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By L. Gao, X. Gui

Fine coal obtained from Kailuan mine served as the processing object of this study. This material was difficult to separate. A flotation rate experiment was designed to investigate the process distribution characteristics of size and density during fine coal flotation. Size and density analyses of five clean were studied. The mineral morphology of flotation rate experiment cleaning was observed through scanning electron microscopy. The fractions -0.074+0.045 mm and -0.045 mm exhibited the best practical floatability and presented the highest combustible body recovery rates, but the selectivity and natural floatability of these two fractions were the worst. The - 0.074 mm fraction has contaminated the clean coal from the early stage of flotation, and the cumulative clean coal ash of -0.074 mm reached up to 17.20%. The low and middle-density classes displayed varying flotation behavior, but the flotation yield difference was only nearly 3%. The middle-density class caused the clean coal to have high ash content. The poor selectivity of fine coals, middle-density fraction, and fine mud resulted in high-ash clean coals during flotation. Thus, improving the selectivity of fine coal, restraining the flotation of fine mud, and grinding the coal to decrease the middle density mass fraction to liberate clean coals can yield high-quality clean coals through flotation.

Jan 1, 2014

By E. L. Chanturiya

During the mineral processing of pyrites sulphide ores of some deposits of Russia loss of gold with tailings and pyrite concentrates amounts up to 40%~90%. The problem of selective allocation of gold-bearing pyrite is crucial. There are 4 mineralogy-technological groups of pyrite determined in copper-zinc sulphide ores, based on the increase of contents of gold in pyrite. The gold associated with group 4 pyrite contents of 85% the total mass of gold found in the pyrite. The flotation behaviour of the enriched fractions of pyrite (98%), of the allocated from the ore of Gay deposit, were studied essentially in various conditions ?? and the charge of Butyl xanthogenate of potassium (ButX). Some products of selective pyrite flotation were investigated by methods of scanning electronic microscopy, energy-dispersive and X-ray spectral microanalyses, definition of specific resistance and thermoelectric moving force.

Jan 1, 2014

By D. I. Verrelli

Within the flotation community a belief has developed that some particle shapes are more ?floatable? than others. This is usually attributed to an influence of particle shape or roughness on the induction period required to achieve attachment between the particles and the air bubbles in the pulp. Up to now, such measurements have not been able to readily isolate the effect on individual flotation subprocesses. In contrast, our experimental apparatus, the CSIRO Milli-Timer, enables us to directly observe the process of particle?bubble interaction and attachment by means of a high-speed video recording, thus providing a direct measure of the induction period for attachment. To assess the influence of particle shape on induction time we used two varieties of methylated borosilicate glass particles ? spheres and angular ?frit? ? in a range of tightly-sized fractions. In doing this, we take care to account for the influence of other factors that could affect the induction time, such as the polar angle of sliding commencement, and approach velocity. These parameters are recorded as variables for each interaction, and corrected for using multiple nonlinear regression. Our results illustrate the importance of particle shape on induction period, with angular particles exhibiting induction periods that were an order of magnitude lower than those of spheres. Furthermore, the induction period was seen to decrease with increasing particle velocity, or kinetic energy on approach, but increased as the trajectory approached the limit of just grazing the bubble. Particle shape in mineral processing is a consequence chiefly of the mineral type and the type of grinding employed. The results presented herein indicate that attention should be paid to the shape of particles obtained from the grinding operation, besides particle size. Keywords: attachment, bubbles, flotation, induction period, particles, shape effects, surface roughness

Sep 1, 2012

By E. Gock

Based on the scientific investigations on mechanochemical synthesis of metal sulphides from metals or metal compounds and sulphur or sulphur compounds, the article describes the industrial production of nanoscale metal sulphides. Special operational conditions such as inert atmosphere, size and type of the grinding balls, grinding time and specific energy input are taken into consideration. A system configuration for the manufacturing of sulphides at a capacity of 100 kg/h is presented.

Jan 1, 2014

By S. H. Morar

Froth flotation is a physico-chemical separation process that takes place in two phases; pulp and froth phase. It is widely recognised as a complex process, due to the range of interactions present within the system. Of critical importance is the role of the froth phase within the system. The pulp kinetics governs the maximum potential recovery within a flotation cell, while the froth phase governs the selectivity via the froth?s stability. Higher froth stability improves recovery at the expense of grade, and lower froth stability improves selectivity. It is well known that the two major factors affecting froth stability are attached particles and solution chemistry. This paper looks at a flotation bank at different froth depth and frother concentrations. The air recovery to the concentrate is determined at each condition and relates the effect of the operating conditions on froth stability and transport to the amount of solids that are recovered to the froth and concentrate by true flotation. The results presented show that, for a given process objective, which in this case was a consistent mass pull profile, depending on the operating conditions, solids recovery in the pulp is affected by the air rate required to maintain the target mass pull. To a smaller extent, the changes in the pulp composition affect down-stream pulp recovery. The variation in solids recovered into the froth drives the froth stability at the start of the flotation bank, while the frother drives the froth stability at the end of the bank. The performance in between these two extreme conditions arises from an interaction of these two effects. The consequences of these interactions can give rise to counter-intuitive responses that can confound efforts to optimise the performance of the bank.

Jan 1, 2014

By Maurício Torem, Gabriela Huaman, Antonio Merma

The purpose of this review paper is to succinctly present the most significant works related to Mineral Processing and Environmental Bioremediation and developed by the Mineral and Environmental Technology Group (METG) of the Materials Engineering Department of the Pontifical Catholic University of Rio de Janeiro (PUC-Rio). In mineral processing it was emphasized the use of the Rhodococcus opacus bacteria as a bioreagent in the bioflotation of some mineral samples (magnesite, calcite, hematite, quartz and apatite). The adsorption of the bacterial cells on the mineral surface can be due to specific and/or non-specific interactions, which will depend on several factors, as their surface charge and hydrophobic character. The zeta potential evaluation of the mineral particles before and after interaction with the R. opacus cells showed that the biomass modified the zeta potential profiles of the minerals, which confirm the adsorption of bacterial cells on the mineral surface. Moreover, the bacterial cells adsorbed caused a change in the mineral flotability which is related to a change in their hydrophobic character, thus, the mineral bioflotability was found to be dependent on the pH and the bacterial concentration. On the other hand, the environmental bioremetiation assessed the biosorption potential of three metal ions (lead, copper, and cobalt) by four different biomass Streptomyces lunalinharesii, Rhodococcus opacus, Rhodococcus ruber and coconut shell powder. For this purpose, biosorption process was characterized under different operating conditions such as initial pH and biosorbent dosage. The Freundlich and Langmuir isotherm models were applied to the equilibrium data obtained at different concentration.

Jan 1, 2014

By V. E. Dementiev, V. I. Kulikov, G. I. Voiloshnikov, Yu. O. Fedorov

"The report presents the summary of the JSC Irgiredmet’s activities in the field of preconcentration of ores. As of 2018, the Institute has almost 40-years’ experience in this area. Over the years, Irgiredmet has done a lot of work – from development to implementation of new technologies of ore piece sorting and concentration based on X-ray radiometric separation (XRRS). INTRODUCTION Preconcentration has been a challenging issue of the mining industry over the last decades. The implementation of this technology can significantly increase mining efficiency. The main application of preconcentration is improvement of mined ores quality, however new and more complex issues have arisen with the evolution of the technology. Irgiredmet has started to develop an efficient preconcentration technology for gold-bearing and rare-metal ores 40 years ago. The X-ray radiometric method widely used at that date as a method of elements determination in geology and geophysics become the ground for this work (1). Since that time, the Irgiredmet Institute has developed and significantly improved the technology of piece ore sorting, or XRRS (2-5), that is currently also known as the X-ray fluorescence method. The progress of the XRRS development achieved by Irgiredmet in cooperation with Rados LLC, Tekhnoros LLC (Krasnoyarsk), Rados-Service LLC and CJSC Tekhnogen (Ekaterinburg) has proved efficiency and applicability of the XRRS technology for processing a wide range of minerals and solving of various technological problems (7-9) compared to other radiometric methods (6). Furthermore, obtained results are supported by numerous studies, trials and implementations. The significance of ore preconcentration for greenfield and brownfield projects determined the establishing a new subdivision of Irgiredmet, the XRRS Technology Center (XRRS TC), that has provided the Institute with a completed range of processing technologies, from preconcentration to producing final products. Over the past few years, the XRRS Technology Center has carried out studies and testing of a numerous (more than 100) projects, mines and deposits of gold-bearing ores, rare metal ores (Be, Ta, Nb, W, Mo), base metal ores (Cu, Sb, Zn, Pb), ferrous metal ores (Fe, Ti, Cr), rough diamonds and coal. The XRRS Technology Center performs various specific studies and testing not only in Russia, but as well as in Kazakhstan, Georgia and Mongolia. Mines and companies from Chile, India, China, Iran and other countries also take an active interest in the XRRS technology."

Jan 1, 2018

By A. I. Urvanzev, N. V. Shikhov

"In this paper, we present the study’s results of electrical separation processes on the basis of new separator designs, new technological solutions, and newly discovered effects. We considered the options of enrichment by magnet separation of magnetite and titanomagnetite ores, ores and products containing chromium and manganese, ores of non-ferrous and precious metals. During pneumo-electric separation of mixed iron ore of SMPC, 43.3% of the output of the concentrate with an iron content of 61.7% was obtained in one step, with extraction of 70.5%. The paper also presents the results of the finalization on the air-electric separator of the magnetic fraction when separating oxidized ores of MPPOO (mining and processing plant of oxidized ores) on the Jans polygrade magnetic separator. A concentrate was obtained with an iron content of 65.1% with the extraction of 95.0% and tails with an iron content of 13.0%. The possibility of obtaining low-silica concentrates from these ores with an iron content of 67.15 and a quartz of 2.88% is shown. Also, the results of tests on the enrichment of chromite ores on the firing-magnetic scheme with corona-electrostatic separation are considered. On the initial ore of the Don MPP (mining and processing plant), a concentrate with a content of 61.8% Cr2O3 was obtained with a quartz content of ~ 1.0%. The results of pneumo-electric separation with triboelectric charge of the separated particles are presented. The results of the tests indicate a principal possibility of enriching chromite ores without costly high-temperature roasting. Dry technology of enrichment of manganese ores with the use of electrical separation increases the quality of the oxidized concentrate to the first grade and raises the total extraction by 2 times. For the Chineya deposit of titanomagnetite ores with copper impurities, electroseparation operations were carried out on two samples with a Cu content of 1.93 and 3.75%, respectively. For a sample with a Cu content of 6.02%, a copper concentrate output of 24.42% was obtained with a Cu content of 23.82% and the extraction of 94.88%. The results of enrichment by electroseparation of gold-containing sulfide ores can have the practical importance. For ores of the Berezovskoye deposit, a pyritic concentrate containing 100 g / t of gold was obtained after two or three operations of IES (integrated energy systems)."

Jan 1, 2018

"The global demand for the copper metal is continuously increasing however, the high-grade copper ore deposits are constantly depleting. As a result, ore bodies with complex mineralogy characteristics and rich in arsenic-copper bearing minerals are increasingly processed. Arsenic-copper sulphides such as enargite can represent a significant amount of arsenic in concentrate, which causes high financial penalties by smelters. On the other hand, arsenic (As) is a highly toxic inorganic pollutant, which causes human health and environmental problems. Recent research studies have demonstrated promising results showing the possibility of separating arsenic-copper sulphides from copper sulphides using controlled pulp potential (Eh) flotation at laboratory scale. However, the selective removal of arsenic-copper minerals in real ore systems is not well understood. Two ore samples were selected from the Tampakan copper-gold deposit located in the Philippines named the HAS (high arsenic sample) and the LAS (low arsenic sample) samples and the mineralogical analyses were performed on both samples. The floatability of enargite in a batch flotation system under controlled pulp potential conditions was investigated for the HAS and the LAS samples. It was observed that it is possible to selectively separate enargite from other copper minerals after reducing the pulp potential to about -200 mV SHE at pH 11 in the LAS sample. However, no separation between enargite and other copper minerals was observed at a reducing potential for the HAS sample. Mineralogical analyses and surface chemistry studies were undertaken for both samples to find out the reasons for different observations. This study has an important implication in sulphide flotation to achieve sustainable development in the utilisation of arsenic-copper mineral resources. INTRODUCTIONAs the demand for copper is increasing, the extraction and development of resources including complex deposits is becoming necessary. These complex deposits often have issues such as: lower grade ores, floatable non-sulphide gangue, very fine-grained ore and therefore poor liberation and significant regrinding, mixed copper mineralogy, complicated galvanic interactions, economic levels of gold and silver, and high levels of impurities such as arsenic. There is currently no established methodology for separating arsenic-bearing copper minerals from other copper sulphide minerals by flotation. The possibility of separating arsenic-copper sulphides from other copper minerals by controlling the potential of the flotation pulp has been shown in previous studies. However most of these studies were conducted on single mineral systems and the selective removal of arsenic-copper minerals in complex ore systems is not well understood. The flotation behaviour of arsenic-bearing minerals within complex ores differs significantly from that of pure mineral systems due to the effects of mineralogical composition, the degree of liberation, and the surface oxidation. The understanding and manipulation of these effects can lead to improvements in the selective flotation recovery of arsenic-bearing species from complex ore systems."

Jan 1, 2018

By Venkataramana Runkana, Pradip Gautham, Beena Rai, Sreedhar Reddy

"IT enabled platforms are the key to provide an integrated view of the business activity or an enterprise as a whole. Attempts to integrate all functions in an enterprise such as mine-to-market initiatives, wherever and to whatever extent implemented, have provided significant benefits to the industry. The transformative potential of IT enabled integration platforms is illustrated in this communication from our own work in this field. TCS PREMAP (Platform for the Realization of Materials and Products) is a knowledge-driven engineering design and development platform which leverages modeling and simulation and artificial intelligence into the engineering design process. We illustrate the customization of this generic platform for the design and optimization of mineral processing plants in an integrated manner. TCS PEACOCK (Process and Equipment Analytics for Optimization and Control) has been developed to enable automation of data analytics in the operating plants. We illustrate its utility and power in improving the plant performance with the help of case studies from our work on pelletization of iron ores and optimization of flotation plants. INTRODUCTION We are living in an exciting digital era. With the advent of cloud computing and social media on the one hand and rapid advances being made in several research areas of interest to us in the minerals and metals industry such as artificial intelligence (AI) & machine learning, robotics, unmanned vehicles including drones, big data analytics, 3D printing, sensor technologies, renewable energies and internet of things (IoT), many disruptive transformations in our industry are on the horizon. Recent advances in information technology (IT) and knowledge engineering, in combination with appropriate domain expertise, that is, our enhanced understanding of the underlying science of mining and mineral processing operations and the availability of a variety of powerful modeling-simulation tools make it possible to address the challenging problems facing the mining and mineral processing industry, in an integrated manner."

Jan 1, 2018

By B. Suresh

Iron ore in Bellary-Hospet region is friable in nature and generates a significant amount of micro-fines (-150 µm) during mechanized mining, handling and processing. Present beneficiation practice generally employs spiral classification followed by hydrocycloning to remove slimes (-15 µm). The iron ore fines, beneficiated at JSW Steel Ltd., Karnataka generates tailing having 48-52% iron content in the form of slimes, which accounts for 50 to 55% by weight with respect to classifier overflow. The loss of iron as slime is considerably high. In this context, laboratory studies were carried out with different combination of beneficiation techniques with an objective to develop an efficient flow sheet to achieve better product grade and recovery from classifier overflow. The results revealed that de-sliming process by hydrocycloning in combination with either magnetic separation or froth flotation leads to increased iron loss in tailing. Based on investigation it is observed that forward flotation is beneficial over the reverse flotation. The experimental approach of forward flotation on classifier overflow followed by magnetic separation on flotation tailing resulted in overall product grade of 62.9% Fetotal and 70.3% yield. The tailing contains 34.6% iron, which accounts for 29.7% by weight with respect to classifier overflow.

Sep 1, 2012

By T. Niedoba

The ash contents in coal particles were examined in the paper dependably on particle size and its density. So, the two-dimensional regressive function Z=Z(?, D) was the searched object, where Z is random variable describing ash contents, ? - density and D ? particle diameter. This dependence is determined basing on experimental data concerning the coal of type 31. For this coal, the method of ordinary kriging is applied to calculate the values of a random variable Z. This method requires the proper selection of so-called variogram function, which 4 forms are considered in this paper in purpose to select the best solution. The given results were then evaluated by the residual deviation value and so compared with empirical data.

Sep 1, 2012

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 Luo Chuansheng, Rao Jinshan, He Xiaojuan, Qiu Xianyang

The dissemination grain size of chalcopyrite is really fine and refractory grains of -10µm take up 25%. Dissemination relationships among chalcopyrite with pyrrhotite, pyrite, marcasite and gangue minerals are complex. Content of Fe-bearing sulphides and Fe-bearing silicates associated with chalcopyrite reaches to about 60%. It’s hard to liberate and separate chalcopyrite from pyrrhotite. The above four are the main mineral processing difficulties of a copper ore in China. Because of the similar floatability and poor separation effect between chalcopyrite and pyrrhotite, enhanced depressing and collecting method was adopted in Cu-S separation before 2009. Due to the different magnetism among chalcopyrite, pyrrhotite and Fe-bearing silicates, magnetic separation is creatively induced in Cu floatation circuit based on the in-depth study of process mineralogy. High efficiency and new Cu-S separation technology of "Rough concentrate regrinding-pyrrhotite rejecting from middling by magnetic separation" and a highly selective copper minerals collector YL-1 had been developed to solve the difficult problems of refractory Cu-S separation, which are heavy load of middling recirculation,difficulty in upgrading Cu concentrate, unstable locked cycle and low separation indexes. And grade of Cu concentrate has been increased by 3.33%, recovery of Cu and Ag has been increased by 19.32% and 10% respectively.

Jan 1, 2014

By Andrey V. Yevdokimov

The results of the test work on gold leaching using high strength of cyanide solution in the presence of activators are presented. The major physical and chemical relationships of gold leaching were determined. Intensive cyanidation results of gravity concentrates with various material compositions using an activator are given. Process design criteria for intensive cyanidation unit were developed on the base of pilot plant test results. Keywords: gold, activators, intensive cyanidation, gravity concentrates

Sep 1, 2012

By W. G. Liu

Phenyl malonic acid (PMA), a new chelating collector, which contains a phenyl structure and a malonic acid chelating group, has been synthesized and its collecting capabilities to calamine, hematite, quartz and hemimorphite are also studied in laboratory. From the experimental results, it can be seen that the PMA has somewhat flotation ability to calamine, hematite and quartz, while it nearly has no collecting ability to hemimorphite. With the increase of PMA concentration, the flotation recovery of calamine increases. When the dosage of PMA was 560g/t and at pH=7~9, the flotation recovery of calamine gets its maximum of 45.94%. The test results about the influence of pH on the flotation recovery of quartz show that the flotation recovery increases with the increase of pH, and the maximal flotation recovery can be gained in alkaline media. On the other hand, PMA has stronger flotation capability to hematite than to other minerals. The flotation recovery of minerals increases with increase of PMA concentration. When the dosage of PMA is 560g/t and at pH=5~7, the flotation recovery of hematite is 82.96%. Mean-while, the influence of pH on the flotation recovery of hematite was studied and test results showed that, as pH increases, the flotation recovery sharply rises until pH=4, then the increasing rate de-creases outstandingly, at pH=6 the flotation recovery reaches its maximum of 82.96% and it de-creases speedily in alkaline media. Finally, through the measurement of infrared spectroscopy and in terms of solution chemistry of collector, the flotation mechanism has been discussed. It was concluded that the adsorption of PMA on minerals surface is chemical adsorption in nature through two oxygen atoms in the polar group of phenyl malonic acid chelating with the metal ions of minerals surface to form a hexagon-cycle chelate complex: C(=O)-O-M-O-(O=)C.

Jan 1, 2014

By Z. Cheng, Y. Han

"For non-sulphide minerals such as oxidized minerals, fluoride minerals, and oxysalt minerals, there are generality in the molecular structure of their floating collectors, and similarity in crystal structure of the minerals. In the paper, adsorbing mechanism of these collectors on the surface of these mineral particles in different pH pulp was investigated by means of Pauling's rules & valence bond theory, Valence-shell electron pair repulsion theory (VSEPR) theory, Crystal and ligand field theory, and quantum chemistry simulation by DMol3 and CASTEP modules of Material Studio software. Besides, the role and status of hydrogen bond in the floating adsorption mechanism were studied emphatically, and the confirmation and characterization of hydrogen bond were explored also based on the test results. What is more, the conclusion “the effect of hydrogen bond can not be overlooked in adsorbing mechanism of flotation collectors on the minerals” and a new viewpoint of multi-polarity collaboration and hydrogen bond coupling were summarized eventually based on analysis of the measurements. Finally, a novel collector 2-Amino-3-Methyl Heptyloxy-Propylamine (AMHP) was developed based on the new viewpoint of molecular structure design, and its collecting performance was exhibited.INTRODUCTIONWhen it comes to the recovery of flotation, it is necessary for researchers to investigate the flotation mechanism of collectors. In traditional theory, when collectors were used to collect minerals, the attractions between collectors and minerals were divided into chemical, electrostatic and physical attractions (Wills, B.A., 2006). Especially, because of the reaction between sulphide minerals and sulphydryl collectors is complex and various mechanism has been proposed (Yoon and Basilio, 1993), when collectors were used to collect non-sulfide minerals, it can be classified into oxyhydryl anionic collectors and cationic collectors. In traditional theory, the adsorption of oxyhydryl anionic collectors were due to water-repulsion, and the adsorption of cationic collectors were due to electrostatic attraction between the polar head of the collector and the charged electrical double layer on the mineral surface (Wills, B.A., 2006)."

Jan 1, 2018

The quality of iron ore fines in terms of high iron content and low levels of deleterious impurities such as Silica, Alumina, Sulphur and Phosphorous is a critical parameter, in sintering and subsequent iron and steel making processes. As the higher-grade ores become depleted, there will be a stronger focus on treating lower-grade haematite/goethite ores and developing suitable beneficiation techniques to reduce the levels of impurities. Innovative flow sheets, based on new and commercially available technologies, is required. These will be needed to include gravity concentration devices, which can handle coarse and fine feed sizes. In this paper, efforts made to reduce the silica and alumina content of a low grade iron ore fines (<1.0 mm size) sample from the Pilbara region in Western Australia are described. The feed sample, a goethite abundant lower grade iron ore fines, which was a plant reject assaying 48.66% Fe with 13.61% SiO2and 5.09% Al2O3 was investigated. To this end, an experimental campaign was undertaken, and beneficiation studies were conducted on the sample using a Floatex Density Separator (FDS), a gravity device which can be operated for size classification and/or relative density separation. The objective was to produce high-quality iron ore material suitable as sinter feed. An iron concentrate with a grade around 57.0% Fe (Calcined Fe of about 63.0%) was achieved while recovering around 67.0% of the feed weight. In addition, a rejection of substantial content of Silica (>75%) and Alumina (>66%) was achieved while securing >77% iron recovery. On the other hand, sharp classification efficiency with low values of imperfection around 0.20 was obtained. Consequently, the response of the lower grade iron ore sample to FDS application, has vast potential to reject deleterious impurities as a single stage separating beneficiation equipment. Remarkably, it was demonstrated, that a great amount of goethite, abundant in lower grade iron ore fines/plant rejects, which are currently being either stockpiled and/or dumped as waste, can be treated using FDS application and potentially can add a significant value to the iron ore mining industry by recovering additional iron ore fines. Keywords: deleterious impurities, beneficiation techniques, classification, relative density separation

Sep 1, 2012

By A. V. Zimin

It is a well-known fact that usage of reverse cationic flotation in magnetite ores processing enables to improve the quality of magnetite concentrates. We designed an iron ore concentrate technology (with 70 -71 % of iron) including reverse cationic flotation in pneumo-mechanical flotators RIF (developed by RIVS Corporation, Russia) with good biodegradable etheramines as collectors for flotation of quartz. Practical application of high biodegradable flotation reagents decreases environmental impact risk of objects and enterprises of mining industrial complex. This work presents results of development of flotation technology for production of high quality ferruginous concentrates from magnetite ores of Russia and Ukraine deposits. Keywords: magnetite ores, reverse cationic flotation, ferruginous concentrates, pneumatic-mechanical flotation machines, environmental impact

Sep 1, 2012

By Ingvar Ymén, Alexandra Lundmark

"The depressive effect of dichromate on galena was evaluated with chemical experiments and small-scale depression experiments at a pH of around 12. The depressive effect was measured with Dynamic Vapor Sorption (DVS), which measures the water uptake of a sample as a function of the % relative humidity. The depression is due to PbCrO4PbO, which in the presence of Ca2+ and SO4 2- forms a more or less amorphous solid solution (Pb,Ca)(CrO4,SO4)PbO, which clogs to the surfaces of the ore. Free Pb2+- ions are needed for depression to occur and at high pH Pb2+ - hydroxide complexes, supply enough Pb2+ - ions to precipitate (Pb,Ca)(CrO4,SO4)PbO. In air CO2, precipitates CaCO3 which slowly lowers pH, precipitating more (Pb,Ca)(CrO4,SO4)PbO and CaCO3 on galena. Similar experiments where performed with five alternative depressors whereof phosphate, which forms an amorphous precipitate of approximate composition Pb3Ca13(PO4)10SO4, gave the best results. Phosphate was tested in laboratory scale flotation experiments giving encouraging results.INTRODUCTIONWithin Boliden Mines, concentrating of copper and lead from complex sulfide ores is performed by bulk flotation, meaning that copper and lead are concentrated in the same product. Downstream, copper and lead are separated by flotation of chalcopyrite, and depression of galena. Boliden has for many decades used sodium dichromate to depress galena (reference 1). Dichromate is both toxic and carcinogenic and Boliden has for many years investigated several alternatives. So far, however, the best results have been obtained with dichromate. Since Boliden has tried to substitute dichromate for a long time without finding a process as effective, Boliden decided to clarify the function of dichromate in the depression of galena and on the basis of the outcome find alternative depressors with similar function. This study was given to RISE Bioscience and Materials / Surface, Process and Formulation as a consultancy assignment. This paper presents the outcome of the combined efforts of Boliden and RISE."

Jan 1, 2018