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By S. M. H. Haddad, M. Saghaeian, R. Hejazi

"Due to limited water resources in mineral processing plants, increasing the efficiency of iron tailing dewatering system in order to obtain more usable water is very important. In this research, flocculation process, as one of the best method for water recovery, was investigated by using one organic cationic and three anionic types of flocculants with different dosages (10, 20, 30 g/ton) and iron ore tailing slurry (8 % w/w solidity) in series of graduated cylinders and obtained results were compared. it is observed that for tailing sample, the anionic flocculants have a significant effect on the settling rate of solid particles compared to the cationic types. Furthermore, effects of temperature (10, 23 and 43 ºC) and pH (2, 7 and 12) on the rate of settlement and turbidity was studied by utilizing the best flocculant. Findings showed that by increasing the amount of flocculant dosage, sedimentation rate went up and turbidity decreased. Comparison the out-put data of tests indicated that at temperature 23 °C and pH=7, the best results for both of faster settling rate and producing more clear water were reached. It should be considered that lower temperature has a more negative effect on the sedimentation rate and overflow water quality. So it will be predicted that for cold seasons, the consumption of the flocculant powder would be higher than the moderate or warm seasons. Also, coagulation/flocculation was evaluated by applying organic cationic coagulant added to anionic flocculant in three different times. Different ratios of coagulant to flocculant was examined (70%:30%, 50%:50%, 30%:70%) as well. Overall, utilizing coagulant had desirable influence on sedimentation experiments and obtaining high quality water. 1- INTRODUCTION In mineral Factories, among the important processes, solid-liquid separation process due to limited resources of water is very important and operates on iron ore tailing in settling tank as thickener in order to gain clear water for preventing water loss and applying again in plant units (Ciftci and Serhat Isik, 2017). Iron ore tailing include inharmonious compounds of iron oxides, silicates and aluminum-silicates. The percentage of solid in the tailing usually changes between 5 and 10 percent (Dash et al., 2011). One of the major problem about dewatering of tailing in thickener is solid-liquid separation of slurries with high stability because of fine particles. It means that rate of sedimentation is very slow and recovered water quality is inappropriate. This issue can be solved to a large extent by factors such as pH control, ionic strength and flocculation/coagulation process which results in aggregation of particles so that settlement by gravity is happened (Dash et al., 2011)."

Jan 1, 2018

As the high-grade copper deposits in the world become depleted, there is an increasing focus on developing lower-grade ores which contain problematic impurities such as arsenic. Indeed, many high-arsenic ore bodies remain undeveloped because of their high arsenic levels. Separation of arsenic from copper at the beneficiation stage is difficult using the current processing techniques and invariably copper concentrates produced from these ores contain high arsenic levels, sometimes so high as to make them unacceptable to copper smelters. New, sustainable approaches are needed to allow development of high-arsenic copper ores while at the same time minimizing arsenic dispersion into the biosphere. The most promising route for separating arsenic from copper at the flotation stage centers on the use of pulp potential control. In recent years CSIRO has demonstrated at laboratory scale, for a number of high-arsenic copper ores, that crude flotation separation between arsenic-bearing minerals and copper-bearing minerals can be made. The differences in specific minerals responses to changes in pulp potential and pulp pH are exploited for this separation. Such separations nominally produce a low-arsenic high-copper concentrate and a low-copper high-arsenic concentrate. The former can be smelted without penalty, while the latter requires further treatment to capture and stabilize the arsenic and to recover the residual copper. Consideration has now been given to treatment options for the high-arsenic low-copper product. A pyrometallurgical option, involving a low temperature roast to selectively fume off the arsenic and leave a high-copper calcine, coupled with an arsenic stabilization step, has been demonstrated in the laboratory, and a preliminary techno-economic evaluation shows the process to be economically favorable. These results were recently published. CSIRO has now investigated an alternate hydrometallurgical option, involving atmospheric alkaline sulphide leaching of the high-arsenic product, where the arsenic is selectively dissolved leaving a copper-rich leach residue. The leaching testwork was carried at on the same high-arsenic low-copper material used in the roasting studies, enabling a techno-economic comparison of the alternate roasting and leaching treatment options to be made. The alkaline leaching work is briefly described and the results of the process option comparison presented and discussed. Keywords: arsenic, copper, economics, enargite, ore flotation, tennantite INTRODUCTION

Sep 1, 2012

By Imre Gombköto, Zoltán Pap, Ákos Debreczeni, Sándor Nagy

Eddy current separators have become generally used in waste recycling industry during the last decade. There are many papers dealing with separation processes on eddy current separators, and also many article describes particle trajectory and different particle features affecting particle trajectory. These data are used in modeling as well. Within the frame of R&D project called ‚Fundamental research into the exploitation of the economic development potentials of critical raw materials in international co-operation - CriticEl?, authors are aimed for using Eddy Current Separator (ECS) as a mechanical separation step of high value critical elements recovery of selected WEEE’s like display panels, PCB’s. ECS, equipped with 305 mm wide belt, and a concentric magnetic rotor is used for experiments targeted development of methodology for determining separability of different particles on ECS. The subject of our work was to investigate the behavior of model particles with different shape, conductivity (aluminum and copper), orientation and size in order to separate Al and Cu according to the results of many experiments were carried out in this field. However it looks like that throwing distance of one particle is only possible to describe by a certain distribution for even the same particle within the frame of the same conditions. Sample mean and standard deviation are depending on some of the particle feature and acting forces. The paper is going to draft the first results on the relationship between distribution of throwing distance and particle properties.

Jan 1, 2014

By I. Baltov

The Chelopech Mine, located in Central Bulgaria, is one of Europe?s largest underground copper- gold mines, currently mines and processes approximately one million tonnes of ore per year. Copper concentrates containing gold and silver with significant arsenic content are produced and sold on the world markets. The operation was acquired by Dundee Precious Metals in 2003. A modernization program for the Mine and Plant has since been in progress to increase both production and mechanical reliability, and also to optimize metallurgical recoveries. Since then, mine output and plant throughput have doubled, plant availabilities and utilization have increased significantly, and overall metallurgical performance for copper and gold improved. The paper presents the systematic approach for obtaining and analyzing data, communicating it, and making suggestions for changes to the technological parameters and flowsheet in order to maximize metal recoveries. These studies have correlated the ore characteristics (particle size distributions, metal assays, and Cu and Au mineralogical and phase analyses) with the actual plant performance (kinetics, recoveries, and throughput). Cu recovery by size has been calculated from the mineralogical analyses of feed, concentrate and tails, with the most significant losses being identified in terms of fraction and phase recoveries. This has provided the recommendations (some of them tested in plant) for changes in the grinding and flotation circuits.

Jan 1, 2014

By Robin J. Batterham

The Bologna Process started in 1999 with a declaration signed by ministers from most European countries. As of 2012, the Bologna Process now has 47 participating countries (EHEA 2012). Overall, the Bologna process has demonstrably changed higher education in many countries to allow for considerably more flexibility in course offerings. Keywords: bologna model, education

Sep 1, 2012

By R. Shiva Kumar, G. E. Sreedhar, Rajan Kumar, K. Suresh, A. K. Aketi Veera, M. Narasimha, P. S. Jodan

"In most of the coal washeries, Dense Medium Cyclone’s (DMC) are deployed to treat coarse coal fraction in the range of 50-0.5 mm. DMC’s are very popular due to its ability of high tonnage, ease of operation and effective separation at high near-gravity material (NGM) in feed coal. The ease or difficulty of washing is merely depending on the NGM fraction present in run of mine coal. However, the quantitative effect of NGM on DMC performance was not explored in the literature. Hence, in this investigation, the influence of NGM on DMC performance is focused. With the help of synthetically prepared coal mixture, the effect of NGM mass fraction on separation efficiency is studied in three different approaches. Firstly, by increasing the NGM coal fraction systematically from low to as high as possible; second by varying the distribution of NGM coal; and third by varying distribution of particles lying just above and below the near-gravity zone. Washability studies are also carried out to establish the theoretical yield for the prepared synthetic mixtures. Pilot-plant experiments are carried out in a 4-inch DMC with 1.4 operating separation density treating coal in the size range of 4 - 0.5 mm. From results, the partition curves are constructed by both density and size wise distributions. It is observed that at higher NGM coal fraction i.e above 60%, the performance of DMC is very poor with significant coal particles misplacement. In second approach with increased distribution at higher density fractions, the separation efficiency reduces. In third series the distribution of fraction in near-gravity zone doesn’t much effect the separation except the shift in separation density. It is observed that smaller size (-0.5 mm) coal particle having high NGM content seems have a profound effect on DMC performance leading to significant fines misplacement to wrong products."

Jan 1, 2018

"The most common comminution testing methods and the associated analytical procedures provide average values and do not capture the variability in breakage behaviour of ore particles. Therefore, plant designs and process performance predictions use only average values; hence, the inherent variability that exists within an ore domain translates into variation in process performance. This paper discusses the drawbacks of using the average approach to impact comminution testing and plant design. It considers breakage intensity from a single-particle testing perspective. To clearly delineate breakage behaviour of each broken particle, an experimental technique using the JK Drop Weight Tester (JKDWT) has been developed by which actual comminution energy per particle and breakage intensities were measured directly. Four different ore types in ranges of -45+37.5mm and -22.4+19mm were tested at three energy levels of 0.1, 0.25, 0.5 kWh/t and six energy levels of 0.5, 1.0, 2.0, 2.5, 3.0 and 4.0 kWh/t, respectively. Sieved results of individual particles, notionally, t5, t10 and t50 showed the presence of large variability in their breakage behaviour, which was not captured by the standard JK impact breakage testing approach. In addition, the original JKMRC model is modified by introducing a third parameter, ‘Emint10’ which describes the minimum energy required to produce the minimum percent t10 for a given ore type and its significance is tested statistically. These results suggest that the analysis of breakage variability may lead to more robust plant designs. Perhaps, the most useful insight from this work is to extend single particle breakage model developed by JKMRC to a comminution percentile envelope which may provide a more detailed picture of ore breakage variability. INTRODUCTION Rock consists of mineral grains, pores, voids and cracks that may differ markedly in size/density which make rock a heterogeneous material by nature. The degree of heterogeneity in rock affects its breakage characteristics where these variations increase local differential strain and stress within a stressed rock (Scholz, 1968) and it depends on many factors such as rock genesis, alterations, etc. One important aspect of this heterogeneous feature is presence of a large amount of experimental scatter in rock breakage results when considered from a quantitative perspective (Bieniawski, 1967; Liu, Roquete, Kou, & Lindqvist, 2004)."

Jan 1, 2018

By Jaeheon Lee, Jae-Chun Lee, Doyun Shin, Minseuk Kim, Hyunsik Park

"The appropriate treatment of cyanide waste water is becoming an emerging issue because of the toxic residue and large quantity produced from gold processing plants. In the present article, we designed and operated a continuous biological cyanide treatment system using domestic sewage sludge and various microorganisms including a cyanide-producing and degrading bacterium, Chromobacterium violaceum. The synthetic wastewater containing 50 mg/L of cyanide was pumped continuously into the reactor at a flow rate of 500 mL/d for 21 days. When 50 mg/L of cyanide was fed, the cyanide concentration in the effluent of the reactor inoculated with activated sludge (S-50) decreased by 7.5 mg/L in the effluent. The other reactors did not show significant cyanide degradation and the reactor inoculated with C. violaceum showed increased cyanide concentration in the effluent. The microbial community in the reactors was analyzed by 16S rRNA-gene based pyrosequencing technique to investigate microbial response to cyanide addition and operation time. The microbial community analysis shows that the phylum Proteobacteria was detected in the reactors showing significant cyanide degradation (S-50), while Firmicutes and Bacteroidetes was dominant in the other reactors with very low cyanide degradation. Proteobacteria could not compete when the other phyla Firmicutes or Bacteroidetes were inoculated. This study shows the feasibility of the biological cyanide treatment system for gold processing plants and contributes new fundamental knowledge about the microbial community in the biological cyanide treatment system. INTRODUCTION Cyanidation has been widely used to recover gold from ores or secondary resources since first proposed by MacArthur and Forrest in 1888 (MacArthur et al., 1888) and it is used in many states of the USA, including Nevada, Arizona, California, Colorado, and Idaho (Laitos, 2012). Cyanide compounds are highly toxic and create serious problems for wildlife and water management (Solomonson, 1981; Donato et al., 2007). Furthermore, because many countries have imposed strict standards for cyanide discharge (USEPA, 1985), it is essential to develop a cost-effective and environmentally friendly technology for treating cyanide-containing wastewater."

Jan 1, 2018

By David Morrow

Fly ash is a by-product from coal-fired power stations that is captured from the exhaust gas stream by electrostatic precipitators (ESPs) or bag houses. It is mainly derived from the inorganic components in coal but also contains residual carbon from unburnt fuel (measured as LOI). In the past, nearly all fly ash was sent to landfills or tailings ponds by power generators but this trend is quickly changing due to landfill costs, sustainability requirements and the inherent value in correctly processed fly ash. The main property that makes fly ash suitable for recycling is its use as a pozzolan. Pozzolans exhibit cementitious properties that make them suitable for partial cement replacement, and that can have beneficial properties for concrete mix designs. Fly ash can be used to replace up to a third of the of the Ordinary Portland Cement (OPC) requirement. Suitable fly ash nearly always requires the removal of the less reactive coarser fraction from the finer fraction. Due to the pozzolanic nature of fly ash, it must be processed dry and separation is normally required at 45 micron. In response to the increasing demand from a range of dry classification applications, Metso purchased an established air classification technology suitable for both mining and construction applications. The classifiers intelligent design efficiently utilizes the air flow which keeps power requirements low whilst including a scrubbing/recirculating function within the classifier that allows extremely efficient separations even at very fine sizes. This technology is of global interest to Fly Ash processors, but should be of particular interest in India which is both the second largest cement producer in the world as well as producing 80% of its power from thermal sources. This paper is intended to give a brief overview of fly ash and requirements for use as a pozzolan, air classification of fly ash and a case study from an established and experienced fly ash producer. Keywords: air classifier, fly ash, pozzolan, fineness, cement, cholla, salt river materials group

Sep 1, 2012

Traditional mineral processing techniques are more and more difficult to recover the increasingly low grade phosphate ores today. Although bioleaching method has been attempted to process low grade ores in hydrometallurgical field due to economical and environmental reason, it has been hardly used in leaching phosphate ore at home and abroad. Strains of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans were collected and separated from the acid drainage of a coal mine in Anhui province of China. Ultraviolet irradiation and Microwave inducement were applied to the bacterial cultivation process to produce strains of Acidithiobacillus thiooxidans and Acidithi-obacillus ferrooxidans able to tolerate extremely low pH conditions and generate sulphuric acid by oxidizing elemental sulfur or sulphide and the mutagenesis can achieve higher leaching rate. The bioleaching result will improve more by the addition of Tween series surfactants.

Jan 1, 2014

The addition of copper sulfate to mineral slurries in order to ?activate? sulfide mineral surfaces for enhanced collector molecule adsorption, and hence enhanced recovery via flotation, is a com-mon mineral processing practice. It has been established in a laboratory situation that the addition of CuSO4 in conjunction with xanthate collector increases the flotation rate of pentlandite as compared to the addition of collector alone. However, it remains unclear whether the addition of CuSO4has a similar effect within mineral processing circuits. We examine here the effect of pre-activation oxidation on the copper activation of pentlandite and monoclinic and hexagonal pyrrhotite. All activation experiments were carried out at pH 9 using a total solution content of copper ions equivalent to one monolayer (0.210 -4 moles, 110-4M). Copper loss from solution was extremely rapid in all cases with less than 10 % remaining after 10s. EDTA extraction and solution analysis clearly demonstrated that copper activation was via direct surface adsorption and not an ion exchange process, as is the case for sphalerite, and that most copper on the surfaces is in the form of Cu(I). ToF-SIMS analyses of the mineral surfaces subsequent to copper activation show increased surface oxidation on increased conditioning time prior to copper activation. However, there is a significant decrease in surface oxidation on comparison of samples that have otherwise been prepared in the same manner but where one has been exposed to copper solution rather than water. This suggests that copper activation stabilises the surface and reduces the propensity for oxidation. Regardless of the length of pre-activation oxidation time only Fe(III) (no Fe(II)-S) was observed by XPS analysis, indicating a highly oxidised surface layer dominated by Fe-O-OH species. The presence of Cu(II) on the mineral surface is indicative of the formation of Cu(II)-containing precipitates and indicates non-mineral specific activation resulting in increased recovery but lower grade. Mineral specific copper adsorption, as evidenced by the presence of Cu(I), is required to improve both grade and recovery. Prolonged oxidation prior to copper activation causes a reduction in the Cu(I) to Cu(II) ratio on the mineral surfaces as compared to either fresh surfaces or surfaces oxidised for 1 minute only. This strongly indicates that the copper activation process is less effective on highly oxidised surfaces.

Jan 1, 2014

By V. V. Lvov, L. S. Chitalov

"The purpose of the research is intensification of physico-mechanical ore properties determination for ball grinding processes in comminution circuits. The research presents comparative studies aimed at intensification of Bond Ball Mill Work Index (BWi) determination, such as testing technique of Ahmadi and Shahsavari, Berry and Bruse, Gharehgheshlagh, Horst and Bassarear, Kapur, Magdalinovich. The subject of the research is a test procedure of apatite-nepheline, copper-nickel, gold-sulfide and iron ores for the Bond ball mill index. The Bond Ball Mill Work Index for the material firstly was determined by standard Bond test methodology. Two the most promising testing techniques - Ahmadi and Kapur testing techniques - were modified. For the Ahmadi technique it was proposed to pay attention to the circulating load, which should be stabilized on the value of 250% as fast as possible. Two methods were put forward to quicker stabilize the circulating load. For the Kapur technique it was proposed to use empirical coefficients, which is determined especially for the apatite-nepheline, copper-nickel, gold-sulfide and ores. The modified Ahmadi and Kapur techniques require no more than two cycles of ball grinding to determine BWi (while normally 6-8 cycles are required) and less than 5 kg of initial feed. The suggested modified Ahmadi and Kapur techniques allow to intensify the physico-mechanical ore properties determination for ball grinding processes and BWi test costs considerably, which makes them useful for mass sampling and monitoring strength properties of ores entering a concentrating mill. INTRODUCTION When designing concentrating mills, the choice of the technological scheme for ore pretreatment, particularly the type, quantity and size of the main process environment, the determination of optimal grinding conditions and the calculation of equipment load are carried out by preliminary studies of grinding in semi-industrial or laboratory-scale plants. Semi-industrial tests on full-scale plants provide the most reliable information for calculating specific loads for equipment. However, this requires a significant amount of ore samples, a high labor costs and the pilot plants. Thence the most researchers performed grinding tests with small laboratory equipment using small ore samples."

Jan 1, 2018

By R. Lestari

Newmont Batu Hijau operates with an accelerated mining rate to optimize life of mine (LOM) project economics. This results in a portion of ore mined being stockpiled for reclaim and processing throughout, and at the end of mine life. LOM economics can be further enhanced by preserving stockpiled ore value by mitigating oxidation effects. A detailed stockpile ore oxidation study was conducted to: ?? Develop a practical understanding of how oxidation affects ore value; ?? Determine how oxidation rate can be controlled, and; ?? Determine how oxidation effects can be mitigated to preserve ore value. The result of the study is a stockpile management strategy that significantly reduces oxidation related losses and, implementation of that strategy within practical constraints. Implementation includes installation of Controlled Potential Sulfidisation (CPS) flotation to facilitate oxidised sulfide copper recovery and, recovery of dissolved copper from stockpile drainage solution into saleable product. This paper describes the study results including managing and predicting stockpile oxidation with time, monitoring performance of implemented CPS flotation and recovery of dissolved copper from stockpile drainage. These are essential elements of successful long term mine operation in Batu Hijau.

Jan 1, 2014

Reverse flotation process tests were conducted for marine sedimentary silicon-calcium phosphate ore in this research. The research findings showed that by adding antifoamer, a concentrate with P2O5 32.36%, SiO2 10.69%, MgO 0.67% was obtained, with recovery of P2O5 being 88.12%. Such is a satisfying result, when compared with the original mineralogical component of P2O5 26.64%, SiO2 11.51% and MgO 3.36%. When using antifoamer, the SiO2 grade of the concentrate increased 0.55%, the MgO grade decreased 0.64%, while P2O5 recovery increased 2.69% compared by adding no antifoamer. Adding antifoamer is favorable to increase the grade and recovery of P2O5. Therefore, antifoamer is necessary. Tests of synergistic reaction of antifomer indicate that the appropriate consumption of the antifoamer is 275g/t CY and 1Kg/t TWF. Keywords: silicon-calcium phosphate ore, desilication, antifoamer, reverse flotation

Sep 1, 2012

By L. X. Yu

As is known, the oxidized antimony and antimonate are hard to treat. A new combined mineral processing flowsheet which is controlled in grinding and classification ?bulk floatation?gravity separation is adopted to dispose of gravity-separated tailings (antimony content: 1.48%; oxidization rate: 68.92%) in Muli Antimony Mine, the grade of floatation antimony concentrates is 32.64%; the grade of gravity-separated antimony concentrates is 26.99%; the combined grade of floatation and gravity-separated antimony concentrates is 30.85%, and the total recovery of antimony is 70.64%. Adopting the new mineral processing technique have solved the problem of over grinding of antimony ore by controlling grinding and classification, recovering effectively the sulfide antimony and the easy floatable oxidized antimony of fine size by bulk floatation, recovering effectively the oxidized antimony which is hard to float by classified gravity separation. This is a great breakthrough in the mineral processing technique of the recovery of the oxidized antimony. At present, favorable economic benefit has been obtained from the application of this processing technique in Muli Antimony Mine.

Jan 1, 2014

By Jing Zhou

2-hydroxy-3-naphthoy hydroxamic acid code name F203 is a good collector of cassiterite, 1-hydroxy-2-naphthoy hydroxamic acid code name ZJ-3. F203 and ZJ-3 are similar series of isomers. They have similar naphthye, and similar series of functional OH and ?CONHOH, but the seat of OH and ?CONHOH group are different, on the F203 is 2.3; on the ZJ-3 is 1.2, ortho position too. According to Isomeric principle ZJ-3 is a good collector of cassiterite slime too. Using ZJ-3 as collector flotation -10µm occupies 90%, grade 1.16% Sn cassiterite slime of Da Chang Chehe concentration plant, pass one coursing flotation, two cleaning and one scarenging flotation, and obtains grand 18.26% Sn, recovery 92.68% cassiterite concentrate. The result proves the Isomeric principle of flotation reagents is correct again. This principle may supply to synthetize new flotation reagents reference. Keywords: F2O3, ZJ-3, cassiterite flotation, Isomeric principle, Isomeric principle of flotation reagents

Sep 1, 2012

By Jim Pae Lem

This study investigates the mode of occurrence of uranium in a copper concentrate from the Prominent Hill mine. Mineralogical and liberation studies of a high grade Cu concentrate (monthly composite) containing uranium (U) were undertaken using QEM-Scan in combination with QXRD and ICP-MS. The study aimed at determining in what form U was recovered, and by which mechanisms. The deportment of U was studied in 3 size fractions; +20µm, -20+8µm and -8µm. QEM-Scan analysis showed that uranium was present as U(Cu)-silicates, U-silicates, UPbOx/FeOx or traces of UThOx and UTiOx, with the U-silicates present across the size fractions. The association of uranium bearing minerals with copper sulphides varied across the size ranges. Interestingly, most of the U (46% by weight) was distributed in the finest fraction (-8µm), in which the deportment of Cu was low (6%). Over 40% of the U mineralisation in the -8µm was liberated. In terms of the floatation response, while recovery of the uranium minerals as a result of their association with copper sulphides (as composite particles) was evident, recovery of UPbOx locked in hydrophilic haematite in the +20µm size fraction suggests, that other mechanisms (e.g. Inadvertent activation by Pb from radioactive U decay) are possible. Furthermore, the high amount of fine liberated U bearing particles in the concentrate points at entrainment as another major mechanism for uranium recovery, and therefore, a target for process optimisation.

Sep 1, 2012

By Dianyin Liang, Hongxiang Ran, Xiaoming Wang, Xiaoou Xia

"This paper presents a new magnetic separator, which can be applied to increase the grade of fine magnetite ore feeding of ball mill. This innovative equipment possesses a rotating magnetic system and has a magnetic field of rapid polarity change which can strengthen the destruction of magnetic agglomerations and the dispersion of minerals to improve the quality of separation. Now this type separators have been successfully applied in several large concentrating plants such as Shuichang Iron Mine under Shouang Mining Company in China. Finally, this paper outlines practical results focused on feed grade and tailing yield, the results are showing that the quality of feeding can be improve tremendously. Hence, a new generator of rotating magnetic field has been paved. INTRODUCTION Jidong region in China is the important origin of iron ore, the characteristics of the iron ore in this region is low grade and complex, the iron mine discharges fine powder tailings reaches tens of millions of tons each year, in the wind action easy to form sand, this poses a threat to the atmosphere environment of Beijing. In order to reduce the mixing of large amount of useless ore and reduce the energy consumption of mill operation, a high efficiency pregrinding equipment is needed. Rotating magnetic field separator (RMS) is an advanced equipment, the main advantage of RMS is the significant reduction in particle entrapment and can easily break magnetic agglomeration. This reduction is so significant that RMS is capable of operating very close to theoritical limit for separator precision and can increace efficiency in selection process.Some expenrimental work on dry rotating magnetic field separation has been carried out in July 1998 in the company Ka Pty Ltd, then in 2008 BGRIMM developed industrial separation XCTG0816 in Shandong province . The wet RMS was researched in1960s in Former Soviet Union and the first industrial equipment was developed by BGRIMM in 1970s,then in 1990s wet RMS was applied in Ansteel group corporation. In 2017,6 units large wet RMS (SXCT1230)which were the largest RMS was applied in Sichuan province. No matter wet RMS and dry RMS, although they are used in differenct applications, they have some common research.in addition ,they all have good use effect."

Jan 1, 2018

By J. H. Starkey

SAGDesignTM Testing for grinding mill design was introduced commercially in 2004. Up to January 2008, 18 projects have been completed and 99 samples have been tested using this method. Two papers have been published describing the patented test procedure and one of these shows how the results compare with other grinding test methods. This paper will briefly discuss the theory on which this technology is based, and explain the procedures used to develop the calibration equation. Case studies are also included to demonstrate the effectiveness of the test work being done. These case studies show how the SAGDesign test is being used today: to design new grinding circuits for commercial full scale use; to calculate throughput in existing mills for production planning; and to accurately define grinding mill requirements at the scoping, pre-feasibility or feasibility study stage of project development, in order to economically identify the size and cost of the grinding mills that will be needed for the project. This is important because if the full rec-ommended SAGDesign testing program is done at an early stage in the project, the definitive cost for a guaranteed throughput, grinding mill design (by Outotec if their mills are purchased) is available. New grinding mill design for final engineering will be represented by the test work done on the Climax Molybdenum Project for Phelps Dodge (now FMI) in Colorado, USA. The SAG mill and ball mill for Climax are now in fabrication with project start up in late 2009. Next, the sizing of grinding mills at the scoping, pre-feasibility or feasibility study stage of mine development will be represented by a large metal mining property in Russia. Finally, calculation of the throughput for existing mills will be represented by work done at a base metal mine, in eastern Canada. Test work for designing SAG mills is now done in four laboratories at the time this paper was written. One in the USA at Dawson Metallurgical Laboratories, Inc. in Salt Lake City, two in Russia at the TOMS Research and Design Institute and at the Irgiredmet Research Institute, both in Irkutsk, and a fourth mill has been installed in Australia at AMMTEC Limited?s lab in Perth. A fifth SAGDesign test mill for radioactive ores has been built by Starkey & Associates, specifically for testing uranium ores and can be moved to any licensed lab in the world on a project basis.

Jan 1, 2014

By Dezhou Wei, Cong Han, Shuling Gao, Wengang Liu, Yanbai Shen

The recycling schemes of copper mineral to a copper raw ore produced in China is investigated in this paper, of which is aimed at copper concentrate‘s grade is over 26.00% and recovery is over 90.00%. The primary copper mineral the raw ore is chalcopyrite and the main gangue minerals are quartz, orthoclase, albite, clinochlore and phlogopite. There are four useful metal elements contained in the copper raw ore, which are Cu, Pb, Zn, Au and Ag, and the grade of each is 3.75%, 0.01%, 0.11%, 0.31 and 483.5 g/t. Two floating recycling schemes and its corresponding flotation reagent system were determined. The results show that calcium oxide, sodium carbonate and sodium sulphide were used as regulators, sodium n-butylxanthate was used as collector and terpenic oil was used as frother in two floating recycling schemes are effective. The open-circuit test’s results show that the copper mineral contained in raw ore can be effective collected, and both concentrates gotten through two schemes are up to grade.

Jan 1, 2014