Mineral analysis, chemical methods

Mineral and Chemical Composition. X-ray diffraction is used to determine the mineral composition of an Mg(OH)2 sample. Induced coupled plasma (icp) spectrophotometry is used to measure the atomic concentrations present in a sample. X-ray fluorescence analysis is another comparative instmmental method of determining chemical composition. 

Feltz, A. Martin, A. (1987) Solid-state reactivity and mechanisms in oxide systems. 11 Inhibition of zinc ferrite formation in zinc oxide - a-iron(lll) oxide mixtures with a large excess of a-iron(lll) oxide. In Schwab, G.M. (ed.) Reactivity of solids. Elsevier, 2 307—313 Fendorf, S. Fendorf, M. (1996) Sorption mechanisms of lanthanum on oxide minerals. Clays Clay Miner. 44 220-227 Fendorf, S.E. Sparks, D.L. (1996) X-ray absorption fine structure spectroscopy. In Methods of Soil Analysis. Part 3 Chemical Methods. Soil Sd. Soc. Am., 377-416 Fendorf, S.E. Eick, M.J. Grossl, P. Sparks, D.L. (1997) Arsenate and chromate retention mechanisms on goethite. 1. Surface structure. Environ. Sci. Techn. 31 315-320 Fendorf, S.E. Li,V. Gunter, M.E. (1996) Micromorphologies and stabilities of chromiu-m(III) surface precipitates elucidated by scanning force microscopy. Soil Sci. Soc. Am. J. 60 99-106... 

We have considered in these pages a number of clay mineral systems based upon the relative positions of clays in chemical space. These systems have further been viewed in P-T space, although briefly. The point of this exercise has not been encyclopedic but more one of method, or analysis of the problems and methods which can be used in an attempt to solve them. It is apparent that large gaps remain in the proposed analysis. I hope that the general use of common physical-chemical methods of analysis will be more systematically employed in future studies on clay minerals. 

Layer charges can be calculated from mineral and chemical composition. Mineral composition can be determined by the comparison of x-ray diffraction and thermal analytical and surface area studies. Chemical composition is determined by a total chemical analysis of the sample. In the classical method, chemical analysis is made after acidic dissolution (Ross and Hendricks 1945). Nowadays, nondestructive analytical methods (e.g., electron microscopy, prompt gamma activation analysis, etc.) are also applied. Chemical composition is usually given as oxides (e.g., Si02, A1203, etc.). The cations are divided into three groups ... 

The chemical compositions of oil shales and oil shale kerogen have been studied extensively (20). However, little work has been done to integrate chemical composition data in order to aid in the selection of suitable extracting processes. In this study, five analysis methods were used to chemically characterize the samples. These methods included Rock-Eval analysis, Fischer analysis, Xi C NMR, Ultimate analysis, and X-ray diffraction mineral analysis. 

J. W. Stucki and W. L, Banwart, Advanced Chemical Methods for Soil and Clay Minerals Research. Reidel, Dordrecht, Holland, 1980. J. J. Fripiat, Advanced Techniques for Clay Mineral Analysis. Elsevier, Amsterdam, 1982. 

Qualitative spectrochemical analysis requires only a very small sample. Frequently a complete qualitative analysis can be obtained from a 1-5 mg sample and a single exposure. All readily detectable elements can be observed from one spectrum of the sample. Qualitative analysis also is possible with samples difficult to handle by more traditional chemical methods for example, glasses, refractory materials, slags, minerals, etc., can be handled by reducing the sample to a fine powder. No chemical treatment or chemical separation is required. 

The ability of X-ray fluorescence to analyze complex solid samples without recourse to time-consuming wet chemical methods has considerable advantages for metallurgy, mineral and cement analysis, as well as petrochemical products. 

For the application of spectroscopic methods for the identification and structure determination of polynuclear hydrocarbons see (29), and for the application of correlation analysis (chemical shifts of protons) for the identification of polyacetylnaphthalenes in mineral oil see (30). 

Many of the most important naturally occurring minerals and ores of the metallic elements are sulfides (p. 648), and the recovery of metals from these ores is of major importance. Other metal sulfides, though they do not occur in nature, can be synthesized by a variety of preparative methods, and many have important physical or chemical properties which have led to their industrial production. Again, the solubility relations of metal sulfides in aqueous solution form the basis of the most widely used scheme of elementary qualitative analysis. These various more general considerations will be briefly discussed before the systematic structural chemistry of metal sulfides is summarized. 

Soil geochemistry is widely applied in mineral exploration, and with advancing knowledge of speciation and residence phases of trace elements in soils, a variety of partial and selective extractions for chemical analysis have been developed over the past decades. Each of these methods has been designed to target and dissolve only those elements that are adsorbed onto labile phases in soil, from carrier fluids and gases that transported them from a deposit to the surface (e.g. Hall etal. 1996). 

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