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By S. Liu

With the development of global economy, the demand of mineral?s quantity and quality are in-creased, valuable minerals are more and more finer and poorer, and the capacity of concentration plant are more and more high. Using large-scale flotation cells can obviously enhance the capacity of treating the mineral, reduce the cost, and increase the economic benefit and competitive ability for the enterprise. BGRIMM advanced advisable technical scheme with optimally parameter and route for the feature of dynamic in large scale flotation machine, and developed the KYF Large Scale Flotation Cells, which have used more than 400. The paper advanced the history, the design principle, the operating principle, the structure feature and the application of KYF flotation ma-chine.

Jan 1, 2014

By M. Gonzalez Fernandez

"Commercially introduced in 2004, the SAGDesign™ test has today proved its efficiency for sizing SAG mills for a wide variety of ores, from very soft to very hard ones. The interest of building a model using the SAGDesign™ test specific energy is the introduction of such a model into a complete process simulator making it possible to predict a complete material balance. The developed model compares the required specific energy with the energy provided by the mill. This energy calculation is derived from the Austin Power Formula. The specific energy provided by the test is corrected, using various parameters, such as the Ball Mill Work Index, to take into account the true operating conditions, the feed and product sizes. The core of this model allows the determination of the product d80 using the mill geometry, its operating conditions and of course the SAGDesign™ test results. To be included in a simulator, the model must also predict the overall size distribution of the SAG mill discharge. Assumptions to answer this point are presented here. The model has been implemented in the USIM PAC simulator. It is used either to predict the product size distribution for a given SAG mill, but also to size a SAG mill for getting a required reduction ratio. INTRODUCTION Over the last few years several types of new comminution machines have been introduced in the market. The most notable newcomer was the HPGR (Morley, 2006). But, even when these machines have some advantages, they have not earned the trust of the mining industry. That is why the established technologies still being the first choice. And, in comminution, that first choice are SAG and ball mills. The design of ball mills has been well understood for a long time. The Bond Ball Mill Work Index is the standard test which helps to describe the ore in terms of energy requirements for milling. Unfortunately, the development of an equivalent test to characterize the ore subject to SAG milling has taken some time. As of today, several tests are available in the market, like the MacPherson test, the MinnovEX SAG Power Index (SPI™), the JK Drop Weight Test, the SMC Test® and the SAGDesign™ test (Verret et al., 2011). The SAGDesign™ test, developed by John Starkey in Canada in the early 2000s (Starkey et al., 2008, 2015), has become one of the standards to assess the grindability of an ore in a SAG mill. One of its advantages is the reduced sample mass needed to perform it, hence, the reduced cost. The second one is that the output of the test is straightforward, it is the energy required to grind the ore between two sizes. Because of this energetic approach, the results provided by the test can be directly applied to size a new mill or to assess the performance of an existing mill."

Jan 1, 2018

By M. Evertsson, E. Hulthén

"In aggregate production and mining the operators are responsible for controlling and monitoring the process to maintain high plant throughput and safe operation. Operators have to make different decisions to control the process due to changed demand on the operation from both management and conditions of the process. The quality of the response and the time it takes for an operator to respond to altered demand relies on what information is available and the experience of the operator. In this work a dynamic simulation platform has been developed to be used for operator training. Models for representing production units and process control for plant simulations have been developed and implemented in MATLAB/SIMULINK to simulate time-dependent plant behavior. Stochastic and scheduled events are included using the discrete events simulation toolbox SimEvents. The human-machine interface was developed using the human-machine interface software ICONICS. The operators’ cognitive process, in interpreting the plants semantic, has been studied by observations and with informal interviews with operators. This was done to get information about the daily operation and the problems that occur in the process. By interacting with operators that experience different physical interactions with the process; more qualitative e-learning software for supporting operator training in a dynamic operator environment could be developed. The quality of the operator training environment was evaluated with a usability study that was performed with operators and others within the production."

Jan 1, 2014

By A. Morrison, P. Brito-Parada

"The separation of valuable and gangue minerals according to their surface hydrophobicity in a froth flotation tank occurs in both its pulp and froth phases. In the pulp phase, hydrophobic particles must be brought into contact with rising bubbles introduced at or near the bottom of the tank. In a mechanical froth flotation tank, this is primarily achieved through the agitation of the pulp by an impeller or by a rotor-stator system. However, the turbulent and mixing effects of such an impeller or rotor-stator system, necessary to promote bubble-particle interactions in the pulp, are not confined to the pulp zone, but are transmitted into the froth zone at the pulp-froth interface. This impeller-induced turbulence at the pulp-froth interface is compounded by the impulse of buoyant bubbles entering the base of the froth phase, reducing the stability, and thus separation performance, of the resulting froth. Hence, turbulence improves separation performance if it occurs deep in the pulp phase, but diminishes it if it occurs close to the pulp-froth interface. For this work, a performance-enhancing pulp phase insert was designed to isolate the impeller-induced turbulence from the pulp-froth interface in a laboratory-scale, continuously-operated froth flotation tank. The result was a shifted grade-recovery curve that allows the insert to be designed to maximize the recovery from the system without sacrificing the grade of the concentrate, or vice versa, along a spectrum of improved performance. This paper will present the insert design and development process that resulted in this improved grade-recovery curve, as well as a set of heuristics that could be used to design a similar insert for pilotand industrial-scale validation and deployment.INTRODUCTIONAn almost ubiquitous design feature of commercial flotation tanks is the enclosure of the impeller to create a concentrated turbulent zone (Mavros, 1992). These turbulent zone enclosures are varied-- from the rotor-stator design of, for instance, Outotec cells, to the air disperser design of Wemco cells-- but all share the same rationale: that turbulence is desirable to promote bubble-particle interactions (Ralston, 1999), and to produce smaller bubbles (Wills, 2006), but also undesirable because it promotes the detachment of valuable mineral particles from bubbles, and exacerbates entrainment-inducing mixing at the pulp-froth interface (Jameson, 2010)."

Jan 1, 2018

By A. Lane

Africa is ripe with opportunity for the mining industry. The continent has large, and relatively unexplored mineral deposits, and recent high economic growth rates have meaningfully improved the political, economic, and infrastructural environments. However, these opportunities are accompanied by significant risks, including resource nationalism, uncertain regulation, corruption, and continuing political instability (up to and including war). Forward-looking companies actively manage these risks by creating a sense of shared purpose with the countries and communities that own the resources, using tools such as stakeholder analysis, local narratives, scenario planning, and constituency engagement. They also measure socio-economic impact to insure the creation and demonstration of shared value.

Sep 1, 2012

By S. Serranti

A fast, reliable, and low cost characterization of ore minerals products, as they result from different processing actions, represents one of the most challenging targets in the mineral processing sector. Today different techniques are available according to different sampling strategies and analytical principles. In this paper, the possibilities offered by the adoption of hyperspectral imaging based sensing units working both at micro- and macro-scale are presented and discussed. According to the different phases and stages of ore minerals and products characterization, and starting from the analyses of the detected hyperspectral firms, it is thus possible to derive useful information about mineral flow stream properties and their physical-chemical attributes. This last aspect can be utilized to define innovative process mineralogy strategies and to implement on-line procedures at processing level. The present study discusses the effects related to the adoption of different hardware configurations, the utilization of different logics to perform the analysis and the selection of different algorithms according to the different characterization, inspection, and quality control actions to apply. Keywords: process mineralogy, hyperspectral imaging, NIR spectroscopy, surface mapping, textural analysis, quality control

Sep 1, 2012

By M. S. Prithvi

Over the decades, mine and mineral processing plant operations for the most part, have been found to have had adverse impacts on the environment. At the same time, mineral processing and mining operations produce mineral products that are indispensable to modern society. Thus, the sector has desirable and undesirable attributes simultaneously. The situation presents itself as a contradiction (i.e.) the mineral processing and mining operations are wanted by society, and at the same time unwanted by society. The existing methods of addressing the issues raised above have evidently not been very successful in reducing the opposition to new projects and to the related activities such as land acquisition. This paper attempts to show the relevance and applicability of TRIZ for addressing the issue. TRIZ, or Teoriya Rezheniya Isobretatelski Zadach, is a Russian acronym meaning Theory of Inventive Problem Solving. TRIZ is a powerful tool that can be usefully applied to resolve such contradictions, using resources usually available within the system of interest. Accordingly, this paper introduces the issue background, followed by an introduction to some key concepts of TRIZ such as the 40 principles, separation principles and directed evolution. The paper goes on to apply the 40 principles to two case studies. The results show that TRIZ could be a useful tool to generate potentially innovative and sustainable approaches. Its most appropriate position would be as a supplement to current decision-making procedures, and as a validation tool to review existing solutions for possible improvements. Keywords: minerals, environment, TRIZ, contradiction, resources

Sep 1, 2012

By G. Bonifazi

Mining activities belong to human history, they are lost in the mists of time. They usually impact on large portions of the territory, both directly (exploitation areas and logistic activities directly related to exploitation) and indirectly (exploited material handling, processing and storage areas). As a result, at the end of mine life cycle, dismissed areas usually cannot be directly re-utilized without efficient and well addressed rehabilitation actions. Main goal of the proposed approach was to analyze the results obtained when a set of procedures, based on the collection and the analysis of remote sensed data, is developed to evaluate the effect of rehabilitation of land contaminated by extractive industry activities and to perform a monitoring and registration of the environmental impact of such operations by the application and the integration of modern information technologies, as Earth Observation (EO) and Geographic Information Systems (GIS). The study was developed in the framework of the EU-Asia program of the European union (EXTRACT-IT Project-Contract No: CN/ASIA IT&C/006 (89870): Application of Information Technologies for the sustainable management of Extractive industry activities) and it was addressed to three different dismissed mine areas in India, Thailand and China, respectively. The results, in terms of methodologies selected, strategies applied and results obtained, are described with particular reference to Fuxin coal mine area in China.

Jan 1, 2014

By Eberhard Gock

The worldwide implementation of corrosion protection of low alloyed automotive metal sheets by zinc coating has led to supply shortages of zinc free non-alloyed steel scrap in the foundry industry. In a collaboration project, partly financed by the German government, with partners from the automotive industry, zinc metallurgy, scrap trading, foundry industry, and plant construction, a new acid-based pre-dezincification process has been developed, and a pilot plant with throughput of about 100 t/d has been put into operation at the Clausthal Umwelt-Institut GmbH (CUTEC) together with the Clausthal University of Technology in Germany. During the treatment process, acid from a zinc metallurgical plant will be supplied, which can be recycled to the primary zinc extraction process after raising the zinc concentration to more than 130 g/L zinc. This way, the separation of small amounts of iron by precipitation and the electrolytic zinc winning are outsourced and, as a result, the pre-dezincification process runs waste-free. In Germany, the amount of zinc coated ?new scrap? is approx. 3 million t per year with a zinc content of approximately 60,000 t per year. The possible additional incomes for the dezincified steel scrap are in the order of ?40 to ?50 per ton of scrap, the gained zinc content during the acid dezincification defrays the costs of the process, if the throughput is more than 700 t/d. In comparison to conventional dezincification during the electro arc furnace process followed by upgrading in a rotary kiln (Waelz process), the acid dezincification process running at a maximum of 50°C will cut the energy costs by up to 74% and the CO2 emission by up to 88%. In fact, a demonstration plant is being designed right now and will be installed for processing a part of the zinc coated metal scrap from the Volkswagen AG in Wolfsburg, Germany. Keywords: steel scrap, zinc-coated steel, dezincification methods, acid

Sep 1, 2012

By O. A. Bascur

It is difficult to analyse the economics without an integrated view of mine transactions, stockpile inventories, process flows and assays. The lack of integration of mining and metallurgical information with sufficient detail to analyse and act is a problem. However, to take action requires real time information from manufacturing assets, corrected for gross errors from trucks, shovels, conveyors, faulty sensors, bad instrument calibration. Validation methods use process models to identify inconsistent information in the case of corrupt actionable information. This paper presents new strategies that transform the data into business information for continuous improvement and optimization. This technical presentation will review recent implementations enabling large metallurgical complexes to improve their data quality for overall production and energy management. A competence center emerges as an enabler for implementing operational intelligence. The evolution of Web services to troubleshoot plant information and to collaborate at the enterprise level is presented.

Jan 1, 2014

By Gabriel Aguilera, Juan Arismendy

"As a separator machine, the hydrocyclone is one of the most commonly used equipment in different types of industries and particularly in mineral processing, hydrodynamic behavior allows efficient separation, but developing tests to optimize experimental equipment is expensive, therefore Computational Fluid dynamics (CFD) becomes a useful tool for optimizing the geometrical and operational parameters, and allows to analyze and understand the dynamics within the equipment. In the research was developed to simulate of 40 mm hydrocyclone where turbulence model was used Large Eddy Simulation (LES) for the continuous phase, for the generation of the air core and for the interaction of particles at low concentrations was implemented (mixture model), after the simulation was completed validation and comparation was done between simulation values and experimental."

Jan 1, 2014

By Shankar Narasimhan

Data Reconciliation is a technique that has been developed more than fifty years ago and has been refined over the past few decades and is now being deployed routinely in several process industries such as refining, petrochemicals, mineral processing and hydro-metallurgy. The main aim of data reconciliation is to obtain accurate estimates of all process variables and parameters using plant measurements that are invariably corrupted by random errors and may also contain biases and other gross errors. These reconciled estimates are subsequently used either in offline exercises such as simulation, retrofitting, and de-bottlenecking or in online optimization and control applications. In this presentation, a brief history of data reconciliation, its assumptions, and uses are reviewed. New developments in this area are highlighted such as robust data reconciliation to handle model uncertainties, and reconciliation using identified models derived purely from operating data. Several case studies in the mineral processing industries reported in the literature are also highlighted to indicate the potential benefits of this technique.

Sep 1, 2012

By Jorge Rubio, Gabriel Berkowitz, Fabiano Capponim, Carlos Perez Guerrero, Elves Matiolo, Denise G. Nunes

This paper describes some advances in flotation research in fines (“F” 38 to 13 µm) and ultrafines (“UF” < 13 µm) mineral recovery by two different techniques, at laboratory scale. Extender flotation and flotation with .multi-bubbles. (bubbles with a wide size distribution) of copper sulphide fines (ore feed of about 1 % Cu) were compared with a .standardised. mill laboratory procedure. Comparative evaluation was made through concentrate grade and recovery (size by size results included), .true. (bubbles-particles attachment only) flotation recoveries and process kinetics. Both techniques yielded higher metallurgical efficiencies than the mill standard but better results were obtained with the extender flotation, with emulsified diesel oil (90 gt-1). Concentrate recoveries were of the order of 85-90 % (84 % in standard conditions), 14-17 % Cu grade (15 % Cu in the standard) and 3.5-4.5 min-1 for the Klimpel rate constant (3 min-1 in the standard). Size by size and true flotation results proved that metallurgical and kinetic gains, obtained with the two techniques, might be attributed to fines and ultrafines enhancement. Data obtained are discussed in terms of physical and physico-chemical parameters related to aggregation and capture (of particles by bubbles) phenomena and the practical potential of these techniques are envisaged.

Jan 1, 2003

By Mario Gerards, Marco Steinberg, Jan Huben

"Wet high intensity magnetic separation or WHIMS is a widely used technical process for the recovery of magnetic susceptible iron ore particles, mostly for fine and ultrafine grain sizes. The JONES® WHIMS - Wet High Intensity Magnetic Separator, has been used for many years and in countries all around the world. This paper outlines the physical principles utilized for the separation inside the unit, as well as some of the recent changes and developments on the design. It will also give an outlook on the theoretical potential of different alternative yoke materials. The aim of this paper is to analyse the suitability of different yoke materials to improve the equipment. This will be done comparing the magnetic and mechanical parameters and analysing availability and price to find the best compromise regarding cost and benefit. As far as the different kinds of materials are concerned, a special material has been identified as suitable during the comparison exercise. After running the economical calculations, especially with respect to the reduction of the total power consumption of the equipment, a tremendous reduction of the total power consumption has been determined. In addition, to the theoretical exercises and due to the promising results of the same, the Pilot Unit P 40 of the JONES® WHIMS has been manufactured with the special material in order to get practical results as well. Finally, this paper outlines the theoretical and practical results focused on the power consumption. The results are showing that the total power consumption can be reduced tremendously. Hence, the way for a new generation of JONES® WHIMS - environmentally friendly - has been paved."

Jan 1, 2014

By Richard A. Williams

The mineral processing community have been amongst the pioneer developers and early adopters of key platform technologies in analytical methods, chemistry, physical separation and advanced modelling. Fundamental research will continue to have a significant impact driven by the continued development of sustainable practices. Major drivers and challenges for change in our industry in the next two decades include: reduction in energy uses in processing; discovery of new energy materials; adoption of green chemistry routes; safeguarding of water resources; and demonstration of adherence to best practice at all times. With increasingly global mining enterprises, the provision of internationally accepted benchmarks for performance will continue to drive the creative process. This lecture highlights major opportunities around a new paradigm of Multi-scale Measurement coupled with Multi-scale Modelling, based on advanced sensors, communications and computing. Connecting real-time measurement sensors with dynamic simulation models opens up new horizons for visualising the process behaviour from an experimental and theoretical basis. Examples are given of the potential of this methodology and its implications for better design.

Jan 1, 2003

By Auhin Kumar Maparu

Metal oxide nano-particles are used as additives in various industrial applications such as pigments in paints, additives in adhesives, plastics, cosmetics, functional coatings, personal care and health care products, for antibacterial applications and more recently in heat transfer applications. In most of these applications, usually dry nano-particle powders are added to the formulations. However, often it becomes difficult to achieve a uniform and stable dispersion of nano-particles in the given formulation. Thus, a scalable and commercially viable process for in-situ production of stable nano-particles suspensions in the desired medium will certainly be more beneficial. Ultra-fine grinding in high energy mills (planetary mill, stirred media mill) has been used to produce fine particles (sub-micron size). However, in order to obtain nano-particles (particle size <100 nm), the choice of appropriate dispersant and solvent is crucial, since freshly generated nano-particles tend to agglomerate due to their high surface reactivity. We have employed molecular modeling (MM) based selection methodology to arrive at the most suitable solvent?dispersant combination for preparation of the given metal oxide nano-particles. Molecular modeling techniques are employed to compute the interaction energy of a given dispersant with surface of the metal oxide particles in the presence of the dispersion medium. The interaction energy helps identify a dispersant that has strong affinity for the metal oxide surfaces allowing for strong dispersant adsorption and hence a more stable dispersion. For example, in case of aqueous nano-titania suspensions, poly-carboxylic acids like citric acid provide better dispersion than mono-carboxylic acids like lauric acid, mysristic acid, and oleic acid. While in non-aqueous medium like ethanol, p-hydroxybenzoic acid and glycerol trioleate perform better. The suspension is produced in-situ by ultra-fine grinding of the metal oxide powder in the presence of the selected dispersant and dispersion medium in a planetary ball mill. By careful selection of various process parameters such as percent loading of powder, jar filling, grinding media to powder ratio, time and amount of dispersant addition, both aqueous and non-aqueous suspensions of metal oxide nano-particles with average particle size less than 100 nm are produced. The aqueous suspensions of alumina and titania produced in presence of citric acid dispersant exhibit median particle size of 83 and 62 nm, respectively. These suspensions have been found to be stable for nearly 3 years. The nano-particles thus produced are used in the preparation of nano-fluids?advance heat transfer liquids, which show enhanced heat transfer capabilities and unaltered stability and performance even after several heating-cooling cycles. The nano-particles are also utilized for making efficient photo catalysts, which are found to be highly effective under sunlight. Keywords: stability, nano-fluid, milling, grinding, thermal conductivity, nanocoolant, photocatalyst

Sep 1, 2012

By H. Allenius

Today, most requests for quotations force all bidders to follow the bid document to the letter. The choice is then made based on price since it is the only difference in technically identical offers. However, clients allow and even encourage suppliers to come up with alternatives. Overall economy again, is much more than low investment costs. Operation costs may affect the economy of a project far more than a million saved in investment. There is almost always the choice: Should we go for the cheapest solution or should we go for the most economical solution? We strongly recommend the study of the long-term effects on investments as they often surpass any apparent savings in capital expenditure. With high operating costs, time is never on our side. Almost all relevant inputs and outputs in a concentrator have a value that can be expressed in a suitable currency. Unit prices may differ substantially from one operation to the other, but everything has a price tag and globalization has made it possible to move both goods and services to almost any place in the world. Even a rather simple exercise can give a good indication on which process improvements are worth pursuing when investing in new systems or equipment. The ones that do not qualify, as money earners, will naturally appear as clearly. No ?rocket science? is required, just process knowledge, practical experience, an open mind and some common sense and the reward may be the difference of having a good or an excellent project. The model we have developed can be made as detailed as required, but we do not recommend too much detail, as it sometimes tends to distract work and obscure the important issues. Two different process solutions compared in a simplified example illustrate the importance of evaluating a project based on its long-term effects rather than focusing on the investment costs only.

Jan 1, 2014

By Juan Estrada, Mirtha Frómeta, Rubén Alcalá, Emilio Montejo, José Castellanos, Juan Berto, María Rivas

"The oxidized nickel ores from San Felipe deposit are composed mainly Smectites which gives to the pulps very unfavorable rheological .properties (cinematic viscosity and high shearing strength) for transportation processes (pumping), very low settling velocities and very low thickened pulps. These properties do not allow the preparation of high % solids, which affects the economic efficiency if a high pressure acid leach (HPAL) process is used. Pulps of close to 30% solids have very high BYS making pumping impossible. CIPIMM developed three technologies to solve these problems and to substantially increase the % solids in the pulps to be leached without a thickening step. These technologies are: • CIPIMM 2. At Preparation of pulps using additives. This method is based on the effect of some additives (inorganic salts) to improve the pulp’s properties. The use of this method allows increasing the % solids in the pulp up to 40% with good rheological properties • CIPIMM 2B. Preparation of pulps by thermal treatment of the ore previous to the preparation of the pulps. This method is based on the thermal destruction of the clays structure. Its use allows to obtain pulps with 50 - 60 % solids with excellent rheological characteristics. As a collateral effect, the Ni and Co grades increases by 10 - 15%. • CIPIMM 2C. Pulp preparation by chemical treatment. This method is based on the chemical transformation of clays, to obtain without thickening, pulps with 43- 45% solids and excellent rheological properties. The use of one of the three technologies depends on the chemical and mineralogical composition of the ores and the results of technical-economical evaluations to determine which one is the best alternative before running higher scale tests."

Jan 1, 2014

By Filippov. L. O.

Metallurgical results for the copper-nickel disseminated ores were improved by using ultrasonic treatment. This has been demonstrated by processing of bubble-pulp flow in the reactor zone of a reactor-separator flotation machine. It can be explained by changes in mineral and size composition of the concentrates. Thus, the selectivity of Cu/Ni flotation for different values of the hydrodynamic parameter increases considerably. Additional effect of the ultrasound treatment has been noticed under conditions when the detachment of the gangue minerals from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose. In fact, the weak diameter of reactors make more efficient the ultrasound effect than in conventional impeller or column flotation machines. A combination of ultrasonic treatment with original organization of gas pulp flux in the reactor-separator allows to obtain significant effects in the flotation attachment/detachment subprocesses, enhancing the process selectivity and/or recovery of substances. Increase of total recovery of copper and nickel into bulk concentrate at constant grade is 8.5% for coarse disseminated ores. For copper ore, copper recovery increased by 10% at unchanged grade of 11.7% and nickel recovery gained 17% at the constant grade of 2%.

Sep 1, 2012

By C. Abbruzzese, F. Vegliò, S. Ubaldini, R. Massidda

"Gold solubilised during cyanidation can be recovered by precipitation (Merrill-Crow process) or by adsorption onto activated carbon, these being the techniques applied in industrial plants.Precious metals (Au, Ag) adsorbed onto activated carbon are extracted during a subsequent stage in aqueous phase, by various technologies, such as hot elution (70-80°C) or under pression desorption (100-130°), with hydro-alcoholic solutions.This stage is of great interest from an economic point of view, due to the high energy costs. Temperature represents the critical kinetic factor.The aim of this paper was to study the influence of different water/organic solvent mixtures (isopropyl alcohol, ethanol and ethylene glycol) on the desorption process.The experimental work was carried out on laboratory scale, using activated coconut carbon with different temperatures and extraction times, without adding cyanide.Best results have been obtained in this order: isopropyl alcohol > ethylene glycol > ethanol. Starting from gold concentration of about 5 g Au per kg of carbon, best kinetics resulted in 97-100% of gold extraction, after 8 hours of desorption, at a temperature of 80ºC."

Jan 1, 2003