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By D. G. Hulbert

"Mineral processes are complex operations that have been modelled, controlled and simulated by diverse technologies. A review is given of some models of mineral processes in the literature. A new variation of a dynamic process model of flotation is presented. Process models, describing real and relevant physical variables, give a good understanding and good qualitative simulations, but can sometimes require prohibitively difficult and extensive parameter estimations. Process control is usually best done on operational plants by the fitting of system models, which can home in on the plant?s observability, controllability and optimisation. System models can be of a form amenable for use in appropriate techniques for controller design and implementation. The control of milling circuits is discussed in some detail. While simulators use models to predict dynamic or steady-state information, part of their strength lies in their ease of use and their ability to test different types of specifications. Some results are given for a flotation circuit simulator that can be made to solve virtually any permutation of specifications.INTRODUCTIONThe development and application of appropriate technology can lead to better operation of mineral processing plants in industry, so that substantial benefits can be obtained from improved throughputs, efficiencies and product qualities. This paper addresses some of the principles and methods used in the quest for the development and exploitation of such technology. Although the design of processes is often the motivation for modelling and simulation, this paper also targets the use of modelling and simulation for the control and optimum operation of mineral processes. The two processes given the most attention here are flotation and milling.Technologies used in mineral processing range from simple to very complex. Simple technical principles, such as mass and component balances, can yield some simple and effective strategies for modelling and control. However, minerals in particulate form have such complex physical and chemical properties that there appears no end to the complexity that emerges, as more and more factors are taken into consideration in the pursuit of better results and understanding. The situation is aggravated by the complexity of mineral processing plants, which have spatially variable conditions within process units, and complicated interactions between these units."

Jan 1, 2003

By Muammer Kaya, Sait Kursunoglu

"Energy is the major concern for society. It is expected that developing country economies and populations will grow and consume more energy. Interest in nuclear power is rising, while the world looks for non-depletable energy source that will not contribute to global warming. However, it still has concerns of nuclear proliferation, radioactive waste and safety. It is necessary to overcome these concerns if nuclear energy is expanded to developing countries. Thorium (Th) utilization as nuclear fuel will be an opening key of these difficulties because Th produces less Plutonium (Pu) and less radioactive waste with enhanced safety. Research into the use of Th as a nuclear fuel has been taking place over forty years, through with much less intensity than that for uranium (U) or U-Pu fuels. Nuclear industry is currently using only 0.7% of the available energy from mined U. With huge resources of Th and relatively little U, Turkey has made utilization of Th for large-scale energy production a major goal in its nuclear power programme. Thorium fuel is plentiful and inexpensive. Energy is major concern for developing Turkish society. Turkey, today exports more than 70% of its energy as fossil fuels. In the last 50 years, Turks are skeptical, anxious and indecisive about having nuclear energy for electricity production. In the last 10 years, Thorium is brought into Turkish government’s attention and national discussion as a new, safe, clean, affordable, CO2-free, alternative, strategic and domestic nuclear energy fuel. Turkey recently contacted four VVER-1200 type Russian Nuclear Power Reactors using U as a fuel in Akkuyu (Rosatom) and another four units will be established in Sinop in the next decade by Japan (Mitsubishi-Westinghouse). Turkish nuclear programme must envisage use of domestic Th as a fertile material. This paper briefly reviews the developments of Th-fuel cycle for nuclear energy from global and Turkish perspectives. Previous Th reserve development and recovery studies from Turkish bastnasite ore are summarized in this paper."

Jan 1, 2014

By T. Bhambhani

Research at Cytec over the past two decades has shown that the traditional approach for ore metallurgical characterization (typically conducted via laboratory-scale batch flotation tests), which involves changing reagents and conditions one-factor-at-a-time, leads to several pitfalls. The chemical solution thus selected has a narrow un-optimized window of performance and will likely fail in the plant. A holistic approach, called the Flotation Matrix 100? process for ore metallurgical characterization, was developed at Cytec about a decade ago and has been successfully used to develop robust reagent solutions for several operations around the world. The premise for the approach is that flotation outcome from ores is variable and is determined by complex interactions between various physical, chemical and operational factors. A key component of the process is the use of efficient multivariate designs focused on the chemistry aspects (reagents and pulp chemistry), which helps identify the best processing conditions for each ore type, as well as the conditions resulting in poor performance. It also includes advanced statistical methods for dealing with the complexity and variability of experimental data. The holistic approach is illustrated in this paper with a case study on Pb/Zn ores. Using just 18 carefully designed batch tests, it is possible to partially simulate the behavior of each ore type in the plant. The best conditions for each ore type, along with the conditions to avoid, are identified. Along with this, insights are obtained into the reasons for high reagent dosages for certain ore types, and interactions between variables. Keywords: flotation, holistic approach, metallurgical characterization, multivariate experimental designs, base and precious metals recovery, sulfide collectors and modifiers, Pb/Zn sequential flotation

Sep 1, 2012

By Q. Cui, Z. G. Song, S. S. Lin, S. Q. Li, S. S. Lu, G. B. Zheng, A. J. Ren

"Mine tailings is one of the most important bulk industrial solid wastes, but its rate of comprehensive utilization is relatively low. Efficient separation, recovery and utilization of the valuable components is one focus of the comprehensive utilization of tailings. Beneficiation recovery of the valuable minerals is the most direct comprehensive utilization method for tailings. There are generally different kinds of nonmetallic minerals contained in the nonferrous metal mine tailings, which are secondary mineral resources waiting for further developing and recovery. Comprehensive utilization test studies on fluorite in tungsten beneficiation tailings and feldspar in molybdenum beneficiation tailings have been carried out by author and good test results are achieved. Some of the technologies developed in the test study have been applied in industrial productions, which have been working well. The economic, social and environmental benefits are remarkable. Our test studies and some production practices will be summarized and current situation and existing problems of comprehensive utilization for nonferrous metal mine tailings will also be discussed. Assumption and prospect for the future study on comprehensive utilization of nonferrous metal mine tailings will be brought at last.INTRODUCTION Mine tailings is one of the most important bulk industrial solid wastes, but its rate of comprehensive utilization is relatively low. Efficient separation, recovery and utilization of the valuable components is one focus of the comprehensive utilization of tailings. Beneficiation recovery of the valuable minerals is the most direct comprehensive utilization method for tailings. There are generally different kinds of nonmetallic minerals contained in the nonferrous metal mine tailings, which are secondary mineral resources waiting for further developing and recovery. Comprehensive utilization of nonmetallic minerals of nonferrous metal mine tailings not only can improve the value of the ore but also reduce the stock of tailings, being the key to reduce emissions at source for exploitation of nonferrous mineral resources (Cai, Yang, 2000)."

Jan 1, 2018

By Michel Brissette, Shaheer Sanuri, Veroljub Mihajlovic

"The main purpose of geometallurgy is to improve the mine planning by mapping hardness and throughput into the mine block model using geostatistics to eliminate the large production fluctuations caused by the ore hardness variability coming from different parts of the pit. However, not all grinding testwork available commercially can be applied to geometallurgy because of large amount of sample required and the associated cost per test. Geometallurgy is now being used in designing grinding mill but as the mining project progress, the accuracy of engineering must improve from 30-35% during the scoping study to 10-15% at the bankable feasibility stage and less than 5% for Engineering Procurement and Construction Management. For SAG milling, the SAG Variability Test (SVT) is an abbreviated version of the standard SAGDesign test developed for this geometallurgical need. The same amount of ore than the original test is ground for three cycles into an open batch SAG test and then the SAG pinion energy is predicted to the standard end point of 80% passing 1.7 mm. For ball milling, a Bond Variability Test (BVT) was also developed using the SAG ground ore from the SVT. The Bond ball mill grindability (Gpb), corresponding to the average of the net grams per revolution from the last three cycles of the Bond test, is also predicted from the third cycle. The relative error for both the predicted SAG ore hardness (WSVT) and Bond Work Index on SAG Variability ground ore (Sv-BVI), in kWh/t, averaged 5.5% and 3.8% respectively compared to the SAGDesign testwork values and are within 7% and 10% respectively from plant benchmark and within 7% from the samples sent to all partner laboratories. Both tests can be continued to measure the true hardness necessary for mill sizing. This article discusses the development of these two new tests, SVT and BVT, their potential use and accuracies in any geometallurgical program."

Jan 1, 2014

By M. Kosugi, M. Kawata, J. V. Satur, K. Mitsuhashi, R. Kawarabuki, W. Kracht, Y. Ebisu

Copper concentration is becoming more difficult because remaining copper ores are more complex and of finer copper mineral grain size, making copper minerals harder to float because of the fine particle size required to liberate the valuable species. The purpose of this work was to study the flotation behavior of fine copper sulfide ores at different conditions of agitation and aeration. The experimental campaign was carried out in a laboratory Denvertype flotation cell of 1 L volume modified to be operated with forced air that allows decoupling air flow rate and agitation speed. Four ore samples from Chile were used, all of them containing copper sulfides such as chalcopyrite, bornite, chalcocite, and tennantite, but with varying grain sizes and compositions. Preliminary flotation tests for establishing the flotation conditions of grinding size and collector dosage were conducted before the kinetic flotation tests that were carried out at different agitation speeds varying from 900 to 1300 rpm for gas flow rate ranging from 1.6 to 7.2 L/min. The flotation products were analyzed by ICP-MS and MLA (Mineral Liberation Analyzer). The results showed that high agitation speeds with corresponding air flow rates resulted in better recovery than moderate agitation speed and air flow rate, and an excess in gas flow rate resulted in bad performances. The flotation rates of the fine copper minerals were improved despite the different improvement rates among the fine size fractions. The impact of these operational variables, however, was different when comparing the results for the four ore samples. While it was found that the order of floatability in the four samples was the same, that is, chalcocite > tennantite > bornite > chalcopyrite, the kinetic constants of the copper minerals in the samples were different, indicating that mineral composition in the sample affects the flotation kinetics.

Jan 1, 2018

By Sushanta Majumder

The physico-chemical characteristics of raw materials used for the production of iron ore pellets have a strong influence on the productivity of pelletization operations and on the quality of pellets. Since iron ores from different sources are used for making iron ore pellets and since the quality of the ores varies with time, there is a need to optimize and control pellet plant operations on a regular basis to achieve optimum productivity while maintaining pellet quality within the desirable specifications. In order to achieve this objective, a model-based on-line optimization system was implemented on two industrial scale induration furnaces. The optimization system consists of a rigorous mathematical model of the induration process, a model for the permeability of the bed of pellets, a statistical model for the quality of iron ore pellets and an optimization module based on sequential quadratic programming. The rigorous model is tested on-line using the wind-box temperature available real-time. The process was optimized to enhance induration furnace productivity for the given constraints on pellet quality parameters such as the cold compressive strength (CCS) and Tumble Index (TI), and other equipment design parameters. Process variables such as induration machine speed, cold air flow rate and hood temperature profile were used as the optimization variables. The on-line optimization system was successfully implemented in two industrial induration furnaces and lead to enhanced productivity. Details of the on-line optimization system and results of process optimization will be presented.

Sep 1, 2012

By Daniel Saramak

"Issues concerning effectiveness of the high-pressure comminution process in technological circuits of copper ore treatment were presented in the paper. Crushing processes taking place in high-pressure grinding rolls devices (HPGR) are currently one of the most efficient methods of hard ore size reduction in terms of the energy consumption. The HPGR products are characterized by a fine particle size and the micro-cracks formation in individual particles, which appear in downstream grinding processes, decreasing their energy consumption. The purpose of this paper was to analyse the effectiveness of a ball mill grinding process depending on the changeable conditions of run for the HPGR crushing process. The research programme carried out included crushing tests in the laboratory scale HPGR device at various settings of the operating pressure volume and selected qualitative properties of the feed material (i.e. particle size distribution). Particle size distribution analyses of all HPGR products were performed and in the next stage the material was a feed to the ball mill grinding process. Grinding process kinetics were investigated through the determination of mass recoveries of individual particle size fractions after defined grinding time intervals. The models, defining the grinding process effectiveness as a function of changeable conditions of HPGR process run, were determined on the basis of obtained results. Based on these models the optimal grinding time in a ball mill was specified which is, in turn, the basis for optimization of operation of the technological comminution circuits for a given material type. The obtained results proved that the application of HPGR devices in a given copper ore comminution circuit may improve the effectiveness of the downstream grinding process which leads to improvement of the entire circuit work efficiency through decreasing the process energy consumption and enhancing product size reduction."

Jan 1, 2014

By Hamid-Reza Manouchehri

"Sustainability calls for maintenance, rational use and enhancement of natural resources as well as balance consideration of ecology, economy, and social justice. The challenges in mining industry call for a sustained global effort using the leverage of available technologies and emerging new technologies. The industry uses significant amount of energy with the highest portion in comminution. To conserve energy, attempts have been made to improve the efficiency of the conventional crushing and grinding equipment. Nevertheless, the new and energy efficient comminution technologies are favorable through a longer term strategy. Since crushers are more energy efficient than mills, it is logic to conduct part of milling, in the crushing stage. After years of research and development, Sandvik introduces a new crushing technology, VibroconeTM, to change traditional crushing concepts. The new crushing device is able to crush and grind particles with a higher reduction ratio, more than two fold, than that of conventional crushers. By implementation of the new technology, a suitable feed size for milling can be provided to conserve energy as well as media and liner consumption, to reduce milling circulating load or increase mill capacity. There are other benefits associated with this machine, one of them being providing a higher surface area. This paper discusses the performance of the machine and its applications for comminuting different ores."

Jan 1, 2014

By M. Kanuchová, J. Briancin, M. Achimovicová

"Faculty of Mining, Ecology, Process Control and Geotechnology, Technical University, Košice, Slovakia An industrial eccentric vibratory mill was used for direct and short-time mechanochemical reduction of ilmenite concentrate (FeTiO3) and anatase (TiO2) with magnesium metal powder in order to reduce Fe and Ti resp. and hereby to convert them to the more soluble phases suitable for further hydrometallurgical processing. X-ray diffraction analysis of FeTiO3 after 60 min of milling with Mg confirmed the presence of Fe0 and Mg2TiO4 phases and for TiO2 after 180 min of milling the new TiO and MgO phases have appeared. X-ray photoelectron spectroscopy has detected Fe0 (metal) and Mg2+ species which are corresponding to the product of FeTiO3 mechanochemical reduction. The product of TiO2 mechanochemical reduction has revealed XPS spectral lines corresponding to Ti2+, Ti4+ and Mg2+ species on its surface. Morphology of mechanochemically reduced samples was studied by scanning electron microscopy analysis. Subsequent leaching of mechanochemically reduced FeTiO3 and TiO2 was performed in dilute HCl and H2SO4 at 80oC and compared with mechanically activated samples. The recovery of Ti has reached 100% for FeTiO3 and 79% for TiO2 after 60 min of leaching. Based on this study the flowsheet for possible processing of natural refractory titanium ores patented by author was adapted and documented. INTRODUCTION Ilmenite (FeTiO3), along with rutile (TiO2) represents the most important titanium resource necessary for titanium industry, for production of titanium metal, alloys and pigment grade TiO2 which are becoming more important and versatile for various industries such as an aircraft and aerospace, navy, chemical, automotive, medical and offshore wind industries, for machine and plant engineering and architecture as well, mainly due to high corrosion resistance. Pigment grade TiO2 is utilizing in pigment, plastic, glass, paper and rubber industries (Zhang, 2011). There are obvious research efforts for development of the potential alternatives to the expensive thermo-chemical commercial processes of titanium raw materials processing. Zhang (2011) has summarized conventional thermo- a electrochemical processes which involved a combination of pyrometallurgical, hydrometallurgical and electrometallurgical technologies and highlighted the improved hydrometallurgical routes promising for commercial application in the future. Such improvement could also be mechanical activation of FeTiO3, TiO2 by high-energy milling which causes their structural disordering, the changes of physical and chemical properties, consequently and has a positive effect on the dissolution kinetics (Achimovicová et al., 2014a, 2017, Baláž, 2008). The various types of mills such as a planetary ball mill, a vertical ball mill, a drum mill, an attritor were used for mechanical activation of FeTiO3 as a pretreatment process for subsequent leaching (Achimovicová et al., 2014)."

Jan 1, 2018

By Yang Zhao, Tao Xiu-xiang, Chen Song-jiang

"China is rich in low-rank coals that account for 45.68% of existing coal reserves in China. The clean and efficient utilization of low rank coals is of great significance for ensuring the effective energy supply and promoting economic development and environmental protection. In order to solve the difficult problem in flotation of low rank coal, it has become the focus of research in the related field that oily bubbles instead of air bubbles are taken as a carrier in flotation to improve the attachment efficiency and recovery of low rank coal. In this paper, low rank coal slime collected from Shendong mining area was used as the experimental material, and it focused on the characteristics of oily-bubble flotation process of low rank coal. Additionally, difference in conventional flotation and oily-bubble flotation was discussed. The induction time between air bubbles, oily-bubbles and fine low rank coal particles was measured. The results indicated that the induction time between oily-bubbles and coal particles was obviously lower than that of air bubbles. By comparing the foam height of air and oily bubbles, it was found that the amount of oily bubbles is less than air bubbles, causing relative low flotation rate of oily-bubble flotation at initial stage. Besides, the maximum foam height and half-life of air bubbles and oily-bubbles were measured respectively. The results showed that the stability of oily-bubbles was higher than that of air bubbles, which is benefit for the enrichment of concentrates. The clean coal water recovery of oily-bubble flotation is lower than that of air bubble flotation, which indicated oily-bubble flotation is lower in water entrainment. INTRODUCTION China is the largest energy consumer in the world, accounting for 23% of global energy consumption in 2016 and 27% of global energy consumption growth. Whereas coal is taken as the major primary energy source and its share of China’s primary energy consumption is 62% in 2016, in which the low rank coals, such as lignite, long-flame coal, weakly caking coal, and non-caking coal, accounted for about 50% of total coal production capacity (China’s energy market in 2016, BP). Moreover, the exploitation and utilization of low rank coals and other coals that are difficult to float have been an important strategy for China’s sustainable development of the coal industry (Liu et al., 2014). However, the combustion of low-quality coals leads to a serious environmental pollution. In addition, the deterioration in geological conditions of coal resources, and the increasing improvement in the mechanization for mining significantly caused the increased amount of fine coal."

Jan 1, 2018

By Stephen Simukanga, Jewette Masinja

"Mining has been going on commercially in Zambia for over 100 years. The backbone of the mining industry has been copper production and its by-products of cobalt and gold. Over these years, the mining industry ownership structure has swung from private ownership to state ownership in 1972, and back to private ownership in 1995. Environmental management was first introduced into the body of Zambian legislation in 1991 through the promulgation of the Environmental Protection and Pollution Control Act (EPPCA). The Act’s main functions included the protection of the environment and control of pollution, and in particular to provide for the health and welfare of the people, animals, plants and the environment in general. This Act, was replaced in 2011 by the Environmental Management Act (EMA). The new Act has a number of new elements including: mainstreaming environment in national planning, it provides for the domestication of multilateral environmental agreements, enhances public participation issue, creates a central environmental information depositary, elaborates access to information principles, establishes an environment fund, creates enforcement orders, provides for both Zambia Environmental Management Authority and members of the public to sue for damages following environmental pollution, and provides for the appointment of honorary Inspectors. In addition to this, the Mines and Minerals Act of 1995 provided, for the first time, a section on environmental management in the mining sector. This section also created the Environmental Protection Fund (for mining), and made it obligatory to undertake environmental impact assessment before mining permits could be issued. The Environmental Protection Fund has now been established, as provided for by the law, and currently has more than USD9.0 million in the account. Secondly, environmental auditing is now being carried out annually on mines around the country, the effect of this has been a significant improvement in the environmental management of mining in Zambia. This paper looks at the response of the Zambian mining sector to these pieces of environmental management legislation, and the direction that the mining sector is expected to take on environmental management going forward."

Jan 1, 2014

By Gianni Shena, Francesco Montanari

"Recent improvements in the resolution of X-ray computed tomography (CT) make it a promising alternative to traditional time consuming, error prone laboratory procedures for mineral liberation analysis, such as heavy liquid fractioning and measurements on polished sections. All indications are that in a few years CT will be well-established in many laboratories as a rapid technique for accurate liberation studies. In this scenario it would be able to provide liberation spectra or washability data in tens of minutes following sampling. However, although CT is a fast evolving technology, its on-line application is unlikely in the foreseeable future.Dual-energy (DE) radiography is another X-ray technique originating from non-destructive evaluation (NDE) and medical fields, which allows retrieval of the volumetric content of valuable components from two-phase particles in a fraction of second. Two radiographic images at different X-ray energies of a single particle or a monolayer of particles are taken in short time sequence. The thickness of the two phases is calculated particle by particle by image subtraction, whereupon particle grades can be derived. The development of the method for on-line applications requires the presentation of non-overlapping particles in the gap in the X-ray source detector measurement couple. Straightforward extension of the principle to multiphase systems is not possible. The paper reviews the state of the art of these two techniques as applied to mineral liberation problems."

Jan 1, 2003

By Diana Drinkwater, Tim Napier-Munn

"This paper argues that, although specialist mineral engineering expertise is essential for the efficient design and operation of mineral processing plants, the environment in which these skills are supplied to the industry has changed forever, and not for the better. Most of the mineral engineering programmes in western universities have died or are dying. The long-service mine site mentors have gone, operations are run on a staffing shoestring so that there is no longer the time (or inclination) for considered decision-making, and the FIFO model has discouraged continuity of optimisation projects and communication between professionals. At the same time the technical challenges of designing and operating effective process plants are increasing. These trends are not going to be reversed any time soon, if ever. The ability to run efficient mineral processing operations has been materially compromised as a consequence. We propose that well-designed professional development can help to recover this situation, and it can be done easily and cheaply. The workplace is the best environment for such skills development. Professional development training should be integrated with normal duties throughout the early years of a graduate’s service (and probably beyond), and the cost should be regarded as non-discretionary expenditure for the business. If such programmes are properly resourced and managed and extended over longer time periods, there will be a measureable rise in the level of technical understanding and competence within companies and a resulting beneficial impact on resource utilisation and thus shareholder value. The paper outlines some of the approaches that we believe will work, and the benefits that we expect will accrue."

Jan 1, 2014

By P. Gao, J. W. Yu

"Pre-concentration is a necessary step for upgrading low-grade iron ores, and its aim is to remove gangue minerals for improving efficiency of downstream separation process. The most important pre-concentration technique for iron ores, including hematite, siderite and limonite, is magnetic separation based on the appreciable differences between the desired iron minerals and gangue minerals in magnetic susceptibility. In this paper, the separation efficiency of one-stage low-intensity magnetic roughing combined with two-stage high-gradient magnetic scavenging for the pre-concentration of a low-grade hematite from Donganshan was investigated. It is a BIF type of ore containing hematite, magnetite and a bit of siderite, and an average content of Fe is about 34.6%. The effects of grinding fineness and magnetic field intensity for scavenging I and II were studied and optimized. The results showed that a magnetic preconcentrate assaying 42.7% with a recovery of 95.4% was obtained under the conditions of ore grinding fineness of -74 µm 70%, magnetic field intensity of 300 mT and 800 mT for scavenging I and II, respectively. Over 20% of the feed was rejected as the final tailings assaying 6.4% Fe. Meanwhile, the XRD, iron chemical phase and SEM analyses of different stage products revealed that hematite, magnetite and siderite could be recovered successfully by magnetic separation. However, some ultra-fine hematite particles (-10 µm) were difficult to be captured by magnet, and lost in the final tailing, resulting in lower iron recovery.INTRODUCTION Donganshan iron ore belongs to sedimentary-metamorphic iron formation called banded iron formation (BIF), which is formed in the Precambrian with a layered structure composed of ore bodies (Shen, 2012). Such type of iron deposit contains various iron-bearing minerals like hematite, magnetite, and siderite, suggesting it may be amenable to pre-concentration with magnetic separation. The pre-concentration process is effectively applied in recovering hematite, magnetite and siderite from iron ore, due to its benefits of further upgrading iron ore and improving separation efficiency. The most important pre-concentration technique for iron ore is magnetic separation, including low-intensity magnetic separation and high-gradient magnetic separation, based on the fact that there are appreciable differences between the desired hematite, magnetite or siderite and the gangue minerals in magnetic susceptibility."

Jan 1, 2018

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 Yuexin Han, Zehong Wang, Fujia Yu, Wanzhong Yin, Xinchao Wei

Bauxite is the main raw material in alumina and refractory industries. China has plentiful bauxite resources, most of which belong to the diaspore type bauxite with characteristics of high aluminum content, high silicon content and low ratio of alumina and silica (A/S). The resources with A/S 4-7 account for more than 60% of the total resource reserves of bauxite. Therefore improving the A/S through bauxite desilication is the key task of bauxite concentration in China. Normally the grinding fineness of 80-90% - 0.074mm is required in the bauxite flotation process. Thus fine grinding of bauxite ores is necessary, which leads to the high energy consumption. In the meanwhile, bauxite ores are easy to produce slime during grinding processes. The large amount of slime produced in fine grinding greatly worsens the process environment of bauxite flotation, affects the separation performance and results in the loss of metal. Also, fine grinding makes the flotation concentrate difficult to dewater, while the water content in the flotation concentrate must be removed by distillation in the subsequent alumina dissolution process, causing the increase of energy consumption and cost in the production of alumina. In this study, the selective grinding behaviors were examined with Henan Bauxite as feed. Separation of alumina and silica at a coarser grinding fineness was achieved and new route was explored to enhance the desilication in bauxite concentration to improve the A/S of bauxite concentrate.

Jan 1, 2003

By F. J. Sotiuo

Variability of the quality of phosphate ore feed to the flotation plant has been of great concern for the industry. This variability sometimes resulted in 10% to 50% decrease of P2O5 recovery, a reduction of P2O5 concentrate grade and/or both due to depression of the system. For this investigation, samples of refractory ore and easy-to-float ore were obtained from the same mining area in Central Florida; and then submitted to bench flotation tests using fatty acids (FA). To understand the cause of difference in flotation behavior of these apparently similar ores (grade, mineralogy, and physical appearance), bulk and surface characterization studies were conducted. Based on the results of characterization studies and bench flotation tests on both refractory and easy-to-float samples, it was possible to determine FA surface coverage. It was found that the surface coverage for the refractory ore was between 6.9% and 9.8%, corresponding to 0% and 80% recovery, respectively; whereas the easy-to-float ore showed surface coverage of 17.2% (89% recovery) to 24.6% (98% recovery). Since size analysis, surface area and pore size measurements showed small differences, it was thought that the surface coverage differences could be caused by the ad-sorption of natural compounds onto the phosphate ore surfaces, depressing the system. SEM, EDS, and Leaching and Solvent Extraction (LSX) studies were performed on the phosphate ores to demonstrate the proposed mechanism. This paper summarized our characterization studies, flotation results, and findings. The study showed that the new identified compounds were responsible for the flotation behaviors of the Florida refractory phosphate ores.

Jan 1, 2014

By David Yang

Commercially available flotation technologies for recovery of mineral fines have remained essentially unchanged for several decades. Recent studies have focused simply on improving mechanical and open column cells. Such studies have explored different control strategies and have aimed to improve reagent selectivity, fine air bubble generation and particle-air contact. However, no study has questioned whether current techniques are the most efficient technology for recovering mineral fines. Given that both mechanical and open column cells have a widely accepted carrying capacity limitation, the lack of extensive research into an alternative technology is surprising. Most recently, open column flotation has become an entrenched technology, and it is undermining the efficient recovery of mineral fines worldwide. An alternative exists. Packed column flotation overcomes the above-stated problems as the technology surpasses the carrying capacity limitation of current means by several-fold and almost always achieves the best performance in many comparative pilot tests and full-scale plant operations. Filling a column with packing plates creates a network of sloped walls capable of supporting a froth bed many times deeper than conventional machines. Having froth up to 75 percent of the total column volume tolerates all feed changes encountered in the plant environment and permits maximum flexibility in concentrate quality control. Furthermore, its scale-up is straightforward by increasing column volume or the number of interconnected small cells. As the air breaks upon rising and is distributed horizontally through packing plates, the air spargers can be replaced with a simple blower, resulting in considerable savings in operation and maintenance costs. Packed flotation technology provides a break-through solution for the separation of fine and ultra-fine minerals. Its simplicity, superior performance, and low cost structure make it an appealing alternative to current technologies and allow greater flexibility in downstream processing. Future industrial applications include a wide variety of metallic and non-metallic ores. This paper focuses on some recent scale-up campaigns for nickel and copper sulphide flotation applications compared directly to conventional equipment.

Jan 1, 2014

By Rainer M. Lotzien, Michael J. G. Battersby, Jan Kleefeld, Julian V. Brown, Rainer M. Imhof

"The standard method of separation using flotation is compromised in terms of kinetics and efficiency, because of the generally slow separating differentials of fine bubbles and fine particle suspensions. A new flotation system has been developed that addresses these issues and imparts other benefits. The new technology is based on established pneumatic flotation designs called Imhoflot which use intensive in-line pre-aeration to aerate the flotation pulp prior to its introduction to the separating cell. Consequently the cell is designed only for the separation of the phases and not for bubble-particle contact. In the new system this separation is speeded up dramatically by the introduction of centrifugal motivation in the separating vessel, without the use of internal moving parts. The design focuses on providing increased differential forces on buoyant mineralised bubbles and hydrophilic fines. The observed result of these differential forces is the improvement of concentrate qualities by the reduction of the amount of misplaced material found in the froth. The commercial benefit to industry is much reduced residence time, less than 30 seconds, which offers considerable cost savings in equipment and infrastructure.Prototypes of 0.65m, 1.7m and 2.2m cell diameter size have been constructed for hydrodynamic and industrial scale tests to assess the previously established computational methods for scale up of the process. The 1.7m cell has been installed and operated for cleaning of potash concentrates in Germany, at throughputs of 150 m3/hr, with extremely encouraging results. A 2.2m cell has been installed and operated in plant trials for superfine coal in South Africa. Results are presented that illustrate the effects of differential separations by comparison with conventional pneumatic and mechanical flotation techniques. Predictions of performance are provided in the contexts of the applications tested."

Jan 1, 2003