Mineral characterization studies

Mineral characterization studies were carried out by X-ray diffraction (Geology Department, University of North Dakota) and scanning electron microscopy (SEM). 

By comparison with many other silicate minerals, isotope studies of natural clays are complicated by a number of special problems related to their small particle size and, hence, much larger specific surface area and the presence of interlayer water in certain clays. Surfaces of clays are characterized by 1 or 2 layers of adsorbed water. Savin and Epstein (1970a) demonstrated that adsorbed and interlayer water can exchange its isotopes with atmospheric water vapor in hours. Complete removal of interlayer water for analysis with the total absence of isotopic exchange between it and the hydroxyl group, may not be possible in all instances (Lawrence and Taylor 1971). 

DETERMINATION OF THE OXIDATION STATES OF THE 4th PERIOD TRANSITION METALS IN MINERALS. The study of the oxidation states of polyvalent cations is an important component of the characterization of minerals as they not only have vital crystal-chemical implications, but are also useful monitors of the ambient oxygen fugacities [21, 22]. The techniques conventionally employed for the determination of the oxidation states, such as Mdssbauer, optical and x-ray absorption, etc., have limited applicability because of the difficulty in obtaining a sufficiently pure amount of the fine grained or inhomogenous mineral sample. EELS avoids... 

Mohammad Fabhat Ah, Ph.D., is Professor of Industrial and Petroleum Chemistry at King Fahd University of Petroleum Minerals in Saudi Arabia. An expert in characterization studies of heavy ends, residues, and asphalt, he is also knowledgeable about crude oils and products, refining process technology, waste oil recycling, and stabihty characteristics of jet fuels. 

Some copper compounds have been used therapeutically in the past. Small quantities of copper salts enhance the physiological utilization of iron and are thus often present in hemopoietic formulations. Copper chloride and copper sulfate are used in parenteral nutrition solutions. The artificial radioactive copper isotope Cu has been used in mineral metabolic studies. Excess accumulation of copper can occur due to an abnormality of ceruloplasmin and causes Wilson s disease and Menkes disease, which are both characterized by copper accumulation (SEDA-22, 244) (9). 

Mineral characterization by SEM-AIA and M6 ssbauer spectroscopy is perhaps less specific than by FTIR or XRD. However, this disadvantage is con5>ensated by the fact that more information is obtained by SEM-AIA. Such added information includes data on particle-size parauneters and semiquantitative determinations of inorganic constituents of macerals, as well as data for a larger number of minerals in the routine analysis. In addition, as the minerals do not have to be separated from macerals for the analysis, SEM-AIA should be cimenable for studies of mineral associations and possibly for mineral-maceral associations. 

Many processes and structures that are difficult to describe by means of traditional Euclidean geometry can thus be precisely characterized using fiactal geometry, for example the complex and disordered microstructures of advanced materials, adsorbents, polymers and minerals. Recent studies have shown that using fiactal dimensions enables the real sizes of pore radii to be determined and pore-size distribution functions to be calculated from the data of programmed thermodesorption of liquids [35],... 

The reactivity of the silanol groups on the zeolite surfaces was studied by Kawai and Tsutsumi (1998), Tanabe (1970), Kazansky (2003), and other authors. However, in the case of natural minerals characterized by a low specific surface area, there is a problem of a low content of surface functionalities (e.g., hydroxyls). Fry et al. (2003b) overcame the problem of low analyte concentration through NMR observation of the highly sensitive F nuclei contained in a fluorinated... 

Other important characterization studies are ion-exchange capacity, especially cationic, and specific surface measurement. CEC is an important parameter in clay characterization and soil behavior, because it affects nutrient availability, among other soil properties. Some clay minerals (smectites and vermiculites) have a high... 

The present study presents the formulation of a new procedure for the design or improvement of flotation circuits for minerals, characterized by (a) Superstructures are developed in a hierarchical form, (b) A mathematical model which includes disjunctive expressions for the selection of the equipment, first principles, operational conditions, and logic expressions, (c) The objective function represents maximization of profit. The resultant model represents an MILP model. 

The crystalline mineral silicates have been well characterized and their diversity of stmcture thoroughly presented (2). The stmctures of siHcate glasses and solutions can be investigated through potentiometric and dye adsorption studies, chemical derivatization and gas chromatography, and laser Raman, infrared (ftir), and Si Fourier transform nuclear magnetic resonance ( Si ft-nmr) spectroscopy. References 3—6 contain reviews of the general chemical and physical properties of siHcate materials. 

The DEP of numerous particle types has been studied, and many apphcations have been developed. Particles studied have included aerosols, glass, minerals, polymer molecules, hving cells, and cell organelles. Apphcations developed include filtration, orientation, sorting or separation, characterization, and levitation and materials handhng. Effects of DEP are easily exhibited, especially by large particles, and can be apphed in many useful and desirable ways. DEP effects can, however, be observed on particles ranging in size even down to the molecular level in special cases. Since thermal effects tend to disrupt DEP with molecular-sized particles, they can be controlled only under special conditions such as in molecular beams. 

In 1894, the Scottish chemist William Ramsay removed nitrogen and oxygen from air through chemical reactions. From the residue, Ramsay Isolated argon, the first noble gas to be discovered. A year after discovering argon, Ramsay obtained an unreactive gas from uranium-containing mineral samples. The gas exhibited the same spectral lines that had been observed in the solar eclipse of 1868. After helium was shown to exist on Earth, this new element was studied and characterized. 

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