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By Leon Lorenzen, Trevor J. Britz, Pierre J. Van Zyl, Ellis R. Els

Enhanced granulation of UASB granules was tested on pilot scale with two different test reactors (about 5 litres capacity each). Sludge from a local sewage works was used, with peach cannery effluent as carbon source. Cyclic motion of the reactor contents, and a daily replenishment of feed material create the necessary stress conditions for enhanced growth. Sizable granules, bigger than 0.5 mm, were produced within 20 days. Of the two reactors tested, the reactor equipped with a horizontal agitation shaft proved more effective.

Jan 1, 2003

By S. V. Volkova, S. V. Mamonov, T. P. Dresvyakyna

"The purpose of the work is complex processing of sulphide-magnetite ores with the separation of iron into iron concentrate, copper and noble metals into copper concentrate.The work shows the research results of the material composition of the sulfide-magnetite ore in the South part of the Peschanskoye deposit. According to the research results it is found that ore contains 0.59% of copper, 66% of which is related to chalcopyrite; 39.9% of iron, 81% of which is magnetite and 3.87% is sulfur, 42% of which is associated with pyrrhotite, 65% of which is a monoclinic modification. According to the results of the mineralogical analysis, it is found that the main iron-containing mineral in the ore under study is magnetite, the content of which is 45%. In addition to magnetite, iron is found in carbonates, pyroxenes, amphiboles, chalcopyrite, pyrrhotite and pyrite. The main copper mineral in the sample is chalcopyrite; covellite, chalcosine, bornite have a subordinate value. The total content of copper minerals in the sample is about 1%. The processing technology provides the three-stage grinding of the ore to a size of 65% of the class-71 µm; a cycle of copper flotation; a cycle of pyrrhotite flotation; wet magnetic separation of flotation hosts. The following optimal parameters are established for the ore under study: the alkalinity of the slurry is 250-280 g/m3 of free calcium oxide in the liquid phase of the slurry; the duration of the main copper flotation is 20 min; the consumption of butyl potassium xanthate is 20 g/t; the consumption of the foam generator T-92 is 15 g/t; the consumption of copper sulfate for the activation of pyrrhotite is 300 g/t; the magnetic field strength is 1500 Oersteds.A complex flotation-magnetic technology for the enrichment of sulfide-magnetite ore has been developed in the laboratory in order to produce a copper concentrate containing 21.6% of copper with 91.7% extraction and an iron concentrate with 66.5% of iron mass fraction and 1.2% of sulfur with an extraction of iron into the concentrate of 87.9%."

Jan 1, 2018

By Gurubasayya Swamy

This paper presents the performance study of sag mill in the processing of gold ore. Deterioting ore grade and high demand of metals has tremendously influenced the SAG mills. Today?s high capacity Semi-autogenous grinding (SAG) mills expand vast amounts of energy and in doing so consume tons of shell liners and steel balls, while processing ore. Semi-autogenous (SAG) mill performance is influenced by ball charge, feed properties, shell, grate, and pulp lifter design. In the performance study of SAG mill, based on the results obtained it can be observed that SAG mill performed better at feed size +4 inch and grinding media consumption 0.90kg/mt. In the present study the effect of crusher bypass on SAG mill performance, an immediate drop of throughput ranging from 10-20tph is observed. Keywords: sag mill, pulp lifters, grinding media, energy, consumption, throughput

Sep 1, 2012

By Q. Huo

The alumina production might not continue when the sulfur content of bauxite was too high. In order to bring down the sulfur content in bauxite, we studied on the bauxite desulfurization by bacteria screened from the acid mine drainage at mines of high sulfur content. The screened bacteria were domesticated by the high sulfur content bauxite. The experiments of bauxite desulfurization were carried out under the conditions of 5% pulp density, temperature of 30?, rotate speed of 120rpm. Bacterial desulfurization for 30 days, the sulfur content of the bauxite was reduced from 5.73% to 1.55% and the desulfurization percent was 72.9%. The recovery percent of alumina was 94.3%. The study showed that it was feasible to bring down the sulfur content of bauxite by bioleaching and this technique might make full use of the low grade bauxite.

Jan 1, 2014

By M. L. Liu

This work reports the results about the determination of mean activity coefficients and relative partial molar free energies for copper sulfide mineral bioleaching solutions by potentiometric method at 25ºC. The experimental potentiometric data were obtained by combining a solid state membrane-cupric ion selective electrode (Cu2+ ISE), containing a KNO3 filling solution, and an Ag/AgCl electrode. The measurements were performed in different series of copper sulfide mineral bioleaching solutions. The non-ideal behavior of the system was described on the base of the Pitzer ion-interaction model for mixed salts. Meanwhile, the relative partial molar free energies of bioleaching solution were investigated. The determination of the thermodynamic properties offers a basic data for the study of copper sulfide mineral bioleaching solutions.

Jan 1, 2014

By Kari Moen, John Rasmus Leinum, Jarle Hjelen, Terje Malvik

"Automatic identification and characterisation of mineral raw materials and beneficiated products are of major importance in mineral processing. However, minerals show great variety in their composition and physical and chemical properties. Industrial minerals may contain the same elements in about the same amount. In these cases backscatter electron imaging or chemical analysis are not sufficient to identify the minerals. Another problem arises when micro textures are not detectable in traditional imaging or the grain size is smaller than the X-ray spatial resolution.As a supplementary technique in these cases, application of crystallographic information by electron backscatter diffraction (EBSD) in the scanning electron microscope (SEM) may be a suitable method. By means of EBSD, diagnostic mineral information can be achieved if indexible patterns are provided.Until now EBSD has not been used frequently on geological samples for mineral and micro structure discrimination.The technique has been demonstrated on three Norwegian mineral raw materials and one Italian marble and shows that it has some advantages compared to traditional techniques."

Jan 1, 2003

By V. Panayotov

Flotation practice usually uses the Sheridan-Grizvold selection method, where zinc minerals are activated by addition of copper sulphate and depressed by addition of sodium cyanide, ferrous sulphate, zinc sulphate or various mixtures of these reagents. The method is suitable for the flotation of sulphide ores, which, do not bear precious metals, such as silver and gold. When classical technology with cyanide is applied to depress zinc minerals, the precious metals, which are contained mainly into lead minerals, are dissolved into the solution, which represents a technological loss. In order to avoid this process, we have made use from the knowledge on the semiconducting properties of lead and zinc sulphide minerals. We have changed the surface charge of minerals by means of an electrochemical impact realized by direct current application and specially designed set of insoluble or semi-soluble electrodes. Thus, flotation separation of lead and zinc sulphide minerals was achieved, at increased recovery of lead, zinc and silver. The technology proposed was implemented in a Bulgarian flotation factory; it worked over 5 years providing significant, positive economic, technological and environmental impact. Silver recovery was increased by 0.8-1.0 %, and lead and zinc recovery was increased by 0.8-1.0 %. The technology is easily controllable and adaptable to raw materials and parameters of the technological process. It can be paid back for 6-8 months after the implementation. Keywords: lead-zinc flotation separation, electrochemical impact

Sep 1, 2012

By Liang Dianyin

In this paper, the molybdenite flotation tailing of cleaner-scavenger bank which has a mass of very fine particles has been taken as raw ore to be processed by flotation with/without ultrasonic. The effect of ultrasonic frequency, intensity, processing time and uploading location on molybdenite flotation efficiency is investigated by four-factor three-level orthogonal experiment, and the effect significances of these ultrasonic variables to molybdenite flotation efficiency have also been evaluated. Single-factor analysis of variance is conducted to investigate whether the effect of ultrasonic on molybdenum ore flotation efficiency is significant or not. The samples extracted from different ore species in different time have been mixed to analyze the particle size. The results show that the particle size of +38µm in concentrate obviously increases while the particle size of -25µmobviouslydecreaseswith ultrasonic, which means that ultrasonic is good for flotation due to sludge removing effect. Keywords: ultrasonic, flotation efficiency, sulfide ore, tailing, grade, sludge removing

Sep 1, 2012

By D. J. Zhao

The reduction of ilmenite pellets was investigated at 950°C and 1000°C under a CO-N2 gas mixture with 10 L/min gas flow rate. All the reducing reactions were conducted in a furnace with a thermogravimetric analysis system. The reduction rate is higher at 1000°C than that at 950°C. At the early stage of the reactions, with the CO concentration increasing in the gas mixture, the reduction rate increased at 1000°C. In addition, at the early stage of the reactions, a rapid temperature increment and a rapid conversion of oxygen were observed on the curves of temperature versus time and conversion of oxygen versus time under different experimental conditions. The solid reaction products obtained in these experiments were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometers (EDS). Metallic Fe with small amount of Ti dissolved in it and oxides of Ti were found in the solid reaction products, but the formation of any nitride phases was not found under the prevailing conditions.

Jan 1, 2014

By Peter Ay, Florian Logsch, Satyanarayana Narra

"The traditional lignin separation process from the precipitated suspension creates severe filtration problems by plugging of the filter medium due to the small particle size (20 to 60 µm) of the suspended lignins. The plugging causes further problems in the successive processing of the filter cake. A new lignin separation process has been developed at the Brandenburg University of Technology (BTU) Cottbus as a part of the Research and Development and Demonstration (R & D & D) project "LignoBioFuel". The new developed process separates lignin in the form of granules with diameters ranging from 100 µm to 300 µm. The restrainment of the granule’s size in their successive treatments is expected to result in higher filtration efficiencies and reduction in plugging of filter mediums. To evaluate the filtration efficiency, the filtration resistance of the produced granules as well as the conventional suspensions has been investigated. The results show that there is a 60 to 80 % filtration efficiency increase and around 60 % reduction in plugging of filter mediums with the lignin granules in comparison to the conventional suspensions. Furthermore the successive processing of lignin granules was easier due to their porous structures removing the impurities such as adherent acids and salts. The purity of the separated lignin was measured with their sulphur (reduced from 7 % to 2.7 %) and ash (reduced from 46 % to 0.5 %) contents. The newly developed process has displayed better results in comparison to that of the conventional process. The new process displays high potentials in optimizing and improving the present state of the art treatments and is promising several ecological, economical and environmental improvements."

Jan 1, 2014

By Pejman Oghazi

During the last decade the output of mining companies has increased rapidly. The key driver is the increase in demand for raw materials in the developing world, and thus this demand has driven up ore prices. From the time when the Raw material group (year 2000) started to introduced their index, it was set to 100 points. Today, year 2011, the index is over 400, which means that ore prices have quadrupled since then. Mine companies have to go deeper in the mines to access the ore bodies to increase the mine capacity and to be able to respond to the market. By going deeper in the mine, there will be new challenges that have to be considered. One of these challenges is how to handle the mine water that is produced in the mine. The water has to be moved to the surface in order to keep the mine from flooding, and this causes more challenges. One solution is to pump the mine water up to the surface without treatment; however, this causes considerable pump wear and the water will still require treatment on the mine?s surface. Another solution is to treat this water in the mine before pumping it to the surface. Metso Minerals has a system solution to treat the mine water, by separating the solids from the mine water. This system reduces the erosion in the pumps and will save many maintenance hours in the long term. One other option is to use the treated water in a closed circuit and reuse it in the process. This system can be divided into three steps: Firstly, a spiral dewaterer to remove the coarse solid particles. For the next step, lamella thickener is used to remove most of the solids, and lastly tube press to handle the sludge from the underflow lamella thickeners. Keywords: mine water, mineral processing, dewatering, separating

Sep 1, 2012

By E. G. Ozhogina, O. B. Kotova

"The ores of black, non-ferrous, rare, noble metals are mostly distinguished by a variety of mineral types and complexity of their material composition. This article is devoted to the promotion of the concept of mineral processing in modern realities of the deficit of high–grade ores and increase in their demand. Normative and methodical documentation for specific types analysis with the definition of the field of application are presented in this paper. . For example, the pyrochlore-monazite-goethite ores from one of the deposits from Eastern Siberia - Chuktukonskoe ore field were tested. The development of mineralogical methods and testing of specific raw materials are shown. The method of small-angle X-ray (and also synchrotron) scattering, which was developed for solving problems associated with structural high-resolution diagnostics, was tested for bauxites of Vezhay-Vorykvinskoye field.INTRODUCTION A highly intense production of many types of mineral deposits results in gradual depletion and of mining-geological and mining-technical conditions of various ore reserves ?. Relatively easily accessible and rich deposits are getting depleted in the first place, and it is necessary to involve low grade and refractory ores into production and processing. Traditional technologies can hardly be applied (Chanturia, 2017; Bazin et al., 2014; Ponaryadov, 2017). The urgency of development of the concept of technological mineralogy focuses on the confirmation of new methods and approaches to the development of mineral deposits, creation of scientific and methodological pre-requisites for solving the problem of rational development of mineral deposits, maximum extraction and integrated application of all minerals (both principal and associated), expansion and strengthening of mineral and ores.The article is aimed at updating tasks that should be addressed within the applied mineralogical research: – forecast of quality of ore at early stages of exploration and technological indicators for the redistribution of properties ore, – interactive monitoring of these indicators by mineralogical and analytical methods;"

Jan 1, 2018

By E. G. Ozhogina, O. B. Kotova

"The ores of black, non-ferrous, rare, noble metals are mostly distinguished by a variety of mineral types and complexity of their material composition.The article is devoted to the promotion of the concept of mineral processing in modern realitiesof the deficit of high-quality ores and increase their demand.Normative and methodical documentationsfor specific types of analysis with the definition of the field of application are shown. For example,the pyrochlore-monazite-goethite ores from one of the deposits from Eastern Siberia - Chuktukonskoe ore fieldare tested. The development of mineralogical methods, and testing of specific raw materials are shown.The method of small-angle X-ray (and also synchrotron) scattering, which was developed for solving problems associated with structural high-resolution diagnostics, was tested for bauxites of Vezhay-Vorykvinskoye field. KEYWORDS Technological mineralogy, rebellious ores, ore quality assessment, ?mineralogical-analytical methods INTRODUCTION A highly intense production of many types of mineral raw results in gradual depletion and deterioration of mining-geological and mining-technical conditions of development. Relatively easily accessible and rich deposits are getting exhausted in the first place, and it is necessary to involve poor and rebellious ores into production and processing. Traditional technologies can hardly be applied (Chanturia, 2017; Bazin et al., 2014; Ponaryadov, 2017). The urgency of development of the concept of technological mineralogy focuses on the confirmation of new methods and approaches to the development of mineral raw, creation of scientific and methodological prerequisites for solving the problem of rational development of mineral raw, maximal extraction and integrated application of all minerals (both principal and associated), expansion and strengthening of mineral and raw base. The article is aimed at updating tasks that should be addressed within the applied mineralogical researches: – the forecast of quality of ore at early stages of exploration and technological indicators for the redistribution of raw, – interactive monitoring of these indicators by mineralogical and analytical methods; – assessment of environmental consequences of mining and processing of minerals and measures that eliminate these consequences."

Jan 1, 2018

By Bhargav Dhavala, Sristy Raj, Ashok Kumar, Suman Krishna Sit, Adity Ganguly, D. P. Chakraborty

"Tatasteel’s West Bokaro washery#3 is designed to deslime raw coal at 0.5mm; the oversize (+0.5mm) is beneficiated in dense media cyclones (DMC) while the undersize (-0.5mm) is beneficiated in froth flotation (FF) cells. Nearly, 80% of the raw coal feed reports to the DMC circuit consisting of four parallel streams. Presently, the performance of DMCs at washery#3 is interpreted by: (a) comparing the actual plant yield w.r.t the lab predicted yield and (b) misplacement of clean coal to middllings.However, the comparison between actual & lab predicted yield is fallacious given the fact that the lab predicts yield of the borehole sample while the feed received at the plant has different characteristics altogether due to the dilution during mining. To mitigate the said limitations, a quick diagnosis tool using the past data has been developed that will give a prediction of performance of different coal seams in the DMCs, inputs being feed ash to DMCs and stream wise feed specific gravity (coal & magnetite combined).The tool also will help in identifying the root cause on real time basis thereby helping the operator to take necessary corrective actions. The operator can intimate the mining personnel in cases of shale reporting to the feed as a result of dilution during mining. In events of higher standard deviations between the parallel streams w.r.t feed specific gravity, the operator can adjust the parameters accordingly to minimize the yield loss. INTRODUCTION West Bokaro came into existence in 1948, as an independent coal company, managed by M/S Anderson Wright. Tata Steel acquired the Company in 1956 to meet its requirement of metallurgical grade coal for Iron making. Subsequently, in 1976, it was made a division of Tata Steel. In 1974, when coal mines were nationalized, West Bokaro was exempted as it produced coal only for captive consumption of the Steel Works. The first washery of India was set up in West Bokaro. The business objective of the West Bokaro division is to produce clean coal at optimum cost for captive use in the steel plant of Tata Steel at Jamshedpur. The strategy is to reduce ash with minimum loss of yield so that quality of coal improves and yet the cost is beneficial vis-a vis imported coal. The primary product is the metallurgical grade coal for coke ovens, which converts coal into coke for use in the Blast Furnaces."

Jan 1, 2018

By S. F. Kaplan, A. S. Dolotov, V. N. Kovalev

"At this point in time, autoclave recovery (POX) followed by sorption cyanidation (CIL) is one of the most promising technologies for the efficient processing of refractory and double refractory gold-bearing sulphide rock. This hydrometallurgical technology requires the use of a large amount of water (up to 5 tons per ton of used concentrate), resulting in highly saline water with high pH (pH 9-11), high content of cyanides (up to 300 mg/l), arsenic compounds, antimony and a number of heavy metals. In order to determine the possibility of using recycling industrial water in POX-CIL technology, several batches of experiments were conducted (using the double refractory flotation concentrate of the Mayskoye deposit). Urban water with a chloride ion content of 10 mg/l was used during the reference POX-CIL experiment as the liquid phase of the ??? feed pulp. At that, gold extraction rate amounted to 89.4 %. A full cycle of POX(200 ºC)-CIL was carried out during the first part of the experiments; at that, fresh concentrate of the untreated recycling water with cyanide ion content of 95.4 mg/l, left after the completion of the previous CIL cycle, was used for repulping. It has been established that direct use of untreated recycling industrial water is impossible due to a sharp decline in gold extraction (preg-robbing) down to 79.5%. The presence of chloride ions, cyanide ions and other ligands in the liquid phase provides effective complexion formation for the recovery gold; complex gold compounds are quickly and firmly sorbed by the natural carbonaceous substances of the concentrate at the stage of autoclave recovery; they are virtually not cyanized onwards, and gold is carried over to the tailings. During the the second batch of experiments, recycling industrial water with cyanide and chloride ions' concentration of 500 mg/l each was subjected to the reverse osmosis desalination (up to 6 times in a successive order). After each desalting cycle, such water was used as the liquid phase of the feed pulp in POX-CIL. 6 cycles of RO desalination enabled the extraction of 86.1% Au (which is close to reference recovery). During the third batch of experiments, recycling industrial water was diluted with distilled water (2, 4, 16, 32, 64 times); after each dilution cycle, this water was used as the liquid phase of the POX-CIL feed pulp. Gold extraction after 64-fold dilution amounted to 82.6%. The results of the conducted researches show that the use of untreated recycling industrial water in POX-CIL hydrometallurgical technology is absolutely impossible due to a sharp decline in gold extraction. Even the 64-fold dilution with pure water is inefficient both from the perspective of gold extraction and of rational use of water. Reverse osmosis desalination solves the problem of water treatment except for the removal of cyanide ion, which requires separate reagent treatment of water."

Jan 1, 2018

By Subrata Roy

The slag produced in metallurgical smelting processes contains considerable amount of valuable metals. The present work focuses on recovery of copper value by froth flotation from the copper smelter slag. The slag samples are subjected to detailed characterization including automated quantitative mineralogy using Mineral Liberation Analyzer (MLA). The MLA results indicate that a part of copper is present in sulphide form in fayalite (iron-silicate) matrix and very poorly liberated. SEM-EDX analyses also reveal that a certain part of the copper is present within the fayalite (Fe-Ca-Si) matrix, perhaps either as lattice impurity or very fine grain. The copper smelter slag is ground in wet mode in a ball mill, to particle size distribution suitable for flotation. Subsequently, the slurry undergoes froth-flotation in lab-scale Denver-type flotation cell. Various combinations of sodium iso-propyl xanthate (SIPX) and alkyl hydroxamate collectors are used along with pine oil as frother. A multiple collector dosage is required for effective flotation of non-sulphide copper phases associated fayalite and alkyl hydroxamate is identified as one of the effective collector for non-sulphide minerals. The copper recovery can be enhanced by 7-10% with a combination of collectors as compared to conventional sulphide flotation using only xanthate type collectors. However, the grade decreases to some extent. Keywords: flotation, copper slag, hydroxamate collector

Sep 1, 2012

By Masoud Askari, Ahmad Rafizadeh, Shahamat Rostami, Mohammad Qaredaqi

Gole - Gohar Iron ore mines located in Sirjan, Southeast of Iran, have more than 1 billion Iron ore deposit and this area comprises 45 % of Iran Iron reservoirs. The aim of Wet tailing processing line is recovering Hematite ore from wet tailing of Gole - Gohar iron ore processing plant. The Investigations of Hematite recovery plant showed that the recovery of Iron ore to concentrate in Wet Tailing Processing (WTP) line is very lower than that has been predicted, sampling, and designing of the process parameters are not accurate and designed magnetic field intensity is not reasonable for the recovery of Iron in form of Hematite in this line feed. Applying of MIMS in WTP separator and changes in circuit caused in overwhelming increase of Fe recovery, from 11 to 40%. Although recovery of WTP line was improved, but low recovery of this processing line and high content of Hematite ore in WTP tailing, made applying Wet High Intensity Magnetic separators unavoidable. Two kinds of WHIMS have tested for processing of WTP line tailing. Results showed that traditional Jones separator with grooved plate matrix, is more suitable to achieve a better quality of concentrate compared to Slon® separator.

Jan 1, 2014

By Ramon V. V de Araújo, Roberto B. E Trindade, Pablo R. Fica-Piras

"Lead has been reported to affect blood vessels and kidneys. It also produces adverse effects in the mental and physical development of children and nervous system of adults. It is also considered as a possible cause of cancer. Because of all these threats to the human life, the reduction of its environmental occurrence, by means of recycling, is an important additional advantage to the usual ones derived of the procedures of the secondary metallurgy: lead can be recycled several times maintaining its characteristics equivalent to the primary one.Furthermore, this way of producing the metal avoids the environmental impacts of primary lead melting. Also, as an additional advantage, it triggers the metallurgical process with a raw material in what we observe higher lead content than in the natural ores. Some of the potential sources for these purposes are: ashes, slags, electrode residues, anodic muds, spent electrolytes, solid and liquid wastes, industrial or automotive catalysts, worn-out or obsolete equipment components and/or final consumption products.About 40% of world’s lead production comes from automotive batteries, mainly composed of four parts: plastic box, electrolyte (diluted sulphuric acid), contacts and connectors of Pd-Sb and plates (PbSO4, PbO2 and PbO). The plates represent 75% of the total mass. Metallic parts can be melted at moderate temperatures and then refined. The remaining fraction, constituted by the non-metallic portions, can be recovered by hydro and electro-metallurgical routes. These routes are preferred instead of pyrometallurgical ones due to the ultimate emissions of lead particulates and sulphur dioxide.The principal constituent of the residual paste of batteries is the lead sulphate. In this process, the paste is treated in two stages: in the first, lixiviating with Na2CO3 (desulphurization of the paste), obtaining PbCO3 and Na2SO4; in the second, the lead carbonate is lixiviated with HNO3, producing Pb(NO3)2, soluble, that can be converted to metallic lead by electrolysis. The reaction of PbSO4 with Na2CO3 in aqueous solutions is fast: the global rate is limited by the diffusion of the carbonate ions inside the reaction medium."

Jan 1, 2003

By P. Radziszewski

In comminution research, ore breakage and wear are usually studied independently of one another. Much of this is due to the fact that wear is usually a slow process compared to ore kage. However, the abrasion wheel test used to determine the abrasive wear contribution to total steel media wear provides the opportunity to study not only abrasive wear and friction but also ore breakage. In this paper, we will explore the use of the abrasion wheel wear test device to study abrasive wear, friction and ore breakage using standard Ottawa foundry sand. We will look into the feasibility of applying the work index as well as t10methodologies to this test set-up. We will also look at how the work index results evolve with abrasive wear and friction. We will then discuss the merits of pursuing the use of this abrasion wheel test for not only wear characterization but also breakage characterization.

Jan 1, 2014

There are some problems in the beneficiation of fine-grained oxidized iron mineral such as high cost, severe sliming, poor results and low recovery due to the fine disseminated size of the mineral. Taking several representative types of finely-disseminated oxidized iron minerals as examples, the author analyzed the main difficulties in the beneficiation of such kind of ores and discussed the existing problems in grinding-classification, technological process, flotation reagents and separation equipments and the resolvents of these problems.

Jan 1, 2014