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By Ricardo Montero

At this time, over 300 tons of Au are used in electronic equipment each year with other precious and strategic metals such as Ag, Pt, Pd, Cu, Nb, Ta, etc. After the use-phase, the electronic devices become electronic waste (e-waste); consequently it is important to consider e-waste as a secondary supply for recovery of these metals. One of the most important components is the printed circuit boards (PCBs) because the amount of their precious metals is ten times higher than rich precious metals bearing ore. This paper presents the recovery of Au, Ag, Cu and Nb from PCBs of discarded computers using leaching column technique. The amount of these metals in used PCBs was: 613 g/ton of Au, 1515 g/ton of Ag, 36 g/ton of Nb and 23.4 % of Cu. The PCBs were crushed with a hammer mill until reaching a particle size between 3.33 mm to 0.43 mm. Then, it was leached with sodium cyanide solution in a glass column using the following conditions: sodium cyanide concentration 4 g/L, flux 20 L/kg PCBs day, pH between 10.5 to 11 and leaching time 15 days. Every day, after leaching, the pregnant solutions passed through a column with activated carbon to complete the closed loop system. The following recoveries were obtained: 46.6% of Au, 51.3% of Ag, 47.2% of Nb and 62.3 % of Cu. The products obtained are: a) loaded carbon that contains the desired metals and b) processed PCBs with precious metal contents. A preliminary technical-economic study shows the feasibility to create a small-scale PCBs recycling plant. The initial investment is on the order of US$ 155 639, considering the recovered metals from loaded carbon. The internal rate of return for 10 years period (IRR) and net present value (NPV) estimated are 27% and US$ 105 926 respectively. Keywords: printed circuit boards, recovery, precious metals, niobium, leaching column

Sep 1, 2012

By Lev Filippov, Lorène Dessalas, Inna Filippova, Yves Foucquet

"Seafloor massive sulphide (SMS) deposits, similar in composition and genesis to terrestrial volcanogenic massive sulphide deposits, are generally found in volcanic seafloor environments along major rifts and mid-ocean ridges. Theyare associated to extensional tectonic settings such as nascent-arc, rifted-arc and back-arc environments. They may represent important source of base metals and be an alternative to on-land resources. Seafloor massive sulphide deposits have particular mineralogical compositions and textural features differentiating them from terrestrial one. When extracted from salty water and exposed to the ambient air, massive sulphide samples strongly oxidize and soon become covered by thin layers of iron, copper and zinc rich sulphates and oxides, as well as elemental sulphur. The textural properties vary according to the degree of maturity and the sample position within the hydrothermal deposit. The total porosity of that type of samples is also relatively high, especially for immature samples such as black smoker chimneys, which can reach 15% of total porosity. Because the secondary mineralization and porosity level are different, seafloor massive sulphides ores respond differently from terrestrial ore to processing methods. Froth flotation, commonly applied to separate all type of sulphides from the gangue, is one possible technique for processing seafloor ore. Sulphide recovery rate is, in most cases, excellent (>90%) however separation of the various mineral phases is difficult to obtain even when applying known methods used for terrestrial ore. Moreover, the flotation behaviour decreases drastically with the time of conservation at the surface, even when the samples were stored in a confined environment. High pH values, which is a good way to depress pyrite and therefore to favour the flotation of copper and zinc sulphides, do not have the same effect on seafloor ore. Consequently, careful flotation procedure must be elaborated to obtain efficient mineral separation technique for this specific marine ores."

Jan 1, 2014

By Venugopal Tammishetti

One of the important technological challenges facing the iron ore industry in India is to find commercially viable technologies to process alumina rich iron ore fines and slimes. The key to solving this problem lies in developing selective reagents for the separation of iron oxide minerals from associated gangue minerals like quartz, gibbsite, kaolinite and montmorillonite. We present in this paper our successful results on the dispersion-flocculation of three different natural iron ore slime samples from mines in India using the reagent combination of PVP dispersant and corn starch flocculent. All the three samples contained hematite, goethite, kaolinite and gibbsite minerals as confirmed by X-Ray Diffraction (XRD) analysis. The effect of various process parameters such as pH, dosage of reagents, settling time and pulp density was studied. We were able to produce a concentrate assaying 66.2% Fe and <2% Al with a yield of 67.4% by weight (with a recovery of 77% of iron values) using PVP (1 ppm dosage) and corn starch (20 ppm) for one of the slime sample (Sample I) assaying 58.2% iron (Fe) and 3.8% aluminium (Al). The XRD analysis of settled and dispersed fractions revealed that alumina-containing minerals like clay and gibbsite mostly remain in the dispersed phase while iron-bearing minerals tend to concentrate in the flocculated fraction. Keywords: iron ore, slime, flocculation, dispersion, beneficiation, starch, polyvinylpyrrolidone

Sep 1, 2012

By A. Qaredaqi, M. Mohammadi

Wet High Intensity Magnetic Separators, for short, WHIMS are used for recovery of Iron ores with low magnetic susceptibility. A Jones patent WHIMS with "grooved plates" matrix is being used in Dry Tailing processing line in Hematite Recovery Plant at Golgohar mining & Industrial Co. for recovery of Hematite. In this kind of separators Matrices are used for increasing the Magnetic field intensity and providing high magnetic field gradient. The laboratory WHIMS in Golgohar Iron Ore and Steel research Institute is capable to provide a background magnetic field strength up to 0.85 Tesla and in presence of ‚expanded metal? matrix, magnetic field intensity could increase up to 0.9 Tesla. More than 50% of feed particles in this separator were finer than 36 micron and recovery of these particles needs more magnetic field intensity. Hence, ‚Grooved Plates? matrices with Js= 2 Tesla and 3.8 mm gap were constructed. Measurements indicated that magnetic field intensity around the matrix will increase to 1.25 Tesla. Graph of Magnetic field intensity around the matrix to background magnetic field intensity was plotted and a model with Rsquare= 0.9 was offered. In addition, magnetic field gradient and magnetic force were calculated. In WHIMS with feed top size of 150 micron, the main effective forces on separation process are the magnetic force and the hydrodynamic drag force. With assuming that the particles are smooth and spherical and the flow is laminar, Recovery of fine magnetic particles is problematic in this separator because of drag force. Considering these facts and mentioned model, finest particles that are recoverable in different magnetic field intensities were calculated. Computations illustrated that with magnetic field intensity more than 0.8 Tesla, particles as fine as 4 micron are theoretically separable but it should be noted that in practice a larger attractable particle size would be expected.

Jan 1, 2014

By I. Yochev, A. A. Metelev, A. I. Stepanenko, A. P. Purgin, M. G. Viduetsky, A. M. Panshin, I. F. Garifulin

"Pneumatic flotation cells of the KFM series are intended for the concentration of various ores and technogenic materials. The key operating principle of the flotation cells of the KFM series is the preparation of pulp for flotation in blowers, offering the advantage of an accelerated flotation process. This report summarizes the results of the implementation and operation of the KFM cells at Russian and foreign projects in 2015-2017. Their implementation and operation experience confirms the high efficiency of the KFM cells, especially in the head of lead and zinc, copper and zinc, copper flotation processes:head KFM-600 flotation cell recovers from lead-zinc ore (Rudmetal AD modular concentrator) up to 52% of lead in a single stage (without cleaner flotation) in a salable lead head concentrate (grade of up to 76% lead, 2.3% zinc). The flotation cell proved to be much more efficient than originally expected in the process description in the design phase,flotation of the copper-zinc ore from Novo-Shemur deposit (PJSC Svyatogor concentrator) in two KFM- 1400M cells recovers up to 65% of copper and 70% of zinc in a high-grade bulk copper-zinc concentrate containing 12-13% of copper and 25-28% of zinc. The installation of the two cells with a combined capacity of 26 m3 allowed to decommission 4 chambers of FPM-16 pneumomechanical flotation cells with a combined capacity of 64 m3 with a simultaneous increase in the overall ore concentration performancea single KFM-1400M cell (13 m3) recovers from the copper ore from Volkov deposit (PJSC Svyatogor concentrator) 53% of copper into a high-grade copper head concentrate (33.0% of copper). For comparison, the pneumomechanical cell FPM-16 (capacity 16 m3) has almost half as low copper recovery (29.6%) into the head concentrate at a lower grade (30.5% copper)."

Jan 1, 2018

By Ming’an Wei, Chuanyao Sun, Zhenguo Song, Zengwen Dou, Yangge Zhu

"The effects of pH value and dissolved oxygen(DO) in the pulp to the Eh and flotation recovery of pyrite were investigated using potential online detection system. The effects of DO on the Eh and flotation recovery were tested which DO changed from 0.5mg/L to 19.5mg/L in six different pH buffer flotation systems (pH: 4.00, 5.62, 6.86, 9.18, 10.01 and 10.96 respectively). Results of potential detected online demonstrated that the pyrite electrode has nearly the same response to potential as with platinum electrode for the FeS2-xanthate-H2O flotation system under the study conditions. Pulp potential and recovery of pyrite were remarkably influenced by pH, both of them decreased with the increasing of pH and, especially, sharp decreased after pH above 9. As the concentration of DO was increased, the Eh was also increased in all the six different buffer solution, while the flotation recovery was decreased. And the amplitude of variation for Eh was not obvious in acidic and neutral solutions, but on the contrary, the change for flotation recovery was remarkable in neutral and alkaline conditions. This may indicate that the flotation of pyrite will be deteriorated in alkaline and high DO concentration conditions."

Jan 1, 2014

By I. I. Maximov

The paper describes the results of studies performed with a view to develop an improved technology for processing high-grade massive and cupriferous ores of the Talnakh deposit, the main valuable components being nickel, copper and PGM. The studies? main task was production of nickel concentrate with nickel content of approx. 15%, nickel recovery being as high as possible. The studies were performed on two ore samples. One sample was a mix containing high-grade massive (78%) and cupriferous (22%) ores with nickel content of 1.93% and copper content of 3.6%; the other sample was a mix of high-grade ores with nickel content of 2.25% and copper content of 3.72%. Main ore minerals were copper sulfides ? chalcopyrite and cubanite, their total content being 10.5% ~ 11%, pentlandite (5.2% ~ 6.1%) and pyrrhotite (36.7% ~ 42.9%). Influence of grinding media on pentlandite and pyrrhotite separation results, achieved through combined use of triethylenetetramine (TETA) and sodium sulfite (SS), was also investigated. It is shown, that combined application of TETA/SS in the ratio of 1:2, permits to grind products in metal mill (mild steel) with metal balls (mild steel), achieving results that are similar to those achieved by means of grinding in inert grinding media with TETA/SS ratio of 1:1. Application of the developed technology provided for production of high-grade nickel concentrate with nickel content of 14.7% ~ 15.6%, nickel recovery being 76 % ~ 77%. Earlier experiments performed on the above mentioned ore mix permitted to produce nickel concentrate with nickel content of 10%, nickel recovery being 75.9%. Consequently, nickel content was increased by 4.7% ~ 5.6%, and a higher nickel recovery was achieved. The paper also describes metallurgical results related to nickel, copper and PGM with regard to all processing products.

Jan 1, 2014

To extract the gold from refractory gold concentrate with high sulfur and arsenic, the gold concentrate was catalytically oxidized to expose the gold for cyanide leaching. The effects of reaction temperature, initial nitric acid concentration, reaction time and initial gold concentrate concentration on the conversion rate were studied. The results show that the appropriate conditions for the catalytical oxidation of this gold concentrate are: reaction temperature of 65 oC; initial nitric acid concentration of 25% (wt.); reaction time of 1.5 hours; initial gold concentrate concentration of 10% (wt.). Under such conditions, the conversion rate of gold concentrate is 92%. The solution can be used to prepare nano-iron oxide red pigment. Gases released in the process can be recycled and reused by oxidation absorption. A chemical background of catalytic oxidation is proposed.

Jan 1, 2014

By A. V. Myaskov, V. S. Valavin, K. D’Elia, I. O. Krylov, Vu Van Toan, T. I. Yushina

"The purpose of this research is the development of a technology for processing the concentration tailings of limonite ores at Kamysh-Burun Mining and Processing Complex into an iron- containing product for ROMELT process. In the concentration and metallurgical processing of iron ores, substantial amounts of waste are generated (tailings, slimes, slags, metallurgical dust, etc.) that can be converted into a commercial product if is properly processed. This article presents the results of experimental studies of the feasibility of processing iron- containing tailings of Kamysh-Burun deposit (slimes from Verkhne-Churbash storage facility (VCh sample) and dumped waste of Kamysh-Burun (KB sample)) to obtaining valuable components for further uses. Applying Mossbauer spectroscopy has been shown that the iron minerals in the studied samples are technogenic varieties of iron hydroxides. The most suitable technology is the magnetic roasting process, since iron hydroxides are easily transformed into a magnetic, easily recoverable form. Have been shown the advantages of a two-stage magnetic separation, in a strong field and with polygradient separators. Concentrating this material through magnetic methods makes it possible to increase the iron content to 20-21 %. Magnetic concentration of the deeper layers materials results in iron- containing concentrates with a total iron content of up to 58% whit a phosphorus content of about 2%. Reducing the phosphorus content is possible by blending upper and lower layers of the material at a ratio of 1:1. Thus, it is possible to process the material accumulated in the slime storage facility using the ROMELT process combined with preliminary three-stage magnetic concentration and disposal of tailings with the permissible iron content of less than 5%. Wastes from smelting will be slags suitable for use in construction industry. The Kamysh-Burun material preparation for ROMELT process should be performed applying gravity-washing with separation of the -0.4 mm fraction and additional blending for dephosphorizing the concentrate. The smelting will produce pig iron and slag."

Jan 1, 2018

By Ray Everson, Henry Kasaini

"We carried out adsorption experiments in chloride media to study the adsorption characteristics of Pd (II) anions on the surface of activated carbon. Throughout the experiments, we used commercial activated carbon pellets (0.8 Norit). The adsorption process was interpreted by using the ionisation and adsorption model. This implies that palladium anions were adsorbed physically on a protonated surface of activated carbon either as anionic complex species (PdCl4 -2) or aqua chloro-complex species [PdCl3(H2O)-] in acidic media. Furthermore, we established that adsorption of Pd (II) species was reversible at high chloride [Cl-1] concentration. The maximum adsorption capacity (Qsat) of Pd (II) anions averaged 27 mg/g. The Toth adsorption isotherms fairly predicted the equilibrium adsorption of Pd (II) species and the associated surface coverage.The effect of temperature and acid strength of the feed solution on the adsorption of Pd (II) ions were quantified. The adsorption kinetics was limited by external mass transfer since the effect of pore diffusion on the overall rate constant was negligibly small. A pseudo first-order kinetics model was used to describe the adsorption kinetics."

Jan 1, 2003

By A. V. Golovanov, A. V. Mihailova

"NPO RIVS employs complex approach to engineering and design of the new facilities in close cooperation of Mining, Research, Hydrometallurgy, Design, Construction, Power Supply, Automation, Production and other departments. General Design Contractor (and then General Contractor) is directly involved in geological exploration, engineering surveys, floatability studies, feasibility study of process solutions and construction options. It delivers greenfield project and guarantee its efficient performance in future. Shiralgin is a small gold and copper deposit, gold average grade is 4.7 g/t. RIVS departments have studied ore floatability, developed process procedures for design and performed pilot testing. Construction of integrated plant including ore crushing and grinding, flotation and hydrometallurgy units with Dore gold production of 5 000 thousand tons ore per year (66.7 t/h) is recognized as economically viable. The technology used of separate dry stockpiling of flotation tailings and cyanidation tailings. Water circuit for concentration and hydrometallurgy is separated, too. Process design was performed based on BIM software like Autodesk Revit, Civil 3D, Rocscience slide using process procedures developed by RIVS Research units. Engineers provided modeling of primary crushing unit, coarse ore storage, main building (including grinding, flotation, thickening, filtration, loading, hydrometallurgy), tailings thickening unit, building for reagent storage and conditioning, tailings pond for dry stockpiling of flotation tailings and cyanidation tailings, sedimentation ponds, laboratories, infrastructure including Administration building and camp. Payback period is 3.5 years. 3D model of facility is currently stored at the State Agency of Geology and Mineral Resources affiliated to the Government of the Kyrgyz Republic.INTRODUCTION The Kyrgyz Republic has substantial potential of mineral resources including gold ores. Mining industry actively develops and involves international investors. Inventory includes 42 deposits (Figure 1) that have reserves of 616.4 t [1] of gold. The Kyrgyz Republic takes the third place in gold mining among CIS countries after Russia and Uzbekistan by producing up to 20 t annually."

Jan 1, 2018

By N. Vorob?ev-Desyatovskii

The process of gold(I) adsorption on activated carbon (AC) from aqueous Na[Au(CN)2] and the state of the adsorbed gold cyanide complex on the adsorbent surface was investigated by photometry, XPS, XANES methods. By DFT method, quantum-chemical calculations were performed of the gold cyanide species on activated carbon surface. It was established that the binding of gold(I) with the surface of carbon involved several simultaneous processes governing the selective adsorption of gold(I) from the cyanide solutions.

Sep 1, 2012

By Elzbieta Mielczarski, Jerzy Mielczarski, Jan Drzymala, Yann Duvalm

Polyethylene glycol monoalkyl ethers (CnEm) render quartz hydrophobic while feldspar remains hydrophilic. As a result quartz can be separated from feldspar in small frothless flotation devices such as the Hallimond tube. The separation can be accomplished at room temperature at pH < 7 and C16E33 concentrations between 10-5 and 10-4 M for quartz particles smaller than 0.4 mm. No separation is observed when feldspar ore containing about 60 % of feldspar and 40% of quartz is subjected to flotation in a laboratory flotation machine. The reason for the lack of separation is a low hydrophobicity of quartz in the presence of polyethylene glycol monoalkyl ethers and high intensity of mixing in the flotation machine. The flotometric tests showed that the contact angle of quartz in monoalkyl ethers of polyethylene glycol solutions is less than about 18 degrees and depends on the structure and concentration of the ether and the pH of the system.

Jan 1, 2003

By Gulsen Tozsin, Ekrem Kalkan, Taskin Oztas, Elif Agirman Akturk, Ercument Koc, Ali Ihsan Arol

Marble wastes are generated by quarries (marble quarry waste-MQW) and processing plants (marble cutting waste-MCW). The large amount of marble wastes is becoming serious problem for industry and environment because of discarded into rivers and lagoons, without any treatment. Marble wastes can cause environmental problem and economic loss if the waste is not used. However, this type of wastes has a good potential to be used as an amendment for the neutralization of acid soils. In this study, MQW and MCW were applied to an acid soil at different rates and their effectiveness on neutralization was evaluated by a laboratory incubation test. The results showed that soil pH increased from 4.71 to 6.36 and 6.84 by applications of MCW and MQW, respectively. It was suggested that MQW and MCW could be used as soil amendments for the neutralization of acid soils, and thus the negative impact of marble wastes on the environment could be reduced.

Jan 1, 2014

By Y. Y. Emelianov

The results of the test work of four treatment options of three refractory gold-pyrite and gold-arsenic flotation concentrates are presented. These concentrates were obtained during the concentration of primary ores of large gold deposits. It was found that ultrafine grinding of refractory flotation concentrates did not increase the recovery of gold during subsequent cyanidation. The elimination of sulfur and arsenic during oxidative roasting is 99 per cent. 88-93 per cent of gold is recovered by cyanidation from calcines. After biooxidation of the flotation concentrates with a mixture of strains Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans 88-91 per cent of gold is recoverable by direct cyanidation. The recovery of gold from flotation concentrates by pressure oxidation is 88-99 per cent. These results suggest that gold recovery is important but the following strategies would have an impact on a plant performance and would be considered when developing an option to treat refractory ores: capital and operating costs, ore reserves, mine location, infrastructure and qualified staff. Keywords: gold, flotation concentrates, recovery, cyanidation, roasting, biooxidation, pressure oxidation

Sep 1, 2012

By P. Knüpfer, B. Babel, M. Rudolph, F. Perez Maldonado, U. A. Peuker, L. Ditscherlein

"In heterocoagulation processes for the separation of mineral particles, the most famous being froth flotation, the main characteristic of separation is a differing wettability of the constituents to be separated. This most crucial property in the economically important process of flotation is often only and incompletely, quantitatively described in terms of contact angles against water. A water contact angle larger than 90° is referred to as hydrophobic and hydrophilic vice versa. Looking at Young’s equation shows that it is actually the surface energy of the solid in interaction with the surrounding phases and their surface energies (or surface tensions for liquids) which describes whether there will be hydrophobic/hydrophilic hydration interactions leading to attraction or repulsion. This, we have previously published for various more or less hydrophobic minerals in correlation to their flotation response, i.e. flotability (c.f. Rudolph & Hartmann, Coll.Surf.A 513, 380-388). In the same paper we also discussed the heterogeneity of wettabilities as assessed with the novel method of inverse gas chromatography. Furthermore we have also reported on hydrophobic force distributions as assessed with atomic force microscopy which are as well due to wettability heterogeneities (c.f. Fritzsche et al., Coll.Surf.A 459, 166-171).In this paper we present wettability distributions of different substrates and particles with various surface roughnesses/shapes and degrees of hydrophobization as assessed with iGC, AFM and dynamic sessile drop analyses. We are putting the results in context in unifying models and present methodologies helpful to make use of the fundamental information and their impact on the actual industrial separation process in fundamental process models. Besides froth flotation we also emphasize the impact on selective hydrophobic flocculation process."

Jan 1, 2018

By J. A. Venter

Mineralogical studies indicate the Pt-Pd-Bi-Te class to react poorly on the flotation stimuli and indications are that these minerals are slow floaters. However, recent studies performed on a number of minerals from this class indicated strong interactions with potassium ethyl xanthate resulting in the formation of dixanthogen (only one of several xanthate species). The poor flotation response is not a result of poor interaction of xanthate with the surface. It is proposed that the oxidation products of sulfides in the process water interact with the PGM surface. To test this, the effect of thiosulfate (an important oxidation product of sulfides) was investigated by employing electrochemical measurements and FTIR spectroscopy. The electrochemical investigations indicate no strong effect of thiosulfate on the interaction of xanthate with the minerals surface as well as the reduction of oxygenthiosulfate is likely not responsible for the poor flotation response of these minerals in industrial plants.

Jan 1, 2014

By M. Saba

In cyanide leaching procedure, achieving an acceptable efficiency for silver and gold is very time-consuming, thus, enough studies have not been performed for optimization and modeling of this process. The kinetics of cyanide leaching includes two steps: first step comprises a sharp slope while the other has a slight increasing trend. In the present study, in order to reduce the time and cost, the cyanide leaching process of a sulfide silver/gold ore was optimized in the first period. The applied parameters and their ranges are: temperature 20-40 (°C); time 1-8 (hrs); cyanide concentration 1-2 (mole cyanide / mole Cu); the percentage of solid to liquid 1-2 (%) and pH 10-12. For design of experiments fractional factorial 2(5-1) was used. Also four center points were applied to increase the accuracy of the model. In addition, by analysis of variance (ANOVA) the most effective parameters were identified and the optimized condition was determined. A regression model was proposed to describe the effects of independent variables and their interacting role on silver recovery. Results showed that the model was linear for silver and nonlinear for gold. In the gold recovery process, the two important parameters are time and pH with the former being more effective. Due to the existence of cyanide ions in the medium, temperature and cyanide concentration have less influence in the gold recovery process. Solid to liquid ratio, in addition, comprises a slight negative impact on the procedure. This emphasizes the different kinetics of silver/ gold cyanide leaching. Finally, using the optimum condition the amount of silver and gold obtained were 61% and 67% in 8 hours, respectively. While in general conditions, the results were 37% and 54% in 24 hours, respectively. Keywords: cyanide leaching, refractory gold/silver ore, modeling, optimization

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 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