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By A. Koizhanova

Kumistinskoye gold- and silver bearing ores (Republic of Kazakhstan) as well as standardized test solutions containing gold, silver, copper, zinc and iron were studied. The best results in silver and gold recovery from Kumistinskoye gold- and silver bearing ores were achieved through use of complex cyanide-thiosulfate solutions as compared to individual cyanide solutions and thiosulfate solutions. It was found that such complex solutions substantially step up leaching process herewith increasing precious metals recovery rates. Thermodynamics of studied chemical processes was calculated. Reaction order, kinetic constant and activation energy of gold leaching process through use of cyanide-thiosulfate solutions were identified. We managed to prove that the sorption rates and holding capacity in process of gold anions recovery with anionite AM-2B are comparable to sorption characteristics for cyanide solutions. Keywords: gold, silver, copper, zinc, iron, cyanide-thiosulfate solutions, anionite AM-2B

Sep 1, 2012

By L. Kuzev

Unknown and unpopular vibrational grinding mills possibilities to horizontal working chambers have been discussed. They can be realized under normal conditions with the typical values of vibrations applied with vibrational grinding which are: vibration frequency from 15 Hz to 50 Hz, vibration amplitude to 6 mm and vibration geometry. These possibilities constantly increase involving new raw materials and processes. Vibration grinding is possible with other technological process accompanied by intensified technological processing, while the process decreases. In many cases these technological decisions are original.

Jan 1, 2014

By T. Wajima

We tried to convert paper sludge ash (PSA) into zeolitic product with high cation exchange capacity (CEC) through acid leaching. Typically, PSA from incineration of paper sludge contains a high percentage of calcium in the form of anorthite (CaAl2Si2O8) and gehlenite (Ca2Al2SiO7). It is difficult to convert the ash with a high Ca content into zeolites, or at least into more desirable zeolite phases. Acid leaching with HCl was applied to reduce the Ca content to synthesize zeolitic product with high CEC. The raw ash was treated with 1 M, 3 M, and 5 M HCl solution for 0.5~24 hours (the ratio of the ash to volume of HCl solution was 1/4), and then zeolitic product was synthesized from leached ash through the reaction with 2.5 M NaOH solution at 80 oC for 24 hours. During acid leaching, gehlenite is readily dissolved in a lower HCl concentration solution than anorthite. With increasing HCl concentration, the amounts of Ca, Mg, Si, Al, Fe and Ti extracted from the ash increased. Ca and Mg contents were easily extracted from ash than other elements. The contents of Ca and Mg extracted rapidly at initial stage, and then levelled off. The saturation times of Mg and Ca are almost 0.5 h using all concentrations of HCl solutions. After the synthesis from leached ashes, zeolite-A and -P were synthesized from ash leached in 1 M HCl solution, and 3 M and 5 M HCl solutions, respectively, regardless of leaching time. With in-creasing HCl concentration, the Ca content eluted from the product decreased, due to the removal of Ca via acid leaching before the synthesis, while the Na content eluted from the product increased to 3 M HCl and then decreased, which was almost similar to the CEC of the product, due to the ion exchange of Na-type zeolitic phase in the product. The change of zeolite phases in the product and the CEC of the product depend on the concentrations of Si and Al in the solution during the synthesis. The highest CEC of the product is about 220 cmol/ kg, which was synthesized from the ash leached in 3 M HCl solution.

Jan 1, 2014

By Mohana Rao Andavarapu

Sandur Schist Belt of Karnataka Craton constitutes a hub of iron ore mining activity. The iron ore deposits of the region are closely associated with Banded Hematite Quartzite (BHQ), Shale, phyllites, & Graywackes. The gradual depletion of high-grade iron ores due to extensive utilization has necessitated the exploitation of low-grade iron ore including BHQ, which are available abundantly in different parts of India. In the present investigation, BHQ samples from Kammaturu mines of Sandur schist belt was studied to assess the possibility of upgrading the iron content to the maximum possible extent, so that it may find the better use in iron and steel industries. The sample collected from the study area analyzing 39.76% Fe, 39.8% SiO2, 0.66% Al2O3, and 1.92% LOI was subjected to beneficiation studies. The mineralogical studies reveals that the samples are predominately consists of hematite as an iron mineral and quartz as gangue mineral. Liberation studies and chemical analysis were carried out prior to the beneficiation process, which is flotation. Cationic Reverse flotation studies were carried out and discussed by varying different process variables such as feed size, depressant, collector cum frother dosage & pH. The results obtained are encouraging with an appreciable improvement in the iron content up to 62.8% Fe with Fe recovery of 50.43%. The concentrate obtained from the flotation can be used for pellet making process.

Sep 1, 2012

By Reinol Compañero, Ivy Gonzales, Herman Mendoza, Brian Buenaventura

"The extraction of gold in the Philippines has been a significant challenge for the past decades. Around 70-75% of gold mined in the country can be accounted from the small-scale mining industry which primarily use the traditional cyanidation and amalgamation; processes which have been advocated due to its adverse affects to health and environment. To address this challenge, an alternative clean and sustainable technology was developed for the small-scale miners to recover gold and other metal/mineral values efficiently from Philippine ores. An initial survey was conducted and followed through with extensive mineralogical investigations ascertain the best method applicable. It was determined that Philippine gold occur in ore as (1) very fine particles in the microns range, (2) free-milling, which is in abundance, and (3) locked particles with sulfides --- it was concluded that enhanced gravity concentration and flotation are viable alternatives. A comprehensive test regime was followed to check the response of the ores obtained from different small-scale mining districts across the country. It was shown conclusively that the gold ores respond positively, with recoveries using gravity concentration and flotation of at least 95% and 88%, respectively; exceeding the nominal recoveries using cyanidation or amalgamation. A specific process flow was designed for each type of ore with customized parameters. It was determined that while capital expenditure of implementing these alternative processes is higher than what is currently being used, the operational aspects show that it is much more economical to apply enhanced gravity and flotation. It should be noted that the process developed addresses the critical issue of environmental costs which should be more than enough to justify the shift from the current to the novel and sustainable technologies."

Jan 1, 2014

By Leon Lorenzen, Victor E. Ross, Anton W. Kleingeld

Key to successful innovation, whether at organization, industry or national level, is the alignment and utilization of resources in the most appropriate and efficient way. Innovation needs to be directed strategically, and it needs to be auditable in a systematic and integrated fashion. In the light of these considerations, this paper describes the construction and use of a topographical map of the innovation landscape. The purpose of the map is to provide a holistic view of the key factors that enable innovation (the so-called ’landmarks’), how well they are aligned to support a particular type/nature of innovation in the organization, and to identify possible gaps. The significance (importance) and height (performance) of the landmarks in supporting and enabling innovation within the organization is determined by means of a selfappraisal audit. The topography of the landscape derived thus is subsequently interpreted in terms of the organization’s particular innovation strategy and environmental context. The application of the Innovation Landscape Methodology is illustrated in a number of organizations within the Mining and Minerals Industry of South Africa. Important observations and conclusions regarding the strategic alignment of enabler strengths within these organizations are made.

Jan 1, 2003

By H. Breuer

Mineral processing is characterized by a constant adaptation to changing raw materials and market conditions. It is the link between the mined raw material and a marketable product. As a lot of high grade reserves are exploited, a steady deterioration of raw material quality can be observed. At the same time, the customers´ requirements for product purity and consistent quality increase. Indian iron ores are characteristically friable in nature that results in generation of sizeable quantity of fines (0-10mm) every year during various stages of mining and processing in the country with grade varying from 50-60% Fe(T) and are high in silica/alumina (Al2O3 5-8%). The fines generated cannot be directly used for iron making (blast furnace/DRI units) in the country due its physical and chemical properties; therefore, large portion of it gets exported or dumped. Value addition to iron ore fines through various activities such as beneficiation & palletization is the need of the hour, which will not only be economically beneficial to the mining sector in the long run but also generate value addition & employment opportunities. Incentives may be given for adopting latest technologies for direct use of fines in iron making by agglomeration of fines in the form of Pellets and Sinters, as fines forms considerable part of iron ore resources. Due to selective mining, although the iron content of the ore is high but the alumina(Al2O3) content in iron ore is also significantly high which demands for beneficiation as high alumina will create problem during iron making like higher fuel consumption, poor quality of slag produced, reduced productivity of B.F. all mineral has been engaged in hematite iron ore beneficiation with its gravity and magnetic separators since the mid-nineties. The delivery of jigs started for the upgrading of iron ore for its utilization in a Direct Reduction Plant in Australia. Since then, various other installations with jigs for lumps and fines as well as upstream separators for fines are in operation in Brazil, Australia, India and South Africa. Low grade run of mine and/or dump ores are being processed with alljig®-, allflux®- and gaustec®-WHIMS as the core equipment. The article describes the technology in use, the characteristics of various iron ores and the product qualities achieved. The data presented shows the specific advantages of jig application on iron ore upgrading due to the possible high gravity cuts and the easy and low cost operation. The allflux®- technology provides the big advantage of high capacities and a two-step process, both in a single unit. The gaustec®-wet high intensity magnetic separators offer high capacity in combination with unsurpassed process flexibility. Keywords: iron ore, gravity separation, jig, upstream classifier, wet high intensity magnetic separation (whims), pelletization, sinteringMineral processing is characterized by a constant adaptation to changing raw materials and market conditions. It is the link between the mined raw material and a marketable product. As a lot of high grade reserves are exploited, a steady deterioration of raw material quality can be observed. At the same time, the customers´ requirements for product purity and consistent quality increase. Indian iron ores are characteristically friable in nature that results in generation of sizeable quantity of fines (0-10mm) every year during various stages of mining and processing in the country with grade varying from 50-60% Fe(T) and are high in silica/alumina (Al2O3 5-8%). The fines generated cannot be directly used for iron making (blast furnace/DRI units) in the country due its physical and chemical properties; therefore, large portion of it gets exported or dumped. Value addition to iron ore fines through various activities such as beneficiation & palletization is the need of the hour, which will not only be economically beneficial to the mining sector in the long run but also generate value addition & employment opportunities. Incentives may be given for adopting latest technologies for direct use of fines in iron making by agglomeration of fines in the form of Pellets and Sinters, as fines forms considerable part of iron ore resources. Due to selective mining, although the iron content of the ore is high but the alumina(Al2O3) content in iron ore is also significantly high which demands for beneficiation as high alumina will create problem during iron making like higher fuel consumption, poor quality of slag produced, reduced productivity of B.F. all mineral has been engaged in hematite iron ore beneficiation with its gravity and magnetic separators since the mid-nineties. The delivery of jigs started for the upgrading of iron ore for its utilization in a Direct Reduction Plant in Australia. Since then, various other installations with jigs for lumps and fines as well as upstream separators for fines are in operation in Brazil, Australia, India and South Africa. Low grade run of mine and/or dump ores are being processed with alljig®-, allflux®- and gaustec®-WHIMS as the core equipment. The article describes the technology in use, the characteristics of various iron ores and the product qualities achieved. The data presented shows the specific advantages of jig application on iron ore upgrading due to the possible high gravity cuts and the easy and low cost operation. The allflux®- technology provides the big advantage of high capacities and a two-step process, both in a single unit. The gaustec®-wet high intensity magnetic separators offer high capacity in combination with unsurpassed process flexibility. Keywords: iron ore, gravity separation, jig, upstream classifier, wet high intensity magnetic separation (whims), pelletization, sintering

Sep 1, 2012

By ?. S. Yusupov, V. P. Isupov, N. Z. Lyakhov, A. G. Vladimirov, S. A. Kondratiev

"Considering the shortage of lithium reserves, the desirability has been shown of studying the possibility of processing into spodumene concentrates the concentration tailings and low-grade ore reserves at Transbaikalian Mining and Processing Project (ZabGOK). The mineral and chemical composition and the particle size distribution of the mineral feed, separability and recoverability of spodumene have been studied, forming the basis for the development of a concentration process and flowsheet for the studied mineral resource. Prospects have been established for impact ore grinding in a disintegrator, the efficiency of mechanochemical processes has been shown in the separation of quartz and feldspar and the recovery of lithium from concentrates.INTRODUCTION Lithium is widely used in various industries - nuclear power engineering, defense technology, power generation, ceramics, special-purpose glass and other technologies. The increasing demand for lithium and its compounds (lithium carbonate and hydroxide) for use in the manufacture of high-tech products (lithium-based materials for chemical sources of electric power and electrochemical energy) explains the need for establishing a sustainable raw material base (Mohr et al. 2012; Moores, 2007). The main sources of lithium are spodumene pegmatites (Vladimirov et al. 2012; Garret, 2004), brines (salars), and hydromineral materials (Garret, 2004; Zeng and Liu, 2009; Kotsupalo and Ryabtsev, 2008). However, in view of the absence in Russia of extractable hydromineral resources of lithium, the practical significance of spodumene ores remains decisive. Russia controls some of the world’s largest reserves of rare-metal pegmatites holding over 8 million tons of Li2O: approximately 7 million tons on the Kola peninsula and 1 million tons in the Sayan mountains. The main lithium mineral in pegmatites is spodumene LiAlSi2O6 containing 8.1% Li2O. It can be efficiently recovered by gravitational concentration and flotation. However, most of the deposits are located in remote areas and none is currently developed. In this connection, special research is focused on technogenic raw materials, which are increasingly seen as a solution to the resource base problem (Chanturia, 2008, Kurkov and Kotova, 2007)."

Jan 1, 2018

By E. N. Levchenko, K. V. Bulatov, G. I. Gazaleeva

"The article highlights the new procedure of choosing special methods of disintegration for very complicated rare ores. Especially, there is a complex approach to criteria of comparing different types of crashing machines. Criteria are as follows: degree of crashing, degree of grinding, degree of slime creation and the new creations criteria for selection. The procedure is tested on tantalium and zelestinium ore. A new methods was shown the preference impact crashing machine MD-7 for zelestinium ore. In product of crashing 0,050 mm size are 9.4 %, 0,005 mm size – 2.5 %.This is gut result, and show the best indexes of slime creation. The check of the proposed new methods was done when comparing the crushing of tantalium ores of the Otboynoe deposit in cone inertial and centrifugal impact crushers and roller press. A research was conducted different crashing machines under laboratory and semi-industrial conditions. Different operation modes of crushers were also checked. The comparison of the crushing selectivity criterion and degree of crashing showed that the centrifugal impact crusher (CC) and roller press (RP) has the lower indexes than the cone inertial crusher (CIC). Degrees of crashing for different crashing machines are:centrifugal impact crusher – 10.1;roller press – 10.8;cone inertial crusher – 14.2. The crusher CC the selection criterion is 0,632 units, RP – 0.730, where as for the crusher CIC – 0.848 units. The best crushing mode for the crusher CIC-300? is as follows: turning angle of debalance is 0°, peripheral speed of a cone rotation – 1420 r.p.m, specific energy consumption- 4.99 kW*t/t. Crusher CIC-300? is the best for tantalium ores of the Otboynoe deposit. The new methodic are verification.INTRODUCTION Rare metal concentration circuits are complex, energy-intensive, and costly. The reasons for this include the multimetal nature of the rare metal ores, their volatile material composition and low grade. That is why careful selection of ore preparation circuits is of great importance for minimizing the energy inputs and maximizing the liberation of the valuable minerals. Recent research (Khopunov, 2011, Gazaleeva, 2015) has demonstrated that the most efficient comminution processes available to the mineral processing industry are selective disintegration, crushing and grinding, allowing to liberate the mineral particles along the cleavage in the comminution process. These methods are indispensable for the processing of finely disseminated refractory ores prone to slime formation. Many rare metal ores found in Russia are of this type."

Jan 1, 2018

By S. V. Balikov

A close association of fine gold with pyrite and arsenopyrite is observed at many gold ore deposits. Gold forms and gold distribution in sulfides of different deposits were studied. A comprehensive method including optical spectrum analysis, X-ray diffraction analysis, high-temperature X-ray diffraction analysis, scanning electron microscopy and X-ray microanalysis was used for the de-tailed investigation of the defectiveness of the structure of pyrites from different deposits. It was shown that gold content in pyrites varied from 1.5 g/t to 100 g/t compared with 30 g/t to 230 g/t in arsenopyrites. The nature and arrangement of inner inclusions of foreign minerals in pyrites as well as occurrence of fractures and macro- and microdefects were examined. Iron, sulfur and arsenic contents in all pyrite samples were determined. Chemical composition of the detected inclusions was defined. Parameters of submicroscopic structure of pyrite were estimated using X-ray Fourier line shape analysis. Estimation of real structure characteristics with calculation of submicroscopic D-blocks and root-mean-square lattice deformation 2()evalues was performed. Defectiveness of the pyrite structure can be defined by the following parameters: K?1 and K?2 reflection resolution and its intensity within high Bragg angles; S content to Fe content ratio; the arsenic content and the local variation in its concentration within the pyrite grain; the size of submicroscopic blocks and the crystal lattice disturbance value. The performed analysis showed some relationships between these parameters and refractoriness of the pyrite concentrates. It was observed that at S/Fe ratio close to or higher than stoichiometry and at a low arsenic content (less than one per cent) pyrite concentrates were not refractory. The analysis results showed that concentrates of the Beryozovskaya gold plant (0.02~0.07 As%) and concentrates of the Kommunarovskaya gold plant (less than 0.05 As%) as well as some pyrites from the Sukhoi Log gold deposit had the same characteristics. It was found that average arsenic content did not excess 0.2 per cent. Arsenic distribution within the grain of all these pyrites was uniform. At S/Fe ratio lower than or close to stoichiometry and at high arsenic content (more than one per cent) and significant variation in its distribution within a pyrite grain the pyrite concentrates are refractory. Such pyrites are typical for the Sukhoi Log, the Bakyrchik and the Mardzhanbulak gold deposits. Direct correlation between arsenic and gold contents, in particular, in fine grains of pyrite was observed by many researches. This correlation was explained by impregnation of arsenopyrite which normally contains more gold than arsenic pyrites. The analyses results showed that no arsenopyrite impregnation was found: arsenic distribution within the grain was uniform but its concentration varied greatly. Such pyrite concentrates are more refractory. This paper presents the results of analyses of sulfides to determine the amenability of the associated gold recovery by hydro- and pyrometallurgy.

Jan 1, 2014

By Gülay Bulut, Ferihan Göktepe

Pyrite is the most abundant and widespread sulphide mineral and its flotation has been investigated by many researchers. It is well known that, pyrite is floatable under acidic conditions and recovery drops with increase in alkalinity due to changes in solubility of iron hydroxides on the pyrite surface. Most of the works also revealed out that pyrite displays variable behaviour in flotation circuits. This behaviour mainly related with origin and mineralogical composition of ore, liberation size, electrochemical behavior of minerals constituting ore, the trace and minor element content of the mineral, texture, application variables belonging to flotation circuits. In this study, copper activation effect was examined on different origin of pyrites. The experiments were performed with five high grade samples of pyrite from the different mining districts of Turkey. The pyrite samples were different from each other with respect to either their physical or chemical properties; they were different physical appearances and contained different associated minerals. In the micro-flotation tests, 1x10-4 mole/L copper sulphate and 1x10-4 potassium ethyl xanthate were used as flotation reagents. First of all pyrite samples were floated using only xanthate at different pH. Results showed that best floatation results obtained at acidic pH range for all pyrite samples. When copper ions were used to activate, all pyrite samples floated at neutral and basic pH values, too but depending on the samples, recovery and pH ranges were slightly changed.

Jan 1, 2014

By A. A. Lavrinenko

There are discussed the possibilities of using of flotation tailings of platinum-copper-nickel sulfide ores of the Norilsk region for the preparation of backfill mixture instead of a specially produced rock and binder materials to reduce the cost of stowing operations and impact on the environment. It is shown that due to the presence in the tailings of flotation up to 10% of sulfide sulphur, which reduces the strength of the fill materials, and more than 1 g/t PGM it is necessary the preliminary extraction of the sulfides in the product for further processing that give an opportunity to reduce the losses of valuable components. It is shown that by the flotation of the current tailings it is possible to extract 91% of sulfide sulphur, 60% of palladium and 30% platinum in 17% sulfide concentrate containing 2.1 g/t palladium, and to reduce the sulphur content in the tailings up to 0.7%. Due to the easy oxidation of pyrrhotite, there is recommended fractional delivery of the collector with a total consumption 200 g/t. There are discussed results of the flotation study with an additional collector of PGM (sodium diizobutyditiophosfinate), which one show the possibility to increase extraction of platinum on 45%, as well as extraction of sulphur and palladium. For the flotation of sulfides and PGM from the current tailings there is recommended a combination of collectors for primary flotation and only butyl xanthate using in control operations. The possibility of using sludge fraction of the current tailings as a component for the preparation of the combined cementing materials after exposure of sulfides is analyzed. It is shown that the efficiency of the flotation of sulfides from this fraction can be enhanced using selective flocculants. There are discussed the advantages of implementation of completely hydrophobic butadiene-styrene copolymer in comparison with partially hydrophobic polymers. There is discussed an efficiency of the mechanochemical treatment of old tailings in turbo mill and sulphuric acid to remove oxide films from the surface of pyrrhotite before its flotation. Due to the pretreatment operation there is achieved increasing of sulphur extraction and after the introduction to the flotation circuit three control operations there is produced the fill material with sulphur content 2.5%. Keywords: tailings, copper-nickel ore, pyrrhotite, butyl xanthate, sodium diisobutyl dithiophosphinate, selective flocculation, butadiene-styrene copolymer, mechanochemical treatment

Sep 1, 2012

By Dmitriy Makarov

The paper presents the modeling and analysis of oxidation of pyrite copper-zinc ore samples from the Letnee, Yaman-Kasy and Valentorskoye deposits. It is found, that the oxidized samples contain copper and zinc sulfates that are leached under the sample and water contact. It is shown, that sulfide floatability is decreased by the longer-term oxidation.We advise to improve nonferrous metals recovery by joint leaching and ultrasonic treatment of oxidized compounds. Study of the geotechnological processes of non-ferrous metal extraction, on the basis of two copper-zinc ore deposits shows, that heap leaching is of little use for the ores of the Letnee deposit. Leaching results for the Yaman-Kasy ore showed more promise.

Sep 1, 2012

By Cuim R., M. L. Li

Fankou Lead-Zinc Mine produced pyrite concentrate (P.C.) from the zinc tailings by rougher and scavenger flotation before 2010, with the averaged S grade of 40.54% at recovery of 79.34% ( to the feed of S circuit). On the one hand, the economic value of P.C. increases with its purity, on the other hand, when the S grade of P.C. feed to sulfuric acid manufacturer is over 47%, the pyrite cinder can reach a high Fe grade of 62% which can be directly sold as iron concentrate. On this background, engineers in Fankou Mine set the P.C. with S grade of 47% as target. The direct way to reach that goal was to clean the rougher P.C.. Lots of cleaning flotation tests were conducted and the compromised strategy was to produce two ranks P.C. with the S grade of 47% and 38% at the recovery of 44.20% and 36.17%, respectively. The dual-product flowsheet was successfully industrialized in 2010. In order to further improve the quality of P.C., gravity separation was introduced into the flowsheet. The numerical simulation and separation tests were performed to evaluate the beneficiation and classification performance of hydrocyclone as it treated the rougher P.C.. It was shown that the underflow of hydrocyclone could addressed the S grade of 47%, and the finer size overflow could also be enriched to P.C. with S grade of 47% by flotation, due to the contained pyrite with well liberation. That is to say, with the ingenious addition of hydrocyclone to treat the rough P.C., single P.C. with S grade of 47% could be achieved. The new flotation-gravity separation flowsheet was commissioned to produce the high quality P.C. at the end of 2013. The averaged S grade is 47.20% at recovery of 82.26% in 2014. The two steps flowsheet improvement maximizes the enterprise benefits and leads to simple utilization of Fe in pyrite in downstream industry.

Jan 1, 2018

By C. A. Perez

Estimation of rock composition in mineral plants is important to determine rock size and grindability which in turn may improve control of the grinding process. Variations in ore grindability and size distribution directly affects mills power consumption and throughput. Therefore, it is desirable to develop new tools to estimate rock lithological composition. In this paper, a new method for lithological classification based on machine vision is proposed. The method is based on a single video camera and employs information about texture using several different spatial scales. Texture information is extracted from rock images using Gabor filters that can be adjusted at different spatial scales and orientations. After feature extraction, rock images are classified using support-vector machine (SVM). The method was tested on a database containing sub-images of 64x43 pixels of five ore types as follows: massive sulphide (MS), disseminated sulphide (DS), net textured (NT), gabbro (G), and peridotite (P). These ore types were assigned to three grindability classes: soft (MS), medium (DS and NT) and hard (G and P). The database was divided in 2 subsets for training, cross validation, and for test. Classification accuracy is compared with previously published results on a dataset with three different classes of rocks according to their hardness. Results show that our proposed method reached significant improvements (between 13%-20%) in classification accuracy relative to previously published results. Keywords: rock classification, lithological classification, grindability estimation, Gabor feature extraction, texture features

Sep 1, 2012

By M. Blagojev, R. Tomanec

"Studies reported in this paper used polymetallic Pb-Zn-Sb-As-(Ag, Au) ore from Dražnja, Kosovo. The ore is comparatively rich in Zn (6.56%) and Pb (2.87%), but with high rates of Sb and As. Conventional lead and zinc concentration by flotation produced galena and sphalerite rich concentrate with high recovery, but with excessive As and Sb. After chemical analyses, which could not detect the reason for the excessive elements, ore minerals were identified under the ore microscope, their texture characterized, and degree of liberation of useful minerals was assessed. Microscopy of the mineral concentrates revealed complex intergrowths of galena and marmatite minerals mostly with sulphosalt minerals (boulangerite, jamesonite and bournonite) and also with arsenopyrite mainly responsible for the unsatisfactory quality of the concentrate. These complex sulphosalts, among other things have similar behaviour during the flotation concentration, and in spite of their interlocking with galena, therefore inadequate liberation, sulphosalts remain in the lead concentrate. Microscopic analyses indicated that a better galena concentration product is possible with a higher rate of mineral liberation, and then by selective floc flotation of some sulphosalt minerals. Purpose of this work was to show that only chemical analysis is not sufficient, according to that we solved the problem by precise mineral identification and time consuming mineral liberation measurements. INTRODUCTION The polymetallic Pb-Zn-Sb-As-(Ag, Au) ore body of Dražnja, Kosovo, fairly rich in Zn (6.56%) and Pb (2.87%) was repeatedly explored and once even worked. Mineralization at Draznja was primarily represented by sphalerite, galenite and marcasite/pirite. Some sections comprise massive sulphides, and others are lower grade zones of semi-massive sphalerite/galena or marcasite/pyrite dominant sulphides. The ore body II was formed in the southern gallery in the structure Çukë – Lajthishtë (with content of 3.16% Pb and 7.31% Zn). Pb-Zn ore with increased content of As, Sb sulphosalts is not rare phenomenon in the world. While previously treated as unprofitable, economical uninteresting ore, today with development processing and new reagents (organic, ecologic), are the topic of scientific papers. The examination of Pb-Zn ore with high content of sulphosalts we find in deposits as: The hydrothermal vein deposit of Harja in the Baia Mare area, contain a wide variety of sulphosalts [Cook, N. & Damian, G., 1997]; also the deposits Fankou Mine in Guangdong Province and the Dachang Mine in Guangxi Province, where the flotation concentration of galena and jamesonite takes place [Runqing Liu et al. 2015], [Zhang Ting, Qin Wen-Qing, 2015];. On a samples from Tibet in China flotation separation test of galena and jamesonite was conducted [Sun Wei, Han Haisheng, Tao Hongbiao, Liu Runqing, 2015]. According to history of investigation, the mineralized area of Dražnja has a long history of exploration and possible exploitation activities [Slowey, Galen, 2009]. Recent workings were carried out in three stages through the 20th century."

Jan 1, 2018

By Qiuyang Hong, Bo Li, Dongyun Liang

"A weathering-crust niobium-rare earth-bearing deposit is formed by the weathering alterationof alkaline granite, which is refractory due to its low grade and complex properties. The mineralogicalcomposition of ore, the grain size of majorminerals as well as the occurrence of Nb and REE are studied in this paper using MLA combined with traditional methods. According to the results, a wide range of Nb-Ti-REE compound minerals including titanoniobite, uranpyrochlore, chlopinite, samarskite and ilmenorutile areformed for the extensive isomorphous substitution among the elements of Nb, Ta, REE, Fe, Ti, U and Th. The occurrence of REE is extremely complex. First, the REEexistingas rare earth minerals including monazite, xenotime, bastnaesite,etcaccount for 21%. Second, the REEexist in the lattice of Nb and Zr minerals as isomorphous additions, which account for 18%. Third, the REE exist as colloidal rare earthdeposit,which account for 35%. Last, the REEexistingas ion-adsorption-type rare earth,which are adsorbedon the kaolinite in the form of hydrated hydroxyl ions, account for 26%.Based on the results of mineralogy, the combined technology process "mineral processing- hydrometallurgical separation" is needed to deal with the ore. The mineral processing tests show that, for the feed ore containing Nb2O5 0.065%, REO 0.13%, an Nb-REE concentrate containing Nb2O5 1.38%, REO 1.98% can be gained by "high intensity magnetic separation-regrinding-gravity separation by shaking tables". The recovery of Nb2O5 and REO is 62.42% and 44.78% respectively. The Nb-REE concentrate is dealt by the metallurgy process "direct reduction- acid leaching & acidulating- neutralization & precipitation- chlorination & distillation" and the rare earth oxide of 92.34% REO as well as the Nb-Zr oxide of 24.62% Nb2O5 can be obtained with the recovery of REO and Nb2O5 being 76.83% and 59.37% respectively."

Jan 1, 2014

"The most common agglomeration technique in iron and steelmaking is sintering, which requires the use of iron ore/concentrate mixtures, limestone and dolomite as fluxes and coke as fuel in order to produce the required melt at high temperature to cause agglomeration of the particles. Sinter feed blends containing high proportions of magnetite concentrate are difficult to granulate and to produce granules of high permeability, and sufficiently robust quasi-particles for successful sintering operations. Since the granulation of iron ore sinter feed requires no use of a binder, the added fluxes play a vital role in holding the granule particles together until they sinter. The fluxes also help to improve the granule quality and control slag composition in the blast furnace. It is well-known that the particle size distribution of the fluxes affects the granulation effectiveness and green bed permeability which determine the productivity, physical and metallurgical properties of the granules and sinter. Hence it is necessary to understand the role of flux particle size on granule properties so as to improve the granulation of iron ore sinter feed blends containing high magnetite concentrate. In this study, laboratory granulation experiments have been carried out on iron ore sinter feed blends containing high proportions of magnetite concentrate at different addition levels of limestone and dolomite mean particle sizes, to understand the influence of limestone and dolomite particle sizes on granulation rate processes and granule properties.INTRODUCTION Increases in iron ore production to meet the global demand for iron and steel products has led to the depletion of high grade iron ores and thus the current utilisation of low grade iron ore fines and concentrates. However, sinter, pellets and the lump are the required feed types used in the blast furnace. The high basicity sinter is the main iron bearing feed accounting for 70-85% in the blast furnace due to its good metallurgical and mechanical properties that allow high productivity, efficient processes and low production cost (Adam et al., 2017)."

Jan 1, 2018

By M. Eraydin

Dewatering fine particles (e.g., flotation concentrates) is inefficient, energy intensive and often requires large capital and operating costs. To address these issues, a series of advanced dewatering technologies have been developed at Virginia Tech. These include novel dewatering aids and a hyperbaric centrifuge. Typically, the moistures obtained using these methods are 30% to 50% lower than those obtained using conventional methods, as demonstrated in laboratory and pilot-scale test programs. With another novel dewatering technology that has been tested in bench-scale tests, the moistures can be reduced to levels once believed to be attainable only through the use of thermal dryers. In this communication, test results obtained with these advanced dewatering technologies are presented and compared.

Jan 1, 2014

By Sarthak Kaushik

Zeta potential measurements show that the isoelectric point of crandallite, in aqueous solution of 10-2 N sodium chloride is at about pH 5.5. Measurements of turbidity confirm the point of zero charge or crandallite. Calcium ions specifically adsorbed on the surface and thus changed the zeta potential and turbidity. From the measured data, it is confirmed that starch acts as a flocculent for crandallite. Oleic acid, which is a collector used in phosphate ore processing is weakly adsorbed on the surface of crandallite. This results in hydrophobic coagulation of particles resulting in a lower turbidity.

Sep 1, 2012