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By H. R. Manouchehri

"In all electrical beneficiation methods, the difference in electro-physical properties of the contributed mineral particles, essentially frictional charge, electrical conductivity and dielectric constant properties are exploited to achieve separation. The composition of the raw material determines what kind of either corona charging, conductive induction, or triboelectric separation method should be employed. The process is versatile and is influenced by different parameters related to mineral characteristics, surrounding ambient conditions and electrical and mechanical attributions of the separating device. Electrical separation is surface based beneficiation method which is mainly affected by the surface and surface changes of the minerals. Therefore, it is essential to understand how the electrophysical properties of the minerals can be changed/modified. During electrical/electrostatic separation process, both charge magnitude and its polarity that developed on the particles and therefore, their electrical beneficiation potential is essentially defined by surface phenomena. Therefore, it is essential to understand how the main electro-physical parameters can be changed/modified with applied surface treatment/pretreatment methods to promote separation. Surface treatment of minerals is carried out by different means, including chemical conditioning, irradiation, thermal treatment, etc. This paper discusses and analyze the electrical separation process, electrophysical properties of the minerals with special focus on the effect of surface pretreatment/treatment methods to affect electrical beneficiation potential of the minerals. The surface treatment methods vary in a wide range from simple surface cleaning to more complicated chemical conditioning and doping. The knowledge of the solid-state physics and chemistry leads to improve the beneficiation potential of different mineral systems by choosing suitable treatment method(s). Despite the complexity and multiplicity of the charging mechanisms, difficulties in separating fines it seems to be beneficial make our attempts to further investigate and develop the process as dry, low cost beneficiation process, especially nowadays when environmental concerns, as well as energy and water consumptions are main concerns for mining industry."

Jan 1, 2018

By Y. Y. Li, T. T. Yang, R. X. Zhou, Z. H. Shen

"Wetting theory is one of the basic theories of flotation. The effects of concentrations, carbon chain length and pH values of saturated fatty acid collectors (lauric acid, myristic acid, palmitic acid and stearic acid) on the surface wettability of collophanite and dolomite were investigated by measuring the contact angle with dynamic captive-bubble technique and calculating adhesion work of bubble-mineral. The results show that the contact angles both of collophanite and dolomite are higher with enhancement of hydrophobicity when pH value of 5~9. The contact angles both of collophanite and dolomite are reduced with improvement of surface hydrophilicity. When strong acid pH value of 2~4 or strong alkaline pH value of 10~13. The reasons for this are that the fatty acids mainly exist with insoluble RCOOH molecules in strong acid condition, and competitive adsorption of OH- and RCOO- in the mineral surface is formed in strong alkaline condition. With the increase of the collector concentration, the contact angles of the collophanite and the dolomite all first increase then decrease. The formation of hydrophilic micelles results in the decreasing of contact angles and enhancement of surface hydrophilicity opposite when the collector concentration exceeds CMC. The contact angles of the collophanite and dolomite and the WSG of the bubble adhesion increase, the hydrophobicity enhance with the increasing of carbon chains of saturated fatty acid from 12 to 18. The variation tendency for the adsorption quantity of collectors and floatability of collophanite and dolomite are in line with the change trend of contact angle basically. It shows that the wettability of solid-liquid-gas interface can be well characterized by the dynamic captive-bubble technique.INTRODUCTIONPhosphorite resources are the main raw material for producing phosphate fertilizer and producing phosphoric acid (Cao et al.,2005), which is an important strategic mineral resource. The useful minerals in calcareous-magnesium phosphate ore are collophanite, and the main gangue minerals are dolomite (SISH et al.,2003). The lattice ions of the phosphorite and dolomite are both Ca2+, their similar surface properties and similar floatability are the main reason for the flotation of calcareous-magnesium phosphate ore difficultly (Fang et al.,2011). Usually, fatty acid collectors are used for the flotation of calcareous-magnesium phosphate ore under acidic conditions by reversing flotation method to remove dolomite (ABOUZEID et al.,2009), or direct flotation is used to gather collophanite in the alkaline conditions (Gong et al.,2017). The flotation behavior of collophanite and dolomite affects the indexes of concentrate and flotation efficiency directly. Therefore, it is necessary to study the action mechanism and the flotation method of the collector with the phosphate rock and dolomite respectively (Moudgil et al.,1988; Hanna, et al.,1990)."

Jan 1, 2018

By Dmitriy Kim, Natalya Ibragimova, Galina Sedelnikova

Gold and copper are lost in flotation tailings in mineral processing of copper-zinc-pyrite ores. Large resources of precious and base metals have accumulated in tailing ponds of Russian plants. Object of the study is the sample obtained from Ural Mining and Metallurgical Company in Russia. The main constituents in flotation tailings are Au, Ag, Cu and Zn with content 1.4 g/t, 12 g/t, 0.66 and 0.5% respectively. The flotation tailings are a refractory material. Gold, as main metal, is fine encapsulated in sulfides, mainly in pyrite. Gold extraction from tailings is 34.0 and 42.7% at P42 and P90 of 0.074mm particle size respectively. In this work heap bioleaching of tailings was studied for oxidation sulfides (pyrite and chalcopyrite) with using mesofilic and moderately termofilic bacteria in acidic solutions. The tailings had low filtration property (< 0.3 m/day) and pelletization was used before bioleaching. Copper containing converter slags flotation tailings and calcium oxide were used as binding material for increasing filtration property of tailings. Copper was extracted in sulfate solution and was precipitated by cementation after cleaning of bacterial solution from iron. Copper recovery was 56.8% at content 61.4% in precipitate. The biooxidation of pyrite was 80%. Cyanidation, leaching with thiourea and heap leaching by cyanide were tested too. Gold extraction from solid bioresidues was 82, 75.3 and 77% respectively. The results of this investigation were recommended for pilot test.

Jan 1, 2014

By S. M. Saghaeian

The studies on the product finer than 12 mm due to crushing and sizing plant of Gol-e-Gohar Iron Ore mine showed which this material contains significant amount of valuable iron minerals. Based on the carried out experimental studies on representative samples of fine hematite iron ore, a processing flow sheet was designed to upgrade iron content. This plant is known as first hematite iron ore enrichment plant in Iran which the dry medium intensity magnetic separators (with magnetic field intensity 4500 gauss and high gradient) has been used. The main objective of the plant is production of high iron product with iron content more than 61% and weight recovery more than 55% from the feed with iron content of 54%. In this plant, at first material are screened by a single deck screen (6mm), then oversize particles is separated at one stage by magnetic separator, while undersize ones at two stages. Based on the results of experimental tests, a final high iron product with iron content of 62.4% and weight recovery 63.9% can be achieved. It should mention which the iron content can be enhanced through increasing the speed of magnetic separators especially at the part of separation of finer iron ore.

Jan 1, 2014

By R. Lestari

Newmont Batu Hijau operates with an accelerated mining rate to optimize life of mine (LOM) project economics. This results in a portion of ore mined being stockpiled for reclaim and processing throughout, and at the end of mine life. LOM economics can be further enhanced by preserving stockpiled ore value by mitigating oxidation effects. A detailed stockpile ore oxidation study was conducted to: ?? Develop a practical understanding of how oxidation affects ore value; ?? Determine how oxidation rate can be controlled, and; ?? Determine how oxidation effects can be mitigated to preserve ore value. The result of the study is a stockpile management strategy that significantly reduces oxidation related losses and, implementation of that strategy within practical constraints. Implementation includes installation of Controlled Potential Sulfidisation (CPS) flotation to facilitate oxidised sulfide copper recovery and, recovery of dissolved copper from stockpile drainage solution into saleable product. This paper describes the study results including managing and predicting stockpile oxidation with time, monitoring performance of implemented CPS flotation and recovery of dissolved copper from stockpile drainage. These are essential elements of successful long term mine operation in Batu Hijau.

Jan 1, 2014

The present study is devoted to improvement of the leaching efficiency during phosphorous removal from high phosphorous gravity-magnetic concentrate. Before leaching the concentrate has been subjected to roasting with the addition of either Ca(OH)2 or CaO. The oolitic iron ore is roasted at 900°C for one hour. This reflects in reaction between alkaline earth additive and quartz, aluminosilicates, phosphorus, and some other minor components of the gangue minerals. The application of leaching, physical separation, and wash out of salts has resulted in the decrease of phosphorus from 0.7 to 0.15 % and it is established that the major influencing factor is the concentration of acid and to a less extent duration of the leaching process. About two third of the phosphorus can be removed by roasting with 3 % CaO to hematite, coarse grinding to d50 0.3 mm, dry high intensity magnetic separation and leaching of the magnetic fraction with hydro-chloric or nitric acid.

Sep 1, 2012

By Andrei Yevdokimov, Ivan Sidorov, Olga Lanchakova, Olga Khmelnitskaya, Tatiana Chikina

"The paper focuses on the results of the research on development of hydrometallurgical process of gold recovery from refractory sulfide flotation concentrates based on fine and ultrafine grinding. Refractory concentrates (the degree of refractoriness is 16.9%-82.6%) were chosen for testing. The efficiency of the process based on fine and ultrafine grinding to treat flotation concentrates with gold intergrown with sulfides and rock-forming minerals was shown. Based on the test work conducted, the process option was chosen. In included grinding of flotation concentrate to the size of 98% minus 20µm in a bead mill, lime treatment with air blow, CIL, filtration and detoxification of liquid phase of the slurry. This process (compared to the basic option) provides the recovery of gold from 82.6%, up to 94.0% and decreases the residual grade in the tailings from 3.3g/t to 1.1g/t at the consumption of 12.6NaCNkg/t. Based on the results of the test work and pilot plant testing, project design criteria of flotation circuit at a Russian plant was developed."

Jan 1, 2014

By Pramila Misra, Jibardhan Meher, Debadutta Das

The concentrated coal-water slurry has been receiving considerable attention recently due its ability to replace fossil fuels. Attainment of stable and concentrated slurry has been succeeded so far through several physical and chemical techniques. The present article reports the formulation and stabilization of a highly concentrated coal-water slurry formed from five varieties of non-coking coals with variable ash contents obtained from Eastern part of India, employing three varieties of starch esters, such as starch benzoate, starch formate, and starch carbamate as dispersant. The apparent viscosity of the modified coal-water slurry has been measured by varying coal loading, dispersant percentage, pH, temperature, etc. The apparent viscosity of the slurry has been found to be decreased substantially on addition of 0.8% of adsorbate in the slurry. The particle-particle interaction has been considerably decreased and stable concentrated coal-water slurry containing high weight fraction of coal (61.5-63.5%) has been achieved in each case. The slurries stay in a non-settling form for about a month with viscosity in a permissible low range. The coal-water slurry has been found to behave as a non-Newtonian liquid. Comparison of the zeta potentials of the naked and modified coals evidences that adsorption of the dispersants at coal-water interface results in inhibition of the agglomeration of coal particles through mostly steric repulsions.

Jan 1, 2014

By S. N. Sahu

Attempt was taken in this study to explore the misplacement phenomena in binary mixture in solid-liquid fluidisation system. The binary mixtures of hematite and quartz particles at different sizes were taken. The closed size range particles were taken to minimize the size and shape effect in fluidization. As both the minerals have appreciable density difference, the separation of both minerals with closed size range has an advantage. The experiments were conducted in different permutation and combination of different sizes of binary mixture to observe the fluidization phenomena. The samples were taken at different heights in fluidized zones and analyzed the distribution of particles of both minerals. The fluidization characteristics were evaluated with respect to operating and design parameters. It has been observed that when the terminal velocity of quartz and hematite particles is same or near to each other, then misplacement is significant. In general, the segregation index value is near to one, complete segregation takes place whereas this value is near to zero, complete mixing takes place. The experimental data were used to find out the segregation index for different size ratios of quartz and hematite particles and the values are within 0-1. When the size ratio is 1 or less, complete segregation takes place whereas this ratio is within 1.0-1.4, partial mixing takes place. Similarly, when the size ratio is within 1.4-2.0, complete mixing takes place whereas this ratio is within 2.0-4.6, then it moves towards complete segregation in inversion manner. Keywords: particulate fluidization, misplacement zone, bed expansion, terminal velocity, mixing characteristics, segregation index

Sep 1, 2012

By Aziza A. Yousef, Suzan S. Ibrahim, Mahmoud A. Arafa, Mohamed A. Abdel Khalek

Due to the shortage of fresh water in the Middle East, seawater has been used as an alternative in flotation beneficiation. The flotation process requires about 7 m3 of water/mt ore. This article aims to study the effect of seawater cations and anions on the flotation. Natural pure francolite, calcite, dolomite and quartz were characterized by chemical, thermal and x-ray diffraction analyses, surface area, solubility and zeta potential. Synthetic seawater was prepared with the major chemical composition similar to natural seawater as follow; 2.45% NaCl, 0.52% MgCl2, 0.41% Na2SO4, 0.116% CaCl2 and 0.07% KCl. Also, natural seawater was used in application. The point zero of charge was estimated at pH 6.5, 7.8, 9.2 and 2.2 for francolite, calcite, dolomite and quartz, respectively. Calcium ions were released from the three minerals with Mg2+ and P2O5 3– released from dolomite and phosphate, respectively. The adsorption of collector, zeta-potential and floatability of pure minerals were studied. The effect of individual cations and anions predominant in seawater are studied on individual mineral or group. The troublesome Ca2+ and Mg2+ ions should be controlled by soda ash addition. Sodium silicate improved the selectivity of mineral mixtures and natural ore. At optimum conditions the calcareous phosphate ore yielded a concentrate of 34% P2O5, at 83% recovery with 0.61% MgO, from an ore assaying 25.3% P2O5 and 9.4% MgO. To minimize the Clcontent, fresh water of about 0.5 m3 /t was used and the Cl- decreased to about 0.09 %

Jan 1, 2003

By L. S. Zhou

Germany-made AFX-100 multi-grade fluidized classifier, with exquisite built-in structure and unique novel design, materializes not only advanced and efficient classification, but also precise particle distribution and safe operation, in addition to lower energy consumption and operational cost. It, simultaneously in place of screw grader, water cyclone, and fine mesh sieve, is equipped with multi-function, and indicates superior advantage in comparison with other else grading facilities. As the third-generation equipment, which is efficient and modern, it, in China and therefore all over the world, will find wide application in processing both fine and ultra-fine iron ore resources. Industrial test, carried out in Benxi Steel?s Waitoushan Iron Mine, shows efficient classification, i.e., ?74µm particle contents in coarse, medium and fine products come to 6.09%,11.82% and 82.73%, respectively, while qualitative and quantitative efficiencies end up by 74.38% and 87.66%, respectively. Its separation efficiencies amount to 2.2 times as many as spiral classifiers, 1.8 times as hydrocyclones, and 1.3 times as vibration high-frequency fine screens. Another industrial test, which was practiced in Anshan Steel?s Donganshan Sinter Plant, indicates that classification qualitative efficiency comes to 65.06%, equal to 1.51 times as many as hydrocyclones; yield, 55.79%; -71µm particle contents in medium and coarse products, 42.02%; -71µm content in fine product, 95.42%; and concentration, 12.33%. Estimated separation indexes are as follows: Yield for concentrate at 31.22%, up 0.22% than that from general processing line; concentrate grade at 66.42%, up 1.13%; recovery ratio comes to 65.84%, up 1.28%, which, based on pilot study, results in 20 million yuan of economic return for Donganshan Floatation Plant.

Jan 1, 2014

By S. N. Titkov

Flotation of halite?new, recently begun to be developed method of processing water-soluble minerals. In the paper the results of studies of the new directions of the application of halite flotation are represented. Studies on the flotation separation of halite and sylvite in the salt solutions of different composition, showed the possibility of the halite flotation realization not only in the carnallite brine (content of salts: MgCl2 25.5% ~ 26.0 %, chlorides of potassium and sodium 5.5% ~ 6.0%), but in the sylvinite brine, which contains 10.5% ~ 10.8% KCl and 20.5% ~ 21% NaCl. On the basis obtained results are carried out experiences on the halite flotation from samples of the converted products of sylvinite ores by flotation method and by the method of the electrostatic separation. It is shown that in all cases it is possible to accomplish effective and selective recovery of halite. The halite recovery into the foam product of flotation makes 80% ~ 90% with an increase in the content of KCl in the cell product of flotation in comparison with a composition of flotation feed: - from the product after the electrostatic separation of ore ? from 76% KCl to 95% ~ 97% KCl; - from the small fraction of ore (- 0.25 + 0 mm) ? from 30% KCl to 60% ~ 64% KCl; - from middlings (intermediate products) of sylvite flotation from 16% ~ 31% KCl to 45% ~ 80% KCl. An increase in the molecular weight of alkylmorpholines increases the selectivity of the flotation separation of halite and sylvite. Halite recovery from small size fraction of ore or/and middling of sylvite flotation with the sub-sequent joint filtration halite product and tails of sylvite flotation allows to reduce considerably expenses for manufacture potash chloride from Pilot-industrial tests for the first time confirmed the possibility of the effective halite flotation in the saturated solutions of chlorides of potassium and sodium (sylvinite brine).

Jan 1, 2014

Calcium carbonate has three polymorphs: calcite, aragonite, and vaterite. Needlelike aragonite CaCO3 with a high ratio of length to diameter (aspect ratio) is widely used in plastics, rubber and ceramics as a filler and in pigments and paints as a carrier. This paper investigated the influence of H3PO4 dosage, reaction temperature, CO2 flow rate, and initial Ca(OH)2 concentration on formation of needlelike aragonite CaCO3. It was found that the presence of H3PO4 in Ca(OH)2 suspension resulted in rapid formation of (Ca5(PO4)3(OH)) crystal nuclei, which facilitated nucleation and growth of aragonite CaCO3 on the formed (Ca5(PO4)3(OH)) crystal surfaces. The results revealed that H3PO4 addition of P/Ca of 0. 2~0. 3, high temperature of 75~85 °C, low CO2 flow rate and initial Ca(OH)2 solid concentration of 1. 5 %~5. 6 % are beneficial to formation of aragonite. Well crystallized needlelike aragonite CaCO3 whiskers with length > 20 µm and aspect ratio > 15 were directly synthesized.

Jan 1, 2014

In many base metal sulphide concentrators reagents such as collector and cyanide are often added to the grinding mill as well as to the flotation circuit. Whilst good reasons can be cited for splitting the reagent addition in this way, the benefits of such are rarely quantified and the complex reagent-mineral-media interactions occurring during milling are often poorly understood in terms of pulp chemistry. A new laboratory batch grinding mill designed by Magotteaux allows the user to measure, monitor, and control the pulp chemical conditions during grinding when testing different ores and media. Some of these parameters include pulp pH, pulp Eh, temperature, gaseous atmosphere, and dissolved oxygen concentration. In a recent development, the mill has been coupled with a simple on-line reagent monitoring system, designed by CSIRO, which allows the levels of species such as xanthate and cyanide in the grinding pulp to also be measured continuously during milling using a robust UV detection system. In this way the uptake of collector during grinding and the rate and ex-tent of cyanide interaction with the minerals and media can be determined as a function of grinding time. A series of grinding tests using an Australian nickel sulphide ore was conducted with the coupled system in which the cyanide dose, xanthate dose, and media type were systematically varied. The xanthate and cyanide levels were monitored as a function of grinding time and the data collected are discussed in terms of the pulp chemistry of the system and implications for plant reagent dosing strategies.

Jan 1, 2014

By Y. Lin

It is difficult to remove arsenic and bismuth from antimony in the process of crude electro refining. The electro refining of antimony has been studied using ammonium fluoride-antimony sulphate electrolyte system. The Influence of temperature, current density and additives on arsenic and bismuth removal from crude antimony has been investigated in this paper. Optimum process parameters, namely, temperature of 25?, current density of 400A/m2, distance between anode and cathode of 50mm, electrolytic period of 24 hours, oxalic acid dosage of 10g/L and complexon III dosage of 0.2 g/L have been ascertained.

Jan 1, 2014

By Junwei Han, Wenhua Li, Wenqing Qin, Fen Jiao, Wei Liu, Jiaqi Xu

"A novel technology was developed to study the process of recycling copper from waste printed circuit boards (WPCBs), which are the main source of metal production in the next decades. The chemical compositions of the WPCBs were investigated. The results indicated that the PCB powder was mainly composed of copper (38.5 wt.%), iron, aluminum, and non-metallic materials. Copper is mainly in the form of Cu and is the most valuable metal for the recycle of WPCBs. The concentrated WPCBs powder, obtained by the mechanical process, were pressed as the anode, which was directly electrolyzed to produce copper. The effects of H2SO4 concentration, Cu2+ concentration, current density, pole pitch, and liquid-to-solid ratio on the voltage, current efficiency, and copper extraction were investigated. The results indicated that the optimum conditions were liquid-to-solid ratio of 30 mL/g, current density of 571 A/m2, sulfuric acid concentration of 180 g/L, 50 g/L of copper ion, polar distance of 3 cm. Under the conditions, a desired current efficiency could be achieved. Meanwhile, about 95.62% Cu was recovered from the WPCBs. The experimental studies also revealed that the purity of copper obtained at the highest current efficiency was higher to 99.98%. Produced copper sheet were characterized by X-ray diffraction (XRD). XRD analysis indicated that the copper was the main phase. INTRODUCTION With the rapid development of electronic industry, more and more waste electronic and electrical equipments (WEEE) are generated every year (Fogarasi et al., 2012; Liang et al., 2013). The production of printed circuit boards (PCBs) is the base of electronic industry, because it is the essential part of all electrical and electronic equipments (Schlummer et al., 2007). As a result, a considerable amount of waste PCBs containing plenty of heavy metals have to be treated. In general, PCBs contain about 28% metals that are abundant non-ferrous metals such as Cu, Pb, and Sn. Printed circuit boards can be considered as a secondary resource for recycling rather than wasting. The contents of gold and silver respectively reach 80 g/t and 3300 g/t, which are much higher than that of primary ores. Copper is the main metal of PCB and its content is as high as 26.8% ( Zhang et al., 2009)."

Jan 1, 2018

By G. Jenny

The particle size distribution of ground minerals is of decisive importance for downstream processes like floatation, separation, drying or others. In order to optimize the process efficiency on one hand and the final product quality on the other hand an early control of the grinding or classification stage is essential. The ultrasound based particle size analyser OPUS is capable of performing on-line particle size distribution (PSD) and solid content measurement of mineral slurries such as iron ore, copper ore, fluorspar, or quartz sand and alumina directly in heavy and rough process environment. The instrument provides a PSD of 31 size classes and can be applied for particles from nanometer range up to several millimetres. Arbitrary interpolations in between the 31 measured points are available. Typical residue values show an excellent agreement to off-line particle size analysis methods such as e.g. sieve analyses or laser diffraction. OPUS is designed as rugged in-line probe made from stainless steel. The applied technique is independent of product flow dynamics, contamination, optical properties, vibrations, pressures or changes in solid concentrations. The instrument provides all data on the system?s PC or on the process control system by a variety of interfaces.

Jan 1, 2014

By F. N. Shi

Ore breakage characterization plays an essential role in the design and optimization of comminution circuits. Recently, the JKMRC comminution research team has developed a Rotary Breakage Tester (JKRBT). The JKRBT uses a rotor-stator impacting system, in which particles gain a con-trolled kinetic energy and are impacted against the stator, causing particle breakage. The first unit of industrialised JKRBT was installed at the Anglo Research in South Africa in March 2007, and five more JKRBTs are currently being fabricated for some of the world?s major mining companies. In addition to the JKRBT, an improved breakage model has been developed at the JKMRC, which more accurately describes the effect of specific energy, particle size and incremental breakage caused by repetitive impacts. The validation outcomes show that the JKRBT, together with the new breakage model, generate statistically similar breakage parameters to the traditional drop weight tester (DWT), but with significant advantages over its predecessor. The limitations of the DWT, specifically its lack of precision of the energy input, the lengthy time required to run individual tests and the challenges en-countered in testing small particles, have all been overcome by the JKRBT. The recent developments in the JKRBT and the new breakage model offer several prospective applications. These developments have the potential to revolutionize the ore breakage characterization in the years to come.

Jan 1, 2014

By M. Rudolph, E. Schach, M. Buchmann, T. Leißner, N. Krupko, U. Peuker, M. Kern

"In mineral processing, density and magnetic susceptibility are two very fundamental properties. For the beneficiation of valuables to produce a saleable concentrate a detailed understanding of these properties is essential. Especially when it comes to the processing of cassiterite, which is the main mineral for tin production, they become highly prominent. Due to the chemically inert character of cassiterite towards most industrial applied leaching agents, density and magnetic separation processes are mainly applied for its beneficiation. To guarantee an optimized utilization of the different operations not only cassiterite but also the different gangue minerals have to be considered. In this study, a skarn ore is characterized by density and magnetic susceptibility. Therefore, the material was first split into different density classes by heavy liquid separation. The obtained classes were further separated by their susceptibility to finally obtain a density-susceptibility matrix. For this purpose, an isodynamic separator was used. A more detailed characterization of the materials is done via gas pycnometer, magnetic susceptibility balance and vibrating sample magnetometer to estimate the characteristics of density and susceptibility for the various classes. Further, the determination of the chemical assay and the mineral intergrowth by mineral liberation analysis is used to generate a three dimensional database for detailed characterization of the present ore. The objective of this study is to estimate potential material streams for a modular processing plant via characterization of the material for the entire deposit by the two afore mentioned characteristic properties. The established multidimensional data matrix, enables predictions for the separation properties of the material and contributes to the characterization of the deposit within the context of geometallurgy."

Jan 1, 2018

By F. Q. Cheng

Despite the successful industrial practice to recovery KCl by flotation, the adsorption state of collectors at KCl salt surfaces is still not fully understood. In this paper, the captive bubble contact angle measurements at KCl and NaCl crystal surfaces in their saturated solutions are reported. The influence of different collectors and their concentration are considered. The results show that both cationic and anionic collectors produce a hydrophobic state at the structure breaking KCl salt sur-face, with finite contact angle values of between 30o and 40o. In contrast, the contact angle at the structure making NaCl salt surface is zero at all collector concentrations, suggesting that no collec-tor adsorption occurs, a supposition that is supported by results from molecular dynamics simulation (MDS). Further, it appears that the presence of surface defects such as edges and corners promote the adsorption of collectors at the KCl surface, and that the flotation is achieved by bubble attachment at the edges/corners of KCl particles with the formation of aeroflocs.

Jan 1, 2014