Variation of critical surface tension for wetting of minerals with roughness determined by Surtronic 3+ instrument

Ulusoy, Uğur; Yekeler, M.

doi:10.1016/j.minpro.2003.09.001

Cited by 27 publications

(5 citation statements)

References 13 publications

(14 reference statements)

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“…very strong basic sites containing O and N atoms in hetero-cycle conjugated structure. 32 We assume that very small nanoparticles are indeed stabilized at these sites. 19,20 The as-received CNT realizes a good support-PVA interaction (0.8% Pd loading) but the low concentration of functional sites leads, during the immobilization, to overgrowth of the MTP (Fig.…”

Section: Morphology and Structure Of The Pd Nanoparticlesmentioning

confidence: 99%

Tailoring the morphology of Pd nanoparticles on CNTs by nitrogen and oxygen functionalization

Arrigo

Wrabetz

Schuster

et al. 2012

Phys. Chem. Chem. Phys.

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The influence of N and O functionalization of CNT on the morphology of supported Pd-PVA nanoparticles is studied with respect to the catalytic activity in the liquid phase oxidation of benzyl alcohol to benzaldehyde. The impact of specific N and O sites on the carbon surface induced by the high temperature N-functionalization in the temperature range 673-873 K was observed by HRTEM as increased nanoparticles dispersion and enhanced metal wetting at the carbon surface. Those small nanoparticles that stabilized at the N-CNTs surface are beneficial for improving catalytic performance. The interaction of O(2) with the metal surface was studied by microcalorimetry. At 353 K, the PVA shell hinders the dissociative oxygen chemisorption at the surface of the fresh catalyst. Differently, a very high (maximum for Pd/N-CNT873K 750 kJ mol(-1)) and oscillating exothermic differential heat is registered for the washed samples. Such high differential heat on the "washed" sample is due to the sum of oxygen chemisorption and PVA oxidation. Thereby, it is demonstrated that the PVA overlayer suppresses the total combustion reaction pathway. This contribution has highlighted the impact of the dynamic change of morphology of these Pd nanoparticles under the reaction conditions on the catalytic performance and how this is modulated by the nature of the support as well as the PVA. The support with its varying ability to strongly bind Pd regulates the morphology of the nanoparticles on which the sub-surface penetration of O, H, C from the reactants depends, all modulating the electronic structure and thus the reactivity.

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Section: Morphology and Structure Of The Pd Nanoparticlesmentioning

confidence: 99%

Tailoring the morphology of Pd nanoparticles on CNTs by nitrogen and oxygen functionalization

Arrigo

Wrabetz

Schuster

et al. 2012

Phys. Chem. Chem. Phys.

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“…Some researchers have also investigated the effect of surface roughness of coal dust on the wettability. However, the obtained conclusions by these researchers on this topic were different and even contrary [53][54][55][56]. At present, regarding the influence of the surface roughness on the wettability of coal dust, the accepted conclusion is that as the surface of coal dust gets rougher, the wettability is better [57,58].…”

Section: Introductionmentioning

confidence: 94%

Effects of Metamorphic Degree of Coal on Coal Dust Wettability and Dust‐Suppression Efficiency via Spraying

Wang

Han

Liu

et al. 2020

Advances in Materials Science and Engineering

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Currently, spraying is a main means for dust prevention and control in underground coal mines. The dust-suppression efficiency via spraying is highly correlated with the wettability of coal dusts. There are many factors affecting the wettability of coal dust, among which coal’s metamorphic degree has great influence. In order to gain in-depth knowledge of the effects of coal metamorphic degree on coal dust wettability and the dust-suppression efficiency via spraying, 6 coal dust samples with different metamorphic degrees were collected and used in the study. In the experiments, the microproperties, wetting performance, and dust-suppression efficiency via spraying were measured. According to the experimental results of coal’s microproperties, with the improvement of metamorphic degree, the content of hydrophilic oxygen-containing functional groups on the surface, the surface roughness, the specific surface area, and the interpore diameter all decreased. In addition, as coal’s metamorphic degree was enhanced from lignite to meager-lean coal, the wettability of the coal dust dropped. On the other hand, as the metamorphic degree of coal quality continued to be improved to anthracite, the wettability of the coal dust increased instead. The measured results revealed that the dust-suppression efficiency via spraying was highly correlated with the wettability of coal dust. The coal dust with better wettability exhibited higher dust-suppression efficiency via spraying. With the increase of water-supply pressure, the effect of coal dust wettability on the dust-suppression efficiency via spraying was weakened, and the difference of dust-suppression efficiency among different coal dust samples was narrowed.

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“…The grinding tests were used as the same method of previously reported studies [34,35] as summarized in Table 2. Two conventional mills, namely laboratory ball (200 x184 mm) and rod mills (200 x 280 mm) were performed in dry conditions using with 5 475 kg of stainless steel balls of 30 and 26 mm and 22 600 kg of stainless steel rods of 29, 24 and 19 mm in size, respectively.…”

Section: Grinding Testsmentioning

confidence: 99%

Review on the Applications of Apparent Mean Shape Factor on the Integration of Coarse and Fine PSDs Measured by Different Techniques: Quartz Example

Ulusoy¹,

Yekeler²,

Gülsoy³

et al. 2019

CWiMP

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In most industry where grinding is utilized, particle size, which is a decisive element in establishing the productivity of production processes and execution of the end product, is analyzed to describe the size distribution of particles in a given sample. In mineral and coal processing, particle size distributions (PSDs) of particulate materials were traditionally accomplished by sieving, which gives inaccurate particle size and PSD below 38 µm. This paper reviews the studies related to the combinations PSDs of different mill products of the same quartz mineral by using different particle size measurement techniques to build the whole PSDs including coarse and fine PSDs. For this purpose, almost pure quartz mineral (which is the most suitable brittle material that gives first order grinding kinetics) ground by ball and rod mill products that are the most widely used conventional mills in mineral processing were measured by different size analysis techniques, i.e. sieving for coarse sizes, Andreasen pipette sedimentation, and laser diffraction for fine sizes below 38 µm and combined them to construct whole size distribution by using apparent mean shape factor, r. The results were satisfactorily well for both cases; PSDs by laser diffraction size distributionsieving and PSDs by Andreasen pipette sedimentation-sieving, i.e., a smooth overlap of corrected laser diffraction and sieving PSDs and Andreasen pipette sedimentation and sieving PSDs were obtained by applying to the particle size distribution with r shifting to the right side of the curves. In the case of determination of PSDs by laser diffraction and sieving, r values determined from the corrected particle size distributions were found to be 1.29 and 1.25 for ball and rod milled products, respectively. The results indicates that there is not significant differences between the shape factors of ball and rod milled products of quartz mineral, i.e. both of them have irregular particles, which deviates from the spherical shape as proved by their SEM microphotographs. On the other hand, for the PSDs by Andreasen pipette sedimentation and sieving, the corrected sedimentation data came closer to the sieving data. It was found that r values determined from the corrected PSDs of the same quartz mineral ground by ball and rod mill were 1.00 and 1.12, respectively. The results show that the rod milled products were not more regular in shape than ball milled products as evidenced by SEM pictures and previous works. Thus, this approach can be utilized for the integration of PSDs analyzed by different techniques for coarse and fine sizes of fine particulate coals, minerals, and similar materials ground finely.

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Variation of critical surface tension for wetting of minerals with roughness determined by Surtronic 3+ instrument

Cited by 27 publications

References 13 publications

Tailoring the morphology of Pd nanoparticles on CNTs by nitrogen and oxygen functionalization

Tailoring the morphology of Pd nanoparticles on CNTs by nitrogen and oxygen functionalization

Effects of Metamorphic Degree of Coal on Coal Dust Wettability and Dust‐Suppression Efficiency via Spraying

Review on the Applications of Apparent Mean Shape Factor on the Integration of Coarse and Fine PSDs Measured by Different Techniques: Quartz Example

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