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By G. N. Jadhav

In India, bauxite deposits are concentrated in Central India, Western Ghats and Eastern Ghats. Bauxites from various regions in Gujarat were identified during the present investigations of geochemical mapping. Different types of Bauxites samples were collected from Kachchh, Jamnagar, Porbunder, Junagarh, Bhavnagar and Amreli areas of Gujarat state and were studied in detail for their geochemical signatures to plot the data on Geochemical map. Raw bauxites were characterized by using powder XRD, XRF, ICP and optical microscopy techniques (with the help of Model microscope having both transmitted and reflected light setups) and were later examined to grade their quality. Most of the bauxites from Kachchh region were of high-grade (gibbsitic) type; while those of Sourashtra region were of low-grade (lateritic / calcitic) types. Most of these bauxites were either of ferruginous/lateritic or of calcareous/calcitic types. Based on the mineralogical composition, such as gibbsite, hematite and/or goethite, Kaolinite and calcite minerals present in particular bauxites, the deposits were graded. Finally, the Geochemical mapping of Bauxites for Gujarat region was prepared and discussed.

Sep 1, 2012

By F. H. Wang

The Yinmao Lead-Zinc Mine Co. Ltd. has got 50 years of mining history. In recent years, the manganese grade in the flotation tailings has been continuously increasing. In order to make fuller use of the existing resources, as well as to increase the company?s economic efficiency, our company adopted the technique ?magnetic separation? and ?iron removal? to effectively recycle the manganese concentrate resources.

Jan 1, 2014

By S. M. Javad Koleini

The aim of this research is to extract zinc from complex lead and zinc ore containing carbo- silicate lead and zinc minerals using sulphuric acid. Samples, taken from Dareh Zanjireh mine located in central of Iran, were subjected to leaching tests after calcination process. Experiments were planed according to the Taguchi statistical method. The calcinated samples contain 13.98% zinc and the constituting minerals being dolomite and zincate. Various parameters such as speed of mixing, temperature, time, solid to liquid ratio and pH were studied. A solid to liquid ratio of 1:6 gr/mL at 60°C and 800 rpm speed of mixing for 30 minutes resulted in a product with 85.96% zinc recoveries.

Jan 1, 2014

By S. Banisi, E. Arghavani, M. Pourkani, M. J. Rajabi, Gh. A. Mohamadian, H. Bidshahri, Gh. A. Parsapour

The Sarcheshmeh copper complex flotation circuit of plant No.1 consists of two identical north and south sections where each includes four rougher (each bank consists of 14 cells), two cleaners (each bank consists of 8 cells), two recleaners (each bank consists of 2 cells), and two scavenger banks (each bank consists of 10 cells). The reduction of feed grade along with a change in the mineralogical composition is the main reason of current lower concentrate grade (24%) compared with the design concentrate grade (32%). Because of a lower feed grade, the amount of rougher concentrate has decreased which in turn has significantly reduced the feed rate to the cleaner, recleaner, and scavenger banks. This has increased the mean residence time of the material in the cleaner section resulting in a lower final concentrate grade. A laboratory study showed that the final concentrate grade can be increased by 2-4% if one cleaner stage is added to the flotation circuit. In this research, based on the laboratory results, one cleaning stage was added to the current flotation circuit. In order to make this modification instrumentally possible in the plant, the final concentrate was gravity transported to the Mo-Cu thickeners. This released 2 pumps and associated tanks which made addition of one cleaning stage practicable. Finally, a part of the cleaner and scavenger cells were used as the third cleaning stage. This decreased the residence time in the cleaner and scavenger banks. After implementation of one cleaning stage in the south section of the plant, the performance of the circuit compared with the identical north section. It was found that at the same recovery, the concentrate grade of the south section increased by 2.5%. The promising results led to the implementation of adding one cleaning stage in all sections of the flotation circuit.

Jan 1, 2018

By N. Karapinar

Ferrihydrite, a member of iron oxides family, has been used as an adsorbent for the removal of heavy metal ions from industrial wastewater. The success of the operation depends mainly on the efficient removal of ferrihydrite from the aqueous phase. Hence, the emphasis of this study was given on the separation of ferrihydrite by high gradient magnetic separation (HGMS) method to overcome solid-liquid separation difficulties of ferrihydrite. Magnetic seeding technique in which the magnetite mineral was chosen as a seeding reagent was used to make magnetic separation available. The method clearly involves the attachment of ferrihydrite to a magnetic seed material and subsequent magnetic separation of ferrihydrite ? magnetite coagulates. Seeding of ferrihydrite with magnetic particles was achieved by exceeding the solubility limit of the ions in the presence of dispersed magnetite. Magnetic separation results of seeded ferrihydrite showed that maximum seeding performance is obtained in the pH range of 7.0~10.0. Iron/magnetite ratio had a marked effect on the separation of seeded iron oxide precipitate by HGMS. This ratio determines the operation parameters such as magnetic field strength and flow rate. It was concluded that when used with magnetic seeding technique, HGMS can be used to surpass separation difficulties of ferrihydrite used in adsorption-based treatment techniques.

Jan 1, 2014

By Zhazira Baltabekova, Nina Lokhova, Arailym Dukembayeva, Madali Naimanbayev, Zhantore Dzhurkanov

"Recycling of industrial waste provided they have enough valuable elements requires significantly less investment compared with ore processing. Promising man-made raw material of rare earth elements (REE) is phosphogypsum. Works performed on dismantlement of phosphogypsum only concern phosphogypsum processing from apatit. In this case, none of the developments was tested for phosphogypsum produced on the basis of phosphorus, chemical and mineralogical composition of which is markedly different from apatites. We studied phosphorites of the Karatau deposits (Kazakhstan). Mineralogically all the layers are composed of three main ingredients: phosphate, silica and carbonate, which account for 92-96% of the weight composition of ores and rocks. Of impurities there are pyrite, iron hydroxides, gypsum, fluorite. In addition to the actual composition of phosphate in phosphate ores there are apatite. Silica is presented by chalcedony and quartz, and carbonate by calcite and dolomite. The results of X-ray microanalysis showed point cluster of grains containing REE in samples of phosphate ore. Analysis of the grain showed that REE are in the form of phosphates and silicates, which according to numerous studies in apatites is not established. In this regard, phosphogypsum, waste of production, is different in composition too. Therefore, transfer of techniques proposed in the methods for extracting REE from phosphogypsum after processing apatite, did not give the stated results and required a new approach to solving this problem. It should be noted that the phosphogypsum produced by processing the Karatau phosphorite contains medium group of REE by 2.6, and heavy group by 7.8 times more than phosphogypsum from processing the Kola apatite. Given the shortage of medium and heavy REE research to develop ways to extract the lanthanides from phosphogypsum after processing phosphate rock is promising. The study contains results of studies on the extraction of REE from phosphogypsum after Karatau phosphorite processing."

Jan 1, 2014

By D. Vega, P. R. Brito-Parada

"Small diameter (10 mm) hydrocyclones have been applied successfully for the separation of particle suspensions in the micron size range. These hydrocyclones are attractive because they show a bypass fraction larger that the water recovery, resulting in a high particle recovery to the underflow as well as low water recovery. However, this is a disadvantage when the purpose of the hydrocyclone is classification because of the large amount of fine particles that are misplaced in the underflow. The aim of this study is to explore, experimentally and computationally, the influence of design parameters on the classification process. In this work, a full factorial experimental design was defined to carry out comprehensive experimental tests using glass beads (0-20 µm) as the particulate system. We show that the dimensions of spigot and vortex finder diameter can be effectively manipulated to change the separation performance of the system and the energy consumption. A CFD model was developed that is able to predict particle size distribution. The numerical results for the partition curves showed very good agreement with the experimental data. INTRODUCTION Small diameter hydrocyclones are a very attractive separation technology for fine particle suspensions. Since the hydrocyclone diameter is directly proportional to the cutsize that can be achieved, 10mm hydrocyclones have been shown to be very effective in collecting particles in the micron-size range. In addition, while in large hydrocyclones the bypass, i.e. the fraction of particles that report to the underflow without classification, is similar to the water recovery, in 10mm hydrocyclones the bypass fraction is considerably larger than the water recovery. Its high particle recovery and low water recovery makes small hydrocyclones ideal for ultrafine particle classification and dewatering applications in mineral processing. The separation of mineral suspensions achieved using small hydrocyclones has been the focus of various studies. Pasquier and Cilliers (2000) derived a general classification model from experimental data of fine silica concentration in 10mm hydrocyclones; the model was able to describe the fish-hook partition curve. The effect of operating conditions has also received some attention in the literature. Cilliers et al. (2004) showed that an increase in temperature positively effects the recovery of fine silica particles in small hydrocyclones, by increasing the bypass and decreasing the cutsize. Neese et al. (2015) showed that the cutsize in 10mm hydrocyclones can be further decreased by operating at higher pressure, which also trebled the throughput."

Jan 1, 2018

By Carlos Pereira, Fábio de São José, Francielle Nogueira

Votorantim Metals Corporation is one of the leader companies in the extraction of zinc in Brazil. One of its mines, located in the city of Vazante - MG, was composed by zinc silicate ores, but recent studies have indicated a change in mineralization type with arise of zinc sulphide’s ore bodies with disseminations of galena (PbS) and silver. The liberation size between sphalerite and galena in this ore occurs in very fine granulometry (approximately 18µm), fact that has negatively influenced into the flotation process. Aiming to reduce this problem, studies about the use of dispersing in the flotation process have started. Thus, this study investigated the action of different reagents dispersing on the stability of the suspensions. The tests were carried out with samples of mineral galena and sphalerite using four types of dispersing within two different dosages and two pH. The reagents tested were sodium hexametaphosphate, sodium silicate, carboxymethiylcellulose, and sodium polyacrylate. The results of the dispersion tests were analysed in relation to dispersion index. The tests with hexametaphosphate showed high dispersion for both galena and sphalerite. The sodium polyacrylate and arboxymethiylcellulose showed a high dispersion index for galena and a low index for sphalerite implying that reagent can be used in the concentration process of galena.

Jan 1, 2014

By X. Q. Cui

The surficial collapse pits of the mining areas are continuously spreading in Beiminghe iron mine of Hebei Province as a result of the exploitation, which has done a lot of damage to the circumjacent ecological environment of the mine. It is a new path to handle the mine tailings at the present time that the thickened tailings are used to backfill the collapse pits, in which way the problems of the surficial collapse and the nowhere discharge of the tailings are both solved, and the rational utilization of the mine tailings and the clean production of the mine enterprise are realized. The?200 mesh content of the tailings of Beiminghe iron mine is 76.87%, and?325 mesh content is 63.50%. Semi-industrial dehydration experiments to the tailings have been done using the hydro-cyclone classified thickening process. The results show that when FX125 hydrocyclone is adopted, the concentration of underflow can achieve 73.31%, and the yield ratio is 61.78%; when FX150 hydrocyclone is adopted, the concentration of underflow is 70.57%, and the yield ratio is 54.31%, which indicate that the minor diameter hydrocyclone is propitious to improve the yield ratio of the underflow. The semi-industrial dehydration system of hydrocyclone classified thickening process is com-posed of FX125 hydrocyclone, D3600 high-efficient thickener and D2000 thickening bucket. The capacity to tailings disposal can achieve 3.07t/h and the tailings can be thickened from 28.86% to 62.45%. Compared with the traditional thickening-filtrating process and the total tailings directly filtrating process, the hydrocyclone classified thickening process has the merits of simple flow and high thickening efficiency, so it is easy to be realized in the mine.

Jan 1, 2014

By G. S. Zeng

The mechanism of cobalt removal from zinc sulfate solution with zinc dust is still not understood well. The experiments in this paper were carried out by zinc dust from zinc sulfate solution with high cobalt to study the mechanism of cobalt removal. Residues after the cementation process from zinc sulfate solution were analyzed by SEM and Electron probe micro-analysis (EPMA) to investigate the morphology of products. Different temperature will cause different structure of particles. With the increasement of temperature, cobalt removal can be improved considerably. The mechanism of cobalt removal by zinc dust is thought as follows: firstly, the cobalt ion forms Co-Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; secondly, the Co-Zn alloy continues reacting to Co with Co2+, which is the control procedure of the whole reaction.

Jan 1, 2014

By J. Kwon, D. Lee, H. Cho

"The use of the combined grinding and liberation model to predict liberation characteristics of iron ore comminuted by a ball mill was studied. Comminution characteristics were obtained using the one-size fraction method. The iron ore samples were crushed and separated into a number of narrow size fractions by screening. The size fractions were further divided by magnetic separation into three classes: concentrate, middling, and tailings. Subsequently, various size-grade classes were subjected to ball milling, and the results were analyzed in terms of the kinetic grinding model. The mineralogical textures of the grinding products were analyzed using mineral liberation analysis. The distribution of iron content within the size fractions was characterized by the beta distribution combined with the Andrew–Mica diagram. It was found that the grinding characteristics of the iron ore samples varied slightly with the iron content. However, the liberation characteristics were well described by the same set of liberation model parameters, regardless of composition. The variation in grinding kinetics with composition and the liberation model parameters was used in the combined comminution–liberation model to predict the evolution of the size-composition matrix as grinding proceeded. The predicted results agreed well with the experimental results. The developed model can be used to construct the yield–recovery graph and to calculate the liberation efficiency to determine the size reduction threshold for efficient separation. INTRODUCTION In mineral processing, comminution is usually the first step that ores undergo to liberate valuable minerals from gangue minerals. Generally, as the particle size decreases, higher liberation can be achieved. However, excessively small particles are unfavorable to subsequent processes, such as separation. Moreover, comminution is a highly energy-consuming process itself that accounts for approximately 60% of all energy used for processing. Therefore, there is a definite need to increase energy efficiency by applying adequate stress so that a high degree of liberation can be acquired at the coarsest size without overgrinding. To this end, it is essential to develop a model to predict the liberation of minerals as a function of size reduction."

Jan 1, 2018

By L. C. Zhou

The floatability of andalusite and associated minerals are studied and their action mechanisms of andalusite and associated minerals with collector alkyl benzene sulphonate are also studied. Through the mensuration of electrical potential and the infrared spectroscopy, as well as desorption tests, it is confirmed that the interaction of andalusite with sodium dodecyl benzene sulphonate (SDBS), is in addition to physical adsorption, but also is chemical adsorption. The study results of the pure minerals are used for the flotation of actual andalusite mineral. By flotation from contain-ing 45.68% andalusite ore, the fine andalusite concentrate is gained which Andalusite grade is 85.88%, containing Al2O355.29% and Fe2O3 less than 1.5%.

Jan 1, 2014

By G. Prabhulingaiah, D. M. R. Sekhar

"A phosphate deposit of estimated 6 billion tons of P2O5 is located 180 to 300 meters below the sea level, 185 kilometers north of port Luderitz, Namibia. The ore bed is 6 kilometers wide and 220 kilometers long. The ore deposit analyzing 16% P2O5 is loose sediment of 1.5 meters thick without over burden. Sizing of the ore to - 1.4 mm + 0.150 mm improves the grade to 23.54% P2O5 with a P2O5 recovery at 83.75% containing phosphate pellets and flakes of sea shells. Clay, bacterial debris as organic matter, flakes of broken sea shells and fine phosphate containing particles report to - 0.150 mm fraction and + 1.4 mm fraction contains sea shells and few phosphate containing pellets. The mineralogical composition of phosphate containing pellets is estimated (Droste, T.C., 2004) 80% frankolite, 6% pyrite, 4% illite, 3% quartz, 3% amorphous SiO2, 1% carbonates, 1% organic carbon and = 1% ilmenite, magnetite, zircon etc. The phosphate content in the pellets is around 27.7% P2O5. Trials to separate by gravity or flotation processes were not successful. Leaching of carbonates (sea shell flakes) under mild acidic condition (= 2% acetic acid or HCl solutions) or calcinations followed by leaching however yielded residues (concentrates) of grades 27.85 - 32.74% P2O5 at P2O5 recoveries ranging from 78.45 - 96.8% P2O5."

Jan 1, 2014

By Kaustubh Joshi, Pradip, Beena Rai, Venugopal Tammishetti

"Rapid depletion of high grade iron ores coupled with the increasing demand for the blast furnace grade iron ore in recent times has shifted the research focus on the development of appropriate technologies for the utilization of low - grade alumina rich iron ore slimes. These slimes are currently being dumped into tailing ponds owing to their high alumina content. Typical constituent minerals present in the Indian iron ore slimes are hematite, goethite, gibbsite and kaolinite. Considering the fine particle size distribution (<37 microns) in the slimes, selective dispersion-flocculation seems to be one of the most appropriate process which has been explored by us. We present our successful results on a natural iron ore slime sample obtained from one of the mines in India. We have been able to achieve a concentrate assaying >67% Fe, and <3% Al2O3 and 2.8% loss on ignition (LOI) from the slime sample assaying 60.4% Fe, 7.7% Al2O3 and 5.45% LOI with an Fe recovery of 62-69% simply by adjusting the pulp pH. We have scaled up the process to a semi batch scale as a prelude to commercialize it for the beneficiation of low grade iron ore slimes."

Jan 1, 2014

By S. S. Indi, D. Santhiya, S. Subramanian, K. A. Natarajan

The interaction of sphalerite- and galena-adapted Bacillus polymyxa (B. polymyxa) cells with sphalerite and galena has been investigated through adsorption, electrokinetic and flotation studies. The amount of sphalerite-adapted cells adsorbed onto sphalerite and galena is found to decrease with increase in pH. On the other hand, the adsorption density of galena-adapted cells onto galena shows a feeble maximum around pH 8, and the amount adsorbed is marginally higher in the pH range of 8 . 11.5. In the case of sphalerite the amount adsorbed is higher in the pH range of 5 to 7. The adsorption density of both the adapted cells is higher for galena vis-à-vis sphalerite. Electrokinetic studies indicate significant surface chemical changes on the chosen sulphide minerals and the bacterial cells, consequent to microbe-mineral interactions. Selective flotation tests on a synthetic mixture of galena and sphalerite confirm that sphalerite could be preferentially floated from galena, using galena-adapted cells, but not with the sphalerite-adapted cells. The cells adapted to galena assay a higher polysaccharide content and are more hydrophilic, while the sphalerite-adapted cells have a higher protein content and possess greater hydrophobicity. Transmission electron microscopic studies have provided evidence in support of the differences between the cell surface characteristics of sphaleriteand galena-adapted cells. Possible mechanisms of interaction between the minerals and the bacterial cells are discussed.

Jan 1, 2003

By D. M. R. Sekhar

Certain types of rock phosphates of sedimentary origin are applied to acidic soils as fertilizer directly. Recent research in India showed that high grade rock phosphate in fine size when used as a mix with organic manure works as efficiently as di-ammonium phosphate (DAP) in alkaline soils. The rock phosphate from Jhamarkotra, India (sedimentary origin), Egypt (sedimentary origin) and South Africa (volcanic origin) showed good agronomic efficiency when used as Phosphate Rich Organic Manure (PROM). Further PROM shows equal residual effect. The results of efficiency of PROM made using two grades (+ 24% P2O5 and 34% P2O5) of rock phosphate mineral from Jordan show that low grade rock phosphate slimes are as effective as high grade phosphate concentrate when used in PROM. Also PROM is very effective in the saline soil of Eshidiya desert where DAP is not at all effective.

Jan 1, 2014

By E. P. Olberg, A. Yu. Chikin, S. V. Petrov, M. P. Belykh, N. L. Belkova

"Bacteria that grow in autochtonous communities of gold heap leaching (HL) wastes are adapted to high concentrations of contaminants and environmental conditions. An example of a mine in the Sakha (Yakutia) Republic showed that the bacterial factor had a significant influence on cyanide breakdown and copper and nickel removal in the conditions of HL ore pile zoning compared to chemical oxidation. The diversity of bacterial communities growing in natural and simulated conditions of a HL ore pile was determined for the purpose of the study. The identified bacterial communities included genus Achromobacter and Serratia, which were found to be adapted to a wide range of temperature and can be considered as potential microorganisms for detoxification of gold HL wastes. INTRODUCTION Technologies and systems of passive treatment are of a special interest in relation to solving environmental problems of gold HL wastes detoxification, when neutralization time is not considered as a limitation (Alvarez et al. 2005). Passive treatment methods are based on reagentless spontaneous breakdown of cyanide caused by natural factors, including activity of autochthonous bacterial communities. Implementation of a reagentless biodetoxification technology for mature HL operations provides reduction of environmental impact on industrial site locations and substantial economic benefits compared to conventional chemical processes of neutralization that prevail in the Russian Federation territory. Passive treatment of cyanide-containing wastes was investigated by M. Botz, T. Mudder, S.V. Petrov, L. Simovic, A. Smith, C.A. Young etc. However, the bacterial factor (autochtonous bacterial communities) role in this process is practically unexplored. Thus, the aims of the study included the investigation of a bacterial factor influence on passive treatment of gold HL wastes and the identification of functional groups of bacteria involved in passive treatment."

Jan 1, 2018

By S. P. Das

Tumbling mill is an important unit operation in a mineral processing industry whose operation needs to be understood to make it an energy efficient unit. One of the important mill parameters is the impact spectra generated by collision of the moving charge mass on the mill shell. This process also generates mechanical vibration on the mill shell and propagates to the plumber block of the mill. In this work, we tried to understand the impact spectra by using different minerals such as Banded Hematite Quartzite (BHQ), Hematite and Quartz as mill feed of a semi-autogenous (SAG) mill. The said mill is of 1000 mm diameter and fitted with a force sensor on the mill shell and a vibration sensor on the plumber block. The analysis of the impact spectra was done by taking into consideration the peak impact force above a certain threshold value. It clearly shows that the impact force decreases as the particle size become finer irrespective of the mill feed material. This can be used as an effective tool by the mill operators to have an understanding of the mill product size reduction. The mechanical vibration tapped by a tri-axial accelerometer was analyzed by power spectral density analysis. The vibration signal analysis shows the variation in the power spectrum magnitude both at lower and higher frequency. It also shows inconsistency in case of BHQ where it shows a significant decrease in vibration at lower frequency and increase in vibration at higher frequency. Therefore, the impact spectra analysis is a better method compared to vibration analysis in understanding the mill product size reduction.

Sep 1, 2012

By M. F. He

The depression of pyrite in marmatite flotation by a new depressant Sodium Glycerine-xanthate (SGX) has been investigated through microflotation, zeta potential, and adsorption measurements in systems open to the atmosphere. The flotation tests of single mineral show that in the presence of SGX, marmatite can be activated by Cu2+ and shows good flotability, while pyrite can?t be activated and therefore shows poor flotability, as a result these two minerals can be separated using butyl xanthate as the collector. The depression mechanism of SGX on sulfide minerals is discussed based on Zeta potential and adsorption isotherm. Zeta potential experiments demonstrate that at the presence of Cu2+, SGX can strongly adsorb on the surface of pyrite, while it can?t adsorb on the surface of marmatite, thus the results are in accordance with those of flotation experiments; the results of adsorption isotherms show that the adsorption density of SGX on pyrite is greater.

Jan 1, 2014

By A. Ceylan

Pyrite is present as a gangue mineral in most of complex sulphide ores and most of time it is removed as a tailing. However, beneficiation of pyrite from tailings could be important because of its economical value and for the environmental concern. This paper presents a research for the enrichment of pyrite from copper plant tailings, Siirt-Madenköy/Turkey, by flotation. Siirt-Madenköy copper mine is operated by Park Electric Production Mining and Industry since 2005. In order to obtain the pyrite from Siirt-Madenköy copper plant tailings, laboratory test work has to be done to determine the type of reagents, the flowsheet, and the size of plant. The objective of the company is to develop a pyrite flotation circuit for concentration of pyrite from tailing dam to obtain 500.000 tons/year pyrite concentrate. There are about 3 million tons tailings that containing pyrite in the tailings dam. Experiments were carried out with three different types of tailings from the plant and the pyrite concentrate with 46% Fe and 90% recovery has been obtained. Therefore, this study shows that high grade pyrite with high recovery can be recovered from the tailings.

Sep 1, 2012