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By Reza M. Rahman

The froth phase plays an important role in the flotation and upgrading of the final concentrate. At present, the techniques that have been used in the mineral industry to measure the froth recovery have limitations. The aim of this paper is to investigate the performance of the froth in an industrial flotation cell. A unique device has been developed which is capable of decoupling the froth zone from the pulp zone. It consists of two concentric tubes. The inner tube acts as a dropback collection chamber or catcher. The particles that detach from the froth phase fall directly into the catcher and are collected as froth dropback. The froth recovery measurements were carried out in a rougher bank of a copper concentrator treating sulphide minerals. The dropback device is designed so that it can be immersed into a plant size flotation cell and plant froth recovery measurements can be taken at any given time. During the experiments, the bubbles laden with valuable mineral particles entered the device from the plant flotation cell, subsequently rising to form a froth layer at the top of the device. The particles that detached from the froth zone were collected in the dropback collection chamber whereas the concentrate sample was collected by a launder. By drying, sizing and chemical analysis of the concentrate and dropback samples, the froth recovery, was estimated on the basis of the valuable component. The effect of air rate on froth recovery was also investigated. Keywords: flotation, froth, dropback, froth recovery

Sep 1, 2012

By Mike Daniel, Eric Wang

"Several new large copper and gold concentrators have been built and commissioned around the world in the past five to eight years. The success of the ramp-up from these very large concentrators has varied. CITIC SMCC Process Technology was engaged to assist some of these mines by gaining a better understanding of the factors that influence throughput capacity. As such, site-specific throughput forecast models that are influenced by SAG mill performance were developed. The forecast models are easy to interpret and modify and can greatly assist the mine management to make predictions and informed decisions for a range of site improvements. The models investigate the influence of SAG mill performance with respect to ore competency, derived from SMC Test® via the measured DWi model parameter. In some cases the benefits of blasting and from fine tuning milling operations are already incorporated into the "site-specific" forecast models. The methodology follows rigorous plant data analysis that is analogous to a "Mine-to-Mill®" optimisation project. The CITIC-SMCC model validation includes extensive data collection, which includes drill core analysis, ore characterisation and comprehensive comminution circuit operational data to assess the limitations within the comminution circuit within the operating mine. The results and models may be used to define the operating base lines of the processing areas and identify improvement opportunities upstream and downstream of the comminution circuit. The predictive capability of the models use logged production data and has enabled the user to differentiate between alternative circuit configuration options and identify optimum operating conditions. This approach minimises the ongoing requirement for costly plant surveys. The improvement strategy for each site, included the ongoing measurement of grindability, rock strength and via the Bond and SMC Test® respectively. Some commentary as to what other practitioners do with input data and their models is also presented as this highlights some of their shortcomings relative to the CITIC-SMCC methods."

Jan 1, 2014

By R. L. Pascual, W. J. Whiten

"The froth flotation process is not well understood. Both flotation models, and the parameters used to describe the stream flows are not well defined. They in fact vary considerably in different applications. This creates difficulties is designing a simulation program suitable for use by plant personnel, consultants, and researchers. In addition to simulation, an effective simulation program can be expected to provide a range of other services.This paper shows how a process circuit simulator can be designed with sufficient flexibility to satisfy these needs, and discusses some of the additional services.OVERVIEWThe development of a simulation program for froth flotation circuits faces several challenges as flotation models and the associated stream descriptions are not well defined. There is little agreement on the best form for a flotation model, or on how the plant streams should be defined.In addition to simulation, a flotation simulator is generally expected to provide other services such as data input, data reconciliation, model fitting, and accuracy estimation. Additional services may also be needed beyond what might initially be envisaged. A summary of some of these possibilities is included.To apply simulation to a flotation circuit it is necessary to develop a flotation cell model, for instance based on the general outline given in the appendices. Experimental data, usually from the plant, is needed to determine cell model parameters. This is generally done by first undertaking data reconciliation to determine if mass flow constraints are sufficiently closely satisfied. At the same time the data is inspected for outliers that might bias subsequent calculations. Next the data is fitted to a model to back calculate ore characteristics. If there is sufficient agreement between the fitted model and the data, the model can then used to make predictions of the effect of changes to the plant. The changes, that the simulation shows are beneficial, can be applied to improve plant performance"

Jan 1, 2003

The flotation of nickel sulphide minerals is normally difficult in the presence of serpentine minerals due to the coating of serpentine particles on the nickel mineral surface. To improve the flotation, dispersants such as polyphosphate and carboxy methyl cellulose are normally used to remove the slime coating. However, in the flotation using high ionic strength process water, these dispersants are invalid due to their ionic nature. In this study, a new type of non-ionic dispersants, Pluronic triblock copolymers were examined with an objective of improving the flotation of ultrafine pentlandite (a nickel sulphide mineral) in the presence of lizardite (a serpentine mineral) in saline water. Three Pluronic triblock copolymers varying in solubility and hydrophile-lipophile balance (HLB) values were studied by flotation tests, settling tests and froth measurement. It was found that two of the copolymers improved pentlandite flotation against lizardite, and one copolymer deteriorated the flotation. The effect of Pluronic triblock copolymers on the flotation was actually linked to their dispersibility and foamability, which were governed by their physical properties. The two copolymers with a higher solubility or HLB value produced more stable mineral suspensions and more stable froth in the flotation resulting in better nickel grade and recovery in both rougher and cleaner flotation. Keywords: ultrafine particle, flotation, slime coating, dispersion, saline water, triblock copolymers

Sep 1, 2012

By Paul Gottlieb

This paper reviews the status of automated applied mineralogy today and describes the history and fundamental theoretical and practical bases underpinning the development of automated systems. Details are given of the technical challenges that were faced in creating the new technology and in applying it to a range of applications. In recent years, automated mineralogy has become established as an essential enabling technology for the reliable acquisition of statistically sound comprehensive mineralogical and metallurgical data. This has had a revolutionary effect on the industrial use of such data in the study of geology, mining and mineral processing. Previously, using manual methods, it was not feasible to attempt this work because the large data sets required could not be assembled in a realistic timescale. There was a reliance on individual expert mineralogists and this was not scalable. The speed, reliability, detail and repeatability of the modern automated measurements has now made this type of analysis routine. Automated Applied Mineralogy has come of age! More than 100 systems have been installed around the World. Automated mineralogical analysers such as QEMSCAN® were originally developed as diagnostic metallurgical tools to improve mineral processing plants using samples drawn from plant surveys, bench and pilot-scale tests. They were used mainly for the assessment and auditing of size fractions of mill products, such as concentrates and tails. Subsequently, they began to be used for concentrator design and optimisation where ore characterisation was used to help understand the relationship between the feed ore and its subsequent behaviour in the plant. They are now widely used to measure exploration cores and drill chips from drilling programs to predict eventual metallurgical performance. Ore samples can be classified into metallurgical, as well as geological types, by combining mineralogical features in the ores with metallurgical properties related to grade control, separation, comminution, flotation and leaching behaviour. Three-dimensional block models of ore deposits are now being created based on processing response in addition to geological and mining properties. The development of automated systems began in Australia, the United Kingdom and Canada in the late 1970s and early 1980s. There were many technical challenges. Mathematical theories of randomness, sampling theory, image analysis and stereology were developed to ensure sample representivity so that meaningful information could be obtained. Sample preparation, presentation and measurement methods were developed to ensure that the random sampling was preserved during the measurements. Methods of automatic measurement and mineral identification evolved from the use of electron microscopes, fitted with backscattered electron brightness and energy dispersive X-ray detectors. Operational procedures were required to ensure that these instruments could accommodate a large number of samples and operate unattended for long periods of time. The new technology was progressively applied to a range of commodities and applications and new analysis methods, such as liberation measurement, were needed for metallurgical interpretation of mineralogical data.

Jan 1, 2014

By C. Kleine

Coal sorting with an x-ray-transmission (XRT) sensor has experienced a lot of development since first described by Jekinson et.al. in 1974. Powerful computers and increasingly sensitive X-ray scintillation counters enabled the development of high-performance sensor-based sorting machines. The first industrial installation of a belt-type XRT-sorting for coal is in operation since 2004. It is upgrading high quality coal from 1% ash to 0.7% ash for cathode production. In comparison to the high quality coal which is treated with a belt-type sorter, the chute type sorter has been successfully optimized for high volume coal treatment of lower quality coals. This project was funded by the German Environmental Fund (Project Nr.244444). In cooperation with the RWTH Aachen University and Isambane Processing, CommodasUltrasort(now Tomra Sorting Solutions) conducted extensive pilot test work under production conditions in 2010 for the destoning of power station coal at Arnot Power Station in South Africa. The experience gained during this pilot test phase led to an optimized, redesigned PRO Secondary XRT Chute sorter which is now in operation at a South African coal mine. This flexible semi-mobile modular destoning plant is treating a size range of -120 mm +30 mm at a throughput of 150 tph. The implementation of this plant not only reduces the ash content, abrasiveness index and sulfur content significantly, but also reduces royalties, water treatment and transport costs.

Sep 1, 2012

By M. Kalicinski, M. Lyssyy

"Access to information is a key component for making improvements to any process. This is particularly true for all aspects of the iron mining and steelmaking process. The ability to make rapid control decisions can significantly influence process outcomes, including ensuring product specification, mining quality, transportation limits, upgrade factors, waste bypass and direct shipping, among many others. While traditional laboratory methods provide feedback for such processes, having access to analysis results in real-time can lead to positive reactive and predictive control decisions to be made rapidly, leading to significant improvements throughout the process. Scantech has been designing, manufacturing and supplying technological products to the minerals industry since 2002 to enable the availability of such real-time information to a mine or plant, with the benefits being enjoyed by a wide range of operators. This paper provides a summary of the available technologies used in the iron ore and steel industries, as well as providing case studies of their use in African and Australian iron ore and European steel, as well as a description of the potential benefits of a range of analysis equipment.INTRODUCTION Access to information is critical for any process, and is a fundamental component for making process control decisions. In order to yield effective processing outcomes, it is important for that information to be readily available, preferably as quickly as possible, and to be as accurate as possible. While speed and accuracy are often traded off against each other, there are numerous technologies available in a processing environment that allow for both rapid flow of information and a high level of accuracy. The use of on-belt analysis equipment has a long trusted history of use in a number of mining and processing environments and industries, providing information such as elemental composition and grade of conveyed materials, moisture content, waste proportion and energy information. Australian company Scantech has been a provider of such equipment since 1981, and has become an industry leader in both the supply and development of on-belt analysers across a range of industries."

Jan 1, 2018

By Axel Pankewitz, Andrew Smith, Mathias Stender, Christian Behrens

"Particle size measurement is one of the most important factors in obtaining peak performance of the mineral processing plant in order to ensure efficient milling and flotation circuit operation. Off-line particle distribution analysis technologies only allow an infrequent check of the ore slurry size and hence do not allow for timely process monitoring or intervention. Most existing on-line particle size analysers suffer from a variety of disabilities such as poor statistics, non-representative sampling or mechanically complex setup. This paper will describe an Ultrasonic Extinction based method which overcomes many limitations of existing online analysers and has proven its performance for mineral applications over many years. Installation examples will be given. Since new technologies usually raise e questions about comparability and agreement to common particle size analytical methods e.g. sieving or laser diffraction analysis, extensive studies were performed comparing these different technologies to quantify the quality of results as well as its mathematical robustness."

Jan 1, 2014

By V. A. Chanturiya

The state-of-the-art of mineral mining and metallurgy industry in Russia is characterized by high demand of nonferrous, rare, rare earth metals, and highgrade coal, on the one hand, and by involvement of natural and technogenic minerals with low content of valuable components, fine (nearly emulsion) dissemination of valuable components and close physicochemical and process properties. This calls for high-productive and ecology-friendly technologies for more efficient mineral beneficiation based on intensification of operating and new methods to extract valuable components from rebellious ore and technogenic minerals, relying on the last achievements of basic sciences, combination of dressing and chemico-metallurgical processes and using advanced pyro- and hydrometallurgical technologies. The transition to a new strategy of processing is only possible based on the new technological–mineralogical appraisal of a mineral raw material. Actually, the process mineralogy has a stock of modern high-resolution physical methods for analyzing composition, structure and properties of geomaterials, inclusive of micro- and nano-levels: - Identification of micro- and nano-size noble metals, and natural and induced formations on mineral surface; - Experimental validation of structural phase and chemical transformation of minerals under different energy input; - Justification of choice and mechanism of interaction between flotation agents and noble metals with complex material constitution; - Analysis of structural, phase and chemical transformations of sulfides and rocks under leaching. Thus, process mineralogy is an informational background for a unified theoretical approach to scientific justification of flowsheets of efficient mineral processing. The article gives a brief review of practices that have found application and proved to be of high economic efficiency. Such practices are: X-ray radiometry and photometry separation (Uchalinsky and Gaisky Mining and Processing Integrated Works of ALROSA); selective disintegration (equipment engineered by Mekhanobr-Tekhnika and IPKON RAS); process selectivity enhancement (IPKON RAS, Central Research Institute for Geological Exploration of Nonferrous and Noble Metals, Chinakal Institute of Mining, Siberian Branch RAS, etc.); bacterial gold leaching (Olimpiada MPIW, technologies developed the Central Research Institute for Geological Exploration of Nonferrous and Noble Metals, Nezhdaninsky deposit projects, etc.); combination processing at a mining and metallurgy plant (Norilsk Mining and Metallurgical Company, Yaregsky deposit projects and others); processing of waste: overburden, mill tailings, slag, etc. (Kovdorsky MPIW, Svyatogor JSC, Ural Mining and Metallurgical Company, plants designed by the Central Research Institute for Geological Exploration of Nonferrous and Noble Metals, Mining Institute of Kola Science Center RAS, Research Institute for Chemical Technologies); water conditioning in mineral dressing circuits (ALROSA, equipment by IPKON, etc.); utilization of process water (ALROSA, Ural Mining and Metallurgical Company, Severalmaz JSC and others). Thus, Russia this time has the academic and engineering background for development of efficient energy-saving technologies for comprehensive advanced processing in accordance with the world’s standards, or even higher in terms of a number of the technologies, which has continually been highlighted by participants of recent international congresses on mineral processing.

Jan 1, 2018

By F. K. Ikumapayi

An approach to environmental sustainability and improved process economy, in sulphide minerals production is recycling of process water in flotation of complex sulphide ores, although the chemistry of process water may be a critical issue to flotation efficiency. The influence of major components of calcium and sulphate ions in process water on xanthate collector adsorption and flotation response using pure chalcopyrite, galena and sphalerite minerals were investigated by Hallimond flotation, zeta-potential measurement, FTIR and XPS spectroscopy studies, while bench scale flotation tests were also carried out using complex sulphide ores. The impact of the species in flotation was comprehended using deionised water, tap water, process water and simulated water containing equivalent amount of calcium and sulphate species in process water. Hallimond flotation results showed a decrease of chalcopyrite and galena recovery in process water and also in the presence of calcium and sulphate ions in both deionised and process waters, whereas sphalerite does not respond to flotation. The adsorption of calcium and metal ions but not sulphate ions on the minerals is evidenced by zeta-potential data. FTIR and XPS studies revealed the presence of surface oxidized sulfoxy species and surface calcium carbonates on chalcopyrite in the presence of process water and water containing calcium ions, surface oxidized sulfoxy and carbonate species on galena in the presence of deionised water, process water and water containing calcium and sulphate ions, all at flotation pH 10.5, and these surface species influenced xanthate adsorption. The presence of surface oxidized sulfoxy and carbonate species at the sphalerite flotation pH 11.5 were seen in the presence of deionised water, process water and water containing calcium and sulphate ions, but the surface species does not influence xanthate adsorption. Bench scale flotation using two different complex sulphide ores showed that chalcopyrite, galena and sphalerite recoveries are better in process water than tap water. The studies showed that the process water can be recycled in flotation with no detrimental effect on grade and recovery of sulphide minerals. Keywords: sulphide minerals, flotation, zeta-potential, FTIR, XPS

Sep 1, 2012

By H. R. Manouchehri

"In all electrical beneficiation methods, the difference in electro-physical properties of the contributed mineral particles, essentially frictional charge, electrical conductivity and dielectric constant properties are exploited to achieve separation. The composition of the raw material determines what kind of either corona charging, conductive induction, or triboelectric separation method should be employed. The process is versatile and is influenced by different parameters related to mineral characteristics, surrounding ambient conditions and electrical and mechanical attributions of the separating device. Electrical separation is surface based beneficiation method which is mainly affected by the surface and surface changes of the minerals. Therefore, it is essential to understand how the electrophysical properties of the minerals can be changed/modified. During electrical/electrostatic separation process, both charge magnitude and its polarity that developed on the particles and therefore, their electrical beneficiation potential is essentially defined by surface phenomena. Therefore, it is essential to understand how the main electro-physical parameters can be changed/modified with applied surface treatment/pretreatment methods to promote separation. Surface treatment of minerals is carried out by different means, including chemical conditioning, irradiation, thermal treatment, etc. This paper discusses and analyze the electrical separation process, electrophysical properties of the minerals with special focus on the effect of surface pretreatment/treatment methods to affect electrical beneficiation potential of the minerals. The surface treatment methods vary in a wide range from simple surface cleaning to more complicated chemical conditioning and doping. The knowledge of the solid-state physics and chemistry leads to improve the beneficiation potential of different mineral systems by choosing suitable treatment method(s). Despite the complexity and multiplicity of the charging mechanisms, difficulties in separating fines it seems to be beneficial make our attempts to further investigate and develop the process as dry, low cost beneficiation process, especially nowadays when environmental concerns, as well as energy and water consumptions are main concerns for mining industry."

Jan 1, 2018

By G. C. He

Effects of irregularity, rough surface and aggregation of fine particles on ultrasonic attenuation are significant. The effects should be considered while predicting particle size by ultrasonic attenuation technology. The scanning electron microscope micrographs analysis also shows that particles surface is rough and irregularity. Any slurries has its fractal structure and its special fractal scale and dimension, so, effects of irregularity, rough surface and aggregation of fine particles can be de-scribed by fractal model. The discrepancies between predictions of ultrasonic attenuation based on the assumption of smooth spherical particles and data obtained from slurries of irregular particles indicated that there were different fractal structures. The ultrasonic attenuation model was modified by fractal dimensions. The result of experimental data and analogue calculation indicated that pre-dictions of the fractal modification of ultrasonic attenuation model show good agreement with experimental data. On the other hand, from the values of fractal obtained by inversely calculation, the degree of effects of irregularity, rough surface and aggregation of particles can be estimated. The positive value of fractal dimension indicates that the aggregation has the dominant effect on ultra-sonic attenuation, otherwise, the irregularity and rough surface has the dominant effect.

Jan 1, 2014

By Zhongxue Li, Cuiping Li, Xiaoyun Hu, Yiqing Zhao, Huaying Wang

"Under the auspices of World Federation of Engineering Organizations’ Committee on Engineering and the Environment (WFEO-CEE) and Society for Mining, Metallurgy and Exploration (SME) Task Force on Sustainability and Mining (TFSM), and aimed at helping raise global understanding on and promote capacity building of risk management, this paper presents a framework and prototype of toolbox or knowledge warehouse for facilitating the application of risk analysis, mitigation and management techniques (RAMT) in the mining and minerals sector. The conception, design and implementation of the intended system of knowledge warehouse of risk analysis, mitigation and management techniques (KWoRAMT) are outlined. The system architecture of KWoRAMT is based on a browser/server (B/S) structured platform with web oriented interfaces and composed of data base, knowledge warehouse, searching mechanisms, and risk assessment methodologies. The knowledge sources for KWoRAMT will come from the TFSM expertise and Internet, including laws and regulations, codes of practice, standards, guidelines and best practices. The functions and outcomes of KWoRAMT consist of guided navigations with web links, categorized risk tools, annotated best practices with cases, and integrated risk approaches and solutions based on typical risk methods. Risk categories include those impacting on mine safety, mine occupational health, and mine community environment throughout the whole of mine life cycle from exploration, construction, and exploitation and processing to post-mining closure. Mining associated hazards will be identified and linked by vulnerability onto risk receptors through pathways. Risk management techniques for assessing impacts and consequences of mining induced hazards will be categorized with their pros and cons or strengths and weaknesses. Best practices and significant cases including experiences and lessons with problems, solutions, and recommendations on how solutions would be derived will be illustrated. Integrated risk approaches based upon typical methods will be developed for alternatives and actions."

Jan 1, 2014

By Leopoldo Gutierrez

Eight oil sand ores with the bitumen content ranging between 3.6 and 15 wt.% and the fines content (-44 micrometers size fraction) between 9 and 69 vol.% were subjected to the standard alkali extraction test used to measure the degree of oxidation of metallurgical coals. The results showed that there is a strong correlation between the absorbance of extracted solutions at a wavelength of 520 nm and the ratio of the fines content to the bitumen content. The latter factor is directly relevant to assessing the extractability of bitumen from oil sand ores. Bitumen extraction tests showed that the bitumen recovery decreased from 90 % to 30 % when the absorbance at 520 nm increased from 0.23 to 0.64. A comparison of the UV/visible spectra of solutions obtained from the alkali extraction tests with solutions of Aldrich Humic Acids suggest that low bitumen/high fines oil sand ores release substantial amounts of organic matter very similar, if not identical, to humic acids. In contrast, high-bitumen and low-fines ores do not release as much of the organic matter, and UV spectra of these leached substances are quite different from those of humic acids. Overall, the results show that chemical composition of bitumen in the tested ores varies greatly with ore type and oxidation, and that the alkali extraction test is a promising technique to quickly assess the extractability of bitumen from a given ore type.

Sep 1, 2012

By Majid Saghaeian, Rasool Hejazi, Parisa Ghobadi

"Pulp handling in mineral processing circuits is very complicated due to its inherent different specifications compared with other fluids such as water. Because any variation in ore property (e.g. size and abrasion index) and pulp specification (e.g. density, solid content and pressure) causes problem in this part and reduces the plant availability and throughput as a result. The most common issues in the hose system are sumps and pipe-line blockage, wearing of the pumps impeller and liner, and pipe tearing specially at elbows and bends. High pressure grinding roll (HPGR) is employed in a closed circuit with a screen as the first stage of grinding in Zarand Iranian Steel Complex (ZISCO). Wearing of the pump and pipeline transferring the screen undersize stream was the main problem from the plant commissioning. The plant couldn't achieve to the design capacity because of this defect. Although various practical solutions such as improving the pipes and impeller material quality and eliminating the elbows, as much as possible, were done in order to downtime minimizing, but damages didn’t vanish. Since HPGR discharge contains somewhat rough and abrasive particles, the mentioned modifications didn't effective very much. Therefore, converting of the wet screen to dry and using of belt conveyor to the screen undersize handling was employed based on the plant capability evaluation and experimental and pilot trial results. Although this reformation imposed another additional cost (for conveyor system), but it had significant advantages such as increasing the plant availability up to 96%, reducing the operating costs of the wear parts, providing more stable operating condition for the HPGR performance and decreasing abrasion rate of the HPGR rolls liner because of the lower moist feed."

Jan 1, 2014

By Jun Xiao, Jianwen Yang, Yanhong Dong, Daixiong Chen

"MANGOTE Surface oxidizied mine is a gold-bearing deposit in Congo's Mai-Ndombe Province. In the past decades, the ore has been exploited in a crude way by local farmers, which directly causes the severe processing difficulty and lack of economy of cyanide leaching. Hunan Research Institute for Non-ferrous metals (HRIM) is currently investigating options to recover gold through understanding the mineralogical characteristics of MANGOTE surface oxidized ore. Chemical analysis , X-ray diffraction(XRD) and Quantitative Evaluation of Minerals by SCANing electron microscopy (QEMSCAN ) were conducted on samples from mine site. The bulk analysis results showed that gold separation of gold from gangue minerals was feasible after grinding the ore samples to 86.53% -74µm and adjusting the pulp specific weight at 100g/L, and gravity separation was conducted with using spiral chute after grading of fine particles. The research results highlight relationship between mineralogical characteristics of abandoned ore and economy of comprehensive utilization that might be directive experience to similar cases. INTRODUCTION The occurrence state of gold in natural gold minerals determines the basic recovery and recovery effect of gold(Komnitsas, C., & Pooley, F. D. 1989). The occurrence of gold in the ore refers to the form of gold in the ore.Generally the existing state of gold can be divided into four major categories according to the viewpoint of the dispersion system: independent minerals and gold, a coarse dispersed system;colloidal gold, a colloidal dispersion; solid solution gold, is atomic ion dispersion; adsorptive gold, according to the adsorbed particle is the micelle or ion, respectively is a colloidal dispersion or ion dispersion(Mao, S. D., & Yang, R. S. 2009; Liu, J. J. et al. 2007; Horisberger, M., & Rosset, J. 1977; Li, Y., & Audétat, A. 2013).With the increasing technology of comprehensive utilization of resources,varied plants can now process different gold ores with various occurrence states(Neesse, T. 2014; 7. Ogundare. et al.2014)."

Jan 1, 2018

By Arkady Senchenko, Yury Kulikov

"Basic theoretical grounds of the methods applied for crushing and grinding parameters determination according to international standards are given in this paper. Statistical data about crushability and grindability research are shown. The potential relationship between the values of Fred Bond Work indices and John Starkey indices (Crushing index, Ball mill index, Rod mill index and AG/SAG index) are discussed in this paper. In order to establish correlation between the crushability and grindability indices the analysis of over 2 500 tests for 165 deposits located in different parts of the world was performed. The relationships among different types of energy consumed for crushing and grinding were determined. A method for preliminary estimation of energy consumption in semiautogenous + ball mill grinding circuit is suggested for its application in preliminary technological solutions development and technical-and-economic assessment."

Jan 1, 2014

By E. V. Bratygin, S. P. Elnikova

"In the article carrying out technique of experiments for estimation of power efficiency of process of crushing in cone crushers «in a layer». The conformity of the granulometric characteristics of the crushed products obtained as a result of the tests, the theoretical equations for the size characteristics, and the choice of the optimal equation for the prediction of the granulometric characteristics of the final products obtained by crushing ""in a layer"". Optimization of granulometric composition of power of crushers working ""in a layer"" is carried out with the purpose of reduction of the electric power consumption at reception of a product of required quality. As a result of the experiments, dependencies are obtained, the relevance and applicability of the crushing process ""in the layer"" for obtaining crushed stone of improved quality is proved. INTRODUCTION A number of equations have been proposed for calculating the breakage energy. These include equations by Kirpichev and Kick, Rittinger and Bond (Bogdanov, Olevsky, 1982). Another equation for calculating the specific breakage work in breakage by impact and in stratum was proposed by Devyatkin (Boiko, 2003). In these equations, the breakage energy is proportional to the particle size raised to some power. In the equation proposed by Devyatkin, the ore piece thickness or the feed average diameter is used. The relationship between energy and breakage can be expressed as an equation (Lynch, 1981; Tikhonov, no. 3, 2008) where k is a coefficient characterizing the energy parameter depending on the strength of the feed, l is size in microns. The Rittinger formula is obtained for n = 2, the Kirpichev-Kick formula for n = 1, the Bond formula for n = 1.5. For n = 3 or higher, the equation describes fine and ultrafine grinding. R. Hookey proposed a formula (Lynch, 1981, Tikhonov, no. 3, 2008), where the size exponent n is substituted by a size function In all of the above equations, a single value of the feed and product size is used; for example, in the Bond equation, size is defined as the particle size of the 20% oversize (P80 and F80). However, a single size value can represent multiple distributions, making that the Bond method inappropriate for determining the size (Lynch, 1981). Describing an equation for estimating the grinding energy will allow to design the electric drive and ore preparation circuit for the given breakage method."

Jan 1, 2018

By J. J. Cai

The status of fossil fuel and secondary resource in metallurgy industry in China were reviewed, and conversion efficiency of fossil fuel, utilization technologies of secondary energy were studied. Fossil fuel, accounting for over 90% of energy structure in metallurgy industry, took in the highest flight in China, and a great deal of which was converted to secondary energy through the equipment of blast furnace and coke oven. These secondary energy which were mostly made of blast furnace gas(BFG), coke oven gas(COG) and Lindz Donawitz gas(LDG) occupied about 30% of total secondary energy. The way enhancing fossil fuel conversion efficiency, secondary resource recovery and the secondary energy such as BFG, COG, LDG utilization promoted to save fossil fuel was discussed in this paper. And efficient use of lower caloric value fuel was studied, such as preheating combustion air and fuel, generating electricity power etc. and regeneration purposes of high-caloric fuel was also researched, for producing hydrogen, methanol or direct reduction iron etc. The using model of secondary energy at iron and steel works was presented as fuel and chemical materials. The results suggest that utilization of these energy efficiently and reasonably could help to energy saving and environment protecting.

Jan 1, 2014

By Kari Moen, John Rasmus Leinum, Jarle Hjelen, Terje Malvik

"Automatic identification and characterisation of mineral raw materials and beneficiated products are of major importance in mineral processing. However, minerals show great variety in their composition and physical and chemical properties. Industrial minerals may contain the same elements in about the same amount. In these cases backscatter electron imaging or chemical analysis are not sufficient to identify the minerals. Another problem arises when micro textures are not detectable in traditional imaging or the grain size is smaller than the X-ray spatial resolution.As a supplementary technique in these cases, application of crystallographic information by electron backscatter diffraction (EBSD) in the scanning electron microscope (SEM) may be a suitable method. By means of EBSD, diagnostic mineral information can be achieved if indexible patterns are provided.Until now EBSD has not been used frequently on geological samples for mineral and micro structure discrimination.The technique has been demonstrated on three Norwegian mineral raw materials and one Italian marble and shows that it has some advantages compared to traditional techniques."

Jan 1, 2003