Clays illites

The recovery of M2D-C3-0-(E0)n-CH3 after exposure to various solid media has been investigated by API-MS, high performance liquid chromatography light scattering mass detection (HPLC-LSD) and HPLC-APCI-MS methods [10]. Recoveries with extraction immediately following application were determined (surfactant concentration 0.1%, surfactant/solid lOmgg-1) with complete recoveries obtained on all media other than the clays illite and montmorillonite (Table 5.5.2) [10]. 

The size of the reactors is quite variable. In length, the biggest reactor has dimensions of 12 x 18 m and has a thickness of 20 to 50 cm (Fig. la). The core of the reactors consists of a 5 to 20 cm thick layer of uraninite embedded in clays (illite and chlorite). Clays around the reactors result from the hydrothermal alteration of the host sandstone during the fission reactions. This alteration occurred at a temperature close to 400 °C in the core. Temperature decreased drastically toward the vicinity with a thermal gradient of 100 °C/m (Pourcelot Gauthier-Lafaye 1999). The uranium content of the core ranges between 40 and 60%. Accessory minerals are mainly sulphides (pyrite and galena), hematite and phosphates (mainly hydroxyapatite). 

Adsorption to the K+-covered siloxane surfaces of the clay, illite, can be estimated using Eq. 11-20. A tnt.eda is 300,000 L mol-1 and the surface area factor, /saf, for illite is 6 (Table 11.2). Since the ground water contains so much calcium relative to potassium (30 1), only a very small fraction of the cation exchange sites on the illite are covered with weakly hydrated potassium ions you assume/K+clay is about 0.01. Thus, you estimate ... 

The mineralogical composition of Sahara dust particles shows the predominance of aluminosilicates (clays). Illite is also present in many cases while quartz particles are rare. Scanning Electron Microscopy (SEM) results on dust composition transported over different regions in the Mediterranean Basin have shown that Al-rich clay minerals such as illite and kaolinite are very common in PM10 for Cypms and dominant for Crete. Dust particles are also very rich in calcium which is distributed between calcite, dolomite and sulphates and Ca-Si particles (e.g. smectites) whereas iron oxides are often detected [43]. 

In Fig.30, the dividing line between predominantly octahedral charge and predominantly tetrahedral charge approximately coincides with the boundaries separating the A1 and Fe clays (illite-glauconite and montmorillonite-nontronite). Actually a simplified division (Fig.31) based on the 0.7 charge boundary and the boundary between predominantly octahedral and predominantly tetrahedral charge coincides well with the divisions based on the plotted data. 

Suspended solid surfaces (particles or colloids) in waters play a prominent role in controlling the concentration of dissolved trace elements. Most of these elements are eliminated by sedimentation after incorporation on to or into particles, generally by complexation with the surface sites. The most common inorganic particles and colloids are non-clay silicates (quartz, potash feldspar, plagioclase, opaline silica (diatoms)) clays (illite, smectite) carbonates (calcite, dolomite) Fe-Mn oxides (goethite, magnetite) phosphates (apatite) sulfides (mackinawite). Particles and colloids in a water body may be classified as a function of their origin ... 

Clay Colloids. Three clay minerals are important components of the clay colloid fraction of soils, namely, montmorillonite, illite, and kaolinite (Adams, 1973). Mont-morillonite consists of one layer of aluminum oxide between two layers of silicon oxide (Figure 11.2). An important feature of this mineral is its multilayer arrangement, which permits smaller molecules such as pesticides to penetrate between them. This is referred to as an "expanding lattice" clay. Illite is also a three-layer clay but it does not form multilayers. Kaolinite is a two-layer mineral of aluminum oxide and silicon oxide. 

For comparison with Tables I and II, Table lit gives the range and typical values of the mineral distributions observed in bituminous coals by the CCSEM and Mossbauer techniques, derived from studies of perhaps a hundred different bituminous coal samples in this laboratory. Some obvious differences in mineralogy are apparent. In addition to the difference in calcium dispersion and abundance already noted, it is seen that certain minerals common in bituminous coals, such as Fe-bearing clays (illite and chlorite) and siderite, are virtually absent in the low-rank samples of Tables I and II. Conversely, minerals such as barite (BaSO ), apatite (Ca5(P0 )30H), and other Ca, Sr phosphates are rather uncommon in bituminous coals. 

Figure 5.11 A log plot of the buffer capacity due to carbonic acid species for = 10 M (see Fig. 5.10) at saturation with respect to calcite for = I0 M and for equilibrium between the clays illite and kaolinite. The lower curve is...

Figure 7.1 Goldich s sequence of increasing weatherability of common minerals (cf. Loughnan 1969 Faure 1991). In parentheses are the lifetimes in years from Table 7.1, assuming olivine = forsterite, augite = diopside, hornblende = tremolite, Ca-plagioclase = anorthite, Na-plagioclase = albite, K-feldspar = microcline, and the stability of muscovite is comparable to that of the related clay, illite.

Because they are the dominant mineral in shales, illites, and illite-smectites (see below) are the most abundant of all the clays. Illites are defined as micalike materials less than 2 yttm in size, which, like the micas, have a basal spacing of 10 A (Drever 1988). Most illites are dioctahedral and structurally similar to muscovite, although some are trioctahedral like biotite. Illites contain less and Al and more Si than muscovite. They also usually contain some Mg + and Fe, The irregularity of occurrence of interlayer K+ makes bonding between the layers weaker than in muscovite. Illitic clays... 

Chemical conditions within the peat swamp influenced the clay mineral assemblage. Kaolinite is enriched towards the margins of the depositional basin an authigenic origin in acidic freshwater conditions is proposed for much of this clay. Illite/mica is primarily detrital, as indicated by the presence of the... 

Clays (Illite and Montmorillonite KjO X 3AI2O3 X 6Si02x 2H2O Al2(0H)2(Si40i(,) X nH20 (Mg Ca) 11-19%... 

The mineralogy of shale, slates, and clays that bloat when subjected to elevated temperatures has been widely reported (Boateng, et al., 1997 Epting 1974). These minerals generally constitute, by volume, 80-97 percent mica clay, 0-10 percent quartz-feldspar, and 2-7 percent accessory minerals, for example, calcite, pyrite, and so on. X-ray analyses have indicated that the major mica-clay constituent of expandable materials is either kaolinite or montmorillonite in still clays, illite and chlorite in the slightly metamorphosed mudstones (shale), and muscovite and chlorite in the more strongly metamorphosed slates. Assays on the raw materials indicate that the oxides may be grouped as shown in Table 10.5. 

Silicates Sheet silicates Clays Illites Illite... 

Potassium micas, feldspars (K), micaceous clays (illite), radioactive evaporates,... 

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