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By J. Roth

The increasing demand of the filler industry regarding fineness and better delaminated products led to the development of a series of different grinding machines, which differentiate basically by the grinding mechanism as well as the kind of classification. Spiral jetmills grind, as it is well known preferably by delamination, therefore a spiral jetmill with integrated dynamic classifier has been developed. Especially the enhancement of the functional properties of the used industrial mineral fillers is a factor of highly increasing importance. These properties are very often bound to the platy shape of the minerals expressed by the aspect ratio. The developed Spiral Jetmill shows sufficient ability for such delamination and therefore increases in aspect ratio. In a series of comparative tests the suitability and advantages of this system regarding achievable fineness down to the submicron range as well as the conservation or even improvement of the aspect ratio of different minerals has been studied. As an emphasis on the results application tests with certain materials in the plastics field have been conducted. Due to the fact that in this range the required specific energy for achieving the necessary fineness increases exponentially another target is to optimize the grinding efficiency. A special feed control system provides on one hand a sufficient load inside the mill to obtain maximum utilization of the applied energy and on the other hand to prevent the mill from overfilling and coming with this a poor classification. The integrated classifier is a combination of a high speed motor with directly attached classifier wheels. This unit on one hand grants the necessary high circumferential speed of up to 190 m/s for providing an exact top cut of the ultrafine products and on the other hand gives the required operational reliability for continuous operation. Hard grindable impurities, which enrich inside the mill chamber, can be rejected from the process leading to an even cleaner product. Comparative tests on a talc product with certain free quartz impurities showed a significant improvement of the final product with respectively low loss on rejected material. This effect again had a beneficiary impact on the suitability of the final product when used in plastics application.

Jan 1, 2014

By F. Concha

A robust theory of sedimentation-consolidation evolved and was accepted by researchers world-wide in the last two decades of the 20th century. This theory provides a reliable method of thickener design and simulation. However, a process model, simple or sophisticated, empirical or phenomenological, is useful only if it is possible to determine, in an objective way, its experimental parameters. Research workers at the University of Concepción, together with Cettem Mineral Technology Center, created an integrated system of thickener design, simulation and control, including instrumentation, algorithm and software, which can be used by personnel in industry without specialized knowledge of thickening theory. In the paper, the development of three instruments for the measurement of pulp concentration, solid flux density and sediment compressibility is described. Each instrument uses software for data input, parameter calculation and results display. The paper also describes software for the optimization of the experimental parameter and for the design and simulation of industrial thickeners. Finally, mathematical algorithm and control strategies based on the phenomenological model are presented and compared with classical feedback control.

Jan 1, 2014

By X. L. Song

A large amount of tailings in concentrators bring a series of problems to the environment and society. It is significant to reclaim the huge tailings and reuse them in industries in order to utilize mineral resources adequately. Primarily Lead-Zinc tailings with a certain quality of clay and feldspar were used to produce ceramic tiles by sintering method under specific technical conditions. By testing the properties of the ceramic tiles, it was shown that the amount of Lead-Zinc tailing used in the tiles was 60%~70%, and the mechanics properties were good. The optimum proportion parameters were Lead-Zinc tailing 60%, clay 35%, feldspar 5%, and the maximum flexural strength of tiles was up to 38.2MPa when it was sintered at 1090? for 30min. Its flexural strength, water absorption and thermal shock resistance reached the State Standard of GB/T4100.4. The product is suitable to be used in pavements and paths of parks.

Jan 1, 2014

By M. I. Panayotova

Some of effluents released by copper smelting plants are highly acidic (pH = 0~1) and contain arsenic and copper in relatively high concentrations (10~20 g/L). Usually arsenic is removed by precipitation with different reagents, such as lime, iron salts, calcium salts, aluminium salts, etc. Precipitates (often voluminous) that require further handling are formed and copper and other valuable components are lost. A method is presented for copper and arsenic extraction from acidic effluents. Effluents are treated in specially designed closed electrochemical cell without chemicals? addition. Gases formed are collected and treated for decomposing the eventual traces of As-bearing compounds and ensuring the environment protection. Initially copper of grade of 85 % is electro-won. Further about half of the initially available arsenic is separated as low-soluble, low volume mixture of intermetallic compounds, oxides and some elemental arsenic. At the next stage the main part of the left arsenic is immobilized as low soluble stable compound. Arsenic content in the treated acid is in the range 0.20~0.25 g/L. Acidity of treated effluent after first two stages remains practically unchanged and the solution can be re-used. Physicochemical and electrochemical processes, governing copper and arsenic removal, are discussed.

Jan 1, 2014

By Swati Mohanty

Spiral concentrator, which works on the principle of gravity separation, is widely used in the mineral industries for separation of solid particles based on the size and density. In the present study, CFD simulation of the flow profile on a laboratory scale spiral concentrator of height 2.29 m, pitch 0.435 m and width 0.17m was carried out. A single computational domain covering the entire spiral was considered. Volume-of-Fluid algorithm was used to track the interface and predict the flow profile. In the present study the Donor-Acceptor method was used for the calculation of volume fraction in the cell. Simulation results show that the velocity increases as the water flows down due to the convective force and gravitational force, but the viscous force acting in the opposite direction retards the flow. Thus the maximum velocity is attained at turn three at which the viscous force overpowers the other forces and further down the velocity decreases. Measured water depths along the radius of the spiral at various heights were compared with simulated depths, which were in good agreement. The simulated liquid phase velocity profile was used to carry out preliminary studies on the flow profile of solid particles of size 500 micron and densities 2600kg/m3 and 5100kg/m3, based on the Lagrangian model taking into consideration fluid-particle interaction.

Sep 1, 2012

By S. H. Shahcheraghi

The four operational parameters including collector dosage, frother dosage, conditioning time and pH, are the most important parameters effective on the flotation kinetic. The present study has been done at the Miduk Copper Complex in the province of Kerman. The effect of operational parameters on the flotation kinetic of copper minerals were studied and analyzed, so the optimum conditions for flotation kinetic of copper sulfide minerals were obtained. Under the obtained optimum operational conditions, the recovery of copper sulfide flotation at the 95% confidence level was estimated to be between 92.76% and 95.48% and the copper sulfide flotation kinetic constant was estimated to be between 1.40 and 1.45 min-1. Results showed that the consumption of the X231 collector (O-isopropyl-N-ethylthionocarbamate) and the A65 frother (Polypropylene glycol) could decrease up to 35% and 50% respectively while the copper sulfide recovery increases about 1 up to 2% at the laboratory scale. Keywords: flotation kinetics, sulfide copper, optimization, the Miduk Copper Complex, response surface method

Sep 1, 2012

By V. Hudecek

Problems of sudden outbursts of rock and gas present in deep mine mining ones of the most complicated interrogation. It is searching for the methods of prediction and prognosis that can be most useful for the government of these phenomena. Till now the pressure and the desorption of gas in bore holes was consider to be the decisive criteria. By the work of authors with using of statistical date was verify that for considerable reliability of forecast and prevent outbursts is necessity investigate characteristics of workplace and other indicators. These indicators were analyzing and assemblage into mathematical dependences which represent active and passive force asserting with in the process of rush. It was validated by using the equations which are presented in the manuscript that the accuracy of pre-diction of the phenomena is higher and methods of preventions are better also.

Jan 1, 2014

By S. S. Yu

In this paper, the producing process of using V2O3 as raw material to obtain vanadium nitride was analyzed through the means of thermodynamic. The analysis shows that conversion follows the principle of reduction step by step in the conversion process of V2O3. The temperature of the reaction system has prominent influence on the nitrogen content of products, and the reaction is very sensitive to temperature. As raising temperature, the fine grain structure of the nitrides is more evident, and the grain size of nitrides increases. At 1703K, the nitrogen content of the products tended to be constant after soaking over 3 hours.

Jan 1, 2014

By A. K. Mukherjee

In this apparatus closed sized particles are placed in a container and then fluidized by passing water through the load of particles. Water flow is adjusted to deposit particles in one or more layers depending on the specific gravity of each of the particles, after which the deposited particles are separated in portions of different specific gravity. The obtained portions represent different ore content of the closed sized fraction. The process is repeated for all other size fractions to generate washability curve of the feed. Three different types of iron ores and one coal sample are tested in this equipment. The theoretical yield-grade curve generated for iron ore feed is unique in absence of any such practice for ore minerals. Similar curve is generated for coal and it is compared with washability curve, an existing practice followed worldwide. This comparison validates the performance of the process and the equipment.

Sep 1, 2012

By H. Y. Ran

Magneto-flotation is a recently developing technology of mineral processing. This technology combines the traditional magnetic separation with flotation and provides a magnetic and buoyant force compound field to separate different minerals based on the differences of magnetism and floatability between useful minerals and gangue minerals. Magneto-flotation is applicable to separate ferromagnetic from nonmagnetic minerals, especially to separate magnetite from floatable gangue minerals. This magneto-flotation column is equipped with pulse electromagnetic field in the middle upper part, a bubble producer and upwell water inlet in the bottom. The pulse time of electromagnetic field in the column can be optionally adjusted and the maximum intensity of pulse magnetic field can reach 35mT. Pulse magnetic field can not only restrain magnetic minerals from entering into the froth layer, but also destroy the magnetic agglomeration to ensure a higher recovery and a higher concentrate grade. The results of experiments with magnetite show that pulse magnetic field has remarkable influence on flotation process. Compared with single flotation, magneto-flotation column can improve the recovery of magnetite by ten percent. After one time?s magneto-flotation processing, the grade of iron concentrate can increase from 65.4% to 69.5%, the content of silicon oxide in iron concentrate decreases from 7.4% to 2.8%, and the total recovery is above 96%.

Jan 1, 2014

By A. F. Usov

The paper is concerned with an analysis of the experience gained in development of special electro-technical installations applied in electric-pulse destruction of materials. A principle scheme of an electric electric-pulse installation is given, and electric circuit variants of its blocks made on various element bases are discussed. Also assessed are some ideas to further improve the technical and economic characteristics of the equipment.

Jan 1, 2014

By W. Fander, Zhonghan Zhang, T. Choo, J. Enraght-Moony

"This paper describes the mineralogical and metallurgical procedures used to determine the recovery and concentrate grade of heavy oxide minerals occurring in lode deposits. The data produced also provide vital information to the processing engineers, which allows them to develop the most suitable flow sheet for that particular heavy mineral, here called an Economic Oxide Mineral (EOM). It demonstrates how results are interpreted to ensure that the proper process is used at each treatment stage to optimise recovery and to produce the most suitable concentrate at that point. Reference is made to some of the current equipment and techniques that can be used to process EOMs. The paper shows that when assessing the economic potential of a new ore body, or existing ore treatment plant, ore characterisation (OC) is necessary. This is especially true for EOMs such as cassiterite (SnO2), wolframite ((Fe, Mn, WO4,) pyrochlore ((Na,Ca)2Nb2O6(OH,F)), and tantalite (MnTa2O6) where often what seem to be small changes in ore types can have major effects on recovery and concentrate grade. Due to advances in flotation technology scheelite (CaWO4) in some deposits can be less vulnerable to OC variability than other EOM’s. Thorough mineralogical examination is shown to be the fundamental basis of correctly undertaking OC. This is because mineralogical analysis identifies each of the steps required to ensure that all ore types and zones are recognised, and differences explained, and shows the benefit in using reference samples to compare differences in the ores. The OC methods used for EOMs containing metals such as tantalum, tin, tungsten and niobium are similar; if two or more of these EOMs occur in one deposit as separate minerals, then OC will show when and how these minerals should be separated. The OC techniques described for EOMs can also be tailored for other heavy minerals, precious metals and graphite."

Jan 1, 2014

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 F. Q. Cheng

As the important potash, the product yield of KCl in winter is low and the resources waste is serious according to the deficiency of collectors, which can be used in this condition currently. This paper studied on the change of contact angle, turbidity, and flotation recovery of KCl particles when different chain lengths, ratios of amines were used as collectors in KCl flotation process to get a new mixed collector. The contact angle values of KCl crystal in its brine solution added different amine collectors were first measured by captive bubble method. The turbidity of brine solutions were then measured by the laboratory turbidimeter at room temperature when different amine collectors were contained. In the end micro-flotation experiment using mixed amine with fixed ratios and ODA as collectors respectively at 5 °C, 23 °C were performed. The results show when the ratio of the mixed amine is DDA- 20%, ODA-60%, C20-20%, the contact angle at KCl surface is the maximum and the hydrophobic state is best. Meanwhile the result of turbidity measurement indicates that the dispersion of mixed amine colloids is better than the ODA collector due to the addition of DDA, which plays the role of frother. The flotation results also prove that the mixed amine is not only fit for the KCl flotation at room temperature but also fit for its flotation at low temperature. This study provides strong technical support to extend the production time of potash business in Chaerhan areas in China.

Sep 1, 2012

By Vishal Shukla, Ashok Kumar, C. Raghu Kumar, D. P. Chakraborty

"Traditional iron ore beneficiation plants using washing, screening, and jigging processes require large volumes of process water. Generated slime during processing, its disposal and impact on water usage, is an important concern for any mining company. The challenge today, during extracting iron ore, is how to dispose of slime such that it is contained and stable, while maximizing water reuse and minimizing surface footprint. The slime disposal methods are sensitive to the environment. Two major technologies presently being practiced for disposing the slime across the world are pressure filtration and paste thickening. In this perspective an attempt has been made to do comparative study between paste thickening and pressure filtration for selection of suitable slime disposable technology for Noamundi processing plant, Tata Steel. From the studies, it is evident that by adopting pressure filtration technique it was possible to produce filtered slime, whereas filtration, rate reduces significantly with the presence of finer fraction. Further , the greatest advantage of paste thickening is volume reduction of slime. By considering the technology limitation and comparative lab test work result, it is opined that combination of filtration and paste thickening technology is favorable in terms of capital and operating cost and slime >45 µ should be filtered and < 45 µ slime should go for paste thickening. The study and the results are presented in details.INTRODUCTION The beneficiation processes always end up with an enriched portion of desired mineral - “Concentrate” and an enriched portion of undesired minerals - “Tailing”. The proportion and nature of tailings generated in every beneficiation process differ from ore to ore and reflects the characteristics of the feed processed. The traditional method of tailing disposal in many mineral processing industries has been to dispose them as thickener underflow at around 35% solids. Though, it had certain advantages of transportation with ease but contribute to a greater volume occupied in the tailing dam. This sustained practice and failure to utilize the space available in the tailing dam judiciously endangered the mining industry. The tailing management has become the toughest task to the mining industry and most of the mines are running out of space for disposing the fresh tailings as many of these are at the verge of getting filled."

Jan 1, 2018

By Gabriel Barrios, Juan Pérez-Prim, Marcelo Tavares

"The application of High Pressure grinding Rolls (HPGR) has been growing in the mining industry for the last 10 to 15 years. The major benefits generally supporting this trend are better energy efficiency, improved grinding capacity, less sensitivity to ore grindability variations and higher metal recovery in downstream processes such as heap leaching and flotation. The HPGR machine comprises a pair of counter-rotating rolls mounted in a sturdy frame. One roll is fixed in the frame, while the other is allowed to float on rails and is positioned using pneumohydraulic springs. The feed material is introduced in the gap between the rolls and is crushed by the mechanism of interparticle breakage. Comminution performance is largely determined by the pressure exerted on the bed of particles by the floating roll hydraulic system. The operating bed pressure depends on the hydraulic system start-up parameters and the loading response of the feed material. The work describes how the coupling of the multi-body dynamic simulation with Discrete Element Method in which particle breakage is described using the particle replacement method, can be effectively used to predict the performance of the HPGR. The model considers important variables as the HPGR rolls geometry and design, the hydraulic spring system start-up parameters and the material loading response, to describe operational key outputs as material throughput, operating gap and roller pressure distribution. The preliminary version of the model has been used to predict the effect of material properties on the operating gap and the load distribution on the surface of the rolls, demonstrating that it can describe qualitatively the HPGR operation, indicating that the model will be a power full tool for the simulation and selection of industrial HPGR units."

Jan 1, 2014

By P. K. Arya

Huge quantity of copper is lost in Crown, Sill, Rib Pillars, hanging wall, foot wall and unexploited ore bodies in several closed underground copper mines and old worked out stopes of Hindustan Copper Limited at Mosaboni and other places. These mines might have been uneconomical to work with conventional mining methods. However, huge quantity of mineral reserves is lost due to their closure. Chemical and in-situ bio-wash leaching, if tried can provide an answer to facilitate the recovery of metallic values economically. Encouraging results were obtained during an experiment at North Badia Mines at Mosabani in the past. Though the experiments were not completed but whatever results obtained were very encouraging and can be successfully tried to make it viable. The results of the experiments are discussed here and a plan is suggested to recover copper from such mines.

Jan 1, 2014

In the present work, the flotation behaviours of zircon, rutile and ilmenite using sodium oleate as collector in absence and presence of depressants were thoroughly investigated. The maximum in the flotation recovery of any of the above minerals falls within similar pH ranges. A range of inorganic and polymer depressants were examined in order to improve the separation of zircon from rutile and ilmenite. Optimum values of conditioning pH and depressant concentration to achieve maximum recovery and best selective floatability of zircon were obtained. Selective flotation of zircon from Ti-bearing minerals was anticipated from single mineral experiments under different pH values, depressant and collector conditions.

Jan 1, 2014

By G. V. Kalabin

"The paper supports applicability of satellite imagery at regional and local level for rapid quantitative assessment of natural environment in zones of activity of mining complex enterprises. Exacerbation of environmental problems during mineral mining and processing associated with their scale and geography of field distribution through the vast territory of our country requires constant monitoring of natural environment status, which necessitates engagement of space surveillance nowadays. It is proposed to use the monitoring of land cover and land use at regional and local level for the environmental assessment of a particular production or complex productions. You must establish the dependence of NDVI change trend with the magnitude of anthropogenic impact on the source or multiple sources of environmental pollution a particular area.. We present the results of studies of vegetation remote sensing methods in a number of territories placing mining enterprises. INTRODUCTION Ensuring a healthy environment is necessary both in untouched areas and disturbed. The condition of the developed territories should be monitored with particular attention, since the restoration of the disturbed territories requires great efforts and financial costs. More narrowly, the health of the environment (Zakharov V.M. and etc.,2001) means its quality ensuring the health of man and other species of living organisms, which includes two aspects (Zakharov V.M. and etc, 2000): - ensuring an environment conducive to human health as a biological species: - maintaining the health of the natural environment, i.e. its constituent species of living organisms and plants. The consequence is the disturbance of natural ecosystems, which determines the quality of the environment, favorable for human habitation and the state of health of the population in total determine the status of the territories where enterprises for the development of georesources are located and allow them to be ranked according to the degree of environmental danger. Without knowledge of the trajectory of ecosystem successions, it is impossible to offer adequate requirements for the technologies used to ensure the implementation of the preserved natural potential after the removal or reduction of man-made stress."

Jan 1, 2018

By D. B. Mazzinghy, D. C. Rocha, H. B. Miller

"The use of ball mills for fine grinding is an inefficient process and has contributed to the increasing popularity of vertical stirred grinding mills in the minerals industry. Over the last decade, the performance and energy efficiency of stirred milling technology has become a preferred alternative to ball mills for fine and regrinding operations. The difficulty encountered in fine grinding is the increased resistance to comminute small particles when compared to coarse particles. Therefore, increased energy inputs are then necessary to raise the number of stress events in a mill to contribute to the comminution of fine particles. This work discusses the effect of operating conditions on the amount of fines produced and torque readings in a screw type batch laboratory vertical stirred mill. A time-based population balance model (PBM) was used to empirically analyze the performance of a vertical mill and to calculate mill breakage parameters for the different operating conditions tested. The results indicate the possibility of applying population balance model to the vertical stirred mill to predict product size distribution with acceptable accuracy. The obtained breakage function shows that the main breakage mechanism in this vertical stirred mill is by attrition, and that the selection function changes with experimental conditions within the mill. Higher agitator velocities are also seen to promote an increase in the degree of attrition between grinding media hence particle selection and fines generation increase.INTRODUCTION Stirred milling technology has been firmly established in the last 20 years as superior to ball mills for fine and regrinding operations due to its superior energy efficiency (Jankovic, et al., 2006). Stirred mills are now commonly used in many sectors of the mining industry, though they have been used in other industries for many years (Stehr & Schwedes, 1983). This technology has proven to be more energy efficient with greater opportunities for future optimization in both fine and coarse grinding."

Jan 1, 2018