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Deposit of Jinbaoshan platinum group metals (PGMs) ore ranks the second in Yunnan province, China. Study on process mineralogy shows that the grade of copper and nickel in the ore is just 0.16% and 0.20% respectively. Moreover, the impurities magnesium and iron and silicon are rich in the ore. The copper and nickel sulfides in the ore, especially the minerals of PGMs, are finely disseminated with the gangues like serpentine. Fine grinding is necessary, and high content of MgO in the concentrate is inevitable through traditional flotation technology on the basis of process mineralogy studies. Achievements on process mineralogy studies are applied to guide the flotation tests successfully. Progress on flotation has been made through comprehensive studies. Suitable grinding by two stages is required for the finely disseminated PGM sulphide ore to achieve the liberation of valuable minerals. Stage grinding and stage separation shall be conducted for a better recovery of valuable minerals. The oxidation state of mineral surface of sulphides has a profound effect on flotation of the ultra-fine sulphides, especially the pentlandite. The combined use of collectors enhances the selective collecting on the ultra-fine and low-grade valuable minerals, is of critical importance.

Jan 1, 2014

By Jochen Petersen, David G. Dixon

"Although heap leaching may be perceived as a somewhat low-tech route for the extraction of low-grade minerals, the underlying physical, chemical and biological processes are in fact extremely complex. There has been increased interest in heap leaching of sulphide minerals in recent years with the advent of controlled bio-heap leaching, and the need to mine more marginal ore deposits.A detailed investigation into the dynamics of heap leach processes has provided much insight into the underlying complexities, and has led to the development of a sophisticated modelling tool. Some of the features include mineral kinetics, particle level effects, bacterial growth, oxidation and adsorption, gas adsorption, pore diffusion, bulk advection, gas balance and heat conservation.Two case studies are presented which illustrate specific features of the model for different applications and how these have helped to identify key areas of concern. In each case the model has proved as an invaluable tool either for the improvement of existing heap leach practice or for the development and assessment of novel applications."

Jan 1, 2003

By Matti Kongas, Kari Saloheimo, Antti Remes

"The paper studies the control performance of the flotation process as a function of the measurement accuracy and sampling frequency of an on-stream XRF analyzer, using a simple dynamic model. An additional aim is to assess how the economical result of a mineral flotation process depends on the quality of process control based on the on-line elemental assays.An on-stream XRF analyzer measures the concentrations of slurry lines in a continuous cycle from several process points. The control performance depends on the analytical accuracy and sampling frequency of the concentration measurement. With a long cycle time, the state of the process changes before a new measurement becomes available. With short measurement times the statistical variance of the counted X-ray pulses increases, increasing the random error in the analysis. In addition, the measurement accuracy depends on the concentration of the component to be measured from the slurry.To quantify the effect of analysis error and frequency to process control, a simple dynamic process model is created in the Matlab environment. Data from a copper flotation circuit is used as a test case. The process model comprises a first order reaction equation and the grade-recovery -relationship estimated from process data. The control was modeled using the control strategies implemented into a rule based advanced control system.The economical performance of the control was studied by calculating the overall net smelter return at various analyzer parameter combinations. The economical performance of the process declines strongly when the sampling cycle is increased. In studied case the sample measurement time did not have a significant effect on the results. The economical performance of the simulated process corresponds to an almost uncontrolled process when sampling cycles longer than 40 min are applied."

Jan 1, 2003

By G. S. Zeng

The mechanism of cobalt removal from zinc sulfate solution with zinc dust is still not understood well. The experiments in this paper were carried out by zinc dust from zinc sulfate solution with high cobalt to study the mechanism of cobalt removal. Residues after the cementation process from zinc sulfate solution were analyzed by SEM and Electron probe micro-analysis (EPMA) to investigate the morphology of products. Different temperature will cause different structure of particles. With the increasement of temperature, cobalt removal can be improved considerably. The mechanism of cobalt removal by zinc dust is thought as follows: firstly, the cobalt ion forms Co-Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; secondly, the Co-Zn alloy continues reacting to Co with Co2+, which is the control procedure of the whole reaction.

Jan 1, 2014

By Dietmar Freyhammer

Grinding is the last stage of the comminution process. In the grinding process the particles size are reduced by impact and attrition stresses. The fine grinding of ores is nowadays finding increased application due to depletion of coarse grained, easily processed ore bodies and the increased need to process distributed fine grained deposits, such fine ground iron ore powder is the basis for the pelletisation process. Depending on the ore type and the project environment different approaches to comminution are requested to provide an adequate ground iron ore for the pelletisation process. Currently the ball mill is the most used equipment in grinding iron ore for pellet feed. Based on the various examination and investigation of minerals on grind ability related to the throughput, to the resulting sieve characteristics and necessary energy consumption, the mill circuit can be: Open dry circuit. Closed dry circuit Open wet circuit Closed wet circuit. CEMTEC GmbH is a renowned name worldwide and offers tailor made solutions to cope these issues.

Sep 1, 2012

By D. H. Xiong

Low grade oxidized iron ores are usually not economic to utilize. However, the development of SLon magnetic separators and other new technologies make the process cost lower and lower. In this paper, several low-grade oxidized iron ore process flowsheets are introduced. The key procedure is that at the early stage, SLon magnetic separators are applied to discharge as more tails as possible with very low cost, only a small portion of rough concentrate going to the cleaning stage, showing the new technologies are profitable for such iron ores.

Jan 1, 2014

By M. Maldonado

A flotation bank is a serial arrangement of cells. How to optimally operate a bank remains a challenge. This article reviews three reported strategies: air profiling, mass-pull (froth velocity) profiling and Peak Air Recovery (PAR) profiling. These are all ways of manipulating the recovery profile down a bank, which may be the property being exploited. Mathematical analysis has shown that a flat cell-by-cell recovery profile maximizes the separation of two floatable minerals for a given target bank recovery when the relative floatability is constant down the bank. Available bank survey data are analyzed with respect to recovery profiling. Possible variations on recovery profile to minimize entrainment are discussed.

Sep 1, 2012

In this paper, various methods, such as XPS, XRD, SEM and zeta potential measurement are applied to investigate the action mechanism of sodium sulfide in flotation of lead and zinc oxysalt minerals. The experimental results show that the mechanisms of sodium sulfide in flotation of lead oxysalt minerals and zinc oxysalt minerals are different: on the surface of cerusite, there is lead sulfide phase formed under the reaction of sodium sulfide, resulting that the cerusite surface shows the form of galena, which is advantageous to the adsorption of anion collector and improves the floatability of cerusite as a result. On the surface of zinc oxysalt minerals, there is no zinc sulfide phase formed, but the sodium sulfide increases its surface electronegativity, and enhances the adsorption of cation collector lauryl amine, so the floatability of zinc oxysalt minerals is improved. The difference of action mechanisms of sodium sulfide on lead and zinc oxysalt minerals exactly explains the reason why different collectors are selected in the flotation of cerusite and smithsonite, which are both carbonate minerals although.

Jan 1, 2014

By H. C. E. Regidor, M. G. Mena, H. D. Mendoza

Cyanidation leaching has always been the most widely used method of extraction of gold in the world. Its low cost and high selectivity has made it the prevalent choice for mining companies, and even for the small scale miners. The use of cyanidation in small scale mining has been an issue for the longest time, mainly due to the operation’s lack of safety measures, health care or environmental protection regulations. In pursuit of more environmentally friendly methods of extraction of gold, several alternative extraction processes have been explored, one of which is chlorination. The chlorination process is advantageous when recovering refractory gold locked in sulfides, as it simultaneously oxidizes the surrounding sulfides as well as dissolve any gold exposed to the lixiviant. This research was conducted to study and develop a safer alternative way of extraction of gold from small scale mining operations, without compromising the recovery of gold. In this study, a variation of the chlorination process has been employed for a refractory flotation concentrate wherein the majority of the gold is locked in sulfides. Hypochlorite-bearing reagents were used as the leaching reagents, and the method developed was a 2-stage leaching process in differing pH conditions. The solution pH and Eh was monitored all throughout the runs, and aliquot samples were taken at time intervals for analysis. SEM-EDS imaging was used to determine the mode of oxidation of the chlorination process, and the image obtained showed that the oxidized layer followed the shape of the particle, suggesting a diffusion controlled process. XRD analysis of the sample before and halfway through leaching further confirmed the oxidation of the sulfides. The amount of gold dissolved in the aqueous solution and in the solid residue were used as the basis for the determination of the recovery of gold. An average gold recovery of up to 84.38% was obtained using the developed method in just 7 hours of leaching. This method was then employed for a pilot-plant scale test and a gold recovery of 79.2% was obtained.

Jan 1, 2018

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 Alan Bye, Nick Beaton, Wayne Stange, Emmy Manlapig, James Groutsch

"For over 50 years the JKMRC has applied a unique education-based research strategy to develop modelling and simulation tools that are "fit for purpose" for industrial application. These tools are widely used for the analysis and optimisation of mining and mineral processing systems. As the mining industry context evolves to deal with declining head grades, falling commodity prices, professional skill shortages, and an exponential growth in the volume of data, a re-evaluation of what "fit for purpose" means in the future is required. It is contended that future industry needs for simulation-based decision support requires tools and systems that incorporate: • Multi-component modelling, • Models of complex sensor behaviour, • Integration across the physical value-chain e.g. resource to market, • Financial analysis including risk and uncertainty assessment, • Enabling multi-criterion decision making (technical, financial and environmental), • Ore-body knowledge at multiple scales, • The use of fundamental numerical models to provide insight for the development of practically useful models, and • Decision support delivered through remote operations centres. JKMRC and CRC-ORE are collaborating to develop a next-generation simulation-based decision support system that assists in addressing these challenges. The Integrated Extraction Simulator (IES) combines many years of pragmatic and successful work integrated with modern technology trends - in particular the rapid move to cloud-based computing."

Jan 1, 2014

By Z. A. Zhou

In Canadian oil sands processing, flotation is used to recover liberated bitumen droplets from oil sands slurries. Similar to conventional mineral flotation practice, a fundamental limitation of recovering bitumen from low grade oil sand ores is its slow and ineffective aeration of the liberated small bitumen droplets. Gas nucleation and cavitation could provide better mechanisms for accelerating bitumen-bubble attachment. A research program was undertaken to examine factors affecting spontaneous bubble nucleation on bitumen surfaces. The results demonstrate that surface hydrophobicity and existence of gas nuclei in process water play a critical role for bubble nucleation. While there are more bubbles nucleated on highly hydrophobic silanated glass surfaces than on moderately hydrophobic bitumen, bubble nucleation on clean hydrophilic glass surfaces is negligible. Heating process water up to 85 ~ 95oC (as used in commercial operation) or boiling tap water prior to gas nucleation tests is shown to remove sufficient amount of gas nuclei existing in the water, thereby drastically reducing the number of bubbles nucleated on bitumen. Enhancing gas nuclei formation in hot process water is identified as a promising strategy to improve bitumen-bubble attachment during oil sands conditioning, and hence to increase bitumen recovery from low grade ores.

Jan 1, 2014

By N. Vorob?ev-Desyatovskii

The process of gold(I) adsorption on activated carbon (AC) from aqueous Na[Au(CN)2] and the state of the adsorbed gold cyanide complex on the adsorbent surface was investigated by photometry, XPS, XANES methods. By DFT method, quantum-chemical calculations were performed of the gold cyanide species on activated carbon surface. It was established that the binding of gold(I) with the surface of carbon involved several simultaneous processes governing the selective adsorption of gold(I) from the cyanide solutions.

Sep 1, 2012

By L. M. Wang

Chengmenshan Copper Mine Concentrator adopts the new process of preferential?bulk stage floatation and utilize reground, largely increase the mineral processing index of the copper and the sulphide concentrates. In addition, the paper describes the remarkable economic benefit of the new process through the comparison of the new and the old processes.

Jan 1, 2014

By W. Z. Yin

With increasing of mining depth, many iron ores in Liaoning Province contain carbonates such as siderite and ankerite. The emergence of these carbonates in ores creates a fatal impact on the running producing process of anionic reverse flotation in Dong Anshan Sintering Plant, which leads to ?concentrate and tailing no separated?. And its reason is still unknown. Moreover, siderite, despite that its ferric theoretic grade is only 48.2%, however, do not affect the blast furnace utilization factor, therefore, can be used as raw materials in ironmaking. In order to solve the separate problem of iron ore containing carbonates, five pure minerals, martite, magnetite, quartz, siderite and ankerite, were selected for a series single flotation experiment. The aim was to discover the flotation difference of these minerals, furthermore, to explore a new flow sheet for the iron ore containing carbonates. The results of single mineral flotation experiment reveal that the combination regulators, starch and CaCl2, in different pH extent, can make these minerals taking on obvious flotation difference, which make it possible to process the iron ore containing carbonates. A new flow sheet, step-flotation, to process iron ore containing carbonates is explored, that is, first step, direct-flotation processing, is to eliminate the bad effect that the carbonates bring in flotation system by collecting carbonates under neutral condition; the second step, reverse?flotation processing, is to get qualified iron concentrate by collecting quartz under alkaline condition. Manual mixed ore sample were processed successfully through this new flowsheet under proper reagent system, which has absolute advantage compared with routine flowsheet. Actual ore sample of compound magnetic separation concentrate were processed successfully both open and closed circuit experiment through this new flowsheet. SEM and EDS were used to probe the reason why carbonates affect the regular processing. It is analyzed that moderate floatability of siderite and its coating on the surface of hematite and quartz make the phenomenon ?concentrate and tailing no separated?. This research provides a reasonable processing scheme for iron ores containing carbonates and can be used for reference in processing other complicated, refractory iron ore.

Jan 1, 2014

By Ljudmil S. Grigorov, Eric Forssberg, Hanumantha Rao Kota, Robert J. Pugh, Lidia B. Alexandrova

"We have used the microscopic thin balance developed by Scheludko at al. (1970) technique to study the stability and interactions within the thin film between the silica surface and air bubble with (i) a long chain C10 amine and (ii) a cationic/anionic surfactant systems consisting of mixtures of a long straight C10 chain amine with long straight chain C8, C10 and C12 sulfonates. It was found that the mixed surfactants caused lower contact angles, lower rates of the thin aqueous film rupture and longer film lifetime, compared to the pure amine system.This behavior was explained by the initial strong adsorption of positively charged interfacial complexes from the mixed surfactant system at the air/solution interface followed by adsorption at the silica interface. It was also shown that the chain length compatibility between the anionic and cationic surfactants controls the strength of the interfacial complex, determining an inhibition in the thin film rupture and dewetting of the film. The rupture mechanism was explained by an earlier established heterocoagulation mechanism between the positively charged air/solution interface and the solution/silica interface which remained negatively charged. The formation of the interfacial complex at the air/solution interface was confirmed by using surface tension data."

Jan 1, 2003

By A. Zangooi

Frothers play major roles in flotation through interaction at the air/water interface. A method of determining frother adsorption density (coverage), i.e., the number of molecules per unit of interfacial area of bubble surface, is introduced. The technique is based on mass balancing the frother around a continuously operated bubble column. The mass balance requires collection of bubbles before they burst. The column design and operating procedure is reviewed, and some preliminary results discussed. Keywords: flotation, colorimetric frother analysis technique, frother mass balance, coverage

Sep 1, 2012

By Christopher Greet, Alfred Van den Bosch

"A range of media alloys with different chromium content has been developed for different milling applications. When selecting the grinding media alloy for a specific application, consideration must be given to the mineralogy of the ore as well as the water chemistry and mill operating conditions. The paper describes the influence of the microstructure of the alloy on the wear resistance and the influence of the chrome content on the pulp chemistry and downstream processing. It also provides information about the in-house tools which Magotteaux have developed to predict the media wear rate with different chromium content alloys and predict their flotation efficiencies that can be expected when the right alloy is selected for a particular application."

Jan 1, 2014

By Wei Qu, Yongsheng Song, Xingyu Liu, Wenjuan Li, Shuang Liu, Guiying Zhou, Bowei Chen

The Pb,Sb,Zn multi-metal sulphide ore is processed in sequence of beneficiation of jamesonite, sphalerite . Due to relative large amount of collector (xanthate), activator (CuSO4) and regulator (lime) during different flotation stage, the flotation wastewater from sphalerite beneficiation stage can’t be directly recycled to the first lead flotation stage. In this paper, the flotation wastewater from sphalerite beneficiation stage was treated by Ozone and BAC technology, results showed that when the influent concentation of COD and copper ion were 850 mg/L, 10.48mg/L respectively, the Ozone and BAC technology could effectively treat such type of water. In the treated wastewater, the COD is 60mg/L, copper ion concentration is 0.023mg/L, pH is 7.0, which satisfy the need of Pb,Sb-Zn preferential floatation separation process. After recycle of the treated wastewater to Pb,Sb floatation circuit, qualified Pb,Sb concentrate and Zn concentrate were obtained.

Jan 1, 2014

By S. Sheng, Y. G. Huang, W. Chai

"Polyacrylamide (PAM) is a typically synthetic depressant and may be used as a depressor of pyrite. The modification of polyacrylamide may improve its physicochemical properties and performances. Sulfonated polyacrylamides (SPAM) with different sulfonation degree (SD) were prepared using sodium sulfite as the sulfonating agent, and the interactions of SPAM and pyrite were investigated by the adsorption experiment in this work. The adsorption tests of SPAM on pyrite were conducted as a function of sulfonation degree, pH value and contact time. Pyrite and SPAM were constructed and optimized through MS software. The interaction mechanisms of sulfonated polyacrylamide and pyrite were simulated by molecular dynamics simulations. The results show that the adsorption capacities of SPAM at neutral and weak alkaline conditions are higher than that at acidic and strong basic conditions. The high sulfonation degree favors the adsorption of SPAM on pyrite surface. The adsorption process can be described best by the pseudo-second order kinetic model. Molecular dynamics simulations show that the adsorption of sulfonated polyacrylamide on pyrite is better than that of polyacrylamide. Sulfonated polyacrylamide can be used as a potential depressant of pyrite with the main interacting mechanism of hydrogenbond force.INTRODUCTIONPyrite is the most abundant sulfide mineral and often associated with valuable minerals such as galena, chalcopyrite, sphalerite, molybdenite, gold, diaspore as well as coal (Forrest et al., 2001; Jaiswal et al., 2015; Maier and Dobiáš, 1997; Qiu et al., 2017; Xin and Liye, 2010). Froth flotation is the most popular method to remove pyrite from valuable minerals. Pyrite could be floated as the flotation concentrate either by its hydrophobicity or activation by metal ions (Chandra and Gerson, 2009). What is more, pyrite could be seperated as flotation tailing by adding highly selective depressants including inorganic and organic modifiers. Polysaccharides polymers and lignosulfonate-based biopolymers are common natural organic depressants (Deng et al., 2017; Mu et al., 2016). While the synthetic organic products have proved to be particularly versatile in terms of molecule tailing capability and controlled structures (Boulton et al., 2001a; Raffa et al., 2015)."

Jan 1, 2018