Search Documents

By P. Hatefi, O. Rahmani, M. Noor-Mohammadi, A. Tohry

"Depressants play an important role in the selective separation of impurities from iron minerals by direct or inverse flotation. In this paper, sodium co-silicate (SCS) with chemical formula of Na4SiCO6, as a depressant with pH modifier features, has been synthesized and used for phosphorus bearing iron ore in anionic reverse flotation. In this process, phosphorus is floated while the iron oxides are depressed, using fatty acids as collector in an alkaline medium. Batch and pilot flotation tests were carried out to investigate the influence of SCS on the separation selectivity of phosphorus from iron oxides. Also the depression mechanism of SCS on hematite surface was investigated by microflotation tests and FTIR spectroscopy measurements. The flotation results indicated that without using a pH modifier, the pH of pulp could reach up to 10, when SCS was used as depressant. In this condition, a better depression performance was observed compared to sodium silicate (SS). Using the SCS, phosphorus and total iron content in iron concentrate was 0.046% and 66.29%, respectively, compared to SS where these values were 0.06% and 65.75%, respectively. As a result the weight recovery of iron concentrate was increase by around 4%, compare to SS. It was also found that 238 g/t of SCS could be used instead of 3 types of reagents collectively, including 32 g/t of NaOH, 151 g/t of Na2CO3 and 400 g/t of SS gel.INTRODUCTIONThe phosphorous presents in iron ore minerals is mainly in the form apatite mineral. The apatite is separated from iron ore minerals by magnetic and flotation methods (Ma, 2012). The reverse anionic flotation of iron is one of the most common method for removing phosphorus from iron concentrate (Araujo et al., 2005).Usually apatite minerals are readily floated using anionic collectors such as fatty acids (Ma, 2012). In this conditions the iron minerals are depressed and by modifying the pH in alkaline conditions, selective separation of phosphorus from iron concentrate can be achieved. Depressants including; sodium silicate (SS), starch, dextrin, guar gum and humic acids play an important role in the reverse flotation of iron ore (Kar et al., 2013; Ma, 2012; Turrer and Peres, 2010; Araujo et al., 2005). Studies have shown that SS has a better effect on iron recovery and phosphorous reduction, compared with other depressants (Tohry and Dehghani, 2016; Qi et al., 1992, Dho and Iwasaki, 1990). In most flotation processes, modifiers are used to adjust the pH. To achieve alkaline conditions, mainly pH modifiers such as carbon dioxide and sodium carbonate are used."

Jan 1, 2018

By B. Courtaud

Uranium plants are generally located quite far from conversion plants, resulting in high transport costs. One way of reducing such costs involves putting more uranium in each drum by increasing the final product?s bulk density, which can be achieved via mechanical compaction of the powder and/or improved precipitation. For most of its plants, AREVA has adopted the latter approach, involving a new precipitation process applicable to all kinds of yellowcake produced (via uranates, uranium peroxide, etc.) that achieves bulk density of 3 for soda uranate, for example, instead of the 1.5-2 density available via conventional processes. At present, this process is being undertaken on an industrial scale and will become the norm for precipitation processes at all AREVA U plants. In addition to producing dense yellowcake, the process also delivers a product with no fines, a spherical particle shape (which allows for high-quality powder flow) and superior post-precipitation filterability

Sep 1, 2012

Due to complex mineralogical and chemical interactions of the value and gangue mineral phases present in uranium-containing lateritic ores, deleterious pulp gelation which impacts on value metal recovery sometimes occur during atmospheric leaching. In this study, the leaching behavior and particle interactions of selected oxide (hematite, quartz) and clay minerals (muscovite, chlorite), which constitute predominant host gangue phases of typical lateritic uranium ores are investigated to provide basic, mechanistic understanding of temporal pulp gelation phenomenon. Isothermal, batch leaching with H2SO4 was carried out on concentrated dispersions (30 ? 57 wt.%) of single minerals at pH 1 and 25 or 70 °C and their concomitant solution, speciation and rheology (shear yield stress, viscosity) were characterized. It is clearly shown that despite the high oxide content of lateritic ores, the pulp chemistry and rheology is largely affected by the incongruent leaching behavior of more reactive, acid-consuming aluminosilicate clays. Furthermore, time- and temperature-dependent alumino-silicate species polycondensation interfacial reactions are shown to be responsible for the enhanced particle interactions, reflecting strong pulp rheology in agitation and pumping. If not properly mitigated, high pulp shear yield stress and viscosity have a striking impact on processability and hence, value metal recovery.

Sep 1, 2012

By A. Deepatana

This study compares the use of an aminophosphonate chelating resin Purolite S950 and a sulphonic acid strong cation exchange resin Purolite C160H to recover nickel and cobalt from the synthetic bioleach solutions. Batch adsorption of metal citrate is performed as a function of metal citrate concentration (15~2000 mg/L) and solution pH (0.01M and 0.1M citric acid). The adsorption mechanism as inferred from the fit to Langmuir (LM), Freundlich (FM) and Redlich-Peterson (RP) models demonstrates that nickel citrate adsorbed onto C160H appears monolayer in comparison to that adsorbed onto S950 exists multilayer. In contrast, cobalt citrate adsorption onto both C160H and S950 agrees with the LM model. The results have shown that loading capacities of nickel and cobalt citrate onto C160H are 60 and 65 mg/g whereas those observed onto S950 are 16mg/g and 6 mg/g respectively. These are achieved in metal citrate prepared in 0.1 M citric acid. Resin regeneration is conducted in using 2 M nitric acid solution. The results show high efficiency of nickel and cobalt citrate elution from Purolite C160H. Findings from this study suggest Purolite C160H is a suitable adsorbent for recovering nickel and cobalt from bioleaching solutions.

Jan 1, 2014

By Z. Q. Zhang

The iron ore from Yichang in China assaying 41.64% Fe and 1.02% P is a low grade and high phosphorus oolitic hematite ore. The separation of iron minerals from gangue minerals in the ore by conventional processing techniques is ineffective owing to their close similar properties. The modification of iron minerals by microwave-assisted reduction was investigated in order to improve separability of the ore. The effects of microwave-assisted reduction on the subsequent low intensity magnetic separation and floatation were examined. The results show that the main factors affecting the reduction and separation process are grinding size, reduction temperature and reductant. Fine grinding of the microwave-treated ore to smaller than 0.074mm was found to be imperative due to the tiny dissemination characteristics of iron oxide minerals. After magnetizing reduction by microwave heating at 500?, the magnetic concentrate containing 58.36% Fe and 0.67% P can be obtained with the Fe recovery of 91.28%. Magnetizing reduction drops the floatability of iron oxide minerals, thus reverse flotation is fit for upgrading the magnetic concentrate to contain 62.13% Fe and 0.21% P with Fe recovery of 81.59%. Compared with present microwave-assisted reduction technique of carbon reductant, using a waste iron powder as reductant is a novel and effective technique without the green house effect caused by the release of CO and CO2. Waste iron powder with a faster response to microwave heating then coke and charcoal can be recovered by magnetic separation in a low cost and plays the role of reductant and microwave heating accelerator.

Jan 1, 2014

By Sergey Ulianov, Arkady Senchenko, Alexey Shvets, Arkady Bakotin

"This paper contains description of research results of technology development for copper recovery from weathered tails of iron processing plant. The predominant host mineral that contains valuable component is chalcopyrite occurring in its free form and in associations with ore and rock-forming minerals. Copper grade is 0.26-0.30%. Emulsion inclusions of chalcopyrite in pyrite and sphalerite were noted. Major problem is low copper recovery (30-35%) by flotation. When studying chalcopyrite in primary concentrate it was determined that the surfaces of many chalcopyrite grains are covered with oxide films which prevented collector attachment onto them. Second issue was deep association of chalcopyrite with pyrite and sphalerite. Sulfidizing reagent addition did not help to reach the required level of copper recovery to concentrate. In the result of research performed the technological flowsheet was developed including preliminary treatment of head material in a special unit aiming at oxide films removal, followed by copper rougher flotation on head size tails, crude concentrate regrinding and a number of cleaner flotation operations. After the treatment of weathered tails according to the flowsheet developed, copper recovery to flotation concentrate became 71.53%, at 23.46% copper grade. The suggested technology allows one to solve the issue with treatment of technology-related copper-containing stockpile material, as well as to include the ores where copper is represented by sulfide minerals covered with oxide films into processing."

Jan 1, 2014

With shortage of sulfide nickel ores, laterite ore was paid more attention by scientists. Because its grade is commonly lower than sulfide nickel ores, laterite ore can not be utilized effectively be-coming the bottleneck of study. Leaching laterite ores from Yuanjing, Yunnan province, organic ac-ids show better selective than sulfide acid in nickel and cobalt recovery. Organic acid has low de-pendent on pH, keeping leaching capability even higher than 3. On the other side, when pH up to 2, sulfide acid can not leach laterite ores any more. After four kinds of organic acid leaching laterite ores, besides citrate, malate and succinate have good leaching and effectively selective capability. Especially, succinate has the best selective leaching capability of nickel and cobalt in four kinds of organic acids for latter anion purification and separation. Isolated from waste water with sugar, Aspergillus niger (zs1) has great capability to produce organic acids and vigorous growth. Laterite ores have been respectively processed by direct-leaching and indirect-leaching. Indirect-leaching gives a better result than direct-leaching. Extraction of nick-el by indirect-leaching reaches 44.3%, far more than that of direct-leaching. Moreover extraction of nickel at pulp density of 5% is higher than that at pulp density of 10%, reaching 63% in 11 days and extraction of cobalt also is 48.1% in the same period. Compared with nickel and cobalt, iron gives low extraction in solution, containing organic acids produced by Aspergillus niger .

Jan 1, 2014

By R. S. Wang

The flotation of pyrite which be pretreated by electrochemical ways under external controlled voltages in different pH is explored. The floatability of pyrite is increased indistinctively after being pretreated in acidic and xanthate environment; Whereas, it is increased obviously between 400~800 millivolt in alkaline and xanthate condition. The reason for higher recovery of pyrite is that oxida-tion reaction, which results in S0 and S02, takes place on its surface, and that ethyl xanthate is oxi-dized into dixanthogen. In the meantime, the kinetics and mechanism is also studied.

Jan 1, 2014

By S. Groudev

Acid drainage waters generated in the uranium deposit Curilo, Bulgaria, were treated by means of a pilot-scale passive system consisting of a permeable reactive multibarrier and a constructed wetland connected in a series. The multibarrier had a total volume of 23 m3 and consisted of an alkalizing limestone drain and an anoxic section for microbial dissimilatory sulphate reduction, bio-sorption and additional chemical neutralization. The waters had a pH in the range of about 2.5 ~ 4.0 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in agriculture and/or industry. The water flow rate through the multibarrier varied in the range of about 1 ~ 17 m3/24 h, reflecting water residence times of about 300 ~ 18 hours. An efficient removal of pollutants was achieved by the multibarrier during different climatic seasons, even during cold winter days at external air and water temperatures close to 0oC. The multibarrier effluents were enriched in dissolved organic compounds and in some cases still contained manganese and iron in concentrations higher than the relevant permissible levels. These pollutants were removed in the constructed wetland as a result of the activity of different heterotrophic microorganisms, including some bacteria able to oxidize the bivalent manganese and iron ions to Mn4+ and Fe3+, respectively.

Jan 1, 2014

In the present work, the flotation behaviours of zircon, rutile and ilmenite using sodium oleate as collector in absence and presence of depressants were thoroughly investigated. The maximum in the flotation recovery of any of the above minerals falls within similar pH ranges. A range of inorganic and polymer depressants were examined in order to improve the separation of zircon from rutile and ilmenite. Optimum values of conditioning pH and depressant concentration to achieve maximum recovery and best selective floatability of zircon were obtained. Selective flotation of zircon from Ti-bearing minerals was anticipated from single mineral experiments under different pH values, depressant and collector conditions.

Jan 1, 2014

By Sravya Kosaraju, Christian Ekberg, Stefan Allard

Li-ion batteries are now used in electric vehicles (EVs), plug-in hybrid vehicles (PHEVs) and, hybrid electric vehicles (HEVs). Nanostructured Li(NiyMnzCo1-y-z)O2 is one of the more popular cathode chemistries for automotive Li-ion battery, due to its enhanced properties such as large surface area, short diffusion length, enhanced ionic and electronic conductivity, improved mechanical strength and structural integrity [Pan et al, 2013]. Recycling of Li-ion batteries helps to mitigate environmental effects of virgin metal extractions along with improper disposal of end of life batteries. To fulfill these objectives of the recycling, recovery of pure streams of the involved metals should be considered. In this study, the batteries were first discharged and dismantled in an inert atmosphere (Ar). The electrodes were then heat treated in a box furnace. This was done in order to break the chains of the adhesive (PVDF) and consequently separate the metallic substrates Cu and Al from the electrochemically active compound. This heat-treatment also helped to simplify the dissolution of the metal constituents in the electrochemically active compound from the cathode in the acid leaching process. Solvent extraction was chosen to achieve separation and recovery of metals with higher purity from these leachates. In the scope of the present work, a complete process from the point of dismantling to separation of constituent metals using solvent extraction was studied.

Jan 1, 2014

By N. N. Orekhova, I. V. Shadrunova, N. G. Novikova, N. ?. Volkova

The purpose of the research is scientific substantiation and formulation of strategy and technical solutions of handling liquid wastes of plants producing and refining copper-zink pyritic ores. In the course of research studied are chemical composition of technogenic waters of mining plants as well as water and alluvia of intake river within and outside a sanitary zone of Southern Ural mining plant using inductively coupled plasma mass-spectrometry and X-ray fluorescence analysis techniques. A particular focus is made on microcomponent composition. Novel data on Cd, Li, Be, Mn, Co, Cu, Zn migration with technogenic flows and accumulation of these elements in alluvia is obtained. It is showed that extraction of valuable components from technogenic waters is a novel problem for refiners that can be solved only in cooperation with mining industry ecologists. Laboratory research of selective copper and zink extraction into corresponding practical products by galvanocoagulation and sulphide precipitation is carried out. Common factors of phase formation are studied using physicochemical modeling, X-ray phase analysis and electronic microscopy. Methods of intensification of processes and increasing of extraction ratio of metals in products are elaborated. A technology of comprehensive processing of undersoil waters is proposed. Enlarged laboratory and pilot plant tests of technological solutions for protecting hydrosphere and extracting metals from mine waters carried out on several plants of UMMC-Holding Corporation showed a possibility of obtaining additional products having weight content of metal which is profitable for consequent metallurgical processing and purification of waters to comply with quality standards. A possibility of transformation of technological chain depending on season variability of water quality is put behind the designed technological schemes.

Jan 1, 2018

By S. H. Lau

Rapid 3D characterization of multiphase mineral particles in a variety of mineral processing applications is described, including: mineral liberation analysis, grain size, mineral exposure analysis, particle damage, and pore network structure for fluid flow simulation in heap leaching. While micro X-ray computed tomography systems (microCTs) have been used for many years, industrial adoption is limited due to a variety of reasons, including insufficient resolution, the general lack of imaging contrast to differentiate different mineral phases within a multiphase mineral particle and the lack of automated 3D mineral processing software. For example, resolution with industrial CTs and desktop microCT is of the order of tens of microns to a few microns at best, depending on specimen size and CT configuration. We describe a novel lab-based X-ray microscope, XRM, which overcomes these resolution and contrast limitations, notably as the industry is going towards finer grains and more complex ore bodies. Using lens-based optics and detectors (similar to its XRM counterpart in synchrotron beam lines), resolution of the lab based system is in the submicron range with contrast better than conventional microCTs. Hence, visualization, differentiation and segmentation of most mineral phases of interest to the industry are now feasible. Coupling these high resolution and high contrast tomography images with a suite of customized 3D segmentation algorithms and analysis software, applications in mineral liberation analysis for process control, particle damage assessment and other mineral processing applications can be achieved. This non invasive 3D technique which requires relatively little sample preparation is currently being considered for coal, industrial minerals, and base/precious metal ores, complementing existing microscopy techniques such as QEMSCAN and MLA for a variety of applications

Sep 1, 2012

By Jacek Kolacz

A new sensor based sorting system has been developed, based on complex image analysis, where an image texture and a shape pattern is considered for identifying particles for separation. The sorting system employs different images generated by visual light and X-ray to provide maximal information about processed particles. Application of X-ray makes it possible to analyse the internal structure of the particles, which provides a 2D image with complicated texture, however, which contains valuable information. The advanced system for the texture and the pattern recognition is applied to analyse these images simultaneously, to provide the required identification of the particles for efficient separation. The mathematical models applied during identification and separation, are assisted by high speed calculations being specially optimised for this kind of process. This allows sorting with high capacity and high accuracy, which is critical for practical applications in mineral processing. The paper describes a number of tests during sorting of iron ore and coal with high separation efficiency.

Jan 1, 2014

By Manochehr Oliazadeh

"Water shortage becomes a major challenge in mining industry. The best example is Chile where the Chilean authorities declared a state of emergency in 2012. Depletion of high grade ore-bodies necessitates the use of low grade ores. If the demand for metals remains constant, more low-grade ores need to be mined to produce the same tonnages of metals. This increases the water demand in mining industry. Mining industry competes with other industries such as agriculture and manufacturing. Agriculture and manufacturing consume 1500 and 2300 billion m3 water respectively. The global use is 4500 billion m3 while the mining uses 80 billion m3 of water per annum.To tackle the water challenges in mining industry and also avoid competing with other users for fresh water, many efforts have been made, including using lower quality waters to reduce the fresh water consumption in ore processing. Saline water or hyper saline water from seas or the ground is accessible; however the cost of desalination is remarkable. Desalination plants and associated pipelines and pumps capital cost can easily exceed $ 500 million. Saline water will certainly increase the operating costs due to high wear rate of mechanical equipment but at current situation of mining industry spending all this money upfront does not look attractive. Desalination leaves salt on land at mine site which may create environmental issues.Dry processing can be a solution for water shortage in mineral processing. Wet processes dispose tailings on land with little or no agricultural productivity. It also may contaminate surface and ground water and generate dust. This paper reviews the water consumption by various mineral commodities, discuss briefly about recent of application of salt water in mineral processes and finally discuss about dry processes as alternative solution for water shortage in mining industry."

Jan 1, 2014

By T. Khonthu

The purpose of this investigation was to evaluate the relationship between different milling procedures, viz. a ball mill and an IsaMill respectively, and the flotation performance of the different mill products. Two ores were used, viz. a base metal sulphide (BMS) and a platinum group mineral (PGM) UG2 ore. Flotation was used as a diagnostic to investigate whether the different milling procedures may have different effects of the floatability of the particles. The present study is part of a research programme investigating this question using a wide range of comminutiondevices and procedures. Similar particle size fractions from the different milling procedures were used in the flotation tests. The particles were characterized in terms of particle size distribution, morphology (using scanning electron microscopy and image analysis software) and rheology tests. The results have shown that in general when comparing similar feeds to flotation in terms of equivalent particle size distributions as indicated by the d80 value, the ball mill generally yielded better recoveries and grades in the case of the BMS and lower chromite recoveries in the case of the UG2 ore compared to the IsaMill. No significant differences were observed in the morphological or rheological characteristics of the particles subjected to the different milling procedures. Although the results appear to indicate that IsaMilling is less advantageous than ball milling in terms of the flotation performance for the two ores studied it should be emphasized that these results do not take into account the relative advantage which IsaMilling has over ball milling in terms of direct and indirect energy consumption and GHG emissions nor, most importantly, does it consider the platinum group element recoveries in the case of the UG2 which may have increased significantly as a result of the finer grind which the IsaMill produces after 4 passes compared to the ball mill after 64 min. Such results which will be reported is due course may show that the greater liberation expected after IsaMilling of the PGMs outweighs any disadvantages indicated in this study.

Sep 1, 2012

By Z. He

Based on full investigation of the characteristic of sphalerite in the residue obtained from cyanidation leaching process and the study of the mechanism of the interaction between flotation reagents and sphalerite with the aid of electrochemical analysis, the reagent named YO was developed for eliminating the depression effect of CN- on sphalerite and reducing the dosage of CuSO4. The achievements have been used in commercial production for the treatment of the cyanidation residue to recover the zinc minerals, obtaining a zinc concentrate with grade of 56.49% Zn and recovery of 86.63% Zn.

Jan 1, 2014

By S. I. Anufrieva, N. A. Permyakova, E. G. Likhnikeevich

"Russia’s rare metal reserves are composed of compositionally and structurally complex ores and are characterized by an increased content of natural radionuclides due to their geochemical similarity with rare metals. For instance, concentrates of Zashikhinsky daeposit are characterized by an increased content of uranium (0,06%) and thorium (0,59%); Beloziminsky deposit holds pyrochlore-apatite-magnetite-carbonate ores characterized by increased radioactivity (130 mkR/h) and containing 0,0016-0,0025% of uranium; Etykinsky deposit is characterized by columbite-pyrochlore-microlith mineralization with an average ore grade of 0,013% of uranium and 0,0020% of thorium; eudialyte concentrate of Lovozero deposit (Alluaiv area) belongs to Class II of mineral reserves. Industrial development of these mineral reserves involves the need to comply with environmental standards, public health requirements applicable to finished core and by-products, to take into account the amount and class of the generated radioactive waste, the possibility of disposal or recycling of the radioactive production waste. Concentration processes of radioactive rare metal feeds most often lead to a concentration of natural radionuclides and their accumulation in concentrates. Comprehensive hydrometallurgical processes are currently under development for such concentrates, aimed at producing salable products compliant with the radiation safety standards. The choice of the hydrometallurgical processing method for radioactive rare metal concentrates is based on the mineralogical component of the concentrate, textural and structural features, the distribution of valuable components and impurities, and the content of radionuclides. A systemic approach to the selection of processing methods, in particular integrating several methods, is an effective solution. Methods may not only be combined, but also inextricably linked with each other. Hydrometallurgical processing methods include leaching by acidic and alkaline agents; sulfatization for selectively decomposing the minerals and moving the bulk of U and Th into solution; fluorine extraction process. Methods of precipitation and co-precipitation, extraction (by liquid and solid extractants), sorption, and ion exchange are used to decontaminate the solutions by removing thorium, mezathorium, uranium, and their radioactive decay products. Agents used in hydrometallurgical processing of radioactive rare metal ores include sulfuric, nitric, hydrochloric, hydrofluoric acid, alkali (NaOH, KOH), sorbents (for example, AB-17) for sorption of uranium and extractants (mono- and bidentate organophosphorus compounds, diamides, etc.) for the extraction separation of rare, rare-earth, and radioactive elements."

Jan 1, 2018

By Chenyang Zhang, Zhigang Yin, Wei Sun, Jingxiang Zou, Jianyong He, Yuehua Hu, Zhijie Xu

"In this work, a novel compound 4-Amino-5-mercapto-1,2,4-triazole was first synthesized and its selective adsorption mechanism on the surface of chalcopyrite was comprehensively investigated using UV-vis spectra, zeta potential, Fourier Transform Infrared Spectroscopy(FTIR), X-ray Photoelectron Spectrscpy Measurements(XPS), and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and first principle calculations. The experimental and computational results consistently demonstrated that AMT would chemisorb onto the chalcopyrite surface by the formation of a five-membered chelate ring. The first principle periodic calculations further indicated that AMT would prefer to adsorb onto Cu rather than Fe due to the more negative adsorption energy of AMT on Cu on the chalcopyrite (001) surface, which was further confirmed by the coordination bonding energies of AMT-Cu and AMT-Fe based on the simplified cluster models at a higher accuracy level (UB3LYP/Def2TZVP). The bench scale results indicated that the selective index improved significantly when using AMT as a potential chalcopyrite depressant in Cu-Mo flotation separation.INTRODUCTIONFroth flotation is one of the most important processes to separate valuable minerals from gangue by taking advantage of differences in the physical chemistry of their surface properties(Laitinen et al., 2014), particularly in their surface hydrophobicity. Hydrophobicity differences between valuable and gangue minerals could be regulated by adding different chemical additives (surfactants)(Kor, Korczyk, Addai-Mensah, Krasowska, & Beattie, 2014), such as collector and depressant. It could be conducted economically to selectively separate and enrich the complicated and/or poor ores, by adopting appropriate surfactants. For example, the beneficiation of molybdenite usually relies on a two-stage process to realize flotation separation of molybdenite from other unwanted sulphide ores(Wie & Fuerstenau, 1974). In the first step, a bulk molybdenite concentrate is produced by utilizing kerosene/ diesel oil and pine oil/alcohols as collector and frother, respectively. Second, sodium hydrosulphide, sodium cyanide, ammonium sulphide, or Nokes reagent are adopted as depressants in the separation stage. However, these depressants are usually toxicant and cannot meet the requirements of environmental protection. A large number of efforts have been taken to develop alternative environmentally-friendly depressants (Ansari & Pawlik, 2007; J. H. Chen, Lan, & Liao, 2013; Li et al., 2015; Yin, Sun, Hu, Zhai, & Guan, 2017; Yin, Sun, Hu, Zhang, Guan, Liu, et al., 2017; Yin et al., 2016). Although some novel and environmental-friendly depressants have been reported to achieve good performance in Cu-Mo flotation separation at a laboratory scale, there are still some challenging problems, including toxicity, high price or poor performance in practice, which severely limit their practical applications in Cu-Mo flotation separation on a commercial scale."

Jan 1, 2018

By O. V. Suvorova, V. G. Minenko, D. V. Makarov, A. L. Samusev, E. A. Selivanova

"Saponite is a valuable marketable product widely used foundry, metallurgy and construction, in the chemical, food and consumer goods industries, in medicine, and in agriculture.The feasibility of producing of high-quality construction materials with enhanced physical-chemical and decorative characteristics from saponite-containing products has been given a scientific basis and experimentally validated. The compressive strength of the samples in the sintering temperature range of 800-1000 ?? varied between 35 and 80.9 MPa; the bending strength 8 and 26.7 MPa, which is superior to the high-grade ceramic bricks of the M-300 brand. It has been established that the saponite-containing product obtained using the electrochemical separation of process water has a high sorption capacitance relatively the heavy-metal ions such as nickel and copper (40.7 and 99.8 mg/g, respectively). As a result of sintering at 750 ?? the sorption capacity of the sorbent for the nickel and copper ions increased to 194.2 and 212.8. Using the XRD and SEM with energy-dispersive spectroscopy studies, we diagnosed the metal-containing phases and validated the metal sorption mechanism.This study opens up the possibility of practical realization of the saponite-containing product as high-quality building materials and heavy-metal sorbents while addressing the issue of process water treatment. INTRODUCTION The Lomonosov deposit of the Archangelsk diamondiferous province accommodates 10 kimberlite pipes. The anticipated volume of diamond-bearing ore and dump rock to be removed before reaching the open-pit mining limit is 300 mln t (Karpenko, 2009; Bezborodov, etal. 2003). Rock in the deposit is almost completely displaced by clay minerals, predominantly saponite, amounting to 90% in the vent facies (Karpenko, 2009)."

Jan 1, 2018