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By S. S. Lu

In sodium oleate and salicylhydroxamic acid systems, sequence of floatability of three sulfate minerals is: barite>celestite>gypsum, in lauryl amine system is: gypsum>celestite>barite. XPS and infrared spectrum analysis are used to find that it is chemical reaction between sodium oleate and three minerals, physical adsorption on the surface of minerals for lauryl amine, and it is chelating reaction between salicylhydroxamic acid and three minerals possibly. Theoretical calculation on chemical bonds in crystal structures of three minerals is carried out, finding that breaking degree of Mn+?O2- in crystal structures of three sulfate minerals is closed related with floatability.

Jan 1, 2014

By P. Holtzhausen, L. Auret, B. Lindner, A. Haasbroek

"Spiral concentrators offer a cost effective way to separate valuable minerals from gangue by displacing lighter materials to the outside, and heavier materials to the inside of the spiral. The separation can be seen as visible concentrate bands and splitters are set at the bottom of the spiral to effectively split the ore into various densities. As there are typically many spirals in a concentrator plant, it becomes ineffective to continually adjust the splitter positions manually. Vermaak et al. (2008) proposed to use image recognition to detect the concentrate bands, thereafter, creating a model predicting the positions under certain input conditions. This model could then be used for optimisation and/or control of splitter position or band position. In contrast an online concentrate band detection system would provide real time concentrate band positions without losing accuracy due to model generalisation. These systems are usually expensive and time consuming to develop, due to a lot of centralised features required (image capturing, image processing and/or feedback to a controller). This study took advantage of the recently developed Raspberry Pi minicomputer to perform rapid prototyping of an online image processing sensor. The Raspberry Pi, and accompanying camera module, offers a portable Linux environment which can natively run the required image processing algorithms. Furthermore, extensive use of OpenCV was made to reduce development time, by relying on existing and proven algorithms to detect the concentrate bands. The Raspberry Pi also incorporates generic input/output ports which can be used in future work to provide the signal to a controller. In conclusion, the Raspberry Pi was successfully used to perform real time concentrate band position detection on a spiral concentrator. This solution is more general than an experimentally identified input-output model and may be used for control or optimisation studies in a wide array of spiral concentrators."

Jan 1, 2014

By Marzio Piller, Girolamo Belardi, Jure Mencinger, Paolo Bozano, Gianni Schena

"The hydrodynamics of the Tri-Flo™, a two stage cylindrical cyclone used in dense media separation, is studied using Computational Fluid Dynamics. The flow field is simulated with an Euler-Euler Volume of Fluid two-phase approach and the Reynolds stress turbulence model.A unique feature of the device is that the separation medium suspension is pumped and introduced tangentially into the two cylindrical compartments while the raw feed is conveyed to the feed hopper and fed at the axial inlet. This feature allows to use less pumping energy and limits the unavoidable production of fines. The Tri-Flo™ complex flow pattern is little known but central to the efficiency of the separation.The velocity field is computed within the two compartments of the separator. The interface of the air-core that forms in the inner axial part of the cylindrical sections is identified and visualized. The numerical results for a reduced-size 100 mm ID Tri-Flo™ are compared against laser Doppler measurements on a transparent acrylic model (Chinè, 1995) operated with water. The robustness of the model and its prediction capability are verified.The possibility to accurately predict the velocity profiles within the vessel and their dependence on the main Tri-Flo™ operating and geometrical variables paves the way to a better understanding of the functioning of the separator, its design improvements and scale-up."

Jan 1, 2014

By R. J. Batterham

The science and practice of mineral processing has been driven for many years by the same set of challenges that shape the mining industry ? demand and supply, grades and their decline with time, mineralogy and the need to handle more complex ores, disposal and minimising of wastes and the availability of water, power, skilled labour and the like together with increasing expectations from the community, concerns on sustainability and safety and, as well, climate change forcing a more targeted approach on energy. In this paper, the author builds on previous reviews to the IMPC and suggests that while step changes are long overdue, the unprecedented demand mitigates against drastic changes. That said, the ?Mine of the Future? is already requiring some different approaches.

Jan 1, 2014

By A. Muhammad, A. Abdelaal, M. EL Salmawy

"Energy is vital for economic growth and sustainable development. Greater efforts are being devoted to developing unconventional energy resources such as oil shale as an alternative promising source of oil or solid fuel supplement. The main object of this contribution is to determine the upgrade potential of El-Nakheil oil shale using froth flotation. Samples were prepared by comminution followed by sieving into different size fractions. The flotation behavior of the material and extent of cleaning was studied with respect to nonionic and ionic collectors of anionic and cationic types. It was found that the organic rich portions could not be rendered sufficiently hydrophobic by the used collectors and selectivity towards surfactant was very low."

Jan 1, 2014

By E. V. Manlapig, M. C. Harris

"The complexity of the flotation process has made the identification of an appropriate model structure for the predictive simulation of flotation circuits far from obvious. Work performed under the auspices of the AMIRA P9 flotation program has indicated that the metallurgical performance achieved from a flotation cell arises from the interaction of two essentially independent property classes, namely the cell operating conditions and the properties of the cell feed stream. These observations have led to the development of a model structure that associates a constant set of flotation parameters to the streams of the circuit, which are transformed into a flotation response depending on the operating conditions within the flotation cell.A variety of alternative model structures exist within the literature which do not make this distinction between cell and stream flotation properties, and many of these models are in widespread use for flotation optimisation and design studies, both in industry and academia.In this paper, circuit survey and laboratory batch flotation data collected from an industrial flotation circuit are analysed. The data demonstrate that streams in an industrial flotation circuit exhibit varying particle floatability – concentrate streams typically float faster than tailing streams (Figure 1(a)). This floatability, however, is generally conserved around the various units within the flotation process (i.e. the effective floatability of the combined feed and product streams of a unit is equivalent (Figure 1(b)))."

Jan 1, 2003

By M. Schneider, J. Regler, Th. Neesse, AKW A. + V GmbH & Co., J. Dueck, F. Donhauser

"In practice the advantages of high-quality hydrocyclone separation are often reduced due to varying feed suspension properties, solids concentrations and particle size distributions. Therefore, a new control system for a battery of hydrocyclones with a nominal diameter of 150 mm was developed for bentonite slurry regeneration associated with tunnel excavation using bentonite slurry as a transport aid and lubricant.As can be seen from Fig. 1, the hydrocyclone battery has been modified for regulation purpose. The battery was manufactured with an overflow collector as a closed pressure chamber (1) with a discharge pipe (2) where the throttling valve (3) was installed.With increased stepwise throttling of the overflow, the volume split is changed with the effect that the solids discharge in the underflow is increased. To stabilize the total throughput, the feed pump speed is simultaneously increased so that the pressure drop ?p across the hydrocyclones (9) remains approximately constant. However, this causes the increasing pressure inside the hydrocyclones, which results in a further intensification of the underflow discharge. After the detection of the break through of the air core (transition state) by the capacitive sensor (4), the throttle valve is shortly opened, and a new regulation interval can start again. The control concept is focused on maintaining the optimum operating state, characterized by the underflow discharge shape at the transition state between rope and umbrella discharge."

Jan 1, 2003

By G. K. Palshikar

Mining operations offer many opportunities for the use of IT and communication technologies to improve automation and thereby deliver higher levels of productivity, cost, quality and safety. In this paper, we discuss a particular application, namely, building a fully automated train control and operation system within a mining area. We first outline the basic architecture and functionality of such a system and then present a real-life case study where the railway system within a remote iron ore mine in Canada was converted to a fully automated train operation system. This hard real-time safety-critical system required the use of advanced technologies such as embedded systems (e.g., on-board train controller), radio communications, formal methods, optimal scheduling, and extensive simulations. We focus on the design aspects for maintaining the system in safe states.

Sep 1, 2012

By B. Vasanthakumar

In this study, the effect of adaptation of B.subtilis to sphalerite and galena with respect to the selective flotation of sphalerite from the sphalerite-galena synthetic mixture has been examined. The changes in the surface charge of the mineral and the bacterium, cell wall components and the profiles of secreted proteins are discussed. The flotation recovery of galena increases with the increase in the adaptation cycle of B.subtilis to sphalerite and galena, while the flotation recovery of sphalerite is independent of the adaptation cycle with either mineral. From the gel electrophoresis analysis, the protein profile for the unadapted and adapted cells is found to differ distinctly and this may be attributed to varying molecular weight fractions arising from different growth conditions. Electrokinetic measurements showed shifts in the iso-electric points of not only B.subtilis but also of the chosen minerals after adaptation. Additionally, the zeta potential of B.subtilis is found to become less negative after bacterial adaptation to the chosen sulfide minerals, while it showed an increase in the magnitude of surface negative charge after various enzymatic treatments. The change in the surface morphology and cell wall components such as phosphate, uronic acid and acetylated sugars of the bacterial species during adaptation to sphalerite and galena has been assessed. Selective flotation tests on a synthetic mixture of galena and sphalerite confirm that sphalerite can be preferentially floated from galena in the presence of the insoluble fraction of lysed B.subtilis cells initially adapted to sphalerite, with a high selectivity index. Keywords: bioflotation, b.subtilis, mineral adaptation, sphalerite, galena

Sep 1, 2012

By Ashiwani Kr Gupta

The floatability of coal is affected by the presence of dissolved inorganic ions in plant process water. Water quality is characterized in terms of conductivity, hardness, turbidity and composition of oil. These quality indices are correlated with coal flotation performance for three different water named, ?R&D laboratory tap water?, ?process untreated water? from West Bokaro wahsey-2 Tata Steel, India and ?process treated water? after passing laboratory developed treatment process. The study clearly indicated that a significant quantity of clean coal is being lost due to poor process water quality used in the flotation process. The laboratory investigations showed that if these dissolved salts and suspended solids are reduced to even 50%, a clean coal yield improvement by minimum 5%~10% at the same ash level could be expected. Therefore, the conventional practice of water recycling though a thickener or a tailings pond needs a complete re-look. The water treatment process for recycled water has also been discussed for improving the process water quality as well as enhancement in flotation performance efficiency.

Jan 1, 2014

By E. Pourjenaei, P. Ghobadi

High Pressure Grinding Roll (HPGR) is efficient equipment in comminution process. HPGR could be a good option for preparing ball mill feed at the first stage of grinding due to its high efficiency and low energy consumption. Closing with a screen, these mills are utilizing as one of the principle parts in mineral processing industries, especially for iron ores. Recently, HPGRs are working as primary mills at 4 developing lines in Gol-e-Gohar Iron Ore Processing Complex, Iran. Different mechanism of particle crushing in compare to the other tumbling mills makes the HPGR as certain equipment with its own particular controlling parameters. Hydraulic pressure, roller speed and level of material inside feeding hopper are the most important variables influencing grinding efficiency of the HPGR. To figure out how they impress the process and operation situation, different industrial tests were carried out and the best result (d80 about 8 mm for HPGR discharge) was achieved at 180-190 bar pressure (P), 300 rpm speed (S) and 50% of hopper level (L). It is worth noting that this finding has been observed through past pilot test too. We also used design expert method (DX7 software) to develop the best design and analysis the test results, as well. According to the mechanical restriction of HPGR and process limitation in the plant (based on the industrial results), we adjusted value of each parameter in a logical range. Therefore, 20 industrial tests were conducted, as DX7 recommended, and the various impacts of the parameters and their interaction were identified based on statistical analysis. As the authors expected, it was revealed that after presser, roller speed is a critical variable because of its significant role in residence time of the particles between the rollers. The function below has been determined to explain the relation between different parameters and the response.

Jan 1, 2018

By V. Sheikhzadeh, M. Saghaeian, R. Hejazi, A. Abazarpoor

The research aimed to compare the chemical analysis (K, Na, Cl) of Iranian concentrate plants, which are the main source of materials corrosion in the pelletizing plants. Cl alongside alkaline elements (especially K) may cause corrosion and plug in the grate plates and other involved equipment. Therefore, it is tried in the processing plants to remove impurities from the concentrate to prevent potential problems in pelletizing and iron/steel making processes. Part of these impurities are existed in the nature of ores and others are sourced in the processing water. Various samples from the largest Iranian concentrate plants including Chadormalu, Gol-e-Gohar, Jalal-Abad and Sechahun were prepared to investigate the possibility of alkaline problems for each samples. The amount of Cl, K and Na of Chadormalu sample was obviously low and therefore no alkaline problem is expected. The Cl content of Gol-e-Gohar sample was high (980 ppm) while amount of K was less (0.008 Wt. %). Due to low content of K, most of Cl will release as Cl2 or HCl and so problems caused by KCl plugging would not be a problem. The amount of Cl in Sechahun case was nearly same as Jalal-Abad (400-600 ppm), higher than Chadormalu and less than Gol-e-Gohar samples. However, the K content was higher than all samples (0.04 Wt. %). Therefore, the amount of evaporated K would be 2-4 times more than other samples. Since the amount of Cl and K is simultaneously higher than usual iron ores, therefore alkaline problems may be a serious prevention factor for the continuous operation of this plant. In order to solve this problem some counter-measures is suggested and discussed including cleaning system, partial dust enriched with KCl removal and variation in the materials type of involved equipment.

Jan 1, 2018

By T. Lang

Clay sorbents from the North Bohemian Brown Coal Basin represent important but still some-what neglected accessory raw material. Submitted paper is concerned with relation between mineral structure, sorptive efficiency and reclamation exploitation of these rocks. Characters and localities of main clay sorbents from the North Bohemian Brown Coal Basin are shortly evaluated in an introduction. In next part, methodology of mineralogy survey for these accessory raw materials is stated, it is based on diffract analyse with D 5000 Siemens X-ray diffracto-meter. At the conclusion results are stated of mineralogy analyses from several clay sorbents. The determination of the zeolite and montmorillonite localities was accentuated. The paper presents also possibilities of practical clay sorbents utilization, especially by reclamation works.

Jan 1, 2014

By H. R. Manouchehri

"In mining and minerals industry, except profitability, there are some crucial factors that represent components in economic machinery of a mine and related activities. These are sustainability and minimizing environmental impact factor. Environmental concerns combined with the water and energy availability and related costs, as well as public license to operate all contrive to demand for more efforts targeting sustainability. Mining industry is highly energy-intensive (estimated to consume 6-7% of total world’s energy), with varying the energy efficiency across the industry resulting in significant costs. Size reduction is the main energy consumer contributing to almost 50% of the total energy used in mining. That means efforts must be made to introduce energy efficient comminution flow-sheets and machineries for sustainable development. Since the crushers are more energy efficient than mills, it is logic to push down-sizing in crushing stage(s) as far as technically possible. That has been strategy for Sandvik Mining and Rock Technology in supplying advanced and effective crushers to provide fine crushed product for subsequent milling stage. Lowering the energy consumption and related costs as well as increasing throughput have been the main objectives in design and development of comminution circuits and related machineries. Inefficiency in comminution technology, particularly in grinding, has long been regarded as a major area for investigation and development, especially when production of fines and ultra-fines are considered. In an attempt to explore the potential of fine crushing and its effects on subsequent milling process the fine crushing performance of Sandvik’s conventional cone crusher and Vertical Shaft Impactor (VSI) in pilot scale to define the energy consumption and circulating load in fine crushing. Tests were conducted to obtain fine crushed products at P = 2 mm in a close circuit. Furthermore, the crushed products were characterized and compared by grind-ability, morphology, and surface area measurement tests. Finally, the energy consumption to grind the crushed products to specific grind size was calculated."

Jan 1, 2018

By G. X. Du

Reaction kinetics of serpentine and hydrochloric acid is theoretical basis for optimizing reaction process conditions of serpentine and hydrochloric acid. Kinetics of serpentine and hydrochloric acid was studied in this paper. The results indicated that apparent reaction order to hydrochloric acid was two and reaction kinetic equation could be expressed as: 2HClHCl,ddtckct-=·. The diffusion rates of hydrogen ions in liquid film on surface of serpentine particle and in amorphous silica layer generated in the reaction and chemical reaction velocity during the reaction had important effects on to-tal reaction velocity. And chemical reaction velocity had the most significant influence. The relation of conversion rate of magnesia xMgO with reaction time could be expressed as: 1(1)xkt--=·.

Jan 1, 2014

By Xubo Chen, Zhiqiang Hu, Zhijian Sun, Gaoyun Zhou

"The research aimed at developing an efficient and environmental frother,which was applied in the flotation of sulfide ores. The flotation properties of an efficient frother and pine oil have been studied relatively by flotation tests of lead and zinc sulfide ores. At the same time, the biodegradability of two kinds of frother has been studied by the method of biological respiratory curve. The test results show that the flotation properties of new frother are superior to pine oil such as flotation rate, dosage etc. and its biodegradability is superior to pine oil. INTRODUCTION Frother is a kind of important agent in flotation reagents.In practice, the criterion of the foaming performance of the frother is what is high and low according to flotation indexes. The difference of different minerals and flotation technologies has great influence on the foaming performance of frother, and it is very important to choose the corresponding frother. The type, dosage and selectivity of frother in flotation process must be considered carefully. In today's society, environmental protection and ecological protection are becoming more and more important, and the environmental and ecological damage from mine development has aroused increasingly more attention. The use of mine agents has promoted the development of mineral resources, greatly improves the recovering utilization of mineral resources, at the same time, the production and use of mine reagents also inevitably bring about pollution, and result some influence or damage in the ecological environment.The frother is a common kind of reagent in the flotation process of the concentrator. In many cases, the waste water in the concentrator can not be let out in the natural water because the higher content of the frother in the waste water results in higher index of COD.This will inevitably increase the cost of waste water treatment in the mine.Therefore, the choice of frother should not only consider its influence on the flotation index, but also consider its influence on environmental protection. Waste water treatment is a way to solve the waste water pollution, but it needs to cost a lot of fund, manpower and material resources.And the development of high efficiency pollution-free reagent is a good way to reduce the production cost of mining enterprises and reduce the environmental pollution."

Jan 1, 2018

By ?. Kostadinov

Theoretical study of the behavior of grinding medium presented by TBP (tetraballpebs) was conducted by computer modeling of the position of grinding medium at different speeds and different drum fill factor. For the modeling were used known equations of motion derived for the ball load. Algorithm was created by SolidWorks software, allowing determination of center of gravity of the load in the mill and energy for grinding. These results were compared with similar results obtained by ball grinding medium. The capabilities of both grinding media are demonstrated by graphics under the following conditions: 1.Equal dimensions of the experimental model of the mill; 2.Equal mass of the grinding loads; 3.Comparison of grinding bodies with the same number, mass and density. Keywords: simulation, behavior, grinding medium, balls, tetraballpebs

Sep 1, 2012

By Y. C. Liu

Ningxiang-type iron deposit is a most important sedimentary oolitic hematite deposit in China. Its? detected ore reserves are 3.72 billion tons, which is 73.5% of all detected reserves, and there are about 10 billion tons of prognostic resources. It is considered as the ?poor mine? for a long time be-cause of its difficult prooerty. But based on the ore characteristics of different deposits, the technological characteristics of ore are different with great diversity in ore baring horizon, distribution range, deposit scale, ore petrology, ore mineral assemblage and iron content. Through the study of deposit features and technological mineralogy of different Ningxiang-type of iron deposits in China, and based on industrial types and natural types of ore deposits, we divide different technological types according the technological features of the ore such as mineral composition, particle size, dissemination, occurrence of useful elements and harmful elements, the main physical and chemical properties of mineral and geological conditions of deposits, etc, moreover, propose the different utilization, mineral processing technologies and product schemes for the different types of ore.

Jan 1, 2014

By A. V. Kanarskay?

The research is aimed at involving in the processing of poor platinummetal natural and technogenic raw materials. The purpose of the research is the creation of a multifactorial complex of innovations in the system of ore preparation and separation cycles, which ensure a high efficiency of flotation enrichment of hard-to-treat raw materials. In the usual practice of enrichment, minerals of the platinum group (PGM) of less than 10 microns in size are the source of inevitable process losses. For poor raw materials, it is precisely thin PGMs that are characteristic, their proportion sometimes being almost 100%, and their opening leads to the formation of a large amount of slime, which adversely affects the efficiency of flotation. To reduce the yield of slimes and increase the selectivity degree of the opening of the PGM in the ore preparation cycle, a dry grinding scheme and pneumoclassification of the milling material has been developed to obtain fractions of different fineness, density and morphology of the particles. From 2 to 5-fold reduction in the yield of slurries for various ores has been achieved. The separation cycle successfully tested are: flotation of fractions in separate cycles with a differentiated choice of the reagent regime; preliminary selective flocculation of slime fraction material; use of a new generation of bioreagents for flocculation and flotation. A new approach to subsoil research is protected by a patent. The dependence of the efficiency of biocollectors on the composition of biomineral extract from the processed raw materials, which forms the basis of new reagents, is established. The possibility of obtaining the degree of extraction of PGM, native gold and sulphides from finely ground pre-fractionated poor ores with the use of biocollectors of at least 85% is proved. With conventional reagents, the extraction of PGM is 12-23% lower, with the use of traditional ore-preparation apparatuses, the PGM recovery rate was halved. Methods for the long-term storage and preparation in industrial conditions of biocollector reagents that do not require the purification of waste waters from them have been developed. The developed multifactorial system of intensification of flotation enrichment can be introduced to recovery PGM from tailings of enrichment of titanomagnetite, chromite and copper-nickel ores.

Jan 1, 2018

By M. Kadiyski, V. Stoyanova, E. Visariev, V. Stoilov

"The present study deals with copper losses in slag from copper smelting. Copper slag cooling at Aurubis Bulgaria is traditionally done in pits. A new type of slag-cooling is introduced in the site, involving cooling ladles. In a previous study, the ladle cooling process was studied in detail, showing an improvement in the recovery of copper in the slag after flotation. The main reason for better recovery of copper is the increased cooling time, which allows for the accumulation and aggregation of copper droplets. The effects of the newly introduced slag cooling process are studied using optical microscopy and scanning electron microscopy. Cooling in pits and in ladles is compared, based on copper droplet size, distribution and content. Specialized image processing software is employed on images taken with an optical microscope. The results are then compared with a similar technique, available in SEM software. The availability of phase-analysing image software in combination with electron dispersive X-ray spectroscopy makes it possible to study the morphological properties, distribution and chemical composition of the copper droplets. The obtained results confirm the initial conclusions about size, distribution and composition of the copper-bearing particles. A large amount of copper particles is examined showing an obvious increase in their size from pit- to ladle cooling. The results show an increase in the average size of the droplets, which doubles from pit-cooling to ladle-cooling. There is a well-pronounced tendency of decrease of the percentage of droplets in the smallest fraction (<5 µm) in the ladle-cooled slag. In addition, the number of droplets in the larger fractions increases, compared to the ones in the pit-cooled slags. It is believed, that the developed methodology for analysis provides a relatively quick and reliable solution for comparison of the cooling rates in the slag. INTRODUCTION In the process of copper smelting and converting, iron-silicate slags are produced that contain various amounts of dissolved and entrained copper. Different physical and chemical techniques are employed for the valorisation of the remaining metals in the slag – magnetic separation, leaching, roasting, flotation, etc. According to Gorai et al (2003), about 2.2 tons of slag is produced per ton of metal. In 2016, about 20 million tons of copper have been produced globally (www.icsg.org). At an average of 0.5 percent copper content after treatment, these slags contain more than two hundred thousand tons of copper which is lost due to inefficient processing."

Jan 1, 2018