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By M. L. Wu

A moderately thermophilic acidophiles strain had been isolated from the bio-heap leaching plant in Zijinshan Copper Mine, and the identification based on the PCR-16S rRNA gene sequence homology analysis with morphologic and physiologic methods was conducted by polyphasic taxono-my and phylogeny research. The results show that the strain by depurated belongs to Acidthiobacillus genus and is considered as Acidthiobacillus albertensis.

Jan 1, 2014

By E. V. Koporulina, E. L. Chanturiya, M. V. Ryazantseva, E. S. Zhuravleva

"The morphology of the surface of sphalerite, galena and chalcopyrite and the adsorption of butyl xanthate under conditions of preliminary treatment of minerals by the products of water electrolysis were studied using atomic force microscopy (AFM) and Diffuse Reflection Infrared Fourier Transform Infrared Spectroscopy (FTIR). It was determined that practically all types of treatment by electrochemically modified water (a product of non-diaphragmatic treatment, anolyte and catholyte) lead to an increase of surface roughness of the studied minerals due to formation of small rounded shape particles. In contrast to that, after treatment of chalcopyrite by anolyte, its surface becomes smoother. Various effects of treatment by the water electrolysis products on the adsorption of chemical and physical forms of butyl xanthate on the studied sulfides were established. As a result, the efficiency of the complex of AFM and FTIR methods, as one of the ex-situ approaches for monitoring the surface state of sulfide minerals and direct investigation of BKx adsorption products was demonstrated.INTRODUCTION In mineral processing, copper-zinc sulfide ores are one of the most complex products in view of their mineral composition, fine dissemination, complex inter-growth and the proximity of the technological characteristics of copper, zinc and iron sulfides. For the most complete disintegration, fine grinding of ores to a size of 0.074-0.044 mm is necessary. Consequently, the main method for processing of such ores is flotation, which bases on the difference in physical and chemical properties of the mineral surfaces, in particular, degree of wettability. The separation of copper and zinc minerals and their separation from ferrous and other sulfides, sulfosalts and rock mineral is a very difficult task (Chanturiya, 2000). For the successful separation of copper and zinc minerals in the appropriate selective concentrates, it is necessary to find conditions for the most complete liberation of ore and rock-forming minerals and for increase the contrast in physical and chemical properties of their surfaces. Despite significant progress in the processing of copper-zinc sulfide ores, the problem of the selectivity of the separation of the main ore minerals has not yet been fully solved and requires innovative approaches (Chanturiya, 2015). To date, various methods of preliminary energy processing of complex ores are used: magnetic pulse treatment, impact by high-voltage nanosecond pulses, electrochemical effects (including products of water electrolysis (Chanturiya et al., 2014; Bunin et al., 2015; Chanturiya et al., 2014a; Chanturiya et al., 2016), processing with flotation reagents, etc. Electrochemical treatment of water in various modes allows to obtain products of electrolysis with different oxidation-reduction properties: acid anolyte with a high oxidation potential and dissolved oxygen content, an alkaline catholyte with high reducing properties and a product of non-diaphragmatic treatment with enhanced reduction properties."

Jan 1, 2018

By I. Nishkov, I. Grigorova, M. Ranchev, S. Dzhamyarov

"Chelopech concentrator (part of Dundee Precious Metals) is located in central-western Bulgaria. The current process plant utilizes conventional primary crushing and SAG mill grinding, copper and pyrite rougher and cleaner flotation stages to produce a marketable gold-rich copper and pyrite concentrates. As in the most processing plants, the pyrite depression is carried out alkaline media using lime. The subsequent activation of pyrite mineral is achieved by adding sulfuric acid, which has an adverse effect on the flotation equipment. Therefore, a series of laboratory flotation experiment for activation of lime depressed pyrite by ammonium salts, such as ammonium chloride (NH4Cl), ammonium sulfate (NH4)2SO4 and ammonium bicarbonate (NH4HCO3), have been conducted. The obtained results showed that ammonium bicarbonate proved to be the most appropriate reagent choice for pyrite mineral activation. These results are confirmed by X-ray photoelectron spectroscopy (XPS), performed to determine the surface chemistry of pyrite in its natural state, after lime treatment and subsequent treatment by NH4HCO3. The registered XPS spectra indicate that the hydrophilic phases on the pyrite surface could be efficiently removed by using the ammonium salt NH4HCO3. The industrial use of NH4HCO3 as an activator of lime-depressed pyrite is a possible alternative for sulfuric acid replacement as a most widely used pyrite activator. Flotation experiments with addition of 200, 400, 600 and 800 g/t from each of the studied ammonium salts have been conducted. Furthermore, the impact of the flotation pulp pH within the scope of 9.00 – 10.50 was also investigated. The obtained results from the laboratory flotation experiments, showed that the pyrite activation with ammonium bicarbonate is an excellent possibility for replacing the sulfuric acid as main pyrite activator reagent, in order to eliminate the gypsum accumulation during the flotation of pyrite in Chelopech concentrator.INTRODUCTION The Chelopech deposit, located about 60 km east of Sofia is one of the largest Cu-Au deposits in Europe. The ore have complicated mineralogical and chemical composition. The main ore minerals are represented by pyrite, enargite (luzonite), tennantite, chalcopyrite and bornite. The average copper content of the mined ore is about 1.1 % and the gold content is about 4.0 g/t."

Jan 1, 2018

The status quo of ecological rehabilitation in metal mine in China and progress in the technology for ecological rehabilitation are presented, including soil reconstruction, soil improvement, plant selection. The present and future research fields are suggested: basic theory of ecological rehabilitation, operative technology of ecological rehabilitation, new technology application research and ecological rehabilitation plan, management and policy.

Jan 1, 2014

By Z. M. Dai

Microorganisms in AMD (Acid Mine Drainage) were enriched in 9K culture medium. The enrichment was applied to leach copper pyrite after the microbial community structure and metabolism was stable. Before and after bioleaching, the microbial DNA was extracted and applied to RFLP (restricted fragment length polymorphism) analysis to demonstrate the relationship between the leaching efficiency and the change of microbial community. Atomic absorption spectrometry results showed that when concentration of the pulp was 10% and pH were 1.5, 2.0 and 2.5, the leaching rate were 56%, 57% and 34% on the 18th day respectively. These results indicated that the rise of pH resulted in the decrease of leaching rate. In lower pH condition, the growth of microbe was faster: when pH was 1.5, the microbial cell number reached to 1.4×107cells/mL on the 9th day; while pH was 2.5, the microbial cell number decreased to 4×106cells/mL. The analysis of microbial community structure showed that Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans were dominant species before bioleaching (account for 43% and 32% respectively). And after bioleaching, these two species were still dominant when the initial bioleaching pH were1.5 and 2.0. While the initial bioleaching pH was 2.5, the proportion of these two species decreased. These results demonstrated that the initial bioleaching pH would affect the microbial community structure in bioleaching system at room temperature, and this affect could lead to different copper pyrites bioleaching efficiency.

Jan 1, 2014

By V. Panayotov, M. Panayotova

"Wastewater from ores processing is often polluted by molybdate and sulfate (SO42-) ions. Sorption is one of suitable methods for removing those pollutants when presenting in low concentrations. This work reports results on adsorption of sulfate and molybdate ions on metal modified (with barium - Ba and lead - Pb) and organic reagent modified (with Hexadecyl-trimethyl-ammonium bromide - HDTMA) clinoptilolite. Zeolite’s modification with Pb, Ba and HDTMA increases its uptake capacity with respect to Mo(VI) at pH 3, with the uptake capacity decreasing in the order CL-Pb > CL-HDTMA > CL-Ba. Lead-modified clinoptilolite shows high uptake with respect to Mo(VI) in acidic, neutral and slightly alkaline conditions. The presence of SO42- in concentrations twice higher than the amount of Mo(VI) do not interfere with the Mo(VI) removal by CL-Pb. Zeolite’s modification with Ba and Pb renders it able to immobilize SO42- from water in the pH range 3-9. Kinetics of the uptake process is best described by the pseudo-first order kinetic equation. Increasing the initial concentrations of Mo(VI) and SO42- increases the removed amount of pollutants. INTRODUCTION Wastewater from copper-molybdenum ores processing is often polluted by molybdate and sulfate ions. Molybdenum (Mo) migrates easily in water and consequently the Mo polluted areas could extend for hundreds and thousands of meters (Ryzhenko, 2010). Molybdate anion is the only Mo(VI) species in natural water, i.e. at pH > 6.0. Its median freshwater hazardous concentration affecting 5% of the species (HC 5.50%) is 38.2 mg Mo/L (De-Schamphelaere et al., 2010). The marine water chronic toxicity (HC 5.50%) is assessed at 5.74 mg Mo/L (Heijerick et al., 2012). The predicted no-effect concentrations (PNEC) are 12.7 mg Mo/L and 1.92 mg Mo/L correspondingly for freshwater and marine water (Heijerick et al., 2012a). When sulfates present in drinking water in excess of 250 mg/L they cause a cathartic action (especially in children) in the presence of sodium and magnesium, and when the concentration exceeds 600 mg/L, diarrhea. When sulfate-rich effluents are discharged into the environment, they may increase the acidity of water bodies and soils (Guimarães and Leão, 2014). Because of the adverse effects to human health and the environment, limits are set for SO42- concentrations in waters and wastewaters in the range of 250 / 500 mg/L."

Jan 1, 2018

By Z. H. Li

In connection with the features of characteristic waste water (containing cyanogen, arsenic and heavy metal) pollutants discharged by gold industry as well as the environmental features at the location of gold production enterprises, this paper briefly described the traditional method of treatment, and focused on the argument for technologies of clean production, advanced treatment and process control technology. Moreover, it clarified the future policies and development trend for treatment on characteristic waste water from gold industry.

Jan 1, 2014

By H. J. Wu

The optimum performance in mineral processing plants usually demands the optimum size reduction, which is frequently achieved by a closed grinding circuit. Due to the difficulty associated with fine size classification, the size separation efficiency in closed grinding circuit is usually very low, which leads to huge circulating load and significant overgrinding. Recent development of Der-rick Stack Sizer has made an efficient fine size separation down to 200 mesh with a satisfactory screening capacity. With the efficient fine size separation with Derrick Stack sizer, the problems commonly associated with typical closed grinding circuit, including high circulating load and over-grinding, have been eliminated. Feedback from numerous Stack Sizer applications in iron ore industry indicated that, compared with conventional fine size classification equipment, the circulating load achieved by Derrick screen was usually decreased from approximate 300% down to 60% or so, while the iron recovery has been increased by 6% to 8% only by more efficient size separation in the closed grinding circuit. To study this phenomenon, this paper discusses the relationship between size classification, circulating load and mineral recovery in the closed grinding circuit. A simulation model to predict the improvement in the grinding circuit from more efficient screening is also introduced with this paper.

Jan 1, 2014

By Gaom M. W.

The Mount Isa copper concentrator started operation in 1973. Its secondary grinding circuit consisted of two 5 meters diameter ball mills in closed circuit with 505 mm cyclones. At the design throughput of 800 t/h, the 80% passing size of the circuit product (P80) was about 140 µm. The then Mount Isa Mines Limited (?MIM?) installed two autogenous grinding (?AG?) mills in 1991 to replace two stages of crushing, a rod milling stage and one primary ball milling stage. One of the AG mills was later converted to semi-autogenous grinding (?SAG?) operation by the addition of a steel grinding medium to achieve the designed plant throughput of 800 t/h. The cyclone over-flow P80of the secondary ball mill circuit was reduced to 120 µm by the increased operating power in the AG/SAG mill circuits. The two secondary balls mills had a grinding power of 5.2 MW. A mineralogical study of the milled products indicated that half of this grinding power was sufficient for adequate chalcopyrite liberation. Eliminating one of the secondary ball mills could reduce energy and operating costs by more than A$2 million dollars per year. An optimisation project team was established to achieve the predicted power saving. Grinding circuit simulations were conducted for different circuit configurations. Ball mill parameters such as ball size, ball charge and feed slurry density were optimised. Cyclone body diameter, spigot and vortex finder sizes, and cyclone types were tested. The secondary ball mill circuit was redesigned and several proposed circuits were run as trial production campaigns to determine their operability and efficiency. The plant trials confirmed that one of the secondary ball mills could be decommissioned. Significant cost savings were achieved as a result. The success of the project demonstrates optimising grinding circuits can not only deliver the plant performance, but also a much lower unit operating cost through energy and maintenance savings.

Jan 1, 2014

By B. H. Zhao

A low grade Pt-Pd ores, with 1g/t Pt and 0.13g/t Pd, and 8.70% Fe and 2.50% P2O5 is experimented to recover of Pt and Pd. The flowsheet is proposed which consists of Pt-Pd selective flotation, apatite flotation from tailings of Pt-Pd flotation, magnetic separation of magnetite from apatite flotation tailing. With butyl xanthate, N-ally group-O-isobuturyl-thioanimoformate and Sodium y-89 xanthate as collectors, sodium silicate as depressant, and sodium carbonate as pH regulator, a concentrate, assaying 324.52 g/t Pt and 45.62 g/t Pd, is obtained with recoveries of 87.23% Pt and 76.89% Pd from surface ore. A concentrate, assaying 1693.53 g/t Pt and 64.12 g/t Pd, is obtained with recoveries of 88.54% Pt and 83.78% Pd from primary ore. At same time, A iron concentrate assaying 64.12% Fe with a recovery of 24.94%, and a apatite concentrate assying 30.32% P2O5 with a recovery of 80.12% are obtained.

Jan 1, 2014

By Y. S. Li

The life cycle assessment method is applied to investigate the environmental impacts of cop-per-slag and copper-ore concentration process. Some environmental load data of copper production are obtained. The result indicates that damage level of human health, ecosystem quality and re-sources respectively is 0.174, 0.0203, 0.246 in the copper-slag concentration and 0.112, 0.0136, 0.299 in the copper-ore concentration. Environmental impact of copper-slag production (0.44) is more than that of copper-ore production (0.42), but can meet the environmental protect demand. With domestic copper concentrate supply gap enlarging, recovering copper from slag will lead to a significant improving of resource utilization and development of circulation economics.

Jan 1, 2014

By Avishan Atrafi, Marek Pawlik

"Gas dispersion properties of sodium salts of 6, 12 and 18-carbon fatty acids (hexanoic, lauric and oleic acid) were investigated as a function of pH. A strong effect of pH was observed on gas dispersion properties of fatty acids. At high pH for 12 and 18 carbon fatty acids, at which these surfactants formed a true solution, the gas dispersion properties were similar to those of MIBC. In the case of sodium hexanoate, which has a much higher solubility than the longer chain fatty acids and therefore does not form precipitates, the gas dispersion properties of this surfactant were strongly enhanced in the acidic pH range, where hexanoic acid was fully associated. This result is an indication that undissociated hexanoic acid is much more surface-active than anionic hexanoate. Only a small effect of the surfactant chain length on gas dispersion properties of the tested reagents was observed. The measured critical coalescence concentration (CCC95) values increase slightly by decreasing chain length and range from 5.8 x 10-5 mol/L (17.7 mg/L) for sodium oleate to 7.2 x 10-5 mol/L (16 mg/L) for sodium laurate at pH 10 and 1.9 x 10-4 mol/L (26 mg/L) for sodium hexanoate at pH 3.7. These are compared to CCC95 of MIBC, which is measured to be 8 x 10-5 mol/L (8 mg/L). The soluble molecular species were recognized as the most effective species in preventing bubble coalescence."

Jan 1, 2014

By F. S. Niu

With the feature of finely-dissemination particle and complex mineral composition, oolitic hematite is considered to be the ore dressing difficult problem in the world. Series research on refractory oolitic hematite in Zhangjiakou Area are introduced as following: ore properties?technology mineralogy and mineral processing technology. The survey shows: with the fine grinding of the hematite to a fineness of -0.076mm 95%, obtaining iron concentrates grading 62.74% Fe at the recovery of 46.80% by high intensity magnetic separation- reverse flotation flowsheet; under the three stages intensity magnetic separation,four stages grinding and four stages gravity separation, getting the iron concentrates grading 61.09% Fe at the recovery of 45% using high intensity magnetic separation- gravity separation flowsheet; with roasting temperature of 800°C, time for 75~90min and ore-coal ratio of 11, gaining the iron concentrates assaying 62.74% Fe at the recovery of 87% by roasting- magnetic separation flowsheet. At present, this research is still doing for the target of raising the concentration recovery on the base of high grade concentrate. It is in the hope of fully utilizing the existing hematite resources in Zhangjiakou

Jan 1, 2014

By C. H. Zhou

Cryogenic grinding of Printed Circuit Board will bring less pollution, reduce energy costs, smaller particles, regular particle size, efficient process, separation various materials due to different fracture toughness. Systemic studies of recycling discarded Printed Circuit Board (PCB) by low-temperature modification and cryogenic grinding have been made in this paper. Firstly test mechanical property of PCB at different low-temperature, including impact strength, flexural strength, and shear strength. Do experiment on the power consumption of different cooling temperature, The results show that the average power consumption is lower between -30? to -60? and the average power is decrease in evidence at -30?. Use ZKB type double roll shear crusher to crush PCB to 20mm×20mm particle size, in a temperature range of -10 ~ -30? Used R type mill to grind sample to minus 3mm under different working condition, the average power consumption is decrease in evidence from -10 ? to -30 ?, power consumption is the lest at rotational speed is 1180rpm.

Jan 1, 2014

By W. Y. Gao

Diaojuntai Concentrator adopts a process of low intensity and high intensity magnetic separation and anionic reverse flotation, with all the concentrate from magnetic separation being treated by re-verse flotation to obtain a qualified final concentrate. The high reagent cost and energy consumption of the reverse flotation have led to a high concentrate cost. The test research on reducing the feed to the reverse flotation was therefore carried out. Based on the study of the properties of the ore sample, the concentrate of low intensity magnetic separation was screened at 0.076 mm and the undersize fraction was concentrated by concentrator with gravity and magnetic field. The results show that a qualified concentrate can be obtained at various rising current rate, pulsating current and power-on style, with the operation rate over 85%. The extraction of some part of qualified concentrate from the concentrate of low intensity magnetic separation by magnetic separation can reduce the feed to the reverse flotation by about 35% so as to reduce the production cost of concentrate.

Jan 1, 2014

By T. Wajima

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

Jan 1, 2014

By E. Szelag

The adsorption and stabilization of mineral dispersed systems by using Pluronic copolymers with different molecular weights and EO content has been studied. The role of sequential adsorption of EO-PO copolymers and cationic surfactant (CTAB) on the carbonate particle properties and in determining the stability of their suspension was studied with particular attention to the conformation of the polymer at the solid-liquid interface. The purpose of this work was to investigate the flocculation phenomena, influence of polymer molecular size on stability of suspensions of magnesite and dolomite and the effect of addition mode of polymer and surfactant. The suspension stability measurements and the determination of sedimentation speed were carried out using an optical analyser (Turbiscan). In most of investigated cases, the biggest floccs and the fastest sedimentation were found for low concentrations of copolymers.

Jan 1, 2014

By V. F. Petrov, O. D. Khmelnitskaya, V. M. Lodeischikov

"The processing of copper gold ores is one of the major issues of gold-mining industry in the beginning of 21st century. In this case, application of ammoniacal cyanidation process for this type of mineral raw materials deserves special attention. Irgiredmet Institute has carried out a wide range of studies on ammoniacal cyanidation process and evaluated the possible commercial use of this process for Russian operating plants. Copper gold-bearing ore from a current Russian deposit was studied. The content of gold and copper in the ore is 9.4 g/t and 0.4%, respectively. Based on the results of preliminary test work, a flow sheet was developed. It included gravity concentration followed by cyanidation of the gravity tailings using CIP. The flow sheet provides sufficient total gold recovery (91.5%). However, this technology has disadvantages, such as high specific consumption of reagents: 4.5 kg/t NaCN and 13.5 kg/t Ca(OCl)2 the ore and the increased gold grade in the liquid phase of the tails slurry (0.2 g/t). In order to improve cyanidation process parameters, test work on gravity tails processing using ammoniacal cyanidation was carried out. After the test work was completed, ammoniacal cyanidation flow sheet for copper gold-bearing ores was developed. Leaching conditions were optimized using recycled process solutions. Recommendations on gold recovery from the solutions and tails detoxification are given. The proposed flow sheet provides 91.5% gold recovery. In this case, compared to the conventional option, the consumption of cyanide decreases by 3-4 times.INTRODUCTION The technology of precious metals recovery from gold-bearing ores is based on cyanidation. This accounts for up to 90% gold recovery and the significant portion of silver (Lodeischikov, 1999). However, there exists the category of so called refractory ores. They are not amenable to direct cyanidation (without using additional expensive processes), or they are characterized by low indices of metals recovery and high consumption of reagents. The latter also include copper gold ores. Their deposits can be found extensively both worldwide and in Russian Federation. A feature of these ores is that they contain not only gold but also copper. It is considered not only as a valuable component but also as a harmful mineral impurity that hinders gold cyanidation, gold precipitation from the solutions by cementation onto zinc dust and adsorption onto activated carbon (CIL, CIP-processes), detoxification of cyanide bearing effluents."

Jan 1, 2018

By A. Makavetskas

"The purpose of the research is to study the mineralogical features of the structure of the wall accretion formed during melting on the working surface of the walls of metallurgical aggregates and adversely affect the stability of the lining of blast furnaces (BF). We presented the results of studies of the material composition of lining and wall accretion of the furnaces of blast furnaces of the metallurgical plant specializing in the smelting of ferromanganese, nodular and pig iron. It is established that the garnissage is an aggregate of layered texture, formed as a result of the crystallization of slag and metallic melts. Refractory calcium and magnesium silicates and aluminosilicates (minerals of the melilite group, leicite, olivine group minerals) and amorphous glassy oxide solid solutions of variable composition crystallize from the slag melts in the upper part of the hearth. In the slag matrix, inclusions of carbon (amorphous and graphite) and products of crystallization of metallic melts of alpha-iron, iron carbides and / or manganese are observed. Evidence of carbon evolution (in the form of graphite) is precisely in the crystallization of metal melts, there are significant differences in the structure of carbon in coke and in the garnissage. The conducted studies confirm that it is impossible to obtain reliable information on the material composition of new formations in the blast-furnace process without using a complex of modern methods of technological mineralogy.INTRODUCTION The formation of the wall accretion (garnissage) - a solid protective layer as a result of smelting products crystallization on the inner (working) surface of the liner. This is due to the design of blast furnaces with a high-efficiency heat sink using copper coolers and the use of carbon blocks with high thermal conductivity in the lining. The objective of the study was research of the material composition of the lining and wall accretion of the blast furnace hearth of one metallurgical plant that specialized in smelting ferromanganese, nodular and pig iron, to assess the effect of new formations for stability of the lining of blast furnaces (BF)."

Jan 1, 2018

By E. Yigit

In the flotation process the physical factors such as agitation intensity air flow rate and pulp solid concentration are very important parameters affecting grades and recoveries of the products. The flotation tests were performed on the samples of Bigadic colemanite ore to investigate these factors at different agitation intensities ranging from 1000 rpm to 1400 rpm and air flow rates from 1000 cm3 ? min-1 to 2000 cm3 ? min-1 with 2 L and 4 L cells using Denver laboratory flotation machine. The tested collectors were Cytec Aero 825, Aero 848N and their mixtures. Agitation intensity and air flow rises resulted in more floated material although sometimes being not selective. These effects can be attributed to powerful collisions between air bubbles and mineral particles. The first observation was the effect of pulp solid concentration on the floatability of minerals, while the flotation in 2 L cell (0.125 g.L-1 solid concentration) at 1000 rpm (0.176 wattcm-3), and with 1000 cm3.min-1 air flow rate was possible, the flotation in 4 L cell (0.0625 g.L-1 solid concentration at 1000 rpm. (0.176 wattcm-3) and with 1000 cm3 ? min-1 air flow rate was not possible. However at 4 L cell after increasing agitation intensity to 1200 rpm (0.201 wattcm-3) keeping 1000 cm3 ? min-1 air flow rate, flotation was possible again. This shows that these factors such as agitation intensity have some critical role on flotation. Another interesting observation was on the selective effect of pulp solid concentration. In the flotation with 1 L cell at different agitation intensities, collector Aero 848N was selective against calcite, while in the flotation with 2 L cell at different agitation intensities the same collector Aero 848N was selective against colemanite.

Jan 1, 2014