Montmorillonite minerals

Figure 15. Alkali (weight percent K2O + Na20) versus percent expandable layers in the illite—and glauconite-montmorillonite mineral series.

Ca and Mg is inversed for vermiculite and montmorillonite (Levy and Shainberg, 1972). Further, the natural mica-beidellite interlayered minerals (rectorite) are sodi-calcic while the mica-montmorillonite minerals (allevardite) are sodi-potassic. Quite possibly, the site of charge imbalance changes the selectivity coefficients for exchangeable ions. The montmorillonite series of interlayering will produce illite and the beidel-litic series could lead to a paragonitic or possibly calcic mica. 

Figure 32. Results of experiments on natrual minerals are schematically shown in Mr3-2R -3R coordinates. Kaol = kaolinite ML j = mixed layered beidellitlc mineral MLj, = mixed layered montmorillonitic mineral I = illite compositional field chi = chlorite Exp3 trioctahedral expandable-chlorite mixed layered mineral (expanding chlorite and corrensite).

G = gibbsite, Kaol = kaolinite, Q = amorphous or crystalline SiO, Mi = potassic mica, Mo = K-beidellite, ML = mixed layered mica-montmorillonite minerals, F = potassium feldspar, Py = pyrophyllite. This is necessary to simplify portions of the diagrams where our knowledge of phase relations is not sufficient to judge the roles which each individual mineral will play. 

Once the illite-chlorite zone is entered, i.e., the facies where dioctahedral mica-montmorillonite mineral solid-solutions are no longer stable, how does the assemblage change into muscovite-chlorite The major... 

Caillere, S. and Henin, S., 1949. Experimental formation of chlorites from montmorillonites. Mineral. Mag., 28 612 -620. 

Greene-Kelly, R., 1955. Dehydration of the montmorillonite minerals. Mineral. Mag.,... 

Oyawaye, M.O. and Hirst, D.M., 1964. Occurrence of a montmorillonite mineral in the Ingerian Younger Granites at Ropp, Plateau Province, northern Nigeria. Clay Miner., 5 427-433. 

Serdyuchenko, D.P., 1953. Magnesium parahalloysites and other montmorillonite minerals from Jurassic sediments of the northern Caucasus. Vopr. Petrogr. Mineral., Akad. Nauk S.S.S.R.. 2 100-122. 

Montmorillonite minerals or smectites are based on a layer lattice in which the ionic replacement is mainly in the central octahedral layer. Once again the ionic substitution introduces a charge deficiency, typically Mg " for Al. Counterbalancing hydrated cations occupy... 

Table 2.3. Measured c-Axis Spacings for Common Vermiculite and Montmorillonite Minerals Saturated with Exchangeable K, Na", and Mg Cations...

Write the half-unit-cell formula for a montmorillonite mineral with a layer charge of 0.3, with 90° of the substitution in the octahedral layer (Mg2+ for Al3+) and 10% of the substitution in the tetrahedral layer (Al3+ for Si44-). The saturating cation is Na h. Draw a diagram of this mineral, indicating the position of Mg2+, AI3+, Si4+, and Na+... 

The a and b dimensions of a typical montmorillonite mineral are a = 0.052 nm, and b = 0.089 nm. Using the data in Problems 12 and 13, calculate the theoretical surface area of the montmorillonite. (Remember that montmorillonite has both internal and external surfaces.) How does this value compare with values normally given for montmorillonite ... 

Definitbn One of the montmorillonite minerals that are the principal constituent of bentonite clay Formula Nao (Mg,Li)6Si,02o(OH,F),... 

E Uddin, Glays, nanoclays, and montmorillonite minerals. Metallurgical and Materials Transactions A, 39, 2804,2008. 

Bentonite ben-t n- It (1898) n. Very finegrained clay (a mixture and not a definite mineral type) derived from volcanic ash and consisting largely of montmorillonite mineral. Two classes of Bentonite are recognized (1) sodium bentonite, which is a swelling type in water and (2) calcium bentonite or subbentonite, which exhibits httle swelling in water. 

Faheemuddin. Clays, Nanoclays, and Montmorillonite Minerals. Metall. Mater. Trans. A, 39,... 

Similar to the studies performed on the SFRSF, the amount of microspheres, for each nanoclay-reinforced syntactic foam, was fixed at 30 vol%. The nanoclay was surface-modified montmorillonite mineral. Figure 2.15 shows the general structure of NCRSF. 

The above results clearly showed that compatibility and optimum interactions between starch matrix, organic modifiers (if any) and the silicate l er surface were crucial to the formation of intercalated or exfoliated starch-layered silicate nanocomposites. Nanomer BOE is an onium ion surface modified montmorillonite mineral. Compared with natural MMT, BOE is more sinface hydrophobic, and therefore is not very miscible in the hydrophilic starch matrix. On the other hand, in the case of natural MMT, due to the strong interactions between small amounts of polar hydroxyl groups of starch and glycerol, and the silicate layers of the nanoclay (inorganic MMT Na+), the starch chains and glycerol molecules can intercalate into the interlayers of the nanoclay. 

Montmorillonite minerals. In The X-ray Identification and Crystal Structures of Clay... 

Little attention has been paid as yet to the high-temperature reactions of vermiculites, although it is known that in the region of 900°C, recrystallization occurs, and diffraction effects resembling those of enstatite and olivine appear on the X-ray patterns of some specimens (Walker and Cole [1957]). It is clear from inspection of the various published differential thermal curves that the nature of the interlayer cation exerts a powerful effect on the course of recrystallization, and one may surmise that a series of complicated reactions similar to those studied by Kulbicki and Grim [1957] and Grim and Kulbicki [1961] for the montmorillonite minerals will also be found with the vermiculites. 

Brydon et al. [1961] report dioctahedral chlorite occurring with quartz and an inter-stratified chlorite-montmorillonite mineral in the AB horizon of the Alberni soil series in British Columbia. The d(060) value of the chlorite is 1.496 A. The 001 reflection at 14.15 A increases in intensity on heating at 550°C and is stable in position to 700°C. Two alternative structural formulas, depending on the estimated amount of free quartz, are given for the clay fraction containing both the chlorite and the interstratified mineral ... 

Brydon, J. E., J. S. Clark, and V. Osborne, 1961. Dioctahedral chlorite. Can. Mineral 6 595-609. Caillere, Simonne, and S. Henin, 1949. Experimental formation of chlorites from montmorillonite. Mineral. Mag. 28 612-620. 

A solonetzic soil from Edensburg shows a mixed-layer illite-montmorillonite mineral only in the top horizon. 

Mitsuda [1960] has found an irregularly interstratified kaolinite-montmorillonite mineral in a contact zone between halloysite and acid clays in Itoigawa. 

Garn, P. D., 1965. Thermoanalytical Methods of Investigation. New York Academic Press. Greene-Kelly, R., 1957. The montmorillonite minerals (smectites). In The Differential Thermal Investigation of Clays. R. C. Mackenzie, ed. London Mineralogical Society, p. 140. 

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