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The effect of NaCl concentration on the interaction energy between feldspar minerale

Güven Onur, Can Muhammed Fatih, Karagüzel Cengiz

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 5

art. no. 151031

EN

The impact of the usage of monovalent ion concentration on the selective flotation of feldspar minerals has been receiving more attention in recent years. Although many experimental studies have been reported to justify its contribution to their flotation recovery, the effect of particle-particle interaction with theoretical calculations has rarely been studied. The objective of this study was, therefore, to explain the effect of monovalent ion concentration (in particular NaCl) on interactions between albite and microcline particles with a theoretical model based on the classical DLVO. The theoretical modeling results suggested that controlling the monovalent ion concentration not only adjusts the energy barrier between particles but also can be used to determine the critical salt concentration for further tests.

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Rheological behavior of sepiolite suspensions homogenized by ultra-turrax high-speed homogenizer

Tonkur Hatice, Can Muhammed Fatih, Sabah Eyüp

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 5

art. no. 153415

EN

The ability to disperse sepiolite suspensions is of great interest in various fields such as the production of cosmetics, pharmaceuticals, colors, etc., and in preparing the sample material for analytical purposes. In this study, the flow curves and time-dependent rheological behavior of sepiolite aqueous suspensions homogenized by Ultra-Turrax high-speed rotor-stator homogenizer were investigated under operating conditions. Forward and backward flow curves for homogenized sepiolite suspensions at different homogenization times and solid concentrations were plotted, and the amount of existing hysteresis loop was measured to determine the best conditions for the obtention of a suitable product having gel-forming properties for industrial and/or analytical applications. The results showed that the dispersed sepiolite suspensions exhibited a substantial increase in the viscosity values owing to gel formation, and thixotropic behavior that was rapidly improved by the increasing the solid content of suspension/ homogenization time, and their apparent viscosity decreased by the increasing the time of shearing, and flow characteristic was time-dependent. However, changing the distance between dispersing tool/bottom showed no favorable effect on preserving the rheological behavior of sepiolite suspensions, although the apparent viscosity decreased marginally due to increased distance between dispersing tool/bottom. Also, two time-dependent/independent models, namely the Power-law model and the Weltman model, were used to describe the thixotropy behavior, and different parameters of these models were analyzed. The Weltman model was found to be appropriate to fit the timedependency behavior of sepiolite suspensions and the most obtained value for model parameters A and B belonged to sepiolite suspension with 6 wt% at 25 min, which was considered as the optimized sample in the applied experiments, its final viscosity level increased from 0.82 to 12.55 Pas.

3

Determination of mineral surface energy using impact of rough topography

Can Muhammed Fatih, Çiftçi Caner

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 4

1002--1013

EN

While some of the studies on the functionalization of surfaces are still in theoretical phase, it is not possible to apply them on natural surfaces which already contain some irregularities. However, progress can be made with a mineral having significant purity, crystal homogeneity, and controllable surface workability for surface treatment operations. Therefore, in this study the effects of roughness on the surface energies of natural stones were investigated by selecting a sample with a distinctive color and metamorphic origin from Mugla, Turkey. First, sample surfaces were prepared using a polishing line with five different abrasives. Three-dimensional surface scans were then performed with ZYGONewView7100 optical-profilometer and ParkSystemAFM to identify the 3D roughness of the surfaces on two different scales (micro and nano) with SPIP-software. The micro average heights (S) of the produced surfaces ranged between 0.423-1.127 µm, nano-scale 0.0806-0.173 µm, while the surface roughness ratio (S_dr) between 33.7%-40.1%, and nano-scale 5.19%-18.5%. The contact angles of the samples were measured in the presence of pure water, formamide, and diiodomethane using AttensionTheta-tensiometer. Changes in surface energy were followed by Van Oss, Good-Chaudrey approach. Young, Wenzel, Cassie-Baxter contact angle theories were tested within these calculations. It was revealed that the inconsistency in solid phase energy could not be determined at this stage, but it could be regulated by modifying the Cassie-Baxter approach. Furthermore, the percentage of air packs likely to be below the water droplet not foreseen by the previous studies was calculated as 26% up to 35% air gap on the solid/water interface.