نتایج جستجو برای: fluorite

تعداد نتایج: 754  

Journal: :Langmuir : the ACS journal of surfaces and colloids 2006
Shoeleh Assemi Jakub Nalaskowski Jan D Miller William P Johnson

Interaction forces between a fluorite (CaF2) surface and colloidal silica were measured by atomic force microscopy (AFM) in 1 x 10(-3) M NaNO3 at different pH values. Forces between the silica colloid and fluorite flat were measured at a range of pH values above the isoelectric point (IEP) of silica so that the forces were mainly controlled by the fluorite surface charge. In this way, the IEP o...

2017
Ying Zhang Youyu Li Rong Chen Yuhua Wang Jiushuai Deng Ximei Luo

The depressing properties of sodium polyacrylate (PA-Na) for scheelite and fluorite were studied by micro-flotation tests, infrared spectroscopy (IR), zeta potentials, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The flotation results reveal that the selective depression effect of PA-Na is better than that of sodium silicate, and PA-Na can depress fluorite more e...

2003

The interaction mechanism of sodium dodecyl sulfonate (NaDS) with mineral fluorite has been investigated by Infrared Attenuated Total Reflection (ATR). Measurements have been done using a modified ATR cell which allows the study of powdered samples without previous manipulations. Adsorption experiments were carried out at 25°C and pH 6.5. Also measurements of the contact angle for water. glycer...

2017
Wei Jiang Zhiyong Gao Wei Sun Jiande Gao Yuehua Hu

Abstract: Fluorite (CaF2), a halogen elemental mineral, always co-exists with other minerals. The Ca element in fluorite is often replaced by rare earth elements (REEs), such as cerium (Ce) and yttrium (Y). In this work, the electronic structures of fluorite crystals containing REE (Ce, Th, U, and Y) impurities were studied by density functional theory (DFT). The calculated results showed that ...

2001
Wei Liu Cyrus Wadia Maria Flytzani-Stephanopoulos

Reduction of SO, by CO to elemental sulfur on fluorite oxide and transition metal/fluorite oxide composite catalysts is discussed within the redox framework. The oxygen vacancies on the fluorite oxide are active catalyst sites and their creation is a key step to initiate the redox reaction. Transition metal/fluorite oxide composites demonstrate a strong synergism for the reaction. A reduction k...

2016
Zhiyong Gao Yuesheng Gao Yiyang Zhu Yuehua Hu

Abstract: Fluorite is an important strategic mineral. In general, fluorite ores will contain a certain amount of calcite gangue mineral. Thus, they need to be separated from each other. For an economic separation, a reverse flotation process is used to float calcite gangue from fluorite. However, little information on the separation is available. In this study, a novel reagent schedule using ci...

Journal: :زمین شناسی اقتصادی 0
زهرا مهربان بهنام شفیعی بافتی غلامحسین شمعانیان

introduction the central alborz in eastern mazandaran province is host to the most important carbonate-hosted fluorite deposits in iran, such as pachi-miana, sheshroodbar, era and kamarposht. in these deposits, mineralization occurs in the upper parts of the middle triassic elika formation (vahabzadeh et al., 2009 and references therein). these deposits have long been studied, and various model...

Journal: :iranian journal of science and technology (sciences) 2007
m. a. rajabzadeh

the komshecheh barite-fluorite deposit is the product of epigenetic hydrothermal mineralizationin dolomitized limestone of middle triassic age. the deposit is structurally and lithologically controlled andoccurs predominantly as bedded stratabound replacement sheets, although the veins and solution-collapsebreccias constitute important modes of occurrence. brecciation, dolomitization, silicific...

2002
S. R. BOHLEN E. J. ESSENE

Thermodynamic calculations for selected silicate-oxide-fluorite assemblages indicate that several commonly occurring fluorite-bearing assemblages are restricted to relatively narrow fo,-fF> fields at constant P-T. The presence of fayalite-ferrohedenbergite-fluorite-quartz *magnetite and ferrosalite-fluorite-quartz-magnetite assemblages in orthogneisses from Au Sable Forks, Wanakena and Lake Ple...

Journal: :The Journal of chemical physics 2010
Asha Gupta Anil Kumar M S Hegde U V Waghmare

CeO(2)-SnO(2) solid solution has been reported to possess high oxygen storage/release property which possibly originates from local structural distortion. We have performed first-principles based density functional calculations of Ce(1-x)Sn(x)O(2) structure (x=0, 0.25, 0.5, 1) to understand its structural stability in fluorite in comparison to rutile structure of the other end-member SnO(2), an...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید