Minerals, characterization

Plenary 21 A. Alian Wang et al, e-mail address alianw levee.wustl.edu (RS). (Unable to attend IGORS, but abstract is available in proceedings.) With teclmological advances, Raman spectroscopy now has become a field tool for geologists. Mineral characterization for terrestrial field work is feasible and a Raman instrument is being designed for the next rover to Mars, scheduled for 2003. 

Among solids, teflon exhibits the largest hydrophobicity (9 = 108°). Solids of teflon type, with their high contact angles, are called naturally hydrophobic and float without the assistance of chemical reagents. Artificial hydrophobicity to which the collector contributes is really not required to float solids or minerals characterized by natural hydrophobicity. 

Polymerization into (Si40,i) units gives rise to minerals characterized as having double chains. The configuration depicted in Fig. 2. IF is common and typical of the amphiboles, a mineral group of special interest because five amphiboles have been mined as asbestos. 

Zeolite, zeolite group A collective term for a family of aluminosilicate minerals characterized by framework structures that allow easy access and exchange of cations and small molecules (see chapter 2), The name derives from the Greek terms zein, meaning to boil, and lithos, meaning stone. The term is also applied to synthetic materials of comparable composition, crystal structure, and physical properties (see chapter 2). 

The use of surfactant-modified zeolite (SMZ) as a permeable barrier sorbent may offer several unique advantages when dealing with mixed contaminant plumes. Zeolites are hydrated aluminosilicate minerals characterized by cage-like structures, high internal and external surface areas, and high cation exchange capacities. Both natural and synthetic zeolites find use in industry as sorbents, soil amendments, ion exchangers,... 

The carbonate minerals, characterized by the presence of the COj anion unit, are dominated petrologically by calcite (CaCOj) and the isos-tructural phases magnesite (MgCOj) and dolomite [CaMgfCOjlj]. The calcite structure is illustrated in Fig. 5.23, and in this phase, as in all the mineral carbonates, the CO3 groups are linked by the intermediate (Ca +) cations (counterions). The mineral carbonates have been reviewed by Reeder (1983). 

Ultimately, in the environmental context, all mineral characterizations, including mineral magnetism, must serve to understand environmental systems, on all length scales... 

Manganese oxides in natural systems are often complex minerals characterized by poor crystallinity and mixed oxidation states (McKenzie, 1989). In addition to being electron acceptors in the oxidation of As(III) to As(V), Mn oxides can also adsorb As. Direct evidence for adsorption of As by Mn oxides comes from laboratory experiments in which pure mineral phases have been used. 

Many soil minerals of interest, including Fe oxides, behave as insulators. However, minerals characterized by metals with mixed oxidation states, such as Mn oxides, are often semiconductors or conductors, in which case electron flow through the conduction band of the solid is possible. Oxidation of dissolved molecules by these types of solids can be viewed as the transfer of electrons from solution and insertion into the conduction band. For example, Mn oxides can oxidize NO to NO without release of Mn to solution. The electrons accepted by the oxide fi om NOr are delocalized in the solid so that no Mn is released. 

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

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. 

Mica mI-ko [NL, fr. L, grain, crumb perhaps akin to Gk. mikros small] (1777) n. Any of a family of crystalline silicate minerals characterized physically by a perfect basal cleavage, consisting essentially of orthosilicates of aluminum and potassium. They occur naturally, mainly as the minerals muscovite (white mica), phlogopite... 

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... 

Mica is a generic term for any of several complex hydrous aluminosilicate minerals characterized by their platy shape and pronounced basal cleavage. This per-... 

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. 

Mica is the name given to a group of alumino silicate minerals characterized by having a layered structure which is easily cleaved to give thin, flexible sheets. 

A Wang, LA Haskin, E Cortez. Prototype Raman spectroscopic sensor for in situ mineral characterization on plantetary surfaces. Appl Spectrosc 52 477-487, 1998. 

It is therefore possible using a monochromatic X-ray beam to measure the spacing of the crystallographic planes within a crystal from the diffraction peaks. Mineral characterization to such an extent is rarely used in a refractory context. More regularly, the unique diffraction pattern each mineral makes is used simply as a means of identification of presence in the sample. 

Chemical weathering refers to the dissolution of rocks by surface waters. Rocks are physical mbctures of silicate minerals, characterized by their symmetrical arrangements of silicon and oxygen. Aluminum, Ca, Mg, Na and K are also present in surface rocks at per cent levels. Chemical weathering of continental rocks may... 

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