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By Arkady Senchenko, Yuri G. Seredkin, Alexander Aksenov

"This paper describes the development of efficient technology for the treatment of complex ores containing gold and copper as major valuable components, where silver is present as well. Copper is mostly represented by oxidized minerals in these ores; however, copper sulfides are also present. Gold is present in its free form and in associations with oxidized and sulfide minerals; silver usually accompanies gold. Complex composition of the ore requires complex solutions for their treatment. The results of searching for the techniques to recover valuable components are described in this paper. Gravity methods allow for free gold recovery, flotation methods allow one to recover major part of copper and precious metals in associations; and in the result of leaching process additional amount of copper, gold and silver is reported to solution. Combining all these methods help achieving high levels of valuable components recovery. When implementing a combined technological flowsheet about 80 % of copper goes to concentrates from gravity and flotation of sulfide and oxidized copper minerals; and sulfuric acid leaching allows increasing total copper recovery up to 90 % and higher. Major part of precious metals (up to 90 % of gold and 80 % of silver) is recovered to these concentrates, and after hydrometallurgical treatment it is possible to increase gold recovery up to 96 %, silver recovery - up to 90 %. The suggested technology helps solving the problem of precious metals recovery from complex gold-copper ores, and allows treatment of the ore with different proportion of sulfide and oxidized minerals, and at different valuable components grade."

Jan 1, 2014

By V. A. Feofanov

Technogenic water of ore mining enterprises, nonferrous metals operations, the enterprises of electroplating and instrument making, containing copper in the form of those or other connections can serve as perspective sources on receiving the copper-bearing raw material. Extraction of copper from the given water also solves a problem of water treating from a toxic component that reduces environmental load at evacuation of water in an open basin. The method of case hardening allows extracting copper selectively with reception of a deposit with the content of copper up to 70%. Weakness of the method is its efficiency basically in acid reduction, and also its low degree of copper extraction. On the basis of case hardening the method of galvanic coagulation is devised. It is based on the work of a short-circuited galvanic cell of iron-coke at variable contact of coupled metals components among themselves, cleared by the oxygen of air. The following processes of galvanic coagulation are considered: ? Extraction of copper; ? Formation ferrites of copper; ? Copper sorption on just-aggregated oxide forms of iron. Establishing conditions for passing the given stages provides an opportunity of copper extraction from technogenic water at any value of ??, content of salt and concentration of copper with reception of a compact deposit from which it is possible to extract copper by the known ways of enrichment and metallurgy. Investigations on optimization and intensification of galvanic coagulation with the purpose of reception the maximum rich deposit on copper have shown that the average contents of copper in a solution of 100~200 mg/dm3 the contents of copper in a deposit is 6%~10% at extraction 85%~90%, depending on characteristics of treated technogenic water. Using methods of scanning microscopy it is determined structures, composition and mechanism of phase formation in investigated electro-chemical process. The second stage of galvanic coagulation increases a degree of copper extraction up to 98%~99% that allows returning the cleared waters in circulation for waste recycling or evacuation in an open basin. Nowadays the method of galvanic coagulation is the most acceptable for copper extraction from technogenic water both from the point of view of efficiency and instrument setting that allows applying the method in conditions of the working enterprises.

Jan 1, 2014

By Alexey P. Tatarinov

Under modern economic conditions in Russia, gold heap leaching is the most effective way of investing into gold-mining industry. Gold is recoverable from small-size deposits, low-grade ores from oxidation zone, cut-off grades, and overburden rocks using heap leaching. This technology is cost-effective and allows a saleable metal to be obtained within the first year of operation. The investments for heap leaching are lower than those of for a traditional plant technology. Production cost per one gram of Au is 5-7 times lower than that of during a plant flow sheet. A seasonal development of mines can be possible. With reference to this, heap leaching resembles the technology of placer deposits development. One of the major advantages of heap leaching is the form of the product. Gold can be obtained as dissolved in a clarified PLS, which allows the further quick treatment. The amenability of ores to heap leaching depends on their mineralogical composition. Oxidized porous ores with a good access of a lixiviant to valuable particles can be treated without pre-crushing. Clayish minerals are often found in oxidized ores with free gold. In order to build ground for heap, several major methods combined with various pad materials are used. These methods have been used at many plants and are reliable. The development of heap leaching technology for gold ores for the deposits from Yakutia, Zabaikalsky region, Primorye region, Uzbekistan, Tadjikistan, and Kazakhstan began in the 70s. However, it has been commercially used only since 1990. The first heap leach plants were built and commissioned in the USSR in 1991 at Vassilkovsloye deposit (Kazakhstan) and at Maiskoye deposit in Russia in 1994. Pilot plant testing was conducted in 1996 using ores from Kuranakh ore field, deposits Phiskulturnaya-Kholodnaya and Lopukhovskoye from the Aldan region. After the first successful commissioning of heap leaching plant in Russia, this technology has been commercially applied for deposits. Every year 1-2 heap-leaching plants were commissioned. More than 30 heap-leaching plants have been commissioned both in Russia and in the former Soviet Union using technologies developed by IRGIREDMET. Keywords: cyanide leaching, heap leaching, ore, percolation, solutions, lime technology

Sep 1, 2012

By S. P. Das

Tumbling mill is an important unit operation in a mineral processing industry whose operation needs to be understood to make it an energy efficient unit. One of the important mill parameters is the impact spectra generated by collision of the moving charge mass on the mill shell. This process also generates mechanical vibration on the mill shell and propagates to the plumber block of the mill. In this work, we tried to understand the impact spectra by using different minerals such as Banded Hematite Quartzite (BHQ), Hematite and Quartz as mill feed of a semi-autogenous (SAG) mill. The said mill is of 1000 mm diameter and fitted with a force sensor on the mill shell and a vibration sensor on the plumber block. The analysis of the impact spectra was done by taking into consideration the peak impact force above a certain threshold value. It clearly shows that the impact force decreases as the particle size become finer irrespective of the mill feed material. This can be used as an effective tool by the mill operators to have an understanding of the mill product size reduction. The mechanical vibration tapped by a tri-axial accelerometer was analyzed by power spectral density analysis. The vibration signal analysis shows the variation in the power spectrum magnitude both at lower and higher frequency. It also shows inconsistency in case of BHQ where it shows a significant decrease in vibration at lower frequency and increase in vibration at higher frequency. Therefore, the impact spectra analysis is a better method compared to vibration analysis in understanding the mill product size reduction.

Sep 1, 2012

By M. Ranjbar, M. Khosravi Rad, A. Tohry

"The filling degree is defined as the volume ratio of the load inside the mill, which determines the power drawn from the motor, as long as the filling degree is not more than the optimum level. As the filling degree increases beyond the optimum level, the impact energy inside the mill will decrease and as a consequent, the mill power output will also decrease. Therefore, the mill filling degree is a key parameter in evaluating the grinding circuit performance, as it determines the mill reaction to the input feed. Since this parameter has an impact on the mill capacity, measuring the mill load is vital for control and optimization of grinding process. As in Choghart Processing Plant no instrument is available to measure the AG mill filling degree, an empirical model based on the bearing-oil pressure is proposed. The AG mill filling degree was related to the differences between the average pressure of input and output bearings, the circulating load and power drawn. It was shown that a quadratic model could relate the mill filling to the above mentioned measurements. This model showed that when the power drawn and circulating load decreases the bearing-oil pressure needs to be checked. If the bearing-oil pressure increases the feed rate needs to be decreased and steel ball be charged to the mill to increase the grinding and prevent mill overloading. INTRODUCTION The feed quality (size and hardness) affects the grinding process in AG mills. Reducing the top feed size and increasing the ore hardness reduce the mill efficiency and increase the particles with critical dimensions inside the mill. These will result in increasing the mill filling degree and reducing the mill throughput and efficiency (Wills and Finch, 2015). The volume ratio of the load inside the mill is called filling degree, which determines the mill power drawn. It is believed that if more energy is mainly spent on grinding (Wills and Finch, 2015). Therefore the mill power draw is used as a mean to control the mill efficiency."

Jan 1, 2018

By V. Avdochin

The main reason of flotation process fluctuations is mixing ores of various properties from various sections of a deposit. Other, also important reasons are changes in parameters of facilities of technological cycle, as well as properties of reagents applied. According to estimates, instability and non-optimized parameters of flotation owe 3% to 6% of valuable component losses. Without ore averaging systems flotation process is characterized by considerable fluctuations of all input, output and intermediate parameters. Stab One more way is optimizing the process, providing for determination and maintaining optimal parameters of the process. In these conditions application of various mathematic models does not allow controlling the process by the way of action on input parameters of the process with further precise reaching required values of output parameters. More effective is to be application of flotation models for solution of questions of choosing and optimizing of automatic control systems. The work presented examples of application mathematic model of flotation process for estimation of effectiveness and choice of parameters of automatic control system that reduces considerably a stage of preliminary studies in elaboration, designing and modernizing automatic control systems.

Jan 1, 2014

By L. A. Vaisberg, E. V. Shishkin, S. V. Kazakov

"This research is targeted at finding solution to the problem of reduction of specific energy consumption during disintegration of solid materials with the help of machines, operating in a quasiresonant mode. The objective of the research is the development of an energy-saving method of disintegration of supestrong rock and by-products on the basis of vibrational units with two movable crushing elements, operating in a rigorous synchronous-antiphase mode without stringent kinematic links. In the course of investigations a mathematical analysis of the dynamics of vibrational units was performed to determine required mechanical parameters, allowing for adjustment of the machine actuating elements to high-frequency synchronous-antiphase oscillations in the quasiresonant frequency range. As a result of performed pilot tests, the reliability of desktop studies was confirmed and the dependency of process parameters on the machine regulated parameters in the quasiresonant frequency range was identified. The analysis of obtained data showed that during machine operation with cone-shaped crushing elements in the quasiresonant frequency range, the yield of the high-quality finished product (WFA grits of -3+1 mm grain size class) in one pass reaches 35%, whereas the form of the particles corresponds to the grain form with sharp edge. The quasiresonant operation mode of the vibrational unit with two freely suspended crushing elements (without stringent kinematic links) provided substantial reduction of energy intensity during crushing down to 0.16 kWh/t, which shows reduction of power consumption for crushing by more than 15% compared to conventional equipment.INTRODUCTION The most common and energy-consuming processes in the mining industry are the crushing and grinding of various solid materials. Such large energy costs are due to the fact that the capabilities of the existing crushing and grinding machines are based on traditional methods of destruction, and are limited by their kinematic features, which do not allow to reduce the energy intensity of processes, to lower the irreversible loss of useful components, to improve the quality of marketable products. In connection with the foregoing, the task of energy costs reducing for disintegration is one of the most important issues in the enrichment of both minerals and processing of man-made raw materials. The solution of this problem is possible only through the creation of a fundamentally new highly efficient technique and technology for processing raw materials [1, 2]. It seems that the greatest prospects in this respect are the vibration methods of disintegration, in particular, the vibratory cone crusher based on a two-mass system without rigid kinematic connections between the crushing bodies, with vertical vibrations of the working bodies. In this machine, the principle of rational material destruction is realized – crushing without re-grinding [3-5]."

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

"The business importance of water for mining companies is unequivocal as it may affect several aspects of mining projects ranging from the life-and-death license to operate to the imperative economic viability. It is thus no wonder that nearly all mining companies acknowledge water-related risks, issues and opportunities in their respective sustainability report. Somehow, this procedure has fostered the idea that water frugality could be the sustainable solution to several water-related issues. The regular exercise of water accounting should then follow as a key strategic requirement. Water accounting is defined as the application of a consistent and structured approach to identifying, measuring, recording and reporting information about water. However, several factors discussed herein have led to the fact that some water accounts are still produced using means (hardware and software) which undermatch the value actually associated with water. The resulting fuzziness about water usage could result in missed opportunities, suboptimal operations or even lead to environmental law violations. This paper subscribes to the distinctive perspective that, once underlying concepts and practical definitions have been standardized under a supported framework, such as the openly available Water Accounting Framework (WAF) published by the Minerals Council of Australia, most of the remaining water accounting issues may be boiled down to accuracy issues and, ultimately, to how much accuracy is valued by the stakeholders. Using the latest WAF document as a baseline for best practices of water accounting and, borrowing concepts from the fields of sensor network design in the process industries and best practices of metal accounting, this paper reviews some essential accuracy issues to be considered when designing or analyzing water accounting systems in mineral processing. The current paper also includes some elements for a promising attempt to include the value of information paradigm inside the water accounting best practices."

Jan 1, 2014

By K. Saberyan

Zirconium and hafnium are two important elements in nuclear industries. Zirconium is used in fuel rod for its low neutron absorption. Hafnium should be separated from zirconium, because it has higher neutron absorption cross section. In this research, separation process of the mentioned elements from (Zr+Hf)Cl4 mixture produced in the Zirconium production plant (ZPP) of Iran (Esfahan) was studied employing solvent extraction method in the nitric acid medium by using tributylphosphate (TBP) as solvent, and kerosene as diluent. The effects of nitric acid, sodium nitrate and amount of extractant, zirconium concentration in aqueous phase, phase ratio, agitation time, and mixer agitation rate were investigated on the separation process. The process was optimized at 5 M nitric acid, 1 M sodium nitrate, 60% (v/v) TBP. The optimum values for phase ratio, agitation time and agitation rate were 1.5 min and 500 rpm respectively. In this condition, the zirconium extraction efficiency, and separation factor were 65.1% and 205.59, respectively. Finally, we accessed to nuclear grade in this research.

Jan 1, 2014

By R. Chowdhury

Axis House manufactures and supplies alkylhydroxamate reagent of various carbon chain lengths for application in flotation of oxide copper and other minerals. As part of reagent performance improvement the structural factors of hydroxamate are examined by various analytical tools in particular with X-ray diffraction of single crystals. In a recent publication, the structure of n-octylhydroxamic acid and its corresponding potassium salt are presented with findings of hydroxamic functional group geometric preference, H-bonding, keto-enol tautomerisation, acid-salt aggregation and alignment of carbon chain. In this paper an example of branched alkylhydroxamate 3, 5, 5-trimethylhexylhydroxamate will be presented and compared with the result of linear alkylhydroxamate.

Sep 1, 2012

By Fedotov Pavel

One of the efficient means of ore disintegration during the processing is its volume breakage in such machines as roller-presses. Up to date neither the ore disintegration mechanism in roller-presses nor the reasons of their high efficiency are thoroughly investigated. In this work, the mathematical model of Finite Element Method of bad material disintegration in roller-press is discussed. The mechanism of the interparticle ore disintegration is traced.

Sep 1, 2012

By Xiaodong Jia, Richard A. Williams

"The packing of particles is a fundamental property of a material or system made up of particulates because it underlies many other physical properties of that material or system. Despite being ubiquitous, particle packing has not been an easy subject to study either experimentally or theoretically, except for a few regular shapes.This paper describes the recent developments, arising from research at Leeds, in the computer modelling of packing of complex shaped particles and prediction of physical properties of the structures represented by the packing. The computer model DigiPac, is capable of packing particles of any shapes and sizes in a container of arbitrary geometry. Figure 1 shows a few examples that are relevant to the mining and mineral industry.The ability to predict packing structure of real particle shapes and to compute directly some structuredependent physical properties (such as liquid permeability, mechanical strength/stability, compaction and sintering, dissolution and leaching, etc.) is obviously highly desirable and has significant potential in industrial applications. Examples are presented relating to the packing of granular materials.The mining and mineral engineering industries are well placed to exploit this advance in digital packing and simulation since they deal primarily with asymmetric and complex particulate mixtures. In the future we expect to see a number of developments in this area including:Algorithms that can optimise packing to achieve user-defined propertiesA more rational approach to determining flowability of complex powdersUse of these more realistic packing algorithms linked to blast and crusher design"

Jan 1, 2003

By Jaime Sepúlveda

"A broad diversity of critical operating conditions may influence, in very convoluted ways, the actual performance of any given mineral processing system, to the extent that it becomes nearly impossible to empirically determine the independent, decoupled impact of each condition. An effective approach to better understand the behaviour of such complex systems is via the extensive use of sufficiently detailed and reliable mathematical models, allowing the process analyst to explore and learn about the independent effect of all relevant operational conditions. Certainly, these tasks are greatly facilitated if the appropriate software tools - such as the Moly-Cop Tools software package - are readily available. Moly-Cop Tools 3.0 is a set of 63 easy-to-use EXCEL spreadsheets designed to help process engineers characterize and evaluate the operating efficiency of any given grinding circuit, following standardized methodologies and widely accepted evaluation criteria. Moly-Cop Tools 3.0 covers conventional and semiautogenous mills, crushers, HPGR’s, rod mills and vertimills, with the corresponding mass balance and parameter estimation routines; plus complementary spreadsheets regarding Bond’s Law calculations, grinding media selection and performance evaluations and other useful utility functions. As a relevant example of application, specifically focusing on semiautogenous grinding operations, the current publication describes how the models can help us learn and rationalise critical empirical observations such as the relationship between feed particle size and optimal ball filling, the role of the rocks as autogenous grinding media as well as the impact of feed size and discharge grate opening on the mill grinding capacity. Over the last 20 years, Moly-Cop Tools has gained wide acceptance around the mineral processing community in recognition to the quality of the mathematical models contained, their simplicity of application and ease of sharing of the calculations amongst all interested parties, since it is available free-of-charge with no restrictions to make as many copies as needed."

Jan 1, 2014

By Z. K. Liu

Production of the amines collectors and cation surfactant gives out the liquid waste containing high COD (Chemical Oxygen Demand) and ammonium & nitrogen, which is difficult to be treated with conventional biological method to reach waste water discharge standard. In this paper an engineering practice of treatment on the liquid waste by the technology combined high effective microbe with A/O (Anaerobic& aerobic) process is presented. The quality of treated water comes up to class A national standard for discharging.

Jan 1, 2014

By Claudio Bisso, Javier Vargas, Charles Lozano

"This paper summarizes the activities performed to predict SAG milling throughput at Minera Esperanza. Having highly reliable geometallurgical models aided by the new computer tools and specific metallurgical testing to rely on has become a major issue in recent times due to their impact on the business. Minera Esperanza’s SAG throughput model was constructed by characterizing the ore feed and operational parameters of the plant. Producing a robust model required satisfying number of requirements for the parameters used for both the ore and the plant as follow: 1) geologic and geometallurgical characterization parameters; and 2) parameters of a plant running at the rated production under optimum operating conditions. Obtaining these parameters required increasing the quantity of samples and metallurgical testing through drilling campaigns, mapping the drill holes and putting samples through various comminution tests while sampling all operational flows at the plant to obtain the metallurgical information for the operational parameters. The information was entered on the JKSimMet software to enable a throughput model to be developed to output SAG mill throughput predictions that are very close to actual throughput figures, i.e., accurate within a range of 2% on a monthly basis."

Jan 1, 2014

By P. Banerjee, P. Dash, S. Sriramoju, A. Suresh, R. Lingam, T. Ray

"One single property that influences the quality and market value of coal to the maximum extent is the ash content. The lower the coal ash higher is the energy utilization and potential for different applications. Even though Indian coal washeries aspire to produce coal with low ash, the intimate distribution pattern of ash bearing minerals in the coal matrix becomes the real bottleneck, as it brings down the clean coal yield to the impractical value. Because of this fact, most of the Indian washeries are operated to produce coal with 14-15% ash content at the yield of around 40%. In this context, with an objective to produce low ash coal at higher yield, a novel chemical beneficiation route has been explored to demineralize the high ash containing Indian coals. In this present work, the production of low ash clean coal from high ash Indian coals using chemical leaching process has been studied at pilot plant level. The leaching process parameters such as reaction temperature, reagent concentration, reaction time, coal-liquid ratio and agitator speed have been optimized for the flotation tailings sample from a captive washery of Tata Steel. The results obtained show that 67% demineralization could be achieved in a single stage of leaching process with a product yield of more than 65%. For further demineralization, multistage leaching was carried out and the results showed that 75-85% demineralization could be achieved with significant reduction in alumina to silica ratio. Additionally, the phosphorus content is also significantly reduced from 0.20 % to 0.022 %. Further, it is interesting to note that there is no increment of sodium content in the product coal after chemical treatment."

Jan 1, 2014

By Hajime Miki, Mutia Dewi Yuniati, Tsuyoshi Hirajima, Keiko Sasaki

Acid mine drainage is mainly due to pyrite/arsenopyrite oxidation processes, and suppressing such processes is important issue. As a promising process it is reported that silicate ion can complex with catechol (1,2-dihydroxybenzene) and this complex is oxidized to a solid silica layer on the surface of those sulphide minerals. Detailed behavior was investigated from the result of electrochemical experiments. Results of polarization potential showed that oxidation peak can be seen only in the presence of both silicate ion and catechol addition at this peak potential and this peak can be identified as silicate-catechol complex oxidation to silica. Potentiostatic experiments indicated the dissolution kinetics of pyrite. Untreated pyrite dissolution rates were higher than pyrite treated with catechol and silica solution. To enhance the silica layer reaction on pyrite, the pyrite potential was held at 550 mV vs. SHE in catechol silica solution. This pyrite dissolution kinetics was almost the same as untreated pyrite. Potential hold followed by drying for 30 min process resulted in much lower pyrite dissolution rates. Drying is important for development of the silica layer. Analysis of this potentiostatic curve provided a way to estimate the thickness of the produced silica layer and kinetic information of treated/untreated pyrite. Untreated pyrite showed thinner initial layer thickness on the surface of pyrite (oxidized passive layer, not silica) and higher oxidative kinetics of pyrite compared with silica-coated pyrite.

Jan 1, 2014

By E. Lee

Cone crushers are widely used within the mining and aggregate industries for the size reduction of minerals, ores, and rock materials. In mining applications for example, the product from cone crushers is often fed to HPGRs or directly to mills in the subsequent grinding circuit. An improved cone crusher performance can therefore result in an overall improved and more efficient comminution process. The objective of this paper is to systematically study a number of different ways of applying compressive crushing. By mathematically modelling these different crushing concepts and then theoretically optimizing crushing sequences accordingly, each concept can be studied and evaluated. In addition, aspects concerning whether or not the results are mechanically or practically achievable are considered. This study thus explores the advantages and disadvantages of different crushing concepts. In this paper, four different theoretical crushing concepts are presented and studied. The results show that in terms of interparticle crushing, optimal crushing sequences with varying compression ratios can be replaced by easier implemented series of constant compressions without significant deterioration. It is also shown that that considerably better performance is obtained for crushing sequences with both breakage modes. The subsequent comparison between such concepts indicates that different approaches can achieve the same results, and that the different concepts are comparable. It is further concluded that interparticle crushing should be kept to a minimum if fines generation or energy consumption is to be minimized, and that each of the studied concepts presents different challenges for implementation. Keywords: compressive crushing, cone crusher, optimization, modeling, crushing concept

Sep 1, 2012

By B. McFadzean, K. Moller

"The mechanism whereby thiol collectors adsorb onto a mineral surface has been widely studied. Most of these studies examine the mineral surface at equilibrium state and, often, well above monolayer coverage. However, the formation of species at the mineral surface is a complex process that is both kinetically and thermodynamically controlled. In a typical industrial application, the dosage of collector will be around monolayer level. This study uses isothermal titration microcalorimetry to measure the heat evolved during the reaction of sodium ethyl xanthate (SEX) and sodium isobutyl dithiocarbamate (SIBDTC) and their mixtures with galena and chalcopyrite. The sensitivity of the instrument allows heats of reaction of sub-monolayer quantities of thiol collector to be measured.The study found that both the magnitude and kinetics of the reaction between a collector and a mineral surface was dependent on the type of mineral and the type of collector. Proposals are made for the reactions based on literature and the evidence from this investigation. It was found that when collectors were reacted with mixtures of galena and chalcopyrite, that the magnitude of the reaction was lower compared to that measured for the pure minerals alone. This may be due to galvanic interactions between the minerals, resulting in a passivating effect on one or both of the minerals."

Jan 1, 2014