scholarly journals Enhanced Flotation Separation of Cassiterite from Calcite Using Metal-Inorganic Complex Depressant

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 880
Author(s):  
Guanfei Zhao ◽  
Dongmei Zhu
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Water Glass ◽  
Colloidal Particles ◽  
Gangue Mineral ◽  
Inhibition Effect ◽  
Inorganic Complex ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Positively Charged

At present, the research on flotation separation of cassiterite and gangue minerals is mainly focused on the development of new collectors or depressants, while the research on combined depressants is rare. In this study, the flotation separation of cassiterite and the typical gangue mineral, calcite, was investigated using the metal-inorganic complex depressant AlSS, composed of aluminum sulfate (Al2(SO4)3) and water glass (Na2SiO3·4H2O). The flotation results indicated that, with the assistance of Al3+, the inhibition effect of SS (water glass) on calcite is significantly enhanced, while the inhibition effect on cassiterite is almost unchanged. The zeta potential and adsorption measurements proved that the formation of the negatively charged colloidal particles composed of Alm(OH)n3m−n and SiOm(OH)n4−2m−n tended to adsorb on the positively charged calcite surface, inhibiting the adsorption of sodium oleate (NaOL), while the adsorption of the colloidal particles on the negatively charged cassiterite surface is relatively less. The contact angle measurements indicate that the contact angle of cassiterite in the NaOL + AlSS solution is obviously larger than that of calcite, which indicates that cassiterite has better floatability in this system. The X-ray photoelectron spectroscopy (XPS) analysis confirms the Al and Si species are adsorbed on the surface of calcite, but not on the cassiterite. In addition, the adsorption of AlSS on cassiterite and calcite changes the chemical environment on the calcite surface, indicating that the adsorption of AlSS on the mineral surface is more inclined to be through a chemical reaction.

Surface Modification of Fluorosilicone Acrylate RGP Contact Lens by Low-Temperature Ammonia Plasma

2009 ◽  
Vol 610-613 ◽  
pp. 1273-1277 ◽  
Author(s):  
Li Ren ◽  
Lian Na Zhao ◽  
Shi Heng Yin ◽  
Ying Jun Wang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Contact Lens ◽  
Photoelectron Spectroscopy ◽  
Ammonia Plasma ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Surface Contact Angle

In order to improve the surface hydrophilicity and the resistance to protein deposition of fluorosilicone acrylate RGP (rigid gas permeable) contact lens, low temperature ammonia plasma treatment was used to modify the lens surface. The changes of surface structures and properties were characterized by contact angle analyzer, X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Effects of exposure time and plasma generating power on surface properties of the RGP contact lens were investigated. The surface contact angle measurements showed a great improvement of hydrophilicity after plasma treatment. XPS analysis indicated that the oxygen content and the nitrogen content increased remarkably after ammonia plasma treatment. Furthermore, the content of the hydrophilic group O-C=O/N-C=O on the surface increased and the content of the hydrophobic group CF2 decreased after plasma treatment. AFM results showed that ammonia plasma could lead to surface etching.

scholarly journals Evaluation of the Effect of the Microscopic Glass Surface Protonation on the Hard Tissue Thin Section Preparation

2020 ◽  
Vol 10 (21) ◽  
pp. 7742
Author(s):  
Melinda Szalóki ◽  
Viktória Hegedűs ◽  
Tamás Fodor ◽  
Renáta Martos ◽  
Tünde Radics ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Glass Surface ◽  
Microscopic Analysis ◽  
Dihydrogen Phosphate ◽  
Bovine Bone ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Bone Section ◽  
Positively Charged ◽  
Frosted Glass

In this study, a new procedure for mounting tissue blocks was described while cutting and grinding the section remains tightly bound to the inert glass surface both chemically and micro mechanically allowing good quality specimens for staining and microscopic analysis. The micromechanical interlocking was achieved by using of frosted glass, the chemical binding was made with 10-methacryloyloxydecyl dihydrogen phosphate monomer (10-MDP) containing bond material. The glass surface activation was achieved by nitric acid etching and the surface was characterized by zeta potential, X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Cylindrical samples were prepared from epoxy embedding materials, cortical bovine bone, and dental titanium to investigate the shear bond strengths (SBS) to microscopic glass slide compared to a routinely used thermoplastic adhesive. Based on the experiments it was found that the micromechanical retention combined with MDP containing bond material improved the SBS data compared to the thermoplastic adhesive. The acid etched glass became positively charged that significantly increased the SBS data of bone and titanium compared with the uncharged version. Therefore, the thickness of the undecalcified bone section with metal can safely reduce to improve histological microscopic analysis.

scholarly journals Selective Flotation of Pyrite from Galena Using Chitosan with Different Molecular Weights

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 549 ◽  
Author(s):  
Wanjia Zhang ◽  
Wei Sun ◽  
Yuehua Hu ◽  
Jian Cao ◽  
Zhiyong Gao
Keyword(s):  
Contact Angle ◽  
Froth Flotation ◽  
Gangue Mineral ◽  
Selective Flotation ◽  
Molecular Weights ◽  
Ethyl Xanthate ◽  
Angle Measurements ◽  
Strong Adsorption ◽  
Contact Angle Measurements ◽  
Weak Adsorption

Pyrite is a major gangue mineral associated with galena and other valuable minerals, and it is necessary to selectively remove pyrite to upgrade the lead concentrate by froth flotation. In this study, the flotation experiments of a single mineral and mixed minerals were performed using chitosan with different molecular weights (MW = 2−3, 3−6, 10 and 100 kDa) as a depressant, ethyl xanthate as a collector, and terpineol as a frother, in a bid to testify the separation of pyrite from galena. Flotation results showed that the selective flotation of pyrite from galena can be achieved under the preferred reagent scheme, i.e., 400 g/t chitosan (10 kDa), 1600 g/t ethyl xanthate, and 100 g/t terpineol, while chitosan with other molecular weights cannot. Furthermore, the results of the zeta potential and contact angle measurements revealed that chitosan (10 kDa) has a strong adsorption on galena yet a very weak adsorption on pyrite at the dosage of 400 g/t. This study showed that chitosan (10 kDa) has great potential in the industrial flotation separation of pyrite from lead concentrates.

scholarly journals Effect of Al (III) Ions on the Separation of Cassiterite and Clinochlore Through Reverse Flotation

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 347 ◽  
Author(s):  
Yumeng Chen ◽  
Xiong Tong ◽  
Dongxia Feng ◽  
Xian Xie
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Interaction Mechanism ◽  
Reverse Flotation ◽  
X Ray ◽  
Angle Measurements ◽  
Mineral Flotation ◽  
Contact Angle Measurements ◽  
Flotation Performance ◽  
Hydrophobic Clay

Most hydrophobic clay minerals, such as clinochlore, are known to cause problems in the recovery of cassiterite. In this study, a new reagent scheme, i.e., sodium oleate (NaOL) as a collector and Al (III) ions as a depressant, for reverse flotation separation of cassiterite and clinochlore was investigated. The flotation performance and interaction mechanism were studied by microflotation tests, adsorption tests, contact angle measurements, and X-ray photoelectron spectroscopy (XPS) analysis. Results of single mineral flotation experiments showed that NaOL had a different flotation performance on cassiterite and clinochlore, and the addition of Al (III) ions could selectively inhibit the floatability of cassiterite. Reverse flotation tests performed on mixed minerals indicated that the separation of cassiterite and clinochlore could be achieved in the presence of NaOL and Al (III) ions. Adsorption experiments demonstrated that Al (III) ions hindered the adsorption of NaOL on cassiterite surfaces but exerted little influence on the adsorption of NaOL on clinochlore surfaces. Results of contact angle measurements indicated that Al (III) ions could impede the hydrophobization process of cassiterite in NaOL solution. XPS results showed that aluminum species were adsorbed onto the cassiterite surfaces through the interaction with O sites.

The diamond-solution interface: the surface energy of hydrogen terminated nanocrystalline CVD diamond derived from contact angle measurements

2011 ◽  
Vol 1362 ◽  
Author(s):  
Stoffe D. Janssens ◽  
Sien Drijkoningen ◽  
Marc Saitner ◽  
Hans-Gerd Boyen ◽  
Ken Haenen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Microwave Plasma ◽  
Sessile Drop ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Silicon Substrates ◽  
Angle Measurements ◽  
Contact Angle Measurements

ABSTRACTIn this work, a determination of the surface energy for hydrogen terminated nanocrystalline diamond grown with microwave plasma enhanced chemical vapor deposition is presented. Five identical hydrogen terminated nanocrystalline diamond layers of ~150 nm thick are deposited on silicon substrates and examined with X-ray photoelectron spectroscopy to determine the surface groups and possible surface contaminations. In order to evaluate the surface energy, contact angle measurements are performed using the sessile drop method in combination with data analysis based on the ‘Owens, Wendt, Rabel and Kaelble’ method. Four different experimental approaches to evaluate the surface energy of hydrogen terminated nanocrystalline diamond are discussed.

Surface Treatments of 4H-SiC Evaluated by Contact Angle Measurement

2011 ◽  
Vol 679-680 ◽  
pp. 374-377 ◽  
Author(s):  
Tomoaki Hatayama ◽  
Hiroyuki Suzuki ◽  
Hidenori Koketsu ◽  
Hiroshi Yano ◽  
Takashi Fuyuki
Keyword(s):  
Contact Angle ◽  
Oxide Layer ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Substrate Surfaces

Surface properties of the 4H-SiC (0001) Si faces could be evaluated by the contact angle measurements with water droplet method, X-ray photoelectron spectroscopy and an atomic force microscope. The contact angles do not depend on the surface roughness under 3nm. The substrate surfaces with the contact angles over 30o will be terminated by hydrogen related species. The contact angles around 20o on 4H-SiC is caused by the removal of oxide layer with fluoride acid and terminated subsequently by the -CF species on the surface. The hydrophile surface of 4H-SiC is caused by the formation of chemical oxide layer as well as the case of the silicon wafers.

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