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By Ana Elisa Casas Botero

The Rhodococcus opacus microorganism was evaluated as a biocollector for flotation of barite. The electrophoretic behaviour of the mineral, before and after R. opacus interaction, was evaluated and showed that the cells adhesion shifted the mineral zeta potential curves. Adhesion tests were suggested a high affinity of the bacteria for barite. The experiments of the adsorption rate of the R. opacus on the mineral surface showed fast kinetics, achieving a maxim of cell adsorption after 5 minutes. Adsorption isotherm curves for barite could be categorized as Langmurian (L) type II. The best bioflotability results for barite achieved values around 75% for a R. opacus concentration of a R. opacus concentration of 250 ppm in the pH around 5.0. The studies were compared with the flotation of barite using a traditional collector. The bioflotation experiments were discussed considering the obtained adhesion tests. The results were supported by the Thermodynamic approach for selected pH values. The fundamental flotation studies showed the paramount potential that R. opacus presents as a biocollector and its possible application in the mineral flotation industry.

Jan 1, 2014

By Kwan Ho Kim

The beneficiation study of low quality pyrophyllite is conducted to enhance the value of it by selective grinding. In mining stage, the main gangue mineral is quartz, and the content of quartz in ore has an adverse effect on the quality of pyrophyllite. Using the huge difference in hardness between quartz and pyrophyllite, the selective grinding is accomplished using stirred ball mill. As a result, a finer pyrophyllite particle can be easily separated from coarser quartz particle by simple size classification, and the content of Al2O3 of fine particle smaller than 45um increased largely. It means that the pyrophyllite particle is ground selectively compared to the quartz particle, and the quality of pyrophyllite is enhanced.

Sep 1, 2012

By A. Ceylan

Pyrite is present as a gangue mineral in most of complex sulphide ores and most of time it is removed as a tailing. However, beneficiation of pyrite from tailings could be important because of its economical value and for the environmental concern. This paper presents a research for the enrichment of pyrite from copper plant tailings, Siirt-Madenköy/Turkey, by flotation. Siirt-Madenköy copper mine is operated by Park Electric Production Mining and Industry since 2005. In order to obtain the pyrite from Siirt-Madenköy copper plant tailings, laboratory test work has to be done to determine the type of reagents, the flowsheet, and the size of plant. The objective of the company is to develop a pyrite flotation circuit for concentration of pyrite from tailing dam to obtain 500.000 tons/year pyrite concentrate. There are about 3 million tons tailings that containing pyrite in the tailings dam. Experiments were carried out with three different types of tailings from the plant and the pyrite concentrate with 46% Fe and 90% recovery has been obtained. Therefore, this study shows that high grade pyrite with high recovery can be recovered from the tailings.

Sep 1, 2012

By André Mans, Frans B. Waanders

Current losses of Ferrosilicon (Fe-Si), which is used in the dense medium separation (DMS) of iron ore at Kumba Resources, Sishen, South Africa occur due to adhesion to the separation products and also by being present in the effluent stream, due to abrasion. The losses contribute greatly to the running cost of the plant and the purpose of this project was to determine the characteristics of the unused Fe-Si and then to characterise the changes that occur during storage and the use thereof. A Scanning Electron Microscope (SEM) and Mössbauer Spectroscopy (MS) were used to investigate the characteristics of the fresh and used Fe-Si. It was found that the biggest loss of Fe-Si was due to the abrasion of the particles during the DMS process, which resulted in the liberation of Fe and subsequent formation of an oxihydroxide froth. A possible change in magnetic properties was also observed, leading to further losses that could occur during prolonged use of the medium. No clear changes to the Fe-Si occurred during correct storage methods, as was initially thought.

Jan 1, 2003

By H. B. Zhou

The process of bioleaching marmatite using moderately thermophilic bacteria has been studied in this research by comparing marmatite leaching performance of mesophilic bacteria and moderately thermophilic bacteria and valuating the effect of venting capacity on marmatite leaching performance of moderately thermophilic bacteria and the effect of pulp densities on marmatite leaching performance of moderately thermophilic bacteria. The results show that moderately thermophilic bacteria have more advantages over mesophilic bacteria in bioleaching marmatite. Aeration agitation can improve the transfer of O2 and CO2 in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. With the increase of pulp density, the total leaching amount of valuable metals increased, however, the extraction efficiency decreased due to many rea-sons, like increasing shear force that results in poorly growth condition for bacteria, etc.

Jan 1, 2014

By K. Hori

In this study, the determination of optimal conditions for jig separation has been investigated with a TACUB jig separator. The TACUB jig, from which a Batac jig originated, is a useful gravity separator that is effective to separate crushed solid wastes as well as coarse ores. A mixture of crushed polyethylene (specific gravity 1.3) and polyvinyl chloride (specific gravity 1.5) was separated by a batch TACUB jig by varying the frequency (wavelength) and the amplitude (pulse stroke length). It was found that the sample particle layer in the separation chamber was fluidized without turbulence by the rising water pulse resulting in the separation. However, a too strong water pulse reduced the efficiency of the separation of the particles. The results indicate that the specific velocity of the rising water is necessary to fluidize the particle layer without turbulence to separate the particles. The expansion ratios of the thickness of the particle layer in rising flows were measured in a cylindrical column. The pressure losses by the particle layer were calculated from the expansion ratios and the velocity of the rising flows by Ergun?s equation. The curve of the pressure loss vs. the velocity of rising flow showed a maximum point corresponded to the point of fluidization. The velocity of a rising flow on the point of fluidization provided the optimal separation condition.

Jan 1, 2014

By V. A. Chanturiya

The results study the minerals oxidation were obtained by us during the methods of microscopic, FT-IR spectroscopic, XRD and chemical analyses of sulphides in tailings of copper-nickel wastes in Kola peninsula. Sulphide minerals begin to oxidize already at the stage of stockpiling and initial stages of storing. The proportion of non-ferrous metals and magnesium oxide increases with time, calcium partially precipitating in the form of gypsum. Comparison of heavy metal contents in pore solutions in cur-rent and stale copper-nickel ore concentration tailings has revealed a significant difference in practically all the parameters. The lower metal contents in current tailing pore solutions (by 5~30 times) are probably due to the presence of float reagent residues blocking oxidation. Much lower concentrations of magnesium and calcium can be accounted for by the difference in kinetics: the rate of sulphide oxidation at this stage is much higher than that of solution interaction with non-metallic minerals as the result of which the solid phase ? solution equilibrium is not achieved. It is generally believed worldwide that it the mining wastes with acidic pore solutions that pose the greatest hazard for the environment. Our findings suggest that although the solution pH in all the samples is higher than 7.8, the contain heavy metal concentrations by far exceeding permissible values. The direct determination of the total and silicate Ni contents in the tailings from current production and in storage tailings has shown that both sulphide and silicate Ni forms occur in tailings. However, the role of silicate Ni is much larger in the storage tailings. The average silicate Ni content accounts for 10% of the bulk Ni content in the current tailings and it increases to 40% in the storage tailings. Thus, the storage tailings are marked not only by sulphide oxidation and the removal of water-soluble sulfates, but also by the interaction of sulfates with the silicate matrix. Although complete equilibrium is not achieved even within 30 yr under polar-region conditions, the major part of the Ni in fine-grained fractions passes into silicate form. The probability of Ni transition to the silicate form directly correlates with the dispersion of the material and the amount of chemically reactive serpentine and hydrochlorite. The migration of Ni as sulfates and its precipitation by chemically active silicates distorts the distribution of this component in the coarse- and fine-grained fractions that are typical of tailings from the current production of copper-nickel ores. On the one hand, the variation of the mode of Ni occurrence in storage tailings lowers the value of technogenic raw materials as a source of this metal.

Jan 1, 2014

By lves Matiolo, Jorge Rubio, Carlos Perez Guerrero, Denise G. Nunes, Fabiano Capponi

The problem (very old) of processing by flotation, the fine (“F”, 38-13 µm) and ultrafines (“UF”, < 13 µm) mineral particles continues to be a major technical challenge in the area of mineral processing. Many different processes have been proposed over the last three decades but, unfortunately, most of them have not found practical applications yet. This paper describes some advances in flotation research in fines (“F”, 38-13 µm) and ultrafines (“UF”, < 13 µm) mineral recovery by two different techniques. Extender flotation (EF) and flotation with bubbles with a wide size distribution-SB of copper sulphide ore fines (1 % Cu) were compared with a “standardised” (STD) mill laboratory procedure. Comparative evaluation was made through concentrate grade and recovery (size by size results included), “true” flotation recoveries and process kinetics. Copper porphyry samples, containing about 1/3 of the mass and about 37 % of the total copper content in the fines and ultrafines fractions were used. In the EF tests diesel-in-water emulsions were used as an extra reagent, added after the collector and frother addition. In SB tests, drawing air through an aspiration nozzle, directly in the pulp, generated bubbles sized about 50-200 µm. Both techniques yielded higher metallurgical efficiencies than the mill standard but better results were obtained with the extender flotation, with emulsified diesel oil (90 gt-1). Concentrate recoveries were of the order of 85-90 % (84 % in standard conditions), 14-17 % Cu grade (15 % Cu in the standard) and 3.5-4.5 min-1 for the Klimpel rate constant (3 min-1 in the standard). Size by size and true flotation results proved that metallurgical and kinetic gains, obtained with the two techniques, might be attributed to fines and ultrafines enhancement. Data obtained are discussed in terms of physical and physicochemical parameters related to aggregation and capture (of particles by bubbles) phenomena and the practical potential of these techniques are envisaged. The following figure shows size-by-size copper recoveries results, after classification of produced concentrates and tailings using micro-sieves. Results clearly show that flotation of the F and UF fractions is highly improved with injection of small bubbles (SB) and with the addition of an extender collector. It is believed that the techniques presented here will establish shortly a new basis for the flotation enhancement of the F and UF, aimed at solving a very old problem. This work is being continued, now at pilot plant scale, and results will be published en the near future.

Jan 1, 2003

By H. Y. Ran

Magneto-flotation is a recently developing technology of mineral processing. This technology combines the traditional magnetic separation with flotation and provides a magnetic and buoyant force compound field to separate different minerals based on the differences of magnetism and floatability between useful minerals and gangue minerals. Magneto-flotation is applicable to separate ferromagnetic from nonmagnetic minerals, especially to separate magnetite from floatable gangue minerals. This magneto-flotation column is equipped with pulse electromagnetic field in the middle upper part, a bubble producer and upwell water inlet in the bottom. The pulse time of electromagnetic field in the column can be optionally adjusted and the maximum intensity of pulse magnetic field can reach 35mT. Pulse magnetic field can not only restrain magnetic minerals from entering into the froth layer, but also destroy the magnetic agglomeration to ensure a higher recovery and a higher concentrate grade. The results of experiments with magnetite show that pulse magnetic field has remarkable influence on flotation process. Compared with single flotation, magneto-flotation column can improve the recovery of magnetite by ten percent. After one time?s magneto-flotation processing, the grade of iron concentrate can increase from 65.4% to 69.5%, the content of silicon oxide in iron concentrate decreases from 7.4% to 2.8%, and the total recovery is above 96%.

Jan 1, 2014

By Shounak Banerjee, Suresh Babu Dasari, Dharmendr Kumar, Shashank Pardhikar, Beena Rai, Venugopal Tammishetti

Recent increase in steel demand has led to the increased usage of high grade iron ores. During the mining, crushing and washing of ore, huge quantities of fines and slimes (<150 µm) are generated, majority of which is dumped into tailing ponds owing to their high alumina contents (~10-15%). Due to rapid depletion of high grade iron ore, it is the need of the hour to utilize low grade iron ore fines and slimes. These fines and slimes contain high iron values assaying 45-60% Fe. Dumping these valuable resources in ponds locks enormous land space and causes environmental hazards. The constituent minerals present in Indian iron ores comprise of hematite, goethite, gibbsite, kaolinite and quartz. Our research is focused on beneficiation of iron ore slimes through selective flocculation. We use density functional theory simulations to screen the reagents and perform experiments with screened reagents to determine the experimental conditions for effective performance of the reagents. Our studies revealed that reagents like starch, guar gum and carboxymethyl cellulose exhibit excellent selectivity in high alkaline pH range. However, the higher cost of alkali makes the process economically less attractive. In the present study, a commercial reagent from NALCO Water (Hi-Tex 83570) has been explored as selective flocculant for beneficiation of iron ore slimes in wide pH range (4-11). However, the reagent was also found to be the most selective in alkaline pH range only. Full factorial design of experiments was done considering three parameters namely, pulp density, flocculant dosage and settling time. Regression models were developed for yield, iron grade, alumina grade and iron recovery in the concentrate, using experimental results. Further parameter optimization was done to achieve high Fe recoveries and low alumina recoveries. The optimal parameters thus arrived at were validated with the experiments. We were able to achieve a concentrate grade of 60.0% Fe and 5.1% Al2O3 with 68.8% Fe recovery from a feed containing of 53.1% Fe and 8.9% Al2O3. The performance of flocculant Hi-Tex 83570 was also compared with reagents starch and guar gum.

Jan 1, 2018

By Chris Plackowski, Bruckard. Warren J., Anh V. Nguyen

"Enargite is a significant penalty mineral in the copper industry and its separation from many copper sulfides by flotation is difficult. The separation may be crudely achieved using selective oxidation techniques or through the use of pulp potential control. This paper summarizes our latest contributions to a better understanding of enargite surface electrochemistry and hydrophobicity. Oxidation, roughness, hydrophobicity and species formation on the surface of natural enargite were examined by a novel experimental approach that combines electrochemical techniques, atomic force microscopy, X-ray photoelectron spectroscopy and droplet evaporation tensiometry. It allows for synchronized electrochemical control and examination of the oxidative surface morphology, speciation and hydrophobicity of enargite at pH 4 and pH 10. At low pH, surface layer formations consisting of metal deficient sulfide and elemental sulfur were identified associated with a limited increase in roughness and heterogeneous distribution of surface species produced by initial rapid dissolution of Cu, followed by diffusion limited surface layer deposition. At high pH, a similar diffusive mechanism associated with oxidation products consisting of copper sulfate and hydroxide and a significant increase in surface roughness were established. Receding contact angle measurements showed no significant difference in the contact angle on a surface oxidized at pH 10 and the freshly polished surface. Contact angle increased from 46° on the polished surface to 59° after oxidation at pH 4. Competing effects of hydrophilic copper oxides and hydroxides, and hydrophobic species of elemental sulfur on the mineral surfaces under oxidizing conditions at pH 4, and the change in surface roughness at pH 10, contribute to the changes in enargite hydrophobicity under electrochemically-controlled oxidation conditions. Most likely, both surface species and surface roughness produced by oxidation are critical to the changes in the wettability of enargite and other sulfide minerals."

Jan 1, 2014

By Y. F. Hou

This paper reports the results of the study of the influences of concentration and modulus of sodium potassium silicate solution (Na-K activator) and curing mode on the phase composition, mi-crostructure and strength development in the geopolymers prepared using Class F fly ash. X-ray dif-fraction (XRD), Fourier transform infrared spectroscopy (FTIR) and MAS NMR are utilized in this study. It shows that the compressive strength increases while sodium potassium silicate solution modulus increases, but when modulus exceeds 1.7, the compressive strength decreases, and it decreases markedly while modulus is greater than 2.0. The compressive strength improves with increase of sodium potassium silicate solution concentration. When the concentration is 36%, the compressive strength reaches the maximum. Elevated temperature can increase the strength of samples synthesized using sodium potassium silicate solution with 32% concentration and modulus 1.2. Compared to the strength of the sample cured at 50?, the strength of the samples cured at 65? and 80? are higher at 1 day and 3 days, but when cured at 80?, strength is smaller than that cured at 50? for 7 days. When temperature is too high, too long curing time will decrease the strength. Long precuring at room temperature before application of heat is beneficial for strength development, and there is about 10%~50% increase in strength of the samples cured at 1 day precuring and 2 days elevated temperature as compared to the strengths of the samples cured for 3 days at elevated temperature or cured for 28 days at room temperature. The main product of reaction in the geopolymeric material is amorphous alkali aluminosilicate gel.

Jan 1, 2014

By T. S. Qiu

In view of the bad effect that Na-bentonite direct adsorb Pb2+-containing wastewater, this article has carried out two kinds modification treatment on Na-bentonite: the direct microwave radiation modification and microwave radiation organic modification by adding quaternary ammonium salt?cetyltrimethylammonium bromide,and analysis the main influencing factors of the modification effect. In static conditions, preparing Pb2+-containing wastewater as the research object, it has respectively studied the effects of Na-bentonite, microwave soil of direct microwave modification and microwave soil of organic modification on the process of adsorption Pb2+, and discusses the effects of pH value, temperature, adsorbent dosage, stirring time on the adsorption Pb2+ in wastewater by modified bentonite, at the same time it does a verification test to the practical Pb2+-containing wastewater. Comparison the effects of adsorption Pb2+ in wastewater, the results show that organic modified microwave bentonite is obviously better than direct microwave modified bentonite and Na-bentonite, and can make 6 mg/L Pb2+-containing wastewater meet the national discharge standards. Through scanning electron microscope, the result of test is that organic modified microwave bentonite is the cause of improving adsorption Pb2+ in wastewater. Preparing modified bentonite by microwave heating will not only shorten the response time, reduce energy consumption and work-load, but also modified effect is good.

Jan 1, 2014

By J. Lampke

The superior characteristics of iron ore pellets compared with natural ore and sinter are well known. Due to the higher grade and bulk density they show improved transport and material handling properties. While charging blast furnaces with pellets an increased productivity is realized through pellet?s uniform structure and composition. The increased productivity is caused by a high permeable furnace burden with a decreased coke usage via fuel injection and oxygen enrichment. Therefore, a narrow pellet size distribution and a minimum content -6.3 mm are necessary (Meyer, 1980). The required pellet size distribution can be achieved on the one hand by screening the fired pellets after the induration furnace and recycle the undersized pellets. On the other hand it is possible to produce high quality iron ore pellets with a high degree of sphericity, the important narrow grain size distribution ranging between 9 to 16 mm with high green strength directly in the pelletizing device. To produce high quality green pellets, possibilities and knowledge about adjustments of the pelletizing device are necessary. The paper presents a classification of state of the art pelletizing systems in accordance with the advantages of the pelletizing disc and pelletizing drum in issues like adjustability, green pellet quality, the recycling rate and the space requirement. By a systematization of the influences on pelletizing the common reliance of objectives on influence like pelletizing moisture, disc inclination, rotational speed, mass flow and rim height are given. A variety of industry-proven examples are shown, too. Keywords: Pellet, iron ore, pelletizing, pelletizing disc

Sep 1, 2012

By B. McFadzean

Thiol collector mixtures are commonly used in the flotation of base metal sulfides and platinum-bearing ores. There are synergistic benefits claimed for these collector mixtures, with mixtures lowering total dosage requirements, improving coarse particle recovery and the rate of flotation. Some of the secondary collectors are known to have frothing effects. Therefore, a previous study aimed to decouple froth and pulp effects and considered only the bubble-particle attachments in the pulp. This was achieved through microflotation experiments, where various ratios of the ethyl and isobutyl chain lengths of xanthates, dithiocarbamates and dithiophosphates were used as collectors. Results from these experiments showed a marked increase in galena recovery using mixtures of xanthate with either dithiophosphate or dithiocarbamate. In the current study, the froth phase was introduced in the form of batch flotation studies to determine whether benefits noted during microflotation experiments would be carried through to a more realistic froth flotation scenario. The findings show that there was no significant difference in the flotation recovery between the best single collectors and mixtures of these collectors. In addition, single collectors that behaved poorly in microflotation experiments showed good flotation performance in the batch flotation experiments. The differences between the microflotation results and the batch flotation results are attributed to differences in particle froth stabilizing properties and/or differences in energy input between the microflotation and batch flotation cells. In addition, galena and pyrite showed marked differences in frothing effects and in their preferences for collector type. Keywords: froth flotation, collector mixtures, sulphide minerals

Sep 1, 2012

By Mojtaba Ghorbannezhad, Abbas Sam, Soroush Arabzadeh

One of the dewatering methods in mineral processing plant is filtration system. Disk filters are included the porous surface with pressure drop on both sides, Water in the pulp passes through the surface and solid particles remain as a cake on it. Wet concentrate production of magnetite processing plant at Golgohar Mining and Industrial Company with solid tonnage of 160 ton per hour and 49% solid amount contains 166 m3/h of water. In the present study, in addition to studying disc filter performance, the effective parameters on cake moisture were studied using Vacuum Bottom-Feed Leaf method (in the laboratory scale). Optimization was performed using the Taguchi method. The results showed that the cake moisture is reduced by increasing particle size and solid percentage (because of specific resistivity reduction), while the rate of cake formation and its thickness are increased. Also, it was found that by increasing pressure, the cake moisture is reduced and cake formation rate and its thickness are increased. In this study, the effect of fabric texture was also examined. Lowest cake moisture was obtained in condition of using compressed plain fabric with mono-multi filament fibres, pressure at 75kPa, solid percentage of 65 to 70, particle size (D80) equivalent to 123µm and disk rotation speed of 1.25 rpm.

Jan 1, 2014

By M. Alvarez-Silva

The control of the amount of chromite reporting to the concentrate during the flotation of UG2 ore is of critical importance since its presence affects the downstream smelting process. It is generally reported that the main mechanism responsible for chromite recovery is through entrainment. This is reflected in analyzing the solids and water recoveries. These in turn are strongly dependent on the froth phase. In the present investigation a laboratory scale column flotation cell was used to investigate the role of the froth phase in the flotation of UG2 ore. Such a device is superior to a standard batch cell since it operates at steady state in open circuit and also allows for a greater degree of flexibility in terms of froth heights. The mass of solids and water recovered in the concentrate as well as chromite (Cr2O3) recovery by size class was determined as a function of froth height, superficial gas velocity and depressant dosage. The results showed that depressants had little effect on chromite recovery but increased the grade due to the depression of gangue minerals. A 60cm froth height always resulted in slightly lower solids, water and chromite recovery than for 30cm. Typically only 20-25 % of solids reaching the pulp-froth interface reached the launder. The relationship between solids and water recovery for a wide range of conditions indicated that chromite is mostly recovered by entrainment. Keywords: UG2 ore, column flotation cell

Sep 1, 2012

By H. M. Gao

According to the difficulty of dolomite removal from collophanite,normal-reverse floatation process has been adopted in floatation with the use of highly selective collector G-4 and depressant S721. Good indexes of flotation have been obtained with the run-of-mine ore containing 17.96 % P2O5 and 2.31 % MgO being upgraded to a concentrate containing more than 30% P2O5 and less than 1% MgO. The reagent interaction mechanism in low grade collophanite flotation has been stu-died by FTIR analysis and theoretical calculation. The results indicate that the interaction between collector G-4 and collophanite is the result of chemical adsorption in combination with physical ad-sorption with chemical adsorption playing the major role. Depressant S721 adsorbs on dolomite surface to form a water film and effectively depresses the flotation of dolomite and reduces the MgO content in the concentrate.

Jan 1, 2014

By Kobus (J. J. ) Rossouw, P. Chris Pistorius, Johannes Sono

"Different coal properties are important in SL/RN (coal-based rotary kiln) direct reduction of iron ore, and in electrical smelting of prereduced iron ore. Laboratory simulation was used to evaluate two candidate coals, which were similar in volatile content and rank, but differed in reactive maceral content. The tests served to evaluate both the reduction rate (during direct reduction) and the dissolution rate of carbon from the coal into an iron bath.Reduction rates of mixtures of magnetite and devolatilised coal were assessed isothermally, using samples of 55 grams. The off-gas analysis was used to follow the extent of reduction. Results are shown in Figure 1 a). Coal B was expected to be more reactive, based on its higher content of reactive macerals (77%, compared with 61% for Coal A). In line with this, Figure 1 a) does show a higher reduction rate with this coal. However, increasing the reduction temperature increases the reduction rate substantially,especially for the less-reactive Coal A.For the dissolution experiments, samples (mass: 250 g) were melted in an alumina crucible (under a nitrogen atmosphere), to give a starting composition around 1%C. When the desired temperature was reached, 25 g of char was added on top of the melt, through a feeding port. Results are shown in Figure 1 b). The more-reactive Coal B was less crystalline (the graphite crystallite size estimated from X-ray diffraction was 4.6Å, compared with 11.4Å for Coal A). This is associated with a lower dissolution rate in iron."

Jan 1, 2003

By Bent Babel, Martin Rudolph

"The characterization of reagent-mineral interactions in flotation systems of finely intergrown ores holds difficult challenges for the applicability of standard techniques like Hallimond tube tests and contact angle experiments or renders them impossible due to a lack of sufficient samples in terms of quality and quantity. This disadvantage may not apply to more sophisticated techniques, but these often do not work in an aqueous environment. We present the utilization of an atomic force microscope with a hydrophobic colloidal probe to characterize the wettabilities of individual mineral domains of an ore sample, while additional spectral information is gathered by Raman spectroscopy. The exemplary ore sample investigated is mainly containing cassiterite and quartz, therefore the reference measurements like Hallimond tube tests and contact angle experiments were carried out with this binary system as a comparison. The focus of the study lies in the correlation of data gathered by the atomic force microscope and the Raman spectrometer with data from standard techniques. Finally, the applicability of the colloidal probe atomic force microcopy technique for reagent-mineral investigations is critically evaluated.INTRODUCTIONThe focus of this paper is the application of colloidal probe atomic force microscopy (CP-AFM) for theinvestigation of reagent-mineral interactions on a binary system of cassiterite and quartz. This and similar concepts using hydrophobic AFM probes have been applied by multiple authors (Rudolph and Peuker, 2014a; Rudolph and Peuker, 2014b; Wada et al., 2017; Xie et al., 2017). The hydrophobic interaction is the main interacting mechanism for the hydrophobic colloidal probe with hydrophobic sample surfaces and the long range attractive component has been accounted to nanobubbles on the interacting surfaces (Yakubov et al., 2000). More detailed information on nanobubbles are available in two reviews compiled by Attard and Hampton (Attard, 2003; Hampton and Nguyen, 2010). This paper is based on the work by Rudolph and Peuker comparing different AFM based measuring concepts, additionally gathering data with Raman spectroscopy and correlating results of microflotation and CPAFM measurements (Rudolph and Peuker, 2014a; Rudolph and Peuker, 2014b)."

Jan 1, 2018