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By Diana Drinkwater

As ore grades decline, ore deposits get harder and mineralogical complexity increases, metallurgical skills are more important than ever to ensure that today?s mining operations are operating efficiently and profitably. Yet specialist undergraduate degree programs have all but disappeared and metallurgical skills training for graduate engineers in the workspace if often haphazard. In response to this situation, specialists at the JK Centre in Queensland, Australia, have put together a professional development program designed to fast-track skills development for early career metallurgical professionals. The program, called ?MetSkill ® ?, is offered as a group training package for young metallurgists in the workplace. It is centred on a meaningful technical investigation negotiated between the JK Centre delivery team and the client company. As well as learning about project management and data collection and analysis, the participants study specialist topics such as comminution, flotation and mineralogy under the tutelage of senior research and consulting professionals. The technical investigation provides an opportunity for immediate practice of these new skills and JK Centre specialists are on hand to provide feedback and support throughout the program. The participants are employed across different operations in Australia and the Asia-Pacific, and although they occasionally come together for group training activities they are often separated by considerable distance. Specialist educational professionals from The University of Queensland have provided an innovative web platform to support collaboration and communication between all participants. This paper will describe the MetSkill ® program in detail, as well as providing a report on its initial roll-out to 2 groups of Australian graduate metallurgists in 2012

Sep 1, 2012

By C. L. Tang

Parts of the wastewater are reused directly and the rest moderately purified and reused, so the utilization rate of wastewater of the whole processing plant reaches 100 percent. At the same time, beneficiation indicators have been improved stably, and great economic and social benefits have been achieved.

Jan 1, 2014

By M. M. Kulkarni1

Kaolin clay is used as a filler and pigment in various applications such as paper, paint, rubber, plastics, adhesives, ink and ceramics etc. Major mineral content in crude kaolin clay is kaolinite along with some accessory minerals as quartz, hematite, mica, feldspar, anatase, rutile, illemnite etc. The Fe and Ti bearing minerals play very important role in determining quality of the kaolin, as these minerals impart yellow, pink or darker color to the white kaolin. Conventional beneficiation methods used in kaolin processing are de-gritting, classification and sodium dithionite bleaching, which improves the optical properties of kaolin, wherein reduction of color imparting constituents such as Fe2O3 and TiO2 is marginal. In the present study, these coloring impurities are separated using selective adsorption of water-soluble polymers. Degritted kaolin samples after passing through 45 micron sieve is used in the study for selective flocculation by polyacrylamide based polymers. The effect of pH, zeta potential, and polymer dose on the reduction of impurities is studied. Analytical tools such as XRF, XRD, SEM, and TEM techniques are utilized and results are discussed in detail.

Sep 1, 2012

By P. Coghill, P. Revell

"Geo-sensing is the ability to routinely measure or infer rock properties at a range of scales using non-destructive scanning devices. These devices can provide information and data flows to support integrated decision making across the minerals value chain. Geo-sensing has been used for many years in minerals exploration using technologies such as satellite imaging and airborne geophysics but to date the use of sensing technologies in between the mine and mill has been very limited. The aim of this research is to develop new mineral sensing technologies that can enable grade engineered ore streams through the rejection of low value gangue or deleterious elements either in the pit or during transfer to the mill. This paper focusses on the research and development being carried out by the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE) and its associated members on new sensing technologies. At the start of their development these technologies were classified on the Technology Readiness Level scale at 3 (TRL3), equivalent to a proof of concept. Laboratory testing and design is aimed at progressing these sensing technologies to TRL5 which is ready for testing at an end users site. New data obtained during the laboratory testing and design phases are presented in the paper demonstrating performance specifications such as detection limits and measurement speed which can be used to infer the pod size of gangue that can be rejected at scale. Grade Engineering® and coarse gangue rejection are considered as key drivers for the mining industry to address the higher mining, processing and environmental costs associated with ore bodies with declining grades. This is an industry wide problem and the development of mineral sensors is seen as key enabling technologies for Grade Engineering® and coarse gangue rejection. The technologies presented in this paper enhance value through early decision making of ore quality and improve the overall resource value case through improved grade and throughput engineering."

Jan 1, 2018

By J. Quinteros-Riquelme

Despite increasing demand, the supply of silver is limited by its inadequate recovery from ores. Due to its scarcity in nature, its high ore variability and complex mineralogy of current silver deposits, its recovery by mineral froth flotation presents a real challenge for process engineers. A silver ore often contains significant amounts of five to ten different silver minerals and knowledge of the mineralogy is a necessary precursor to flotation testing. In this work, a complex silver ore was treated by using batch laboratory flotation, in an effort to find the best experimental conditions to obtain the optimal silver recovery. Mineralogical characterization of feed samples was conducted using a combination of tools, namely the mineral liberation analyzer (MLA) and inductively-coupled plasma mass spectrometry (LA-ICP-MS), which indicated that most of the silver occurred as ?invisible? silver in pyrite. The pyrite assay of the ore was approximately 4%. The ore was processed in two flotation stages. The first stage, sulphide flotation, aimed to collect a sulphide mineral rich concentrate; then a non-sulphide flotation stage was performed by adding sodium sulphide and collectors to the remaining material in the cell, with the objective of obtaining a pyrite rich concentrate. To reach the target recovery of silver from this ore, various variables were altered. In the first stage: mixed collectors, activators, dispersants, and mainstream inert grinding were assessed. In the second stage, the conditions for sulphidization and subsequent flotation were both investigated. From the grade recovery curves for silver and sulphur it was possible to observe a similar metallurgical behavior for both elements, supporting the results given by the mineralogical characterization. Keywords: silver oxide, froth flotation, sulphidization, mig

Sep 1, 2012

By Kyoungkeun Yoo

A citric acid leaching test after heavy medium separation process was performed to remove the heavy metal contaminat such as Pb, Cu, and Zn from contaminated soil. The lead component was removed from soil by heavy medium separation whereas zinc component shows 0 % - 37.9 % removal ratio with particle size. The citric acid leaching was conducted to remove the remained zinc component. The removal ratio of Zn reached to more than 95 % under the conditions; 10 % in pulp density, 200 rpm in agitation speed, 50 °C, 2 mol/L in citric acid concentration at 2 hrs in leaching time. These results suggest that the heavy medium separation method followed by citric acid leaching is effective for treatment of soil contaminated with various chemical forms of heavy metal. Keywords: metal contaminated soil, citrate, heavy medium separation, zinc

Sep 1, 2012

As a kind of collector, Xanthates are generally used to make sulfide minerals hydrophobic in flotation process. Xanthate adsorption on a galena surface has been widely studied experimentally. In this paper, DFT methods were employed to investigate the local adsorption interactions about the collectors,such as ethyl xanthate (CH3CH2OCS2?, EO) and ethyl trithiocarbonate (CH3CH2SCS2?, ES), absorbing on two different PbS clusters. From the results, it can be easily found that, on the edge or at the apex, both collectors, with two S atoms bidentate coordinating on the clusters, have surprising interaction energies, while on the surface, its interaction is relatively weak in the form of monodentate ligand. NBO analysis results reveal that there is at least a covalence bond with sulfur atom about 10% and lead atom about 90% when the absorbed lead is on the lattice edge or at apex, but, if the absorbed lead is on the lattice surface, no covalence band would be found. Meanwhile, the S-Pb bond, formed by the absorbed Xanthate and galena lattice, seems to have much more covalence characteristic than that formed in the PbS lattice inner. Furthermore, those data also imply that the difference of the collecting effect between the EO and the ES may be not notable, because of the similar distance and the interaction energy for the same interaction mode.

Jan 1, 2014

By W. H. Yong

The molybdenum ores currently utilized in China are mostly molybdenum sulfide ores, whereas oxidized molybdenum ores have not been exploited and utilized efficiently. The aim of this article is to study the applied mineralogy of an intergrown iron-molybdenum oxidized ore in order to provide a mineralogical basis for the ore beneficiation research. The ore occurred in a surface oxidized zone seam and contained 23.65% Fe2O3 and 1.58% Mo. Various characterization techniques were employed to study the chemical composition and mineral composition of the ore, the particle size distribution of the minerals in the ore, and the tex-ture and structure of the ore. The results showed that the iron-molybdenum ore occurred in a wet, soft and earthy state. The ore was composed mainly of several oxidized minerals and colloidal min-erals, including wulfenite, barite, limonite and quartz. Wulfenite was one of the major and stable components in the ore and occurred as a separate mineral. Wulfenite, barite and quartz were granu-lar minerals with particle size ranging from fine to coarse but mainly in the fine particle range. Li-monite showed a crust and honeycomb-like colloidal state and composed the framework in the ore for the formation of the other minerals. They filled the pores in the framework and the size of the pores affected the size of the minerals formed in the pores and hence the recovery of wulfenite in ore beneficiation. According to the applied mineralogical properties of the oxidized molybdenum ore, a promising ore beneficiation process was proposed as follow Magnetic separation should be carried out first to separate the magnetic iron minerals and then the molybdenum mineral will be recovered by gravity concentration or a combination process of gravity concentration and flotation, depending on the distribution of the molybdenum mineral in the product of the magnetic separation.

Jan 1, 2014

In order to determine the optimal process parameters of agitation leaching and provide industrial process design parameters, experiments were carried out on leaching behaviors of copper oxide ore with high mud content. Condition tests show that the main factors affect the leaching efficiency as follows: Temperature, Initial acid concentration, leaching time and particle size. As the temperature increases, the copper leaching rate was increased. At 60 ?, the initial acid concentration 80g / L, leaching time 2h, liquid-solid ratio 2:1 and grinding fineness65%-0.074mm, the optimal copper extraction was 83.15%, the acid consumption was 187.91kg / t. ore. Keywords: agitation leaching, copper oxide ore, mud

Sep 1, 2012

In recent years, coal beneficiation has gotten considerable attention. Selective oil agglomeration has been accepted as the best method to produce clean coal with a high removal of pyrite sulphur. In this study, spherical oil agglomeration of Datong coal fines was carried out using diesel oil as a bridging liquid. The oil agglomeration has a surface properties based on coal cleaning technique. The effects of fundamental parameters have been investigated including the concentration of bridging liquid, the size of coal particle, the solid content of slurry, the agitation time and rate, pH, surfactants on the agglomeration performance and various salts on the ash rejection and removal of pyrite of the agglomerated products. The optimum conditions of particle size, diesel concentration, solid content, agitation speed and time, pH and the dosage of active agent have been determined as less than 8µm, 20wt%, 1200r/min and 10 minutes, 7.5g/t and 100g/t, respectively. Under these conditions the ash content in the products can be achieved 1.5% below, the ash rejection was up to 92%. It has been observed that ionic strength of the aqueous medium affects the agglomeration performance. The precombustion coal cleaning process based on improved selective agglomeration results in high ash and pyrite sulphur removals. Over 80% removal of pyrite sulphur can be achieved from run-of-mine coals by offering a more cost-effective sulphur reduction solution rather than any other SO2 removal technology. In addition, the removal of pyrite sulphur is very necessary for not only the prevention of environmental pollution but also economical reasons.

Jan 1, 2014

By Sepideh Javanshir

The process of liquid?liquid extraction of gold from chloride solution is complicated by the presence of many variables acting simultaneously in an unknown non-linear fashion for the determination of the final extraction efficiency. In practice, it is quite difficult to develop a model for predicting various properties of such process. Therefore, an alternative approach based on Artificial Neural Network (ANN) is considered to assist in the simulation process. Artificial neural networks (ANN) are powerful tools that can be used to model and investigate various highly complex and non-linear phenomena. This paper presents application of Multi-Layer Perceptions (MLP) to construct relationship that will be employed to develop a quantitative method for the estimation of the extraction efficiency as a function of hydrodynamical parameters such as stirrer speed, [AuCl4]- and DBC concentration, organic and aqueous flow rate. The model is shown to be in excellent agreement with the experimental data (R2 value for training and testing data was 0.9992 and 0.9915 respectively). Therefore, it can be used to optimize the parameters of liquid?liquid gold extraction with dibutyl carbitol (DBC).

Sep 1, 2012

By A. K. Suri

India plans to increase the nuclear power share in overall energy-mix to about 30% by 2032 using both indigenous and imported reactor technologies. In the immediate time-frame, it is envisaged to generate 10000 MW electricity by PHWR technology by 2020 using indigenous uranium resources. This necessitates setting-up of new uranium mills and augmenting the existing resource, mining and milling capacities. This paper describes the current status and future R & D needs towards achieving the targeted demand of yellow-cake. Keywords: uranium, hydrometallurgy, leaching, yellow cake

Sep 1, 2012

Under the sponsorship of the U.S. Department of Energy, a project was completed in 2005, which studied the use of a special pneumatic capsule pipeline (PCP) system, driven by linear induction motor (LIM), for transporting minerals and/or mine wastes. In this study, the pipeline is a rectangular tube of 1m × 1m cross section. The capsules are similar to railroad cars running on small rails imbedded in the tube. A LIM is placed AT the entrance of the tube to transfer power electro-magnetically from the LIM to capsules. The capsules going through the LIM, propelled by the electromagnetic field generated by the LIM, move faster than the air and hence impart energy into the airflow. This in turn pushes the capsules in the tube forward. When the tube is long (say longer than 10 km), additional LIMs may be needed along the tube to serve as booster pumps. An advantage of using LIMs instead of blowers as used in ordinary PCPs is that capsules can pass through the LIMs unhindered. This enables the use of booster pumps for long tubes. It also enables PCP to achieve much higher cargo throughput than that of PCPs using blowers, thereby reducing unit cost ($ per ton-km). Advantages of using capsules with steel wheels running on steel rails in the tubes including: (1) contact friction is only about one-fifth of that using rubber tires, thereby conserving energy, (2) capsules can run at a much higher speed than those using rubber tires without overheating and damaging the tires, and (3) rails make capsule motion control simple; they restrict lateral movement of capsules, and make branching easy-by using standard rail crossing equipment. This advanced PCP system combines the advantages of LIM with the advantages of rails, resulting in a super-efficient tube system having throughputs an order of magnitude greater than that of conventional PCPs, and having an energy efficiency better than railroad transport. Analysis shows that the system is highly cost-effective when throughput is high-at least 5 million tons per year. The system is most suitable for long-distance transportation of minerals (including coal and flyash) and wastes (including both mine wastes and municipal solid waste).

Jan 1, 2014

By Kari Niiranen

LKAB (Luossavaara-Kiirunavaara AB) is operating iron ore mines, concentration plants and pelletizing plants in Northern Sweden. The largest of the apatite magnetite deposits and the mines are Kiirunavaara with annual production rate of approximately 27 Mt crude ore underground. LKAB produces two varieties of pellets: blast furnace pellets and direct reduction pellets (LKAB DR Oxide Pellets). Meanwhile the concentration process in a sequence of the low intensity magnetic separation (LIMS) and flotation at the concentration plant. In spring 2007 there were noticed great fluctuations of SiO2 grade in the crude ore. The high SiO2 grade is particularly problematic in the case of direct reduction pellets. In consequence, a project was started (called Silica in the Mine) to define exactly the problem related with silica and to find out, if possible, the reason for the great fluctuation of SiO2 grade in the crude ore going to the processing plant. A further target of this project was to develop a simplified method at the laboratory scale, to predict SiO2 grade in the magnetite concentrate in the future, but also predict the physical properties of the ore with respect to mineral processing. The essential stage of systematic characterization of the ore body for mineral processing properties is the estimation and simulation of different parameters from the laboratory scale to the large scale at the concentration plants using empirical data collected at the mineral processing by LKAB in Kiruna. Further a target was also to find useful physical parameters for mineral processing and implant those parameters into the existing geological 3D-model of the deposit. This information will be used for making prognosis of the future mining and the quality of the crude ore. It will also give better control and improve the production planning in the mine and the performance at the concentration plant in Kiruna concerning the decrease of the SiO2 grade of the magnetite concentrate.

Sep 1, 2012

By Yury V. Kulikov, Rakan Rahbani, Arkady Y. Senchenko

"The relevancy of complex minerals treatment is constantly increasing taking into account mineral resources depletion. Different refractory ores and concentrates, oxidized and polymetallic ores, as well as metallurgical products (slags) can be assigned to such mineral type. The treatment of such products via conventional flowsheets requires considerable capital and operational costs and does not always provide high recovery level of valuable components into a saleable product. Therefore, considerable amount of ores and metallurgical products are not treated, or treated inefficiently. One of the most promising approaches that allows economic treatment of refractory products is their ultrafine grinding down to 5-20 µm with subsequent processing or hydrometallurgy. Horizontal bead mills - the IsaMillTM, developed by Xstrata Technology, received their wide application in mining industry. Standard testing is performed under laboratory conditions in an M4 IsaMillTM (volume - 4 liters) to define the parameters of fine grinding. This mill completely simulates the operation of full scale industrial mills up to 50 m3 in volume (up to 8000 kW motor). The paper describes fine grinding technology performed in bead mills, and the importance of testing according to a certified method for industrial equipment selection. The paper contains description of promising directions of fine grinding technology application for several projects in Russia and Kazakhstan."

Jan 1, 2014

By Mojtaba Ghorbannezhad, Abbas Sam, Soroush Arabzadeh

One of the dewatering methods in mineral processing plant is filtration system. Disk filters are included the porous surface with pressure drop on both sides, Water in the pulp passes through the surface and solid particles remain as a cake on it. Wet concentrate production of magnetite processing plant at Golgohar Mining and Industrial Company with solid tonnage of 160 ton per hour and 49% solid amount contains 166 m3/h of water. In the present study, in addition to studying disc filter performance, the effective parameters on cake moisture were studied using Vacuum Bottom-Feed Leaf method (in the laboratory scale). Optimization was performed using the Taguchi method. The results showed that the cake moisture is reduced by increasing particle size and solid percentage (because of specific resistivity reduction), while the rate of cake formation and its thickness are increased. Also, it was found that by increasing pressure, the cake moisture is reduced and cake formation rate and its thickness are increased. In this study, the effect of fabric texture was also examined. Lowest cake moisture was obtained in condition of using compressed plain fabric with mono-multi filament fibres, pressure at 75kPa, solid percentage of 65 to 70, particle size (D80) equivalent to 123µm and disk rotation speed of 1.25 rpm.

Jan 1, 2014

By H. Ding

Calcium carbonate/Titanium dioxide composite, characterized by coating TiO2 on the surface of CaCO3 particles, is an important substitute for titanium dioxide. This paper studies preparation method of CaCO3/TiO2 ,composites based on mechano-chemical effects, measures its properties as a pigment, analyzes the binding form and interface reaction mechanism between CaCO3 and TiO2. Through single finely grinding of CaCO3, co-grinding of CaCO3 together with TiO2, and mecha-no-chemical effects produced in the course of grinding, CaCO3/TiO2 composites can be prepared successfully. Results indicate that grinding fineness of CaCO3, co-grinding time of CaCO3 and TiO2, the weight ratio of grinding media to mineral feeding, and the amount of TiO2 have much influence on the properties of CaCO3/TiO2 composites. CaCO3/TiO2 composites have the properties same as titanium dioxide pigment, oil adsorption and ultraviolet adsorption same as TiO2, and 90% of hiding power as that of TiO2. Wet grinding of CaCO3 causes the production of mechano-chemical effect and hydroxyl group, through which CaCO3 and TiO2 can be bonded together. Repulsion occurs between the particles of CaCO3 and the particles of TiO2, respectively, they are both in good dispersion. But attraction occurs between CaCO3 and TiO2. TiO2 particles are distributed evenly on the surface of CaCO3. Therefore, coating of TiO2 on the surface of CaCO3 particles and chemical bond between them make CaCO3/TiO2 compo-sites have pigment properties of Titanium.

Jan 1, 2014

By F. Göktepe

Flotation gases and conditioning of the pulp with them are one of the important parameters of flotation and should be taken into account especially in the flotation of sulphide ores. In this study, flotation of pure chalcopyrite and pyrite samples were investigated with air, oxygen and nitrogen as flotation gas and the effect of conditioning with these three gases also were performed. Flotation gas was introduced for 5min, 10min, 15min and 20 min. For chalcopyrite flotation there was no drastic change in recovery when air, oxygen and nitrogen were used as flotation gas but conditioning the pulp with oxygen for 10 minutes increased the recovery about 8% where pulp potential has been approximately 25 mV with chalcopyrite and 150 mV with platinum electrodes. Conditioning with all three gases decreased the pyrite recovery by about 20% with 20 minutes conditioning. Pulp potential decreased in the presence of nitrogen while conditioning with air and oxygen increased the pulp potential for both electrodes. Generally potential increased for both minerals with oxygenation and aeration time but it was stable or slightly decreased with nitrogenation. Comparison of the gases showed that the different flotation gases do not effect flotation recovery but conditioning the pulp with these gases at pre-flotation effects chalcopyrite and pyrite flotation recovery, most dramatically pyrite.

Jan 1, 2014

By D. X. Chen

Comprehensive utilization of the copper associated with the complex lead and zinc sulphide ore is a recognized and difficult technical issue in ore dressing field. Qi Baoshan lead-zinc mine is a typical complex copper-lead-zinc polymetallic ore deposit and difficult to process. The application of the. traditional process is not able to make the substantive progress. According to its mineralogical characteristics, the association of copper minerals with lead minerals is very close, and their particle sizes are very fine, and the copper and lead minerals are partially oxidized. Based on the laboratory tests and comparison between different process flowsheets, preferential flotation of copper minerals, being suitable for this ore, was chosen to recover copper. The separation of copper from lead applies the following technology: regrinding middlings with cyclones to classify, which improves copper lead mineral liberation, and increases copper and lead recovery; using new high-efficient collector with good selectivity, which is able to float copper minerals; and non-toxic combined depressant which depresses lead minerals. The above technical innovation, optimizing the process flowsheet, overcoming the complex traditional process flow with high production cost, obtained good technical and economic indicator. The difficult technical problem of copper lead separation was solved smoothly. After successful performance of the bench-scale experiment, commercial-scale test was carried out. In industrial trial, a copper concentrate containing Cu18.60 %, Pb7.40 % and Zn2.50 % was obtained with copper recovery of 58.49%, lead concentrate quality improved largely. The process opened up an unique path for the comprehensive recovery of Cu from similar lead and zinc non-ferrous metals mineral to comprehensively recover copper.

Jan 1, 2014

By T. Wallmach, S. B. Blancher, A. Delaporte, P. Goncalves

"Fe-Ti oxides concentrates produced from heavy mineral sand deposits are widely used for the production of titanium dioxide pigments that are critical components of white paint, plastics and paper. According to mining industry, the Fe-Ti concentrates mostly consists of three phases: ilmenite, leucoxene and rutile. However, a few mineralogical studies have shown that the variety of Fe-Ti oxides found in sand deposits is far more complex, mostly due to alteration processes. The aim of this contribution is to characterize in detail by means of Qemscan analyses the mineralogy of the three main concentrates (ilmenite, leucoxene and rutile) produced by the Grande Côte Operation (GCO) mineralurgical plant in Senegal. The ultimate goal is to characterize the different products and textures formed during the natural ilmenite alteration processes, to localize the phases carrying the main impurities (Cr and P), and finally to determine the physical properties of each mineral component to improve metal recoveries. Along alteration processes, Ti content increase. Ilmenite (FeTiO3) is progressively transformed into pseudorutile (Fe2Ti3O9) particles which could also be altered and transformed into hydroxylian pseudorutile [FeTi6O12(OH)3.3H2O] or complex blends of anatase microcrystals (TiO2). These transformations are accompanied by significant changes in particle textures. Microporosity and fractures appear and the impurity content also increases. Anatase rich microcrystal assemblages, so far described as Leucoxene, could be identified to consist of grains with higher porosities, water contents and higher intrapore impurities. These particles are the main carriers of chromium and phosphorus. The observed mineral transition textures have a significant impact on the ore dressing processes. During these transformations, the physical properties of these phases change, the magnetic susceptibility as well as densities decreases, due to the increase in porosity. The separation of particles, especially those with high porosity will help improving the GCO mineralurgical plant performance and to reduce the impurity contents in finals products."

Jan 1, 2018