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By I. N. Babich

"Complex technological problems associated with the processing of mineral raw materials require the search and development of new means and ways of thinking. At present, computer cognitive graphics (CCG) are one of the most actively developing areas of new information technologies. The aim of the study was to optimize the cycle of technological evaluation of ores at all stages of geological exploration of deposits on the basis of analysis of geological sampling data using CCG. A new approach has been developed that facilitates optimization of the whole cycle of subsoil exploration. At the gold ore deposit, the results of the geological sampling data were processed by the method of constructing the CCG in the form of a histogram showing the frequency of gold extraction and the average amount of its content. Significant peaks of the metal content in the ore, exceeding the level of the average content in the ore by tens of times, have been revealed. Graphical interpretation of the parameters of mineralization reflects the uneven nature of its variability, which indicates the presence of large, rarely occurs of gold in the ore and the need to conduct studies on a sample of ore of greater mass than for ores with tiny gold. On a sample of 50 kg gold-quartz ore studies were carried out on gravity enrichment. The maximum size found in the gold concentrate was 0.07 mm. In the course of integrated tests in a gravity concentrate, gold particles up to 3 mm in size were found, which predetermined the need to include the operation of gravity before flotation. A new approach to subsoil research is protected by a patent (RU 2620823).The technological problems that arise before the researcher associated with the processing of resistant ores require the exploration and development of new means and ways of thinking. New problematic situations on complex mineral and raw materials objects are practically not amenable to resolution by existing methods. Integration of industrial and information technologies is necessary. At present, computer graphics (CG) is one of the most rapidly developing areas of new information technologies. For example, in scientific research, including in fundamental research, the accent from the illustrative function of CG (the visualization of what is already known) is increasingly shifting towards the use of computer cognitive graphics (CCG) tools (Bashlykov, 2016). The function of the CCG is to obtain a new knowledge with the help of a graphic representation - a cognitive image or at least to promote the intellectual process of the logical acquisition of this knowledge. In this study, cognitive images are used to graphically represent the distribution of valuable components in the bowels of the deposit, characterizing the state of mineral-raw materials."

Jan 1, 2018

By Megha Patel

"The objective of this project was to investigate the application of Prompt Gamma Neutron Activation Analysis (PGNAA) technology to provide real-time on-belt elemental analysis of feed ore in base metal sulphide processing, in this case at the Mount Isa Mines Zinc-Lead Concentrator Heavy Medium Plant (HMP). After initial exploratory testwork proved successful, a Geoscan On-Belt Elemental Analyser was retrofitted onto the existing HMP feed conveyor. Dynamic calibration of the Geoscan was conducted based on laboratory XRF analysis results of the HMP feed conveyor hammer autosampler samples from May to November 2013. Comparison of the Geoscan results to the laboratory XRF analysis results during and after dynamic calibration indicated the technology had acceptable accuracy to be incorporated into HMP process control. The variation between the two sets of data includes all primary sampling, sample preparation and XRF analysis errors as well as the Geoscan errors themselves. The Geoscan instrument precision must be calculated separately through a duplicate sampling campaign and independent laboratory analysis before extending the scope of its range of application beyond HMP process control. The expected benefits of integrating the Geoscan real-time data into HMP process control are optimised HMP metal recovery, improved cost efficiency and improved stability of the downstream processes (milling and flotation). Utilisation of the Geoscan will also enable improved feedback to mines on grade control and dilution, and provide additional information on individual ore types when fed as campaigns to HMP."

Jan 1, 2014

By Dilip Kumar Mohanty

In today?s world, Sustainability is the key issue before the mankind. With the ever-increasing population & unimaginable boost in industrial growth to cope up with a steady increase in demand and fast change in life style of a human being, the natural resources are exploited to such an extent that the very existence of living beings in this earth planet is threatened. In such devastating situation, the concept of Sustainability emerges out as a great savior. This concept focuses on minimum/ judicious use of natural resources, thereby preserving the resources for future generation while meeting the bare minimum requirement of the present generation. For an emerging economy like India, Mining and Mineral based industries form the back bone of our economic development. Thus, sustainability of mining and mineral processing industry has a far reaching impact on sustainable economic development of our nation. While at a macro-economic level, we have to strike a balance between economic development vis-à-vis socio-economic & environmental impacts, Industries have to ensure judicious and frugal use of natural resources by making use of energy efficient plants & machineries and adopting befitting technology for reduction & recycling of waste. In the context of the above, it would be interesting to look into the sustainability measures taken up by National Aluminium company (Nalco) at its Crushing & conveying plant at Panchpatmali Bauxite Mine, which is incidentally Asia?s largest Bauxite Mine. In the backdrop of the above stated facts, in this paper the authors make an attempt to bring out the sustainability issues in areas of energy conservation, environmental impact/pollution vis-a-vis mitigation measures adopted in crusher & conveyor plant of Panchpatmali Bauxite Mine & CSR / peripheral developmental activities undertaken by Nalco to mitigate the socio- economic impacts. Keywords: sustainability, energy efficiency, recycle, csr, peripheral development

Sep 1, 2012

By A. T. Sutaone

"In the Dongri Buzurg Manganese Mine of M/s Manganese Ore (India) Ltd., high grade lumpy manganese ore required for iron and steel industries is produced through multi-stage crushing and screening. This has resulted in accumulation of 50,000 tonnes of low grade fines over the years. This production of such fines is still going on. The fines create environmental problems, like air and water pollution and siltation in adjoining fields. Besides containing lot of manganese values, they occupy large space which is very scare in mining area.The Indian Bureau of Mines under one of its statutory functions has suggested the company to explore the possibility of recovery of additional values under conservation and environmental aspects. Hence the company has sponsored a bulk sample for beneficiation studies in the Modern Mineral Processing Laboratory and Pilot Plant of Indian Bureau of Mines at Nagpur, India. The main manganese minerals present in these mine rejects have been identified as pyrolusite and psilomelane. The purpose of this study was to explore the possibility of evolving a suitable beneficiation flowsheet to obtain manganese concentrates assaying over 72% MnO2 to be used as raw material for the manufacture of dry cell batteries.The sample/material was subjected to characterisation studies in terms of chemical analysis, granulometry and mineralogical compositions. Based on these characterisation studies, the beneficiation process developed comprised of desliming, jigging and low intensity magnetic separation mainly to reject quartz, silicates and jacobsite. The manganese concentrate thus produced assayed 70.2% MnO2 with MnO2 recovery of 78% and weight per cent yield of 63.5. This natural concentrate could be mixed with the electrolytic manganese dioxide produced by the company and this blend can thus be used as a raw material for the manufacture of dry cell batteries by the end users. The paper deals with the details of test work carried out in evolving the process flowsheet."

Jan 1, 2003

By Shen Zhengchang

Based on the flotation features of coarse particle mineral, a new type of impeller & stator unit is developed. Particles suspension state generated by this impeller & stator unit under different speeds are tested in laboratory, and critical impeller speed suit for coarse particles flotation is presented. Comparing particle suspension parameters of the new impeller & stator unit with that of KYF impeller and stator unit, it comes up that the distance between the interface of two slurry circulation channels and the cell bottom is larger in the flotation cell with new impeller & stator unit. The test results indicate that the new type of impeller & stator unit is suitable for processing coarse particles due to its good suspension capacity for coarse particles. Keywords: coarse particles, flotation, suspension, critical speed, impeller and stator unit

Sep 1, 2012

By A. J. Lynch, D. K. Tungpalan, Y. Reja, E. C. Avelar, G. Figueroa, S. Gómez, R. Alanis, M. A. Corona-Arroyo

"Have you been on a mine site? This question was posed by Emeritus Professor Alban Lynch to Higher Degree by Research (HDR) Students from the Sustainable Minerals Institute - Julius Kruttschnitt Mineral Research Centre (SMI-JKMRC) in the Student Technical Presentations in 2015. From that question, five HDR students from SMI-JKMRC organised a placement on mine sites in Mexico. The SMI-JKMRC is well known for its tradition to provide their students with opportunities to enhance and test their skills in mineral processing plants. The Student Venture became a short internship for HDR students which had the objective of establishing collaboration with mining companies in Australia and overseas, and of providing a unique experience for the HDR students in regard to their training, professional development, networking and cultural interchange. In return for the companies’ support, the students conducted plant audits to evaluate the process performance thereby providing valuable data to the host company. The 2016 Student Venture was held at the Grupo Peñoles & Grupo Fresnillo in Mexico, in which three mine sites received five HDR students from JKMRC and one young researcher from Universidad de Guanajuato (UG). This paper describes the positive outcomes for the mining company and the students for this experience. The Venture was considered very successful, as it provided valuable training for the students as well as in depth information about the operation of the comminution and flotation circuits of the host sites for the Grupo Peñoles & Grupo Fresnillo. The experience also provided an opportunity for an exchange of knowledge between the HDR students and the site personnel from the host operations. The indication of the success of the experience for all involved was the support of the host company in future student internships."

Jan 1, 2018

By H. Araneda

Throughout Chile?s history, mining has consistently been a leading industry in the country. The 1990s marked the beginning of a boom in Chile?s mining industry, especially in copper mining, due to both foreign and local direct investment in the sector. Mining?s contribution to the GDP was 15.6% at current prices in 2009, and it accounts for 56% of the country?s exports. Chile?s copper market share reached 35% in 2009. The investment portfolio in mining in Chile for the coming decade has been estimated at 90 billion US dollars. The acute scarcity of human resources currently experienced by the mining sector in Chile will be accentuated in the coming decade as a result of this scenario of investments. The situation is, additionally, similar to the one confronted by other countries involved in the mining industry such as Australia, South Africa, Canada, and in Latin America includes, Peru, Colombia and Brazil. A study carried out by Fundacion Chile, ¨Labor Force in the Chile Mining Industry, Diagnostic and Recommendations, 2011-2020? shows the projected labor shortage for the operation of projects in the development stage, considering only the requirements of the process of extraction, processing, and maintenance. The demand, accumulated incrementally, will be around 115,000 technically skilled workers, professionals, and qualified workers. This figure refers to the operational work force, and does not include the human resources that will be required for the prior stage of the engineering and construction of the projects (brownfield and greenfield). The demand for technically skilled workers and professions for the stages of engineering and construction of the projects that have already received investments is estimated to be 190,000 people for the period 2012-2020. The peak of the demand for engineering is 2012, with a figure that surpasses the 12,000 professionals for all of the engineering specialties. The analysis of the formation of human resources at the tertiary level (where tertiary includes technical/vocational and academic degrees at the undergraduate level) for mining and related majors demonstrates that the programs are scarce with a bias toward theoretical contents and that they are excessively long (40% longer than comparable programs in Australia, Canada, and in OECD countries). The completion rates are low, especially in the technical-vocational programs, which have a completion rate of only around 30%. Finally, the rates of attraction of technically skilled labor and professionals towards careers in mining are insufficient to reduce the identified skill gaps. In the case of university professionals such as geologists, mining engineers and engineers in metallurgy, 80-90% will work in mining. In the case of graduates of relevant majors, that cover skills also utilized by other industries, not only mining?such as maintenance workers, operators of fixed and mobile equipment, etc.?the mining sector appears to be unattractive for reasons such as shift schedules, geographical location of work sites, and other factors. On the basis of the available diagnosis a strategy for the sector has been developed (Workforce Development and Skills Strategy) whose objective is (i) to define a Mining Qualifications Framework to identify the critical roles to be filled (ii) to start, with public resources, a ¨fast-track? training program to assure the availability of at least 28,000 operators (machinery operators, truck drivers, etc.) and maintenance specialists in 2015 (iii) to promote the development of training hubs for mining with learning technologies to train technical labor and professionals on the basis of world class standards (iv) to design and implement a campaign oriented toward the perception of mining as an attractive field of employment opportunity (v) to develop curricular innovations for tertiary education programs, on the basis of international benchmarks. Keynotes: Chile, mining, copper mining, skilled human resources

Sep 1, 2012

By Jan Cilliers

The demand for minerals has never been higher. Moreover, the rate at which this demand is growing is unprecedented, and expansions and new mines will be required to fulfill these growing needs. This, in turn requires a skilled engineering workforce that can develop and operate minerals extraction processes to utilise effectively more complex ores. The International Mineral Processing Council (IMPC) has established a Commission on Mineral Processing Education to consider the global challenge of ensuring an adequate supply of well-trained mineral processing engineers. The Commission has, for the past four years, been collecting international information of the recent mineral process engineering supply position and with a view into the near future. The data collected by the international Commission members are as follows: ? Undergraduate student numbers in minerals engineering ? A breakdown of their male/female ratio ? The fraction of the students from each course that enter the minerals industry ? Teaching staff numbers and age profile This data has been collated and analysed, and the findings are presented. It is clear from the analysis that the supply situation is very different in different regions of the world, and that great opportunities exist for targeted recruitment into the industry to meet the future talent demand. Further, an attempt at correlate the supply of minerals engineers based on the local mineral production rate is shown, which shows that there are clear outliers.

Sep 1, 2012

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 E. Ashirbaeva

"Ores of ferrous metals traditionally make up the bulk of recoverable reserves of solid minerals, and iron ore concentrates - in the processing and consumption. To obtain concentrates, three main methods are used: dry and wet magnetic separation, gravity and flotation. But even their integration into complex developed schemes with finishing operations often do not solve the problem of obtaining high-quality concentrates, which are necessary for powder metallurgy and electric steelmaking. Increasing the iron content in the concentrate by removing harmful impurities is the goal of this work. The possibility of reducing the operations of wet magnetic separation twice and completely eliminating concentrating operations in ball mills from the scheme of operations has been established. Selective leaching agents for each type of iron ores have been created, allowing to obtain concentrates with an iron content of not less than 68-69% and negligible concentrations of harmful impurities. Methodical recommendations for long-term storage of bioreagents in the active state, their immobilization and preparation in industrial conditions at the enterprise Nedropolzovatelja are developed. The proposed biotechnology, which allows to obtain high quality iron and conditional concentrates for harmful impurities, is protected by patents (RU 2537684 ""Method for fine-tuning of high-sulfur magnetite concentrate"" for magnetite ores and Pat. RU 2599068. For the industrial implementation of the new technology, organizational and technological measures have been developed in the system with Road maps for types of ores. The developed technology makes it possible to condition noble metal, tin, tungsten, nickel and other concentrates in harmful impurities such as arsenic, antimony, mercury, sulfur, copper, zinc, iron, phosphorus, manganese, in total 30 components that pass into solution under the influence of bioreagents.INTRODUCTION Consumption of various metals is steadily increasing every year, the volume of mining is constantly increasing. Ores of ferrous metals traditionally make up the bulk of the recoverable reserves of solid minerals. Enrichment technologies for iron-containing ores are reduced to the combination of three main methods: wet and dry magnetic separation, gravity and flotation. But even the use of complex advanced technological schemes often does not lead to the production of high-quality concentrates suitable for metallurgical processing. In this case, either lapping operations or effective technical and technological solutions are used in the main enrichment cycle. Widely used in practice methods for improving the quality of iron ore concentrates include the use of finishing operations (fine screening, reverse cation flotation), staging of concentrates, the use of more sophisticated equipment (separators with running magnetic field, magnetic gravity classifiers, column flotation machines)."

Jan 1, 2018

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 A. V. Kozub, D. O. Sharkovsky, R. I. Ismagilov

"Due to complex mineral composition and fine ingrained nature concentration of iron ores deposited in Mikhailovskoye mine field requires application of wet magnetic separation to produce 65–66% Fetotal and 8.2–8.6 %SiO2, concentrate with 90–94% of material being –0.044micron grain size. Higher specific consumption of ROM, increase of production costs with concurrent reduction of output - those are inevitable side effects of desired concentrate grade improvement. Large-scale complex analysis and surveys have been carried out aimed at concentrate grade improvement with concurrent output increase. Classification of feed in hydraulic cyclones (hereinafter referred to as hydrocyclones) has been the bottleneck for improvement of processing throughput and concentrate output. Hydrocyclone classification efficiency is 50-60% and further improvement is practically impossible. Actual circulating load may achieve as much as 500-600% while the optimal rate is 200-250%. Application of wet fine screening has been considered to improve iron ore concentrate grade. Objective of this work is to design processing flow diagram for unoxidized ferruginous quartzites with implementation of wet fine screening. Large-scale tests have been run in Crushing and Concentrating Plant with application of wet fine screening stage. These tests included application of wet fine screening in 2 and 3 stages of classification to separate desired grain sized material; replacement of hydrocyclone classification with fine screening; application of fine screening as additional stages to concentration process and screening of final concentrate. Testing Methods. EXPERIMENTS AS WELL AS THEORETICAL RESEARCH HAVE BEEN APPLIED FOR THE PURPOSES OF THIS WORK; INCLUDING MAGNETIC, GRAIN-SIZE AND CHEMICAL ANALYSIS OF CONCENTRATION PRODUCTS. MODERN ANALYTICAL DATABASE HAS BEEN APPLIED TO STUDY WET FINE SCREENING FEATURES, MINERAL AND PHYSICAL COMPOSITION OF CONCENTRATION PRODUCTS. Work Results: - analysis of wet fine screening application for iron ore concentration. - technological solutions enabling to improve slurry classification of fine ingrained low magnetic iron ore have been developed. - effective process flow diagram including fine screening has been designed based on the feasible and reasonable arrangement solutions."

Jan 1, 2018

By C. Suazo, O. Alruiz, A. Hofmann, I. Fernandez, W. Kracht, N. Mora

"Compañía Minera Dona Inés de Collahuasi, CMDIC, has developed a methodology that allows estimating economic benefit taking into account the variability of the ore characteristics (geometallurgical models). Currently, the grinding model allows predicting the treatment capacity, specific power and balls consumption for short, mid and long term planning. An alternative impact test to estimate SAG grinding parameters is presented in order to bring the geometallurgical model from mid and long term to short term planning. The impact test uses either the production bench or geological drill holes. This allows Geologists increasing the density of grinding parameters within the block model improving the geostatistical estimation of the rest of the blocks. The test requires a small amount of sample to obtain the requires grinding parameters for the grinding model in comparison to the well known grinding test and also, it can be performed easily and quickly by the geology team of a mining company. The alternative grinding test is presented in this article. The grinding model using this short grinding test has been successfully used in mining planning and the accuracy of the model is demonstrated using monthly average instantaneous throughput from January 2013 to March 2014, showing an average relative error of 5% and an R2 value of 0.9. Also, 111 individual variability samples were divided into two each, in order to compare the estimated grinding parameters based on this alternative test to the grinding parameters obtained from the conventional grinding test. The comparison shows an average relative error of 4% and an R2 value of 0.9."

Jan 1, 2014

By Gustav Hawlitschek, Henrique Kahn, Carina Ulsen, Renato Contessotto

"The problems related to waste dumping increased with the growth and development of large cities. In the U.K., more than 50% of landfill waste comes from construction use and the U.S. alone produces around 200 to 300 million tons of CDW annually. The exhaustion of natural sand deposits close to large urban centres stimulates the recycling of construction and demolition waste for the production of recycled aggregates as a construction material. This paper presents a flowchart for the production of recycled sand with low porosity and regular shape by the selective removal of the cement paste attached to recycled aggregates. The products characterization was carried out by the determination of the particle size and shape distribution, chemical and mineralogical composition, heavy liquid mineral separation and quantification of all present phases using a scanning electron microscopy with automated image analysis (SEM-MLA). The comminution of CDW by vertical shaft impact crusher made possible the production of a lower porosity recycled sand. The heavy liquid mineral separation showed that the proportion of low porous phases (d>2.5 g/cm3) is very high, exceeding 70% of the weight, encouraging further mineral processing separation to obtain a fine recycled aggregate with less cement paste content. The mineralogical characterization by XRD and SEM indicates that the main phases are tectosilicates, phyllosilicates and calcite which one can be attributed to both calcareous aggregate and cement paste. The precise quantification of cement paste and calcite/dolomite alone is just possible by automated image analysis. The characterization results demonstrated that proportion of phases with no cement paste attached increases progressively in denser products. The results of heavy liquid separations and image analysis are comparable and automated image analysis can be used for the characterization of phase content and their main associations."

Jan 1, 2014

By Arkady Senchenko

The application of centrifugal separation methods with the use of gravity concentrators has been assigned high priority while gold-containing minerals processing. The separation proceeds under centrifugal force resulted from the rotor spinning and wash water flow in the concentrators. The high specific gravity particles are retained at the trapping surface of the cone, and the low specific gravity particles are brought in the tailings. The centrifugal field in such concentrators (Knelson, Falcon) is generated by the rotating cone provoking the swirling of the free fed slurry flow. The author investigated the regularities of the separation process in the centrifugal gravity concentrator where a two-phase flow of the separated mineral media is under the pulsed pressure of the fluidization water and air. As a result of the study the possibility of the deeper penetration of the fine heavy fraction into the cone rings, providing the fluctuation of the fluidization water or air flow, was theoretically argued and experimentally proved. This allows the increase of the separation performance at low pulsation costs. The developed mathematical models are in close conformity with the actual process of interest and they enable the prediction of the heavy phase behavior at the isolated process stages in the concentrator. Keywords: gold, centrifugal gravity concentrator, containing, specific gravity, cone ring, pulsation, cost, fluidization water, Knelson centrifugal separator

Sep 1, 2012

By Hermann Wotruba, Lars Weitkämper

"Dry coal dressing was popular during the 1950.s and 60.s in many parts of the world. The devices mainly used were air jigs and air tables.The increase in ash and moisture content of run-of-mine coals due to the wide advanced mechanisation of mining mechanisation during and after this period led to that pneumatic devices being unable to treat run-of-mine coals with the desired efficiency. Since the 1960.s almost all new coal preparation plants have been based on wet processes that are highly efficient in terms of coal recovery and their ability to handle damp and sticky run-of-mine coals. (Frankland, 1995)However, water is becoming increasingly costly and the disposal of fine products, containing most of the water, is an environmental concern. There would be significant cost savings and a lower total energy consumption if coal could be cleaned dry. Efficient dry coal treatment would be an interesting solution in desert, arid or cold areas.In Germany one dry coal dressing plant is in operation. The process and the advantages and disadvantages are presented below.Further on new developments in the field of dry density separation of coal are reviewed and analysed. Test results of new dry coal separation methods e.g. new developed air jig and magnetic separator are reported."

Jan 1, 2003

By E. Hulthén

Crushing plants are widely used around the world as a pre-processing step in the mineral and mining industries and as standalone processing plants in the aggregates industry. Despite automation and different advanced model predictive control, a lot of the process is still managed by operators. The operators affect a lot of the performance. The numbers of the improvement they can achieve are at least as big as the advanced control algorithms?, today. Therefore, it is also important to train the operators so they know how to behave in different situations. Models for crushers and other production units have been developed during the years and the latest add is the different units? dynamic behavior being brought in, which gives the crushing plants dynamic time dependant performance. This can be used as a simulator for operators training. By connecting a Human Machine Interface (HMI) to a dynamic simulator with the models incorporated, a training environment for operators can be achieved. In this paper, a dynamic crushing plant simulator implemented in MATLAB/SIMULINK has been connected to an HMI via a PLC. The HMI is placed in a control room at the university and complemented with monitors showing sequences from the process connected to the simulations, thus creating a realistic control room for training. In the created training environment, the operators can be trained under realistic conditions. Simple training scenarios and how they could be simulated are discussed. Apart from the increased level of knowledge and experience among the operators, the time is an important factor. While a real crushing plant is still being built, the operators to be can already be trained, saving a lot of the commissioning time. Keywords: crushing, cone crusher, simulator, control room, operator, training

Sep 1, 2012

By Guanzhou Qui

The utilization status of copper ore resource, the application and development of biohydrometallurgy technology in the world was reviewed. Furthermore, according to the analysis of the characterization of Zambia?s copper resource, biohydrometallurgy technology was shown to be a good way to explore and utilize the enormous low grade copper resource, such as ore tailings and low grade copper ore in this country. Through the cooperation of CSU, China and MMMD, Zambia, ?CNMC-CSU Demonstration Base of Biohydrometallurgy Technology in Zambia? was launched and several biohydrometallurgy plants are being constructed, that indicates the biohdyrometallurgy technology would be applied soon in Zambia and even in the whole Africa. Biohydrometallurgy technology stands as an efficient alternative to the traditional pyrometallurgy process can be the key to unlock mineral resources value. Keywords: biohydrometallurgy, Zambia, copper processing, CNMC-CSU

Sep 1, 2012

By R. Bugueño, W. Calderón, G. Montes-Atenas

From the point of view of industrial performance of metal extraction, the efficiency of a column leaching operation depends strongly on the leaching agent and the ore properties such as mineral composition, mineral liberation and particle size distribution. One aspect that has become particularly important is how the leaching solution flows through the porous structure which contains the valuable minerals. It is known that the output flow rate of leaching solution depends mainly on factors of the input flow, environmental condition and porous bed properties. The latter factor is often evaluated and reported under saturated conditions but in practical leaching systems unsaturated conditions are dominant. This investigation has the purpose of determining the residence time of the leaching solution in columns with different diameters under unsaturated conditions by using experimental data and numerical simulations. Laboratory leach test were performed using isothermal jacketed columns with top cap to reduce the evaporation. The simulations were performed using the software SVFlux® which incorporates material properties such as Soil Water Characteristic Curve (SWCC) and Unsaturated Hydraulic Conductivity. Preliminary results indicate a non-linear asymptotic behavior of the saturation rate with respect to the operation time. Results from numerical simulations show the same non-linear behavior and a considerable delay between input and output flows. Further analysis concerning with the effect of transpiration and evaporation mechanisms is discussed.

Jan 1, 2014

By Nicolás Luis, Qi Liu, Gonzalo Montes-Atenas

"The prediction of froth flotation performance is still an unresolved topic. Classic industrial models based on particle size, elemental and mineralogical information provides recovery results with deviations that may become significant. One possible reason for this deviation may be the fact that the current liberation analysis provided by electron microscope based techniques does not take into account the outmost surface layer composition of liberated particles. In order to complete the description provided by the liberation analysis, other spectroscopy techniques measuring the extreme surface of the minerals can be tested. For instance, X-ray Photoelectron Spectroscopy (XPS) is a technique which measures the first tens of nanometers providing elemental composition over the particle surface and allows resolving the elemental associations present at the surface sample. However, this information needs to be statistically robust, reproducible and most importantly representative of what is occurring in the process. The aim of this research work is to develop a statistical model based on particle population to evaluate the feasibility of turning the XPS technique into a metallurgical tool. The model consists of classic statistical population arranged in a bed of heterogeneous particles with a known grade and mineral liberation. The simulations showed that the XPS results statistically followed a well-defined pattern. The statistical results were confronted with pilot plant results obtained from a rougher bank when processing a copper sulfide ore from a Chilean mine site. It was observed that the probability function distribution was in agreement with the experimental data. Further analysis on how the XPS results provide valuable information improve the computation of froth flotation recoveries is also discussed."

Jan 1, 2014