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By G. Voiloshnikov, A. Bogudlova

"The deleterious effect of carbonaceous matter during cyanidation of gold ores (so called preg-robbing) has been recognized for many years. Based on this, a new method using flotation to reduce the content of carbonaceous matter was developed. Low-sulfide gold-bearing ore with carbonaceous matter of 0.14% from a Russian deposit was processed. The purpose of these tests was to compare two flow sheet options. Option I comprised removal of carbonaceous product prior to sulfide flotation. Option II comprised removal of carbonaceous matter from flotation concentrate. It was found that the content of carbonaceous material can be reduced in sulfide gold-bearing concentrate prior to leaching. High gold recovery was observed during the separation of carbonaceous material prior to sulfide flotation using Option I. Due to lower reagent consumption the costs for reagents were decreased using Option II. The results have shown the effectiveness of a new method. Patent No. 2783808 was obtained for removal of carbonaceous material prior to sulfide flotation. This information will be used to design a large processing plant flow sheet in Russia."

Jan 1, 2014

By Paulo Castillo, Cesar Gomez, Jaime Alvarez

Operations using flotation to produce mineral concentrates require testing of frothers to characterize their ability to preserve bubble formation size and to build a stable froth. Many techniques have been proposed to measure parameters associated with these two roles. These techniques focus, in general, on only one of these roles and are based on special equipment operated at conditions quite different from those existing in industrial cells and columns. Both roles have been simultaneously characterized in a laboratory flotation column, but the requirements associated with the installation and operation of one of these units, are a serious limitation for its use on-site. A technique based on the use of a laboratory mechanical cell, a common piece of equipment in operations, will have wider application. Establishing the ability of a frother to control coalescence by preserving bubble formation size is done through bubble size measurements as a function of frother concentration. Froth build-up and stabilization is associated with the amount of water carried by bubbles into the froth layer, which has been demonstrated to correlate with the gas holdup in the collection zone. Procedures devised for determining the critical coalescence concentration (CCC) from measurements of bubble size as a function of frother concentration, and the gas holdup by collection of water displaced from the cell by the presence of bubbles at different frother concentrations, were tested. Three analytical-grade frothers were utilized: a straight-chain (1-heptanol) and a branched (MIBC) alcohol and a polyglycol (PPG425). The results obtained at a standard set of conditions, demonstrated consistent differences between these frothers, and the ranking from least to most effective for reducing bubble size or decreasing water drainage followed the same sequences found when more complex frother characterization techniques are used.

Jan 1, 2014

By Marianella Perez, Williams Calderón, Gonzalo Montes-Atenas

The lack of fresh water sources, particularly in the Northern part of Chile, has driven the mine sites to search for new and sustainable paths to obtain water resources to run minerals processing operations. Among them, the use of seawater in concentrators appears as an interesting solution to this problem. However, the presence of seawater will have an impact onto the operation, not only because it will enhance corrosion reactions in the equipment installed in a plant, but also because it may affect how particles will effectively be processed across the numerous unit operations existing in the mine site. Among such unit operations, the grinding stage is a highly regarded as it defines the success of the separation of valuable minerals from gangue material in the froth flotation operation. Then, one important aspect to be addressed is to understand how the presence of seawater will affect the different mechanisms acting during the operation of a ball mill. The aim of this research work is to assess the effect of changing the aqueous matrix from process water to seawater in ball mills onto the mill performance. The methodology considered the use of Fluent® software and its capabilities to run numerical simulations with heterogeneous media. On one hand, from the data analysis, it is possible to infer that breakability mechanisms should not be significantly affected. On the other hand, the high ionic strength of the matrix should impact importantly particle transport mechanisms within the mill. Particularly, when transporting finer particles. Rheology results were in agreement with previous published research studies suggesting the suspensions to behave as Newtonian, Dilatant o Pseudo-plastic fluid depending on the amount of fine particles present in the grinding media. The latter will result in changes in the residence time of particles in the mill producing overgrinding or an excess in the circulating loads.

Jan 1, 2014

By M. S. Eygi

This study covers the investigations based on the electrokinetic and rheological properties to explain the interactions between kaolin minerals and commercially available polyelectrolyte in anionic character. Additional adsorption test were also conducted to support the interaction mechanism. Adsorption tests showed that adsorption densities decrease by increasing the solid content. In-creasing the solids contents from 1% to 30% by weight resulted in the decrease on adsorption from 2.14 mg/g to 1.85 mg/g. Because of its difficulty, the solids ratio at 70% was not studied. However, following to trend of the curve plotted adsorption density-solid ratio, an estimation was made and adsorption density at 70% solid content was extracted from the curve as 1.75~1.80 mg/g. The electrokinetic studies pointed out that the presence of polyelectrolyte increase the zeta potential of kaolin from 40 mV to 60 mV which is reasonable conditions to disperse and stabilize the kaolin slurry and lower the viscosity. When these result of the different tests are combined and considered together, 2 mg/g polyelectrolyte concentration was noted as optimal concentration where adsorption density, viscosity and zeta potential of the slurries give maxima and remain constant after this concentration.

Jan 1, 2014

By D. Govender

Theoretical flotation models suggest that there is a positive relationship between bubble-particle collision rates and turbulent kinetic energy dissipation. Fine particle flotation performance is generally enhanced by increased collision frequency and hence higher energy dissipation. Contrarily, increased turbulence in the rotor-stator region is related to higher detachment frequency of the coarser size range. Therefore, the optimal modes of recovery for the ?fine? and ?coarse? size classes are diametrically opposed. Industrial applications have previously confirmed that applying greater power to flotation slurries yields significant improvements in fine particle recovery. However, recovery of the coarser size class favors a different flotation environment. An improvement in the kinetics of the fine and coarse size classes, provided there is no adverse metallurgical influence on the intermediate size ranges, is obviously beneficial to the overall recovery response. Managing the local turbulent kinetic energy dissipation, and hence the power imparted to the slurry, offers the benefit of targeting the particle size ranges exhibiting slower kinetics. FLSmidth recently introduced the practical implementation of this concept. In principle, it decouples flotation regimes where fine and coarse particles exhibit preferential recovery. In the case of naturally aspirated machines (Wemco®), it is referred to as Hybrid Energy Flotation? and incorporates at least three phases: ? Standard flotation machines (standard energy input, rpm, rotor size/type) at the beginning of the row, where flotation is typically froth phase limited and operational, and set-up parameters have a limited influence on the recovery. ? Higher-powered flotation machines (high rpm, high power rotor size/type) at the end of the row to improve fine particle recovery. ? Lower-powered flotation machines (low rpm, low power rotor size/type) to enhance coarse particle recovery. In evaluating the effect of turbulent kinetic energy on flotation performance, the spatial distribution and its effect on size denominated recovery needs to be evaluated. The mean energy dissipation rate is a measure of the bulk energy input, but CFD-based models offer a more introspective view of flotation sub-processes. A CFD-based flotation model is used to highlight the effect of turbulent dissipation energy on attachment and detachment rates. Preferential collection zones for ?fine? and ?coarse? particles are predicted for both forced air and naturally aspirated machines. Keywords: CFD-based model, attachment, detachment, energy dissipation, hybrid energy flotation?, forced air, naturally aspirated

Sep 1, 2012

By A. V. Kozub, D. O. Sharkovsky, R. I. Ismagilov

"Due to complex mineral composition and fine ingrained nature concentration of iron ores deposited in Mikhailovskoye mine field requires application of wet magnetic separation to produce 65–66% Fetotal and 8.2–8.6 %SiO2, concentrate with 90–94% of material being –0.044micron grain size. Higher specific consumption of ROM, increase of production costs with concurrent reduction of output - those are inevitable side effects of desired concentrate grade improvement. Large-scale complex analysis and surveys have been carried out aimed at concentrate grade improvement with concurrent output increase. Classification of feed in hydraulic cyclones (hereinafter referred to as hydrocyclones) has been the bottleneck for improvement of processing throughput and concentrate output. Hydrocyclone classification efficiency is 50-60% and further improvement is practically impossible. Actual circulating load may achieve as much as 500-600% while the optimal rate is 200-250%. Application of wet fine screening has been considered to improve iron ore concentrate grade. Objective of this work is to design processing flow diagram for unoxidized ferruginous quartzites with implementation of wet fine screening. Large-scale tests have been run in Crushing and Concentrating Plant with application of wet fine screening stage. These tests included application of wet fine screening in 2 and 3 stages of classification to separate desired grain sized material; replacement of hydrocyclone classification with fine screening; application of fine screening as additional stages to concentration process and screening of final concentrate. Testing Methods. EXPERIMENTS AS WELL AS THEORETICAL RESEARCH HAVE BEEN APPLIED FOR THE PURPOSES OF THIS WORK; INCLUDING MAGNETIC, GRAIN-SIZE AND CHEMICAL ANALYSIS OF CONCENTRATION PRODUCTS. MODERN ANALYTICAL DATABASE HAS BEEN APPLIED TO STUDY WET FINE SCREENING FEATURES, MINERAL AND PHYSICAL COMPOSITION OF CONCENTRATION PRODUCTS. Work Results: - analysis of wet fine screening application for iron ore concentration. - technological solutions enabling to improve slurry classification of fine ingrained low magnetic iron ore have been developed. - effective process flow diagram including fine screening has been designed based on the feasible and reasonable arrangement solutions."

Jan 1, 2018

By Y. M. Zhu

Lead in environment often causes a serious health hazard. The removal of Pb2+ from aqueous phase is a beneficial project. In this paper, deposited Saccharomyces cerevisiae (S.c.) was chosen as adsorbent, Pb2+ ions as adsorbate, and the process of biosorption was studied. The dynamics of the adsorption was investigated. The adsorption mechanism of Pb2+ by S.c. cells was also investigated by detecting microstructure, zeta potential under different pH value, FT-IR spectra of the S.c. particles before and after biosorption. It was shown that the biosorption of Pb2+ by deposited S. c. is a rapid process, and the adsorbing equilibrium is reached within 10 minutes. The Zero point of zeta potential of S.c. cells is pH=3.3. When 2.0<pH<3.3, there exists biosorption (biosorption rate 76%~88%), which means static bio-sorption been not the only kind of biosorption. FT-IR spectrum analysis showed that groups on bacteria surface were mainly characteristic groups of protein and amylase; oxo-groups and nitric-groups on S.c. cell surface could chelate with heavy metal ions. Chemical adsorption might exist in the process.

Jan 1, 2014

By Olli Haavisto, Heikki Häkkänen, Tommi Kauppinen, Navid Khajehzadeh

Raman analysis is a well-established method for finding the abundant minerals in an ore sample. In this study, Raman spectroscopy is tested as a method for rapid and contactless on-line mineral analysis. Rapidness might enable on-site analysis of rock drillcore, which in turn would lead to more cost-efficient solutions in mineral exploration. This paper discusses the use of Raman analysis to identify minerals and to measure their concentration. The sample set under study consists of rock drillcore collected from Agnico-Eagle Kittilä Mine, Finland. Selected parts of the sample set are measured by Raman spectroscopy and the minerals are identified using reference spectra from a public source. Moreover, the direct measurement of concentration of different minerals with the help of Non-negative least squares (NNLS) optimisation algorithm is considered. The optimisation algorithm was constructed to form a linear combination of reference spectra which best represent the measured spectrum, or an average of measured spectra, from an ore sample. The results show that NNLS can identify abundant minerals in a given sample. Also through this method of analysis the results of a traditional point-count method can be expanded: It was observed that, due to grain size, multiple minerals consistently appear in the spectra measured over an area, which means that point-count method is not a proper way to interpret the spectra. This can be seen as a new result, as formerly the discussion has attended to other methods.

Jan 1, 2014

By Bianca Foggiatto, Marcos Bueno, Rajiv Chandramohan, Eddie McLean, Greg Lane

"With the increasing depletion of high-grade ore deposits, smarter mineral processing solutions are required to achieve sustainable and economic methods for mining and processing low-grade deposits. In order to make the treatment of low-grade deposits economically viable, large quantities of rock need to be mined and processed. The associated infrastructure costs (power, water supply, accommodation and support services, waste storage) result in a substantial penalty on the project, from both capital and operating cost perspectives. As a consequence, the challenge for the mining industry is to overcome the associated rise in energy and water consumption as well as increased project complexity when processing large amounts of low grade ore. Ore sorting technologies have been used for many years, predominantly on small projects, enabling the upgrade of marginal ores. Several sorting methods based on characteristics including specific gravity, radiometry, colour, particle size, grade and other detectable physical characteristics have been employed. The challenge for large low-grade ore bodies is to crush and sort at coarser rock size in order to minimise specific energy consumption in comminution and to reduce waste disposal costs. For large projects, the understanding of the economic impact of ore sorting is limited. The economic drivers include plant head grade improvement; sorting infrastructure capital, operating and maintenance costs; waste material handling and other environmental costs related to waste disposal. This paper analyses the economic impact of ore sorting in a large mineral processing operation. The focus of the analysis is to compare NPVs for a circuit including screening and ore sorting stages. A project for processing an Australian copper sulphide ore is considered as an example for this study."

Jan 1, 2014

By M. Lak, M. Asghari, M. Saghaeian, R. Hejazi, A. Haratian

"Magnetic separation techniques are used extensively in mineral processing operations. Magnetic separators are robust and relatively easy to operate. As the ore get hard and low grade, fine grinding must be required mostly to allow for a high degree of mineral liberation. These processes encounter the magnetic separation process difficulty due to a significant change in the separation behavior of particles. This study investigates the effectiveness of a novel proven wet magnetic separator for the beneficiation of Lebedinsky (Russia) iron ore achieved through developing pole arrangement and tank design. Basis on the results of multiphasic simulation of a medium intensity magnetic separator (MIMS) and dense media tank using Magnetic Design Software, a new model of the MIMS separator was developed. The main of the new MIMS separator was focused on improving separation and the decreasing the number of separators in cobber stage of the plant. The new MIMS separator was tested into a pilot plant on the received samples from Lebedinsky iron ore plant. In addition to the basis on the results of the modeling, promising results of test work and previous experiences, it was claimed the unit capacity of new separator is 33.33% more than the existing separator that could decrease the number of separators. In addition, the significant energy saving in the same operational condition could be obtained without any important adverse effect on the final concentrate quality.INTRODUCTION Magnetic separation is a long-established method for the purification and removal of substances from fluids (Augusto et al., 1999; Buck et al., 2015; Hoffmann et al., 2002; Lauda et al., 2016; Lindner et al., 2010; Podoynitsyn et al., 2016; Rashidi et al., 2016), mainly in mining processing industries ranging from steel production to coal desulfurization as commercial technology (Andres, 1994; Augusto, 2002; Svoboda, 1987). High gradient magnetic separation as an effective method for recovering of weak and fine magnetic particles separation has undergone dramatic developments, and has also achieved extensive application during this time (Svoboda and Jujita, 1987). Magnetic separation operations can be categorized into high intensity as electrical (up to 20,000 gauss), Medium intensity (2000-5000 gauss) and low intensity (less than 2000 gauss) techniques. Magnetic separators offer a simple, clean and economic way to sort magnetizable ores and minerals. After pulverization, the material is run through an inhomogeneous magnetic field, where particles of different susceptibility experience different magnetic forces. The force increases with susceptibility, magnetic field and field gradient (Jongst et al., 1984).In magnetic separation, the difference in the susceptibilities of the various particulate materials is used to separate the material flow into two or more products (Wasmuth and Unkelbach, 1991). The magnetic force acting on a particle can be calculated using the following equation:"

Jan 1, 2018

By D. Hatfield, G. de Jager

"The rapid developments in computer vision and computational resources are creating new possibilities for the use of machine vision systems for industrial control. A number of commercial image analysis systems exist, and research into improved measurements of froth performance is ongoing. An integral part of the implementation of these systems is the validation of the relationship between image analysis measurements and flotation cell performance. This paper discusses the factors affecting concentrate flow and presents the results obtained from one such system with respect to its ability to estimate the flow of concentrate from a flotation cell.The relationship between froth flow speed and the rate of recovery of concentrate from a flotation cell was investigated on two industrial operations, both processing PGM (Platinum Group Metal) bearing ores. Results are presented that show a relationship between froth flow speed and concentrate yield."

Jan 1, 2003

By H. Araneda

Throughout Chile?s history, mining has consistently been a leading industry in the country. The 1990s marked the beginning of a boom in Chile?s mining industry, especially in copper mining, due to both foreign and local direct investment in the sector. Mining?s contribution to the GDP was 15.6% at current prices in 2009, and it accounts for 56% of the country?s exports. Chile?s copper market share reached 35% in 2009. The investment portfolio in mining in Chile for the coming decade has been estimated at 90 billion US dollars. The acute scarcity of human resources currently experienced by the mining sector in Chile will be accentuated in the coming decade as a result of this scenario of investments. The situation is, additionally, similar to the one confronted by other countries involved in the mining industry such as Australia, South Africa, Canada, and in Latin America includes, Peru, Colombia and Brazil. A study carried out by Fundacion Chile, ¨Labor Force in the Chile Mining Industry, Diagnostic and Recommendations, 2011-2020? shows the projected labor shortage for the operation of projects in the development stage, considering only the requirements of the process of extraction, processing, and maintenance. The demand, accumulated incrementally, will be around 115,000 technically skilled workers, professionals, and qualified workers. This figure refers to the operational work force, and does not include the human resources that will be required for the prior stage of the engineering and construction of the projects (brownfield and greenfield). The demand for technically skilled workers and professions for the stages of engineering and construction of the projects that have already received investments is estimated to be 190,000 people for the period 2012-2020. The peak of the demand for engineering is 2012, with a figure that surpasses the 12,000 professionals for all of the engineering specialties. The analysis of the formation of human resources at the tertiary level (where tertiary includes technical/vocational and academic degrees at the undergraduate level) for mining and related majors demonstrates that the programs are scarce with a bias toward theoretical contents and that they are excessively long (40% longer than comparable programs in Australia, Canada, and in OECD countries). The completion rates are low, especially in the technical-vocational programs, which have a completion rate of only around 30%. Finally, the rates of attraction of technically skilled labor and professionals towards careers in mining are insufficient to reduce the identified skill gaps. In the case of university professionals such as geologists, mining engineers and engineers in metallurgy, 80-90% will work in mining. In the case of graduates of relevant majors, that cover skills also utilized by other industries, not only mining?such as maintenance workers, operators of fixed and mobile equipment, etc.?the mining sector appears to be unattractive for reasons such as shift schedules, geographical location of work sites, and other factors. On the basis of the available diagnosis a strategy for the sector has been developed (Workforce Development and Skills Strategy) whose objective is (i) to define a Mining Qualifications Framework to identify the critical roles to be filled (ii) to start, with public resources, a ¨fast-track? training program to assure the availability of at least 28,000 operators (machinery operators, truck drivers, etc.) and maintenance specialists in 2015 (iii) to promote the development of training hubs for mining with learning technologies to train technical labor and professionals on the basis of world class standards (iv) to design and implement a campaign oriented toward the perception of mining as an attractive field of employment opportunity (v) to develop curricular innovations for tertiary education programs, on the basis of international benchmarks. Keynotes: Chile, mining, copper mining, skilled human resources

Sep 1, 2012

By V. A. Chanturiya

The application of High-Power Nanosecond Electromagnetic Pulses (HPEMP) irradiation in dressing of resistant gold- containing ores appears attractive as this technique provides for a significant increase in precious metal recovery (30-80% for gold and 20-50% for silver), therewith helping reduce both energy consumption and the cost of products. The prospects for applying pulsed power technologies in the mineral processing in order to increase the contrast between the flotation properties of raw minerals dictate the need to perform special studies of the effect of HPEMP on the structural state, phase composition, and physical and chemical properties of surfaces of sulfide minerals as the main carriers of precious metals. This study deals with plausible mechanisms of the micro- and nanophases formation on the surfaces of sulfide minerals under the effect of high-power nanosecond electromagnetic pulses (HPEMP) with high electric field strength ~107 V/m. This paper discusses reasons for the changing of flotation behavior of natural pyrite and arsenopyrite during the pulsed-power treatment. It was concluded that HPEMP treatment may be regarded as a tool to change the surface composition and sorption ability of collector (xanthate) onto mineral surface, and, therefore, it allows to control the hydrophobic-hydrophilic surface balance. Single mineral flotation tests have been shown the significant increasing of the pyrite recovery while the arsenopyrite was depressed. The results of gold containing pyrite (pyrrhotite)-arsenopyrite ore flotation in batch approve the decreasing of arsenic recovery in sulfide concentrate. Keywords: pyrite, arsenopyrite, high power nanosecond pulses, activation, selective flotation

Sep 1, 2012

By C. Y. Jia

Adsorption of Thiooxidans ferrooxidans and Mycobacterium Phlei on the surface of pyrite and galena was studied. From the experimental results, it was observed that Mycobacterium Phlei adsorbed preferentially on pyrite than on galena at neutral and alkaline pH values, while Thiooxidans ferrooxidans is not at all pH range, and the scanning electron microscopy photograph also indicated that. FTIR and XPS of two strains of bacteria indicated that there are much functional groups on surface of them, such as O?H, N?H, C-O, C?N, C?O etc, but S-O group occurred on Thioox-idans ferrooxidans cell surface and the P-O group appeared on Mycobacterium Phlei cell surface, and the content of C?O?H and C?O?C groups on Mycobacterium Phlei cell surface is higher than that on Thiooxidans ferrooxidans cell surface, this also been known from UVS investigation. The affinity of these groups to metal ions on sulfide minerals is able to explain the selective adsorption.

Jan 1, 2014

By L. Rintala

The design of a hydrometallurgical process starts with the analysis of the raw materials to be treated, for example mineralogy, chemistry, deposit size are analysed. Based on this information suitable unit processes for pre-treatment, leaching, solution purification and product recovery are selected. Typically, process design for the new ore deposit relies on laboratory tests such as pre-treatment and leaching experiments. The experimental work is the most time consuming and expensive part of the process design. Reducing the number of experiments would shorten the time of designing a new flowsheet or development of new process technology. A large amount of information is available about the hydrometallurgical experiments and the amount is increasing continuously. For example, word search using ?hydrometallurgy? from Scopus database results in over 4 000 publications with the word in title, abstract or keywords. This number consists of 2 500 articles, 900 conference papers, and 90 reviews since 1972. The number of hydrometallurgical publications per year has increased from 13 in 1972 to 150-200 in the last few years. The objective of this study was to analyze how detailed data of experiments about the gold extraction is published and how that data could be exploited more effectively when designing hydrometallurgical processing for new ore. The leading idea is that similar ores should have the similar response in leaching. If the published information was used more efficiently, the amount of experiments would be reduced. More than 200 cases of experimental data of gold leaching have been analyzed for this study. There are over 30 factors that could be used in comparison when selecting process alternatives, but challenging fact is that not all these factors are documented in all publications. Results show that the usefulness of the published data in the development of hydrometallurgical flow sheet for gold using decision-support tools is not that straightforward. The quality of the published information about gold extraction varied between the publications and the descriptions of the raw materials, experimental arrangements and results were often missing details. Methods to normalize the data for description of the cases and a system to describe different features unambiguously are needed. Keywords: refractory gold, host mineral, leaching, data analysis, case-based reasoning

Sep 1, 2012

By Cristiane Ericksson, Ananda Scomazzon, Irineu Schadach, Juliano Tonezer

The state of Rio Grande do Sul, southern Brazil, appears on the national and international scene as an important producer of precious stones and the main gems are amethyst, citrine and agate. However, despite the immense potential of this mining activity, the extraction and processing of gemstones in Brazil present critical issues of infrastructure, which prevents a better development of these activities. In general, local production is still concentrated in small rudimentary mining. Recently some of these mines have begun to regularize their activities, in conjunction with the National Department of Mining Control. Besides these problems best practices for extraction activities and environmental control are not usually observed. Another problem which is placed in a critical way is the absence of aggregate value for the products of small mines. In this situation, the miners have great problems to obtain access to technology and adequate infrastructure. In most cases miners need negotiate their gems without processing, transferring most of the profit to intermediate traders. These results in heavy losses for the producer and for the communities involved. Given this scenario, the present study aimed at defining systems technically and operationally viable to be implemented in these communities in order to add value to gemstones. In this study best practices to thermochemical coloring systems, analysis of effect of raw materials and operating parameters on the final color of the gem were analyzed with attention.

Jan 1, 2014

By Y. H. Wang

Micro-flotation tests of spodumene, beryl, quartz and feldspar have been carried out by using CaCl2 and FeCl3 as modifiers and a blending collector of oleic acid and hydroximic acid. CaCl2 shows efficient activation for spodumene when pH is above 11.5, and FeCl3 exhibits a markedly activation and good selectivity for spodumene in the range of pH 4 to 10. The main species of CaCl2 are CaOH+ and Ca(OH)2 when pH is above 11.5, and the main species of FeCl3?6H2O are Fe(OH)+2 and Fe(OH)3 during the pH range of 4 to 10. A selective flotation of spodumene and beryl from pegmatic ore had also been completed while using FeCl3?6H2O as activator and the blending collector. A bulk concentrate containing 1.087% BeO and 4.70% Li2O has also been obtained in the flotation of spodumene and beryl from pegmatic ore assaying 0.097% BeO and 0.45% Li2O, and the recoveries of BeO and Li2O in concentrate are 74.38% and 69.50% respectively.

Jan 1, 2014

By Peter J. Coghill, Michael J. Millen, Brian D. Sowerby, Kirby D. Cunningham

"CSIRO Minerals has developed an integrated particle size analysis system for deployment in the grinding circuits of minerals processing plants. The system includes a slurry sampling station, a de-aeration tank and an ultrasonic particle size analyser (UltraPS). The UltraPS analyser is based on ultrasonic attenuation and velocity spectrometry combined with gamma-ray transmission. The technology is applicable to the measurement of 0.1 to 1000 µm diameter particles directly in highly concentrated slurries without dilution. The analyser incorporates a gamma-ray transmission gauge utilising an ultra-low activity radioisotope source that is exempt from International Atomic Energy Agency (IAEA) and Australian licensing regulations.The UltraPS analyser consists of a submersible probe and an electronics package. The probe can be immersed directly in a minerals processing plant stream if the aeration level in the stream is low. For applications where a de-aerated slurry stream is not available, CSIRO has developed an integrated system that includes a sampling station, a de-aeration tank as well as the UltraPS analyser itself. A schematic drawing of the continuous flow gravity fed system is shown in the figure. A commercial sampling system is used to supply slurry at a rate of 2.5m3/hr to the deaeration tank. The aim of the de-aeration tank is to remove air in the slurry to a level where meaningful particle size measurements can be performed. The tank volume is about 0.2m3, thus giving the slurry flowing through the tank a mean residence time in the tank of approximately five minutes. Tests at a number of concentrators have shown that five minutes is sufficient time for slurry to de-aerate to a level where ultrasonic measurements can be made. The tank incorporates an ultrasonic level detection sensor and flow to the deaeration tank is adjusted based on the level of slurry within the tank. The UltraPS probe is mounted through a flanged section of duct, which is bolted to the bottom of the de-aeration tank."

Jan 1, 2003

By Ben Murphy, Alejandro Yanez, Tatu Miettinen

"Flotation using large volume cells has grown in importance during recent years, particularly given the increasing demand for minerals whilst ore grades are decreasing. Outotec introduced the TankCell® e300 in 2007 to enable concentrator plants to process these higher tonnages. From the beginning, TankCell® e300s with FloatForce® mixing mechanisms have demonstrated good metallurgical performance with decreased operating costs and high availability. This paper deals with specific engineering challenges that need to be considered when installing these units rather than giving examples of performance. Today there are over 100 TankCell® e300s operational worldwide. As more of these units are installed new technical challenges are encountered and solutions developed to maximize their productivity. Lessons have been learnt by operators, engineering companies and the cell manufacturers on how best to design and layout these cells in modern concentrators to ensure smooth transition from design to installation to operation. This paper presents information on important design considerations and learning that has been obtained through the design, installation and commissioning of the TankCell e300 around the world. Areas pertaining to cells layout such as feed and discharge arrangements along with items of metallurgical concern such as sampling, reagent addition and the potential benefits of installing a variable speed drive on the motor will be covered in depth."

Jan 1, 2014

By D. W. Fuerstenau

Understanding how cationic surfactants affect the interfacial behavior of quartz is important in mineral processing and environmental engineering. This paper presents the results of a study of the effect of the molecular structure of cationic surfactants on the interfacial behavior of finely ground natural quartz. Most of the experimental work involved the determination of zeta potentials and the stability of quartz suspensions. Some measurements of induction times and the flotation response of coarser particles are also included. How these surfactants affect interfacial behavior is discussed in terms of adsorption mechanisms. The molecular structure (number of hydrocarbon chains, type of ionic head group, number of ionic head groups on the molecule) of these reagents was found to significantly affect their surface activity.

Jan 1, 2014