnetic separator supporting isodynamic and polygradient fields; pneumatic separator for the dry separation of finely dispersed mineral mixtures; dielectric separator using the resonant frequency of the electric field. The laboratory unit supports various modifications and combinations of the lab equipment. The experimental studies led to the development of a unified process scheme for lab tests of mature and non-ferrous smelter tailings using dry separation methods.INTRODUCTION The huge amount of waste from mining and processing of mineral resources Russia inherited from the extensive use of mineral resources in the Soviet Union and amount of waste continue to grow. Often the content of valuable non - ferrous, rare and noble metals in waste exceeds the balance contents in natural ores of the developed deposits. The availability of a rich scientific reserve for the creation highly effective innovative technologies for waste processing determines the necessity of the acceleration in the resolution of problems of the complex assessment, capitalization and involvement in the processing of technogenic resources in Russia (Chanturiya and Kozlov, 2014.)."

Jan 1, 2018

By Yong Liu, Peng Qian, Shu-Feng Ye, Shao-Jun Chu, Pei-Wei Han

"Chromite with a low mass ratio of Cr to Fe (Cr/Fe ratio) was treated by the carbochlorination method using solid chlorinating agent (MgCl2 and CaCl2) and carbon in the present paper. The results showed that iron could be selective removed mainly in the form of FeCl2. The removal of iron was indirectly, which consisted of the decomposition of solid chlorinating agent to release Cl2/HCl and the carbochlorination of FeO•Cr2O3 by Cl2/HCl and C. The Cr/Fe ratio increased as increasing temperature from 700 ? to 900 ? in air atmosphere, while the tendency was opposite in N2 atmosphere. The removal efficiency of iron by CaCl2 was better than that by MgCl2. At last, a new pelletizing process was proposed to treat fine chromite with a low Cr/Fe ratio based on carbochlorination method, which could produce the high quality roasted chromite pellets with higher Cr/Fe ratio and compressive strength. INTRODUCTION Chromite is mainly used for the production of ferrochromium. A high Cr/Fe ratio (>2) of chromite is usually required to meet the technical specification of ferrochromium.(Gasik, 2013) Attentions have been attracted to the economic and efficient methods for the recovery of chromium from lower-grade ores as the higher-grade ores become depleted. However, the Cr/Fe ratio is difficult to improve through the conventional beneficiation methods (such as gravity concentration, flotation) due to the spinel composition, although beneficiation methods could increase the metal content of chromite ores by removing gangues.(Nafziger, 1982) The main industrial mineral of chromite is (Fe,Mg)O•(Cr,Al,Fe)2O3, which belongs to spinel magnetite.(Liu, 2013) Iron should be selectively removed through the structural dissociation of spinel to increase Cr/Fe ratio.(Nafziger, 1982)"

Jan 1, 2018

By Peter Ay, Harry Pempel, Satya Narra, Mike Müller, Jens Markowski

"Within the next few years major changes in mobility are expected. Increasing numbers of electric powered cars, electrobikes and E-Scooters define the transport sector. Recently lithium based traction batteries as storage medium have led into matrurity of series production combining high electrical efficiencies with low weights and compact dimensions. Due to the relatively young development with lithium batteries utilization, only few investigation were conducted regarding their recycling. Conventional battery recycling processes can not be applied due to differences in design and chemistry. So an automated disassembly and processing procedure for lithium traction batteries has been developed in the R/D-project ""Li-WERT"". Instead of complete smelting of the batteries without pretreatment, an automated disassembly and specific treatment of the material streams was realised, adjusted to the needs of the subsequent recovery technologies. A higher quality, with reduced expenses for the separation of fine-grained or fused material mixes, can be obtained for the individual components. The automated disassembly using an industrial robot significantly reduces dangers for the operating crew. The selective disassembly and beneficiation allows full recovery of the fractions. The batteries will be disassembled to cell level by the industrial robot. Anodes, cathodes, and separation layers are isolated and processed. The technology is designed, that no waste is generated for disposal. The pelletised cathode coating and the other separated metals (stainless steel, copper, aluminum) can be used in respective metallurgical plants. Circuit boards and plug contacts are also coveted secondary raw materials for reuse. The process is modular and offers high flexibility, e. g. for new battery types/ sizes by quick adjustment of the robot and tool change. Adaptation to other cathode materials (e. g. Li[FePO]) is possible. After finishing the R/D-project, a pilot plant for demontage was realised in 2013."

Jan 1, 2014

By B. S. Moroney

Elemental distribution varies widely in the ores, minerals and beneficiated products depending on the constituents. Accurate analysis of each element present in various beneficiated products is utmost required to assess the grade in view of zero waste technology. Hence, the suitable methods and instrumental technique is of prime importance as the distribution of various elements differs in the beneficiated products. Conventional classical technique of analysis is absolute and due to this, it has not become obsolete. Besides, it is much needed for making standards for various relative techniques. Instrumental techniques comprising of X-ray fluorescence, Induced Coupled Plasma Analyzer, Carbon-Sulphur Analyzer, Atomic Absorption Spectrometer etc. are important for quick and accurate analysis. However, the selection of these instruments depend on the nature of material to be analyzed. This paper highlights the importance and use of various methods/techniques and instruments involved in the analysis of various ores, minerals and beneficiated products. Keywords: wet classical, x-ray fluorescence, induced coupled plasma analyzer, atomic absorption spectrometer

Sep 1, 2012

By Magnus Evertsson, Rebecka Stomvall, Josefine Berntsson

"Understanding the effect of particle shape on dry rheology is considered to be an important aspect in order to replace natural sand used in concrete with manufactured sand. Crushed particles from solid rock are normally less rounded and have less equally shaped dimensions compared to natural sand. Thus, the flowability and workability of the concrete will be different. In previous research, it has been demonstrated how different crushing techniques affects the shape of the particles. In many cases it is believed that Vertical Shaft Impact (VSI) technology is a way forward to replace natural sand. To be able to study the effect of VSI at the smaller fractions (63-2000 µm) sufficient measurements methods to determine particle shape are required. Optical tools to analyze the aggregates would make it possible to study a large amount of particles at small fractions. The determination of particle shape of aggregates is challenging since the shape is highly irregular and the size span of particles are very large. This study aim to evaluate one of the available optical tools, the Camsizer, for digital imaging determination of shape and size distribution. The available default shape parameters of the Camsizer are studied to understand the meaning of the parameters and their suitability for determining the quality of manufactured sand. To evaluate the capacity to determine particle shape, tests are made with 35 different materials. The results are compared with the dry rheology measured with the standardized "flow cone" test. Dependence has been previously proven between particle shape and the mass flow rate in the cone. Three different shape parameters, aspect ratio, sphericity and symmetry, are studied with the Camsizer and the results are compared with the mass flow rates in the cone. The results indicate a strong linear relationship between the optical parameters and the flow cone test."

Jan 1, 2014

By Tuan V. Nguyen, Kosta Simic, Louis Mittoni, Murray Rudman, Jean D. Swift, John B. Farrow, Phillip D. Fawell

"Research projects towards developing a sound understanding of the factors controlling the performance of gravity thickeners have been conducted by the AJ Parker Cooperative Research Centre for Hydrometallurgy since 1988 through AMIRA International. The current phase of this work, the three year P266D .Improving Thickener Technology. project, has 27 sponsors comprising mineral processing companies, reagent suppliers and thickener manufacturers.These projects have resulted in the development of a range of tools and techniques to address flocculation, thickening and associated dewatering issues. A number of Computational Fluid Dynamics (CFD) models have been developed to predict likely full-scale thickener performance under various process conditions, based upon a knowledge of thickener design, plant flows and assessment of the flocculation behaviour of the feed slurry. At the same time, various laboratory and plant studies have been used to quantify important thickener processes, and to provide validation of the CFD models. These numerical and experimental capabilities have been applied to various thickener issues across a broad range of mineral processing operations, leading to significant process improvements and substantial financial benefits.This paper presents an overview of the work conducted during these projects, focussing on the research tools, the nature of the information that has been gained and the implications for thickener performance."

Jan 1, 2003

By Tomasz Niedoba

Coals occurring in nature are characterized by various properties. According to Polish norms, the classification of coals taking into consideration their calorific value contains coals from type 31 (flaming coal) until type 43 (meta-anthracite). The samples of coal of type 31 were taken for investigation. To this purpose, the approximations of ash contents and density distribution functions were done for this coal type (determination of marginal distribution functions). They were the basis for application of so-called Morgenstern distribution functions to approximate the function Z=L (?), where Z is ash contents and ? - coal density. Then, the comparison between obtained results was performed and the results were statistically evaluated. They are the basis for the further research of other types of coals.

Sep 1, 2012

By G. Merazchiev

In the selection of copper ? molybdenum concentrates with the use of reagents containing sulfide ion ? sodium sulfide, sodium hydrosulfide etc for depression of copper minerals and pyrites, big part of depressor is oxidized by oxygen, which is dissolving in pulp during aeration with air in flotation machines and it is expended unproductively. This is the main reason for the big expenditures of depressor, reaching up 15~20 kg/t collective concentrate and the high exploitation expenditures for the copper ? molybdenum selection. Effective direction for lowering expenditure of depressor and increasing of the technical ? economical effectiveness of moly production is the conducting of the selection in nitrogen medium. In the paper are shown the results, obtained by applying of this direction in selection of collective copper ? molybdenum concentrate from the porphyry copper deposit ?Ellatzite? ? Bulgaria, in which the ratio Mo:Cu is over 1:120. In laboratory conditions, through comparative experiments in medium of air and nitrogen are defined: expenditure and initial concentration of NaHS in pulp for effective depression of copper minerals and pyrites; kinetics of flotation process of molybdenite; influence of pulp density; emf (negative milivolts) of pulp and the expenditure of nitrogen on tech-nological indexes of molybdenum flotation. When working in nitrogen medium decrease of NaHS in rougher molybdenum flotation from 40% to 45% is settled. When nitrogen is also fed in cleaner stages, the total expenditure of depressor is lowered by 64%. The quality of end molybdenum con-centrate is raised with over 5%. On the ground of the results of laboratory studies and of world practice data, an industrial installation for selection of copper ? molybdenum concentrate in nitrogen medium in Wemco inert ? gas machines.

Jan 1, 2014

By A. Gueciouer, A. Akkouche, K. Chalah, A. Benmounah

"Drilling solid waste is a typical industrial solid waste, and it is a major pollutant source to ecological environment. Generally, waste management dewatering systems separate solids and fine particles from the liquid phase of drilling fluid, thereby leaving a clarified aqueous solution and allow the cleaning of waste fluids. Typically, dewatering waste management systems clean drilling fluid through coagulation, flocculation and/or mechanical separation. Chemicals used in dewatering are based on the coagulation-flocculation process, which it facilitate the removal of suspended solids and colloidal particles. The factors which can promote the coagulation-flocculation are velocity gradient, contact time, and PH. The objective of this work is to optimize a formulation adequate for dewatering based on the coagulation-flocculation process used coagulant (Aluminum sulphate), anionic flocculants (Partially Hydrolyzed Polyacrylamide) and anionic polyelectrolytes (in solid form with linear chain with very high molecular weight). The results obtained show the good efficiency of the coagulant and flocculants. INTRODUCTION Rig site dewatering of drilling fluids with recycling of processed water can help an operator to comply with environmental rules by reducing volumes of waste and reducing long term liabilities. It can also reduce disposal costs and provide a cleaner drill site overall. Most of the environmental concerns during the 1980s involved hazardous materials and toxic wastes. Drilling fluids, many of which are chemically benign, have escaped many of the difficult-to-comply-with rules and regulations. During the 1990s, however, operators may be required to submit a written plan for liquid waste reduction for even nonhazardous materials. Many states and local agencies may institute total bans on oil field wastes. Drilling rigs typically produce about 1 bbl of liquid waste for every 1 ft of hole drilled. Thus, a typical drilling operation can produce a large quantity of waste [1]. To improve the dewaterability of sludge, different pretreatment processes have been widely studied and developed including thermal, chemical, magnetic, mechanical, acoustic, electric, electro-acoustic and their hybrid treatment processes [2]. Rig site dewatering (figure 1) is the process of injecting coagulants or flocculating chemicals into the mud entering a large clarifying centrifuge. Coagulation occurs when the solid and allowing it to be attracted to other solids by van der waals forces. Flocculation is the binding of individual solid particles into aggregates of multiple particles. It is physical, rather than electrical, and occurs when one segment of a flocculating polymer chain absorbs simultaneously onto more than one particle [3]."

Jan 1, 2018

By Grigory Voyloshnikov, Sergey Petrov, Vladimir Petrov

"The treatment of high-grade copper gold-bearing ores is practiced extensively. However, due to low concentration of copper the application of a separate process for copper recovery can make this process uneconomical. The copper, in particular: in oxide minerals, intensively bounds with cyanide during conventional cyanidation. In this case, cyanide is not able to react with precious metals and the consumption of cyanide increases. The resulting copper cyanide complexes have a negative effect on the recovery of gold. Due to decreasing of the process parameters, a repeated use of the recycled solutions can be hindered, especially in the case of heap leaching. The technology of copper removal from the process solutions with simultaneous regeneration of free cyanide from copper-cyanide complex and producing of a saleable high-grade copper concentrate was developed. An important feature of this technology is simplicity, the absence of complex or dangerous operations and the use of common reagents. The choice of equipment depends on the ore treatment option: heap or vat leaching. Also, simpler equipment schemes are available. The studies, tests and industrial practice show that if the concentration of copper can be decreased down to the first numbers of mg per ppm or lower, it is reasonable to maintain the process copper grade in the recycled solutions at 30-50 mg/L. In this case, recycling of cyanide-bearing solutions is unlimited. The regeneration of free cyanide from that of bound with copper and other cyanide complexes is 95-98%. The grade of copper in the concentrate is 55-60%. This technology is an economically competitive option, in particular: with the account of the sales of copper concentrate. The removal of copper has a positive effect on gold recovery, especially during heap leaching. In addition to, this offers significant benefits in reduced costs."

Jan 1, 2014