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There is a strong demand for nickel metal due to quick development of stainless steel and new electrical materials, most of which is extracted from sulfide resources, resulting in a serious depletion of sulfide resources. Therefore, more attentions have been paying to extracting nickel from nickel laterite, which accounts for some 50% of total nickel metal production. In this paper prereducing?magnetic separation?reduction smelting process is developed to manufacture ferronickel rom two types of nickel laterite DN and GN, assaying 1.42% 1.83% Ni and 49.09% 26.08%Fetotal, respectively. Mineralogy of two types of nickel laterite was determined and optimization of process parameters was conducted to manufacture ferronickel. Prereduction?magnetic concentration process is used to upgrade low grade nickel laterite firstly, two kinds of Ni-Fe concentrates being prepared of DN assaying 2.26% Ni and 69.45% Fetotal and GN containing 2.76% Ni and 38.00% Fetotal. Finally, two types of ferronickel were produced by reduction smelting of prereduced concentrates DN and GN, DN and GN ferronickel contains 2.97% Ni and 6.58%Ni, 89.25%Fetotal and 89.95%Fetotal, respectively. The total recoveries of Ni and Fe of the two ferronickel are beyond 90% and 80%, respectively. There is significant difference in grade of magnetic concentrates and ferronickel between DN and GN laterite due to their different mineralogy, the former belongs to limonitic laterite and the latter saponite one. There are some advantages for this process to manufacture ferronickel from nickel laterite, including effectively upgrading low grade nickel laterite by prereducing?magnetic separation technique, higher throughput and lower energy available for reduction smelting section due to some 40% gangue being rejected in pre-upgrading section, and much less metallurgical coke consumption by using non-coking coal as reductant for prereducing?magnetic separation?smelting process.

Jan 1, 2014

By D. J. Hallbom

The ?yield plastic? rheological model describes the flow behaviour of a variety of non-settling suspensions, including many types of mineral slurry. The current paper presents the laminar flow relationship (pressure gradient vs. flow rate) for a yield plastic fluid flowing through a pipe or cylinder. Simplified algebraic equations, suitable for engineering purposes, are presented for yield plastic fluids with values of the scaling factor in the range that includes most industrially important slurries. The laminar pipe flow relationship is one of the most important fluids engineering calculations. It may be used to determine the rheological parameters of a material in a capillary rheometer or flow loop. If the rheology is known, these relationships may be used to determine the laminar flow pressure gradient in pipelines of various sizes.

Jan 1, 2014

By S. Mohanta

In composite washeries optimization of operating parameters to achieve maximum clean coal yield at the desired clean coal ash level is a major problem. This problem is more acute in countries like India, which have predominant reserves of difficult-to-wash coals. The constrained operational parameters of washing for some equipments make it more severe. In addition to this, the dependence of separating performance of different equipments upon various variables aggravates the situation. Here an attempt is made to find a numerical solution to get maximum yield and minimize the difference between the actual and the theoretical yield. The solution is arrived through constrained non-linear optimization of a multivariable objective function that utilizes spreadsheet tools; the method accommodates any number of source coals or washing size fractions. By using a designed Ep value the predicted yield of composite clean coal has been calculated and the yield is optimized subject to constraints on both the ash and specific gravity. It is shown that operational constraints of different washeries in the composite plant that utilizes gravity separation methods can also be over-come. The technique offers the coal preparation engineer an effective and straightforward method for determining the optimum cut-points of separation for different coals or blended coals to obtain maximum product yield at a specified level of ash content.

Jan 1, 2014

By D. Endara, E. De la Torre, S. Echeverria

"The study was conducted with the sulfide mineral from the province of Zamora Chinchipe. It was characterized physical, chemical and mineralogical, obtaining between its main results a copper concentration of head ore of 0,58 %. The mineral was homogenized and taken to direct closed circuit: rollers mill - vibratory sieve (mesh # 16). Flotation was carried out in two stages: the collective and selective where in each one were performed 6 water recirculation as suggested by the technique used to relate information of a batch flotation to a continuous circuit called cyclic flotation tests (LCT). In the collective flotation (bulk) 2 Kg of mineral were grinded with 10 Kg of balls for 30 minutes and 62.5% of solids, the pulp was taken to the flotation process with solids percentages of 33.3% and pH 7, it was conditioned with 45 g / t of KAX 1%, 50 g/t of Aerofloat 208 and 20 g /t of Pine oil. The concentrate and tailings bulk obtained were filtered separately for the recovery of water and it was recirculated to the next grinding of 2kg mineral. In the selective flotation 1Kg of bulk concentrate was carried to regrind for 40 min, 62.5% percent of solids, 10 g of lime and 5 g of tannin FLOATAN T5, the pulp was taken to the roughing-collection-refining flotation circuit controlling the pH between 10.5 and 11 where conditioning (60 g/t of Aerofloat 208 and 30 g/t of Pine oil) and adding lime to the circuit and FLOATAN according to the procedure. The four fractions obtained from the circuit were filtered; the water was recirculated to the regrind process of the bulk concentrate. In the collective flotation process tends to stability in the fourth recirculating water to obtain a copper content of 4.5% and a recovery of 87%, recirculated water represents 69.8% of all water used in the 6 recycles. In the selective flotation circuit the fifth recirculating of water is the optimal where obtaining a copper content of 13% and a recovery of 72%, recirculated water in the selective flotation circuit represents 95% of the total water used in the 6 recycles."

Jan 1, 2018

By Matheus Tocchini, Henrique Kahn, Juliana Antoniassi, Carina Ulsen, Eldon Masini

"Sand and gravel are the second and third largest minerals in production in Brazil, and this is increasing noticeably. The extraction of natural sand from river beds is increasingly restricted and most of the sand used in large cities comes in from more than 150 km away, resulting in high transportation costs. As a result, it has become more common to use crushed rock as artificial sand. The main difficulties in this process are controlling the shape of the particles and the content of deleterious materials, such as mica. Within this situation, this paper presents an alternative to using artificial sand for concrete use. Our procedure involves the following steps: a) sampling sand from different production days, b) characterizing the bulk sample by particle size and shape distribution, chemical composition by X ray fluorescence and mineralogical composition by X ray diffraction, c) removing fine grains by air classifier, d) performing intensive attrition with high pressure washing and e) characterizing products. The results demonstrated that this sample contains a huge proportion of fine grains and a notable content of mica, which is distributed along all sieve fractions. The presence of mica makes the use of sand in concrete unfeasible, moreover scanning electron microscopy analysis demonstrated that this phylossilicate is finely grained and associated with coarse fractions. Thus, the removal of fine fractions made possible a partial reduction in mica content. Furthermore, intensive attrition demonstrated that the procedure was efficient to remove most of the mica while also reducing sharp edges, which improved the shape of these particles."

Jan 1, 2014

By Ralph J. Holmes, Victor Sharp, Steven J. Spencer, Kevin J. Davey, Jonathan J. Campbell, Peter L. Phillips, David G. Barker

"Improved measurement tools for monitoring and control of AG/SAG mill performance have a high level of interest in industry. Historically, acoustic emission monitoring has been widely used on SAG/AG/ball mills and hydrocyclones to provide new information on the conditions inside these devices affecting their performance. The current work was focused on a new technique using surface vibration monitoring of a number of pilot-scale and production-scale AG/SAG mills to yield insights into the events occurring in the mills. The development of relationships between signal analysis outputs and mill operating conditions can be used for soft-sensor measurement of mill process variables. The technique used an array of accelerometers mounted on the mill lifter bolts linked to a fast data acquisition system which monitored the surface waves generated during operation. Details of the system are presented. Mill operating variables were adjusted systematically to provide a wide range of operating conditions for surface vibration signal collection. The experimental approach is discussed.The signals acquired during the experiments were analysed using a range of techniques. The results show that strong relationships exist between measured vibration power (both total power and within certain frequency bands) and mill load level/power and mill speed. A new method for extraction of power spectral density and band power information on features of interest in a mill rotation cycle is also presented.These results show that single sensor analysis information from the surface vibration system can be used as soft sensor inputs for monitoring process variables such as mill load that until now, have not been reliably measured. System outputs also show considerable promise in the area of condition monitoring. An example of the signal analysis output is presented showing elevated vibration levels in an area with higher resultant wear. Eventually, it is considered that outputs from this system for process variable and wear condition monitoring will be key new inputs to an online AG/SAG mill monitoring and control system."

Jan 1, 2003

By Y. G. Sun

This paper mainly reported separation manganese silver oxidized ores process by amylum de-gradation reduction and its influencing factors. When dosage is given according to nMn : nH2SO4 : n(C6H10O5)n : nH2O=1:k21.8: k116.66:30, the amount of up to 95.93% Mn leach rate and less than 2% silver loss can be obtained. Cyanidation process was used to extracted silver from leaching Mn residues. Silver leach rate could reach 94.15% at consumed amount of 1kg/t NaCN for 1h. Silver leach recovery rate was more than 92.27% by leaching Mn and cyanidation two-step processes so manganese and silver were separated effectively.

Jan 1, 2014

By A. Pirson, J. Souza, A. Araujo, M. Barbosa, F. Guimarães, J. Lima

"Although a large number of processes have been developed and applied to the separation of barite from other minerals, there is a lack of information in the literature about the separation of barite from iron ores. Nowadays, there are millions of tonnes of iron ore disposed as a waste or tailings given its high content of sulphur in the form of barite. In order to effectively separate barite from iron ore and ensure that mining business is truly creating economic and sustainable values, this paper provides a greater understanding of barite properties, the origin and occurrence of this barium-bearing mineral, and the employed beneficiation processes. A test work is conducted in a barite bearing iron ore from a deposit located in the Republika Srpska (Bosnia and Herzegovina) in order to separate the barite and check if a marketable by-product can be produced by drawing upon rich barite tailings. INTRODUCTION The exploration of iron ore containing barite results in a large amount of unrecovered material. The main difficulty in processing and using barite bearing iron ores is given by their high content of sulphur, silica and barium, which are unwanted chemical compounds in the subsequent processes in iron industry. As a result, millions of tonnes of iron ore are discarded every year into tailings or as a waste, which results in production losses, higher operation costs and environmental impacts (Praes et al. 2013). Therefore, the separation of barite from iron ores not only means reducing the environmental impact, but also an opportunity to generate income and beneficiate society. The beneficiation of barite bearing iron ores is a subject which requires a deeper investigation to solve the challenges faced by the iron industry. There are only a few studies that describe flowsheets proposed for the production of barite concentrate of iron ores. The most likely reason for this gap is that barite is frequently exploited commercially as a primary product rather than a by-product. In order to effectively separate barite from iron ore and ensure that mining business is truly creating economic and sustainable values, this paper provides a greater understanding of barite properties, the origin and occurrence of this barium-bearing mineral, and the employed beneficiation processes. A test work is conducted in a barite bearing iron ore from a deposit located in the Republika Srpska (Bosnia and Herzegovina) in order to separate the barite and verify if a marketable by-product can be produced by drawing upon rich barite tailings."

Jan 1, 2018

By A. N. Zagorodnyaya

The results of research on recovery of ammonium perrhenate from by-products of lead production are presented in the article. For the first time in the world, rhenium marketable products were produced on lead plant of Kazakhstan. Distribution of rhenium in lead production has been studied. During oxidative agglomeration of lead charge, 67.43% rhenium is sublimated and at that, 67.27% rhenium is trapped by the dusts of a system of gas purification, out of them 6.21% is transferred into different solutions, 1.89% into slime and only 0.09% into exhaust. During agglomerate smelting, up to 72% of its rhenium is sublimated and condensed in the dusts also. At leaching stage of sulphate product under dusts processing by the method of sulphatization, 15% of its content in the dusts is transferred into solution. The sorption method on the ionite ?N-21 has been proposed for recovery of rhenium from the solutions of sulphatization. At the same time, rhenium recovery from the dusts into commodity was 13%. The method of direct hydrometallurgy - leaching the dusts by solutions of sulphuric acid under presence of manganous concentrates, has been proposed as alternative method of recovery. This method has allowed increasing recovery of rhenium and other metals from the dusts into solution up to 90%~95%. Rhenium solvent extraction by ??? has been proposed for recovery of rhenium from the leaching solutions. At that, extraction of rhenium into marketable product from the dusts is above 75%.

Jan 1, 2014

By U. A. Peuker, T. Mütze, F. Shayo, A. Wikedzi

"Buzwagi Gold Mine (BGM) is operated by Acacia Mining and located in the Lake Victoria Goldfields of central Tanzania. The mine treats a sulphide copper-gold ore to produce gold in form of doré bars and a concentrate containing gold, copper and silver. The BGM comminution circuit includes a primary crushing stage with a gyratory crusher and two grinding circuits using a Semi-Autogenous Grinding (SAG) mill and a ball mill. Currently, the grinding circuits are inefficient in achieving the aspired product fineness of xP,80 = 125 µm even at low to normal throughputs (450-600 t/h). An optimization study of the circuit performance was conducted to improve product fineness through circuit surveys, experimental lab work and simulations. The analysis of survey data revealed inefficient grinding operation characterized by ball mill product (xP,80 > 400 µm) coarser than designed and higher hydrocyclone cut sizes (xT > 200 µm), too. In MODSIM several options were simulated such as reduction of vortex finder and apex diameters, reduction of SAG screen aperture, and modification of cyclone feed density. An improvement of product fineness could be achieved by simulation of the cumulative changes but it was also concluded that the current equipment cannot achieve the target. Further simulations showed that a second ball mill might help to achieve the desired fineness as well as an increase of grinding throughput by up to 26 %. INTRODUCTION Simulation of comminution, particularly grinding and classification, has received great attention for many years, due to the fact that the unit operation is by far the most important both in terms of energy consumption as well as overall plant performance (King, 2001; Wills et al., 2006). The use of simulation is advantageous due to low cost as well as its ability to consider many variables simultaneously. Moreover, there are some benefits for optimizing grinding operations by simulation like decreased unit operating costs, increased capacity, and improved performance of downstream processes due to improved feed size distribution. This paper presents an optimization study for the grinding efficiency at Buzwagi Gold Mine. This was achieved through three full scale circuit surveys, lab work and simulations with MODSIM."

Jan 1, 2018

By L. G. Wang

The stability of foams and froth plays an important role in flotation, in which small amounts of relatively weak non-ionic surfactants (frothers) are used to produce air bubbles and foams. In the present work, factors affecting the stability of the foams produced in the presence of common frothers, such as n-pentanol, n-octanol, methyl isobutyl carbinol (MIBC), and polypropylene glycol (PPG), have been studied. We used the thin film pressure balance (TFPB) technique of Schelud-ko-Exerowa type to measure the equilibrium film thicknesses. The results were used to determine the contributions from the various surface forces to the disjoining pressures in the thin lamellae (foam) films formed between air bubbles. In addition, we used a model developed by Wang and Yoon (Colloids and Surfaces A: Physicochem. Eng. Aspects, 2006) to calculate the elasticities of the lamellae films at the critical thicknesses at which films rupture. The surface forces and elasticity da-ta were then compared with the foam stabilities in the presence of the various flotation frothers. It was found that foam stabilities are controlled by both film elasticity and surface forces, the relative contributions of which change with frother type and concentration. In general, surface forces play a more important role at relatively low frother concentrations, while elasticity plays a more important role at higher concentrations. At the frother additions usually employed in the mining industry, MIBC relies on surface forces while PPG-400 relies on film elasticity in producing stable foams. The former is capable of dampening the hydrophobic force, which is a major attractive force destabilizing lamellae films, while the latter is capable of reducing surface tensions at low concentrations.

Jan 1, 2014

By A. P. Chaves, D. Jose Neto, M. G. Bergerman, E. S. Mano

"More complex ore comminution and concentration operations have found increasing application in the mining industry due to lower grades and higher complexity of the available ores. An alternative to coping with the higher capital and operating costs of ore processing plants is the use of pre-concentration stages. They allow removing a significant mass of material with little or no content of the relevant mineral before the ore is fed into the processing plant, with the consequent reduction in the mass to be processed in downstream operations. Significant benefits arise out of the use of pre-concentration, such as higher contained metal output without the need to increase the grinding or flotation capacity, and longer mine life. The grade of marginal ores could be enhanced to a level that would make their exploration economically feasible, which would result in increasing exploitable reserves. Nevertheless, few studies to date have assessed the resulting impacts on ore grinding energy consumption and wear after the gangue is removed through pre-concentration operations. This study evaluated the energy consumption and wear of grinding circuits in Brazilian mining operations in which the feed has gone through a pre-concentration stage. Such assessment was based on different samples of sulfide and oxide ores. Laboratory tests were carried out to investigate the power consumption and wear of grinding circuits with and without a pre-concentration stage. Laboratory test results were used to simulate industrial grinding circuits based on both alternatives and illustrate the environmental and economic benefits of each one.INTRODUCTION Increasingly complex ore concentration operations in several stages have found broadening application in recent years in view of lower grades and higher complexity of the available ores. An alternative to coping with the higher capital and operating costs of ore processing plants is the use of pre-concentration stages. Different ore processing technologies can be used for that purpose, such as magnetic separation, density segregation, and separation methods based on high-tech sensors (ore sorting). Currently, the most common methods are gravimetric processes, in view of their low cost, particularly jigging and dense medium separation methods, such as the drum and cone separators manufactured by Western Machinery Company, Teska, Drewboy, Norwalt, Dynawhirlpool and Tri-flo, and dense medium cyclones (CAMPOS; LUZ; BRAGA, 2010). The use of dry ore sorters has also grown significantly in recent years (Jose Neto et al. 2017). The selection of the separator type depends essentially on the ore particle size, required flows, and operating density ranges. All these methods may even be used after preferential blasting in mining (Grigg & Delemontex, 2015)."

Jan 1, 2018

By D. DePaoli, P. Zhang

"Phosphate ore is one of the most significant secondary resources for rare earth elements (REEs), and Florida phosphate is of particular interest due to its much higher ratio of heavy REEs, especially yttrium. Analyses of numerous samples from different phosphate processing streams in Florida showed that heavy REEs account for about 50% of the total REEs in Florida phosphate with yttrium accounting for approximately 30%. It was estimated that the amount of yttrium from US phosphate processing could meet the world demand for this critical element. This research aimed at recovering both REEs and phosphorus from a phosphate flotation tails. This tails is composed of mainly silica and phosphate with a small fraction of heavy minerals including monazite and xenotime. Since the specific gravity of silica is 2.6 versus 3.2 for phosphate and 4.5-5 for rare earth minerals, pre-concentration of the minerals of interest by gravity separation was investigated first. A pilot scale shaking table was used in this study. One pass gravity concentration achieved a shaking table concentrate analyzing over 600 ppm REEs at about 40% recovery. Flotation of the shaking table concentrate resulted in a product containing 1809 ppm REEs and 26.37% P2O5 with corresponding recoveries of 73% and 82%. Sulfuric acid leaching at 75oC could recover over 60% REE and nearly all the P2O5. Higher REEs (>90%) recovery was achieved by conducting leaching at higher temperature with concentrated sulfuric acid. The phosphoric acid from leaching of the flotation concentrate is of superior quality compared with that generated from regular phosphate rock.INTRODUCTION Rare earths are a group of 17 elements including those of the lanthanum series, as well as the non-lanthanides, yttrium and scandium. These elements have very specific critical uses in a multitude of markets. For example, lanthanum is used as a catalyst in breaking down crude oil to produce gasoline, diesel and jet fuel and neodymium is the core magnetic component in high-strength magnets for electric car batteries, wind turbines and hard disk drives. Rare earths are also essential for many military applications. Many of these applications have no substitute materials and the move to green technologies has dramatically increased their demand."

Jan 1, 2018

In recent years, coal beneficiation has gotten considerable attention. Selective oil agglomeration has been accepted as the best method to produce clean coal with a high removal of pyrite sulphur. In this study, spherical oil agglomeration of Datong coal fines was carried out using diesel oil as a bridging liquid. The oil agglomeration has a surface properties based on coal cleaning technique. The effects of fundamental parameters have been investigated including the concentration of bridging liquid, the size of coal particle, the solid content of slurry, the agitation time and rate, pH, surfactants on the agglomeration performance and various salts on the ash rejection and removal of pyrite of the agglomerated products. The optimum conditions of particle size, diesel concentration, solid content, agitation speed and time, pH and the dosage of active agent have been determined as less than 8µm, 20wt%, 1200r/min and 10 minutes, 7.5g/t and 100g/t, respectively. Under these conditions the ash content in the products can be achieved 1.5% below, the ash rejection was up to 92%. It has been observed that ionic strength of the aqueous medium affects the agglomeration performance. The precombustion coal cleaning process based on improved selective agglomeration results in high ash and pyrite sulphur removals. Over 80% removal of pyrite sulphur can be achieved from run-of-mine coals by offering a more cost-effective sulphur reduction solution rather than any other SO2 removal technology. In addition, the removal of pyrite sulphur is very necessary for not only the prevention of environmental pollution but also economical reasons.

Jan 1, 2014

By Yuhua Wang, Haitao Zheng, Guangli Zhu, Yuehao Zhao, Fushun Yu, Dongfang Lu

"Spodumene, feldspar and quartz possess similar surface properties, which make the difficult to separate spodumene from other silicate minerals by flotation. The differences of crystal structure, surface property and floatability of three minerals were studied by various technical means. The results show that Li-O and Al-O bonds in spodumene structure are not strong and easy to be broken. However, Al-O and Si-O bonds in feldspar and Si-O bond in quartz are very strong and not easy to be broken. High contents of Al and Li on spodumene surface were found by XPS measurements, which is benefit for the adsorption of anionic collector. The surface energies of main cleavage planes of spodumene (110), feldspar (001) and quartz (001) are 1.88 J/m2, 2.97J/m2 and 2.68J/m2, respectively. Hence, the exposed surfaces of feldspar and quartz are not saturated and easy to adsorb OH- ions from solution and cause the lower IEP than spodumene. The contact angles of three minerals in water are lower than 16º, suggesting that the hydrophilicity of three minerals is high, and the order of hydrophilicity is quartz > feldspar >spodumene. Correspondingly, contact angles and flotation recoveries of spodumene are bigger than that of feldspar and quartz in presence of a combined anionic and cationic collector named YOA.INTRODUCTION Flotation technology plays most important role for the recovery of spodumene from pegmatite ore. Generally, spodumene with fresh surface is easy to be floated using soap and oleic acid as collector, and the best flotation pH range is 4.0 to 9.0. However, the flotability of spodumene will become worse when its surface was polluted by slime which produced by the weathering of spodumene and other silicates (Dresler et al. 1998; Moon and Fuerstenau 2003; Menéndez et al. 2004; Yu et al. 2015). In addition, the species of Ca2+, Fe3+, Mg2+ and other metal ions in pulp can not only activate the flotation of spodumene, but also the activation of gangue minerals, and then the flotation selectivity of spodumene from gangue minerals became wores (Wang and Yu 2007; Yu et al. 2014). In order to eliminate the negative effects of slime and metal ions on the flotation of spoddumene, the desliming and long time scrubbing with the addition of NaOH and Na2CO3 were adopted. Usually, NaOH shows the activation for spodumene flotation, and the recovery of spodumene increases with the increase of NaOH dosage. Na2CO3 can eliminate the non selective activation of Ca2+, Fe3+, Mg2+ ions in the pulp, and the concentrate grade of spodumene increases with the increase of Na2CO3 dosage. Anionic collectors such as chelants, hydroxamic acid, oxidized paraffin soap, naphthenic acid and oleic acid were widely used for the flotation of spodumene (Dresler et al. 1998; Moon and Fuerstenau 2003; Menéndez et al. 2004; Yu et al. 2015)."

Jan 1, 2018

By F. Karakas

In this investigation, one of the most energy consuming stage of the cement manufacturing process, grinding stage, was studied. The aim of the study is to reduce the energy consumption. Optimum operating parameters were determined. Experimental studies were performed at three differ-ent stages. Grinding of limestone, clay and marl which are the main components of the cement, to approximately below 90 microns, was the first stage of the cement grinding. At this stage, effect of feed size and ball charge were investigated. At the second stage, the Bond work index of clinker and additives (slag, trass, limestone and gypsum) was found separately. After forming composite cement with clinker and additives, the Bond work index of this mixture was also determined, thus the results of separate grinding and grinding of mixture were compared. The Bond work index of mixture was found as 13.59 kWh/t, while the arithmetic mean of the Bond work index values of components was 14.90 kWh/t. Finally, clinker and additives (slag, trass, limestone and gypsum) were ground under the same conditions. At this stage, laboratory type of ball mill was used in order to understand grinding characteristics of the cement components. As a result of the experiments, it was found that energy consumption for the grinding will be lowered if the mills with 38 % ~ 40 % ball charge are used in the cement grinding. Moreover, grinding with mixture of clinker and additives gave better results than separate grinding of these components in terms of energy consumption.

Jan 1, 2014

By D. R. Nagaraj

The traditional (popular) approach to reagent development and optimization, which has become entrenched in both research and practice for many decades, is highly reductionistic, incremental and costly, does not produce robust chemical solutions, and is not sustainable. There are also several other key drivers and changes in the mineral industry that clearly warrant a new approach. In response to these, an intense effort was made at Cytec over the past fifteen years to develop a meaningful, efficient, and sustainable approach to develop new reagents and robust chemical solutions in mineral separations. This effort culminated in three important outcomes: a) development of the holistic approach, called FLOTATION MATRIX 100? process, b) novel reagents, and c) enhanced application knowledge for reagents. In this paper, the efficiency, utility and power of the holistic approach will be demonstrated with examples using both existing and new reagents in the processing of Cu-Au, Au and Cu-Mo ores.

Jan 1, 2014

By V. A. Chanturiya

There is an obvious disproportion in Russia gold-mining industry between the structure of gold reserves and the gold-mining techniques. The bulk of gold (over 70%) is extracted from alluvial deposit, 20%~25% from bedrock occurrences and 5%~7% from complex copper-zinc and polymetallic ores. The proved gold-bearing reserves are distributed as follows: alluvial ?19%, bedrock ?80%, the latter being sufficient to supply gold at the current production level for 100 years to come. In Russia, like elsewhere in the world, development of primary gold deposits is considered a first-priority line of development for gold-mining industry. Most of the gold-containing ores characteristic of Russian gold deposits are resistant ores with gold content varying between 3 ppm and 5 ppm usually showing quite low gold and silver recovery by cyanidation. Processing resistance of gold-containing mineral complexes is related to the presence of gold particles of submicrometric (<1.0 µm) and nanometric (10~100 nm) size, mostly asso-ciated with pyrite and arsenopyrite. Therefore switching over to processing bedrock entails a num-ber of technological problems that stem from chemical and physical resistivity of ores. The chemical resistivity can be overcome through flotation, oxidation roasting, autoclave leaching (biohydro-metallurgical oxidation), etc. The physical resistivity can be dealt with by resorting to traditional power-intensive methods,e.g. grinding to a ?40µm size, thermal treatments of sulphide concentrates and non-traditional high-energy methods of liberating the sulphides by means of power attack, e.g. electro-chemical oxidation, exposure to electron beam radiation and other methods. The modern non-traditional processes for treatment of rebellious noble metal-bearing ore, aimed at improving disintegration efficiency for finely dispersed mineral complexes are analysed. Advantages and perspectives of a new high-efficient, energy-saving and ecologically safe process of the nanosecond high-power electromagnetic pulses (HPEMP) effect are proved. The said process provides a stable increase in the valuable component recovery at lower energy consumption and production costs of the finite product at the stage of dressing rebellious gold-bearing ores and concentrated products. The experimental data prove high efficiency of the preliminary impulse treatment, thus, the increase in the gold recovery at the cyanidation stage amounted to 4%~12% from rebel-lious ores, 10%~30% from gravity concentrates, 5%~45% from flotation concentrates, 30%~80% from oil flotation tailings.

Jan 1, 2014

By Zhang Yuejun, Feng Tianran, Shen Zhengchang, Han Dengfeng

"With continuous mining industry development and dressing plant scale expansion, flotation cell is developed towards to large scale and intelligence. Based on flotation cell scale-up theory and industrial practice, KYF-320 air-forced mechanical flotation cell with effective volume of 320m3 was successfully developed by Beijing General Research Institute of Mining and Metallurgy (BGRIMM) and adopted by China Gold Inner Mongolia Mining Co., Ltd, Luming project of China Railway Resource Group Co., Ltd, and Toromocho project of Chinalco in Peru. In this paper, the structure and technical characteristics of KYF-320 flotation cell are introduced, and the application of that equipment in China Gold Inner Mongolia Mining Co., LTD is demonstrated. The tank of KYF-320 flotation cell is cylinder-shaped, 8200mm in diameter and 7500mm high, with double froth lauders and large inclined angle cone bottom. 16 sets of KYF-320 flotation cells of which the processing capacity is 26,000,000 tons/a, are used in the second phase project of China Gold Inner Mongolia Mining Co., LTD. Their stable running shows the long life of impeller and stator and the power intensity (power consumption divided by effective volume of flotation cell) of KYF-320 flotation cell is only 0.73kW/m3 which is significantly less than that of small scale flotation cells. The industrial production obtains good results that the Cu grade of final concentrate of entire flotation circuit is 22.90% at the recovery of 86.73%, when Cu grade of feed is 0.35%, which indicates that KYF-320 flotation cell has good performance and can be widely used in large scale mine."

Jan 1, 2014

By Takashi Furuyama, Sukeyuki Mori, Takafumi Okuma, Norio Hashiguchi

The Tower mill KD-3 is an improved version of the laboratory mills VD-1, KD-1 and KD-2 in which the classifying column has been modified to ensure a quick discharge of products from the comminution section and, on the other hand, a better separation of coarse and fine particles; the latter being collected in a cyclone with a central spiral ribbon. To level the circling airflow through the classifying column and have a strict control over the maximum size of collected particles, a series of experiments was carried out, modifying the internal structure of the column: insertion of a vertical plate, a cone, or a horizontal net. The relationship established between the maximum size of products collected in the cyclone and the duct airflow rate indicates that, independently of the latter, the insertion of a cone in the classifying column could stabilize the maximum size of products collected in the cyclone around 15.1 - 17.5µm. With a horizontal net, the maximal size could be reduced to 8.4 - 11.3µm. This occurrence might result from the collision of coarse particles blown from the comminution zone with the base of the inserted materials and their settling down the bottom of the classifying column.

Jan 1, 2003