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Öğe An investigation of the effect of clay type on coal flotation along with DLVO theoretical analyses(Taylor & Francis Inc, 2020) Gungoren, Can; Guven, Onur; Cinar, Mustafa; Ozdemir, OrhanCoals generally exist with clay minerals, which are very fine-sized minerals, and adversely affect the flotation of coal. For instance, they make the coal surface hydrophilic by coating coal surfaces and therefore, they inhibit bubble-particle attachment. Clay minerals can also cause over-consumption of reagents due to their high surface area. Additionally, clay minerals can transfer into the concentrate during the flotation process by entrainment because of their low weight and small particle size, and thus, increase pulp viscosity and changing froth stability. In this study, the influence of various clay minerals (kaolinite, illite, and bentonite) on the flotation behavior of coal sample was studied in detail by conventional flotation tests. In addition, the values obtained from flotation tests were correlated with theoretical energy barrier values established with classical DLVO theory based on zeta potential values of coal and clay samples measured at different pH values. According to the results of this study, no significant effect of clay minerals was observed on coal flotation. This was probably because of the high floatability of the coal used for this study. Both the results obtained from the experiments and theoretical analysis, DLVO calculations, showed that the type of clay mineral is the main indicator parameter for coal flotation.Öğe Analysis of flotation of unburned carbon from bottom ashes(Berg Fac Technical Univ Kosice, 2016) Sahbaz, Oktay; Cinar, Mustafa; Kelebek, SadanBottom ash from power plants contains unburned carbon (UC) as a waste, which is a potential contaminant for the environment unless recycled as a source of energy. In the present study, separation of the UC (3.1%) from the bottom ash of a power plant has been studied. The overall grade of combustible matter for the concentrates ranged from 20.6% to 28.8 while the recovery levels varied from 45.7 % to 84.0%. A statistical analysis of the combustible recoveries according to a 3-variable 2-level (2(3)) factorial experimental design, examined the influence of dosages collector (kerosene) and frother (AF65) and also impeller speed. The main effects of all three factors on the recovery are positive. The most important factor is collector dosage, while the frother has a secondary significance. The effect of impeller (conditioning) speed is also statistically significant. Two of the 2-way interaction effects are significant. Recovery of combustible matter increases with an increase in the dosages of kerosene and AF65. The main and interaction effects involving kerosene consistently point out the selectivity of the flotation process for carbonaceous particles, which have been discussed in relation to dispersion and attachment of collector droplets to the particles, interfacial area and probable collecting properties of the frother used.Öğe Effect of blunging process on purification of halloysite ore from ferrous impurities by dry magnetic separation(Oficyna Wydawnicza Politechniki Wroclawskiej, 2024) Durgut, Emrah; Cinar, Mustafa; Boylu, Feridun; Ozdemir, OrhanThe objective of this research is to study the effects of feed particle size, splitter angle, and washing process on Fe2O3 removal efficiency in the separation of ferrous impurities from halloysite ore by dry magnetic separation in order to increase the purity of halloysite sample after crushing and blunging processes separately. Firstly, after crushing ore in a jaw crusher and sizing to -2+1 mm, -1+0.5 mm, and -0.5+0.212 mm fractions, the sized materials were fed to REMS-type dry magnetic separator at a constant belt speed of 300 rpm with the splitter angles of 0, 15, 30 degrees separately. Maximum Fe2O3 removal efficiency (FRE) (97.1%) was obtained in the nonmagnetic product at -0.5+0.212 mm size fraction and 0 degrees splitter angle. The minimum Fe2O3 content (1.3%) was reached in the nonmagnetic product obtained in the experiment with the feed size of -2+1 mm and a splitter angle of 0 degrees. Secondly, dry magnetic separation was applied to the washed -2+0.212 mm size fraction after drying at room temperature to evaluate the coarse particle -sized halloysite ore that was gained by mechanical dispersion in the aqueous medium towards sodium hexametaphosphate (SHMP), while a significant part of the clay minerals went into fine size after the dispersion process. In the experiment performed with a 0 degrees splitter angle after washing, it was determined that halloysite concentrate of 0.4% Fe2O3 content could be obtained with 98.8% Fe2O3 removal efficiency. As a result of dry magnetic separation experiments, it was seen that Fe2O3 removal efficiency decreased as the splitter angle increased, while Fe2O3 content in magnetic and nonmagnetic products increased. It was determined that washing and cleaning of finesized minerals plastered on particle surfaces after mechanical dispersion and particle release of minerals with different magnetic properties increased the dry magnetic separation efficiency, and nonmagnetic products with very low Fe2O3 (0.4%) and high Al2O3 (31.9%) content was obtained. The blunging process in the presence of dispersant caused the dispersion of clay minerals and allowed to liberating of the ferrous minerals from the halloysite ore, hence the increase in the FRE for the magnetic separation.Öğe Effect of Blunging/Dispersion Parameters on Separation of Halloysite Nanotubes from Gangue Minerals(Mdpi, 2022) Durgut, Emrah; Cinar, Mustafa; Terzi, Mert; Unver, Ilgin Kursun; Yildirim, Yildiz; Boylu, Feridun; Ozdemir, OrhanClay minerals need to be dispersed with blungers before their utilization in the related industries due to their plastic properties, and size reduction is carried out in a wet medium. Clay minerals also contain impurities such as nonplastic materials in their structure. Mechanical dispersion parameters are important in the separation of clay group minerals (halloysite and kaolinite) from their typical non-clayey gangue minerals (quartz and goethite). In this study, the removal of impurities from halloysite ore obtained from Kizildam, Turkey, was examined in terms of mechanical dispersion parameters, namely, feed size, blunging time and speed, pulp concentration, pulp temperature, and the aging process. The effect of these parameters on halloysite dispersion was determined by particle size, chemical, and mineralogical analysis, and optical and scanning electron microscope images. The results obtained from the studies of the mechanical dispersing and particle size distribution of the products indicated that the optimum dispersion parameters were determined as -10 mm feed size, 8 h, and 1000 rpm blunging time, and speed, 35% pulp concentration at 25 degrees C pulp temperature. Under these optimum conditions, a 72.3% amount of -38 mu m clay product containing 35.6% of halloysite, 46.5% of kaolinite, 12.0% quartz, 1.9% goethite, 0.9% gibbsite, and 3.2% other minerals were obtained from the halloysite ore, having 30.5% of halloysite, 43.4% of kaolinite, 19.1% quartz, 2.9% goethite, 1.4% gibbsite, and 2.7% other minerals. In this study, it was understood that feed size, pulp concentration, blunging time, and speed were important parameters, while pulp temperature and the aging process had no significant effect on the mechanical dispersion of Kizildam halloysite. In addition, impurities such as quartz and iron-bearing minerals were separated from the ore by blunging and sieving.Öğe Effect of calcite and mica contents in nepheline syenite samples on the ceramic body sintering behaviours and surface roughness(Oficyna Wydawnicza Politechniki Wroclawskiej, 2022) Durgut, Emrah; Cinar, Mustafa; Ozdemir, OrhanIn this study, the effects of calcite and mica contents in nepheline syenite (NS) samples beneficiated by high intensity dry magnetic separation and flotation methods on ceramic bodies were investigated in detail. The NS samples were, first, sintered to observe the physical and surface roughness properties, and characterized based on the change of NS samples such as color, shrinkage, water absorption, and surface roughness after the sintering process. L-a-b color and Ra, Rz, Rt values for the NS samples were determined. The decrease in calcite and mica contents affected the surface of sintered specimens positively by reducing roughness values. Additionally, the water absorption values were found to be directly proportional to Ra values for unglazed surfaces. In conclusion, calcite and mica minerals in NS samples negatively affected surface quality by forming pinholes due to dehydroxylation and outgassing reactions in the sintering process.Öğe Effect of crystallinity and surface silanol groups on rheological properties of different sepiolites(Oficyna Wydawnicza Politechniki Wroclawskiej, 2022) Cinar, Mustafa; Guelgoenuel, Ilhan; Ozdemir, Orhan; Celik, Mehmet S.In this study, differences in the rheological properties of three different types of brown sepiolites (K1, K2, and K3) along with one beige (B) sepiolite with different physicochemical properties were explained based on their crystallinity and level of surface silanol groups. Towards this aim, SEM images, XRD and chemical analyses, cation exchange capacity (CEC), and water absorption tests were conducted along with surface area measurements and time-dependent pH profiles. The pH profiles at 3% by wt. revealed that each sepiolite sample attained the equilibrium at different times. These differences showed a parallel behavior with the degree of crystallinity. While sepiolite with better crystallinity (K1) was rather slow in reaching the equilibrium pH, the sepiolites with poor crystallinity (B and K3) reached their equilibrium pH more quickly. The rheological studies conducted with different sepiolites at 3% solids concentration exhibited time-dependent flow of the Bingham plastic model and thixotropic. Differences observed in the rheological behavior of sepiolites were found to correlate with the fiber size, CEC, surface area, and water absorption. The results further indicated that sepiolites with low crystallinity or high level of surface silanol groups (K3 and B sepiolites) show the best rheological properties.Öğe Effect of roughness and shape factor on flotation characteristics of glass beads(Elsevier, 2016) Hassas, Behzad Vaziri; Caliskan, Hidayet; Guven, Onur; Karakas, Firat; Cinar, Mustafa; Celik, Mehmet S.The effect of surface roughness and shape factor on behavior of particles in flotation has been investigated. Surface roughness of various degrees was applied on spherical glass beads of 150 + 106 mu m by means of acid etching. The same procedure was also performed on ground glass beads of the same size interval with different shape factors. The effect of these variations on surface morphology of particles was investigated in terms of flotation recovery, contact angle, and bubble-particle attachment. An Atomic Force Microscope (AFM) was used for surface roughness characterizations and a correction methodology on roughness measurements of spherical particles is proposed. A digital image analyzer was used for shape factor characterizations. It is shown that increase in surface roughness improves the flotation recovery, contact angle, and bubble attachment. Shape factor, however, was found to be more predominant in flotation and bubble attachment. This is attributed to the effect of sharp edges of ground particles which triggers the film rupture process and shortens the attachment time. (C) 2015 Elsevier B.V. All rights reserved.Öğe Evaluation of Different Dispersants on the Dispersion/Sedimentation Behavior of Halloysite, Kaolinite, and Quartz Suspensions in the Enrichment of Halloysite Ore by Mechanical Dispersion(Mdpi, 2022) Durgut, Emrah; Cinar, Mustafa; Terzi, Mert; Unver, Ilgin Kursun; Yildirim, Yildiz; Ozdemir, OrhanIn this study, the dispersion properties of pure halloysite, kaolinite, and quartz minerals in halloysite ore were determined in the absence and presence of dispersants (sodium silicate, STPP, SHMP). First of all, the samples were characterized by chemical, mineralogical, BET, FTIR, and TEM analyses. Afterward, the physico-chemical properties of these minerals were investigated by zeta potential measurements and dispersion/sedimentation experiments in the absence and presence of the dispersants. The zeta potential measurements showed that the surface charges of all minerals changed from negative to positive as the PH changed from basic to acidic. The presence of dispersants at natural pHs indicated that the mineral surface charges tended to become more negative as the concentration increased in the zeta potential measurements. SHMP showed the most effect on the zeta potential. In the dispersion/sedimentation experiments, settling was slowed down with the use of dispersants. Finally, the dispersion properties of halloysite ore in the presence of dispersants were explored using mechanical dispersion and pulp viscosity experiments based on the amount of material passing to <38 mu m size and the chemical changes in the materials. As a result of the mechanical dispersion tests carried out in the presence of dispersants (sodium silicate, STPP, SHMP), 71.3% of the material with 30.8% Al2O3 and 50.5% SiO2 content passed to <38 mu m size without using dispersant, and 73.2% of <38 mu m sized material with 35.5% Al2O3 and 46.1% SiO2 content was gained in the use of 7.5 kg/ton SHMP, which was determined as the optimum within the scope of the study. In conclusion, dispersant use enhanced the mechanical dispersion effect for plastic clay mineral separation from hard minerals in an aqueous medium.Öğe Improved flotation of heat treated lignite with saline solutions containing mono and multivalent ions(Oficyna Wydawnicza Politechniki Wroclawskiej, 2018) Ozdemir, Orhan; Ersoy, Omer F.; Guven, Onur; Turgut, Hatice; Cinar, Mustafa; Celik, Mehmet S.Flotation of lignites is inherently difficult. However, pre-heat treatment of coal is also known to make coal surfaces more hydrophobic possibly through removal of water entrapped in the structure of coal. In this context, the objective of this study was, therefore, to determine changes in the hydrophobicity of some lignites under moderately controlled heat treatment, and correlate the flotation response of lignites in different salt solutions of NaCl, KCl, CaCl2, and MgCl2 without using any reagent. The results of flotation tests suggested that, under the present test conditions, it was possible to float thermally pre-treated lignite samples of partially hydrophobic character in salt solutions in the absence of collector and frother. In addition, the effect of heat treatment on hydrophobicity, and in turn flotation was explained by a theoretical model based on extended DLVO interactions to quantify the effects of both heat treatment and salt concentration on bubble-particle interactions. The results of theoretical modeling suggested that the removal of hydrogen containing groups from coal surfaces significantly contributed to the electrical double layer and hydrophobic forces that governed the magnitude of energetic barrier and also the extent of bubble-particle attachment.Öğe Mineral beneficiation of nepheline syenite with combination of dry magnetic separation and flotation methods(Oficyna Wydawnicza Politechniki Wroclawskiej, 2019) Cinar, Mustafa; Durgut, EmrahNepheline syenite is an important raw material for ceramic body composition as a melting agent. However, impurities such as iron, titanium, mica, and calcite minerals in nepheline syenite can lead to quality problems on the surface of floor tile because of different sintering properties. Therefore, these impurities should be eliminated from syenite before sintering process to increase its quality while reducing economic and environmental impacts. In this study, it was aimed to reduce impurities of nepheline syenite using dry magnetic separation and flotation methods. The dry magnetic separation results showed that the amount of TiO2+Fe2O3 in the sample decreased from 2.50% to 0.06%. In addition to this, optimum flotation conditions were determined while separating calcite, mica, and further iron bearing minerals from the nepheline syenite by using sequential flotation method. The optimum flotation conditions for calcite flotation were determined as natural pH: 7.9 and 500 g/Mg DER NA7 collector dosage; for mica removal pH: 3.1 and 500 g/Mg Custamine 9024 or A4 collector dosage. After overall mineral beneficiation experiments, albite+microcline mineral content increased from 78% to 97%. In conclusion, a clean concentrate for ceramic body and frit composition quality was gained from nepheline syenite containing high amount of Fe2O3 and TiO2 with dry magnetic separation and flotation experiments.
