Chlorite chemical analyses

Most likely, the chemical system remains closed, as far as the other components in the silicate phases are concerned, as diagenesis or low grade metamorphism becomes more evident. Although there may be transfer of calcium, it seems, from bulk chemical analysis, that there is no systematic increase in potassium nor decrease in sodium content of argillaceous sediments. The transfer of Na and K is between the two size fractions—clay and coarse fraction—or between phyllosilicates and tectosilicates. Albitization of argillaceous rocks should be a common phenomenon where mixed layered phases are predominant in clay assemblages and especially evident in the illite-chlorite zone. 

Trioctahedral clay chlorite is an abundant constituent of soils formed by the weathering of basic volcanic pumice and tuffs in North Wales (Ball,1966). The adjusted chemical analysis (29.35% Si02, 16.82% A1203, 4.42% Fe203, 15.08% FeO, 0.25% MnO, 21.54% MgO, 12.00% H20+, 0.54% H20 ) produces the following structural formula ... 

Weaver (1959) noted that the chlorite, which is a common constituent of the Ordovician K-bentonite beds of the eastern United States, has a dioctahedral 2 1 layer and a trioctahedral hydroxide sheet. A partial chemical analysis indicated the chlorite contained less than 2% Fe203. Both layers were probably formed in place from the alteration of volcanic ash in a marine environment. Only one other chlorite of this type had been detected in X-ray patterns of approximately 75,000 samples of sedimentary rocks. The other sample was from a Paleozoic argillaceous limestone at a depth of 24,400 ft. in Oklahoma. Chlorites of this type might well go undetected when chlorite is only a minor component. 

Eggleston and Bailey (1967) published a study on dioctahedral chlorite and gave five examples of chlorites having a pyrophyllite-like layer and a brucite-like sheet (designated di/trioctahedral by the authors with the trioctahedral sheet including all species of chlorite with 5 to 6 octahedral cations per formula unit and dioctahedral 4 to 5 octahedral cations per formula unit). Identification of di/trioctahedral chlorites is indirectly accomplished. Eggleston and Bailey stated that identification depends on the intermediate value of c (060), on chemical analysis of impure material, and on the ideal compositions of the recrystallization products of static heating . The composition of one such chlorite for which they refined the structure is ... 

Chemical analysis for the main constituents of wood was carried out on tissues taken from the different zones of ach wood sample and on fresh wood of the same species according to the standards of the Technical Association of the Pulp and Paper Industry (TAPPI Standards Nos. 12, 15, 203, 204, 207, 212, and 222). Chlorite-holocellulose was determined as proposed by Wise et al. (iO). Results are listed in Table I and Figure 1. In the cases where the sum of the determined constituents is less than 100%, this discrepancy reflects the presence in the wood of soluble degradation products of carbohydrates or acid-soluble lignin fragments that are not retained on the filters used in the analysis. The density flg (g/cm ) is based on dry weight and waterlogged volume, and can be calculated from the maximum water content (w ax) by the formula ... 

Reactions with chlorite resulted chiefly in the formation of katoite, identified by XRD, morphology (SEM and ATEM) and chemical analysis (ATEM). The ATEM-derived chemical data for this phase are presented in Table 4. 

The identification of kaolin minerals in mineral mixtures in soils is not difficult. Separation from chlorite is the one exception and is discussed separately below. Combination of X-ray diffraction with and without chemical pretreatments, electron microscopy, differential thermal analysis (DTA), and chemical analysis serve to effect the identification. The determination of which kaolin mineral is present can, however, be very difficult, particularly if it is a minor constituent of the mixture. Electron diffraction analysis of single crystals is probably the only certain technique. 

The absolute quantities of the elements present in the unit cell can be obtained if the density and the volume of the unit cell are available in addition to the chemical analysis. In most cases, this is not possible, and the allocation to a structural formula must be made on the basis of some assumption about the formula unit. For chlorites, one of the following assumptions is usually made ... 

Schultz [1963] has described the occurrence of 20 samples of aluminian chlorite from sediments in Triassic rocks of the Colorado plateau. The rf(060) values are between 1.50 and 1.51 A, and the 003 reflection is considerably more intense than should be the case for a trioctahedral chlorite. A chemical analysis of impure material shows slightly more AI2O3 than MgO and, according to allocation by the present writer, yields an octahedral total close to five atoms. These data suggest the presence of mixed di,trioctahedral sheets, but further details are needed for verification. 

Frenzel and Schembra [1965] have described dioctahedral chlorite from hydrothermally altered arkose in the Kaiserbach Valley. The < (001) value of 14.11 A does not change after solvation. The X-ray powder pattern is similar to those of Bailey and Tyler and of Hayashi and Oinuma, but contains impurities of quartz, dolomite, and feldspar. The (chemical analysis yields 4.80 octahedral cations plus 0.13 exchangeable cations. 

Caillere et al [1962] describe dioctahedral chlorite in bauxite from the east Pyrenees. The /(060) value is 1.50 A. The chemical analysis of quite pure material (Table 8) yields the following structural formula, neglecting the H2O content ... 

Frank-Kamenetsky et al [1965] have given the name tosudite to a regular interstratification of dioctahedral chlorite and montmorillonite. The material has a basal spacing of 28.5 A in its natural state, increases to 32.0 A on glycerol solvation, and decreases to 23.6 A on heating. The authors describe the chlorite as dioctahedral in both sheets, but could not obtain a pure sample for chemical analysis. The fi (060) value of 1.497 A supports the view of two dioctahedral sheets, but further confirmation is desirable. 

The four chlorites, whose structures are known in detail, can be used to test the validity of the proposed relationships between d(001) and composition. Poor agreement was found using the published compositions and cell parameters. For this reason, samples of all four chlorites were obtained from the original sources. The compositions were determined by electron microprobe analysis, adjusted to give the same ratio of ferrous and ferric iron as present in the original wet chemical analysis, and the unit-cell parameters determined by least-squares refinement of X-ray powder data. Major differences from the reported data were found both in composition (primarily Si, Al) and in certain cell parameters (primarily b) for... 

Tuddenham, W. M., and R. J. P. Lyon, 1959. Relation of infrared spectra and chemical analysis for some chlorites and related minerals. Anal Chem. 31 377-380. 

The similar chlorite-montmorillonite interstratification has been identified by Di Paola [1968] from the upper cretaceous in Argentina and by Morelli [1967] in Italy (X-ray, D.T.A., chemical analysis and cation exchange data). 

Consequently, when D /Dj exceeds the critical value, close to the bifurcation one expects to see the appearance of chemical patterns with characteristic lengtli i= In / k. Beyond the bifurcation point a band of wave numbers is unstable and the nature of the pattern selected (spots, stripes, etc.) depends on the nonlinearity and requires a more detailed analysis. Chemical Turing patterns were observed in the chlorite-iodide-malonic acid (CIMA) system in a gel reactor [M, 59 and 60]. Figure C3.6.12(a) shows an experimental CIMA Turing spot pattern [59]. 

In the AWWA specification standards, technical soHd sodium chlorite should not contain less than 78.0 wt % NaC102. The impurity limits for 80% assay sodium chlorite should not be more than 17.0 wt % sodium chloride, 3.0 wt % sodium carbonate, 3.0 wt % sodium sulfate, and 0.0003 wt % arsenic. The AWWA standards also specify the analysis procedures for all of the chemical components ia the sodium chlorite. 

Fox, R. O., G. Erjaee, and Q. Zou (1994). Bifurcation and stability analysis of micromixing effects in the chlorite-iodide reaction. Chemical Engineering Science 49, 3465-3484. 

Although as already mentioned, the information on the chemical composition of natural, low temperature chlorites in sedimentary rocks is limited some new data has been gathered using microprobe analysis of grain mounts or rock thin sections. The samples studied come from rather different geographic areas—western Montana, Algeria and the Franco-Italian Alps and African off-shore Atlantic coast shelf sediments. 

J, Maselko, M. Alamgir and I. R. Epstein, Bifurcation analysis of a system of coupled chemical oscillators bromate-chlorite-iodite . Physica, 19D, 153 (1986). 

Figure 5.8 Analysis of the infrared spectrum of a mineral, (a) Sample spectrum 50% albite (k-feldspar) 23% siderite 17% illite 10% chlorite, (b) Calculat spectrum 49.7% feldspar (8.0% albite, 13.2% orthoclase and 28.5% microcline) 25.2% siderite 19.0% illite 6.8% chlorite, (c) Residnal difference spectrum. From Brown, J. M. and Elliot, J. J., The Quantitative Analysis of Complex, Multicomponent Mixtures by FTIR the Analysis of Minerals and of Interacting Organic Blends , in Chemical, Biological and Industrial Applications of Infrared Spectroscopy, Durig, J. R. (Ed.), pp. 111-125. Copyright 1985. John Wiley Sons Limited. Reproduced with permission.

Chemical characterization of fines implies the elemental and mineral compositional analysis of migratory fines in porous media. Khilar and Fogler (1998) presented the range in chemical composition of migratory clays primarily of kaolinite, illite, montmorillonite, and chlorite particles in Table 5.6. We observe from this table that silica, Si02, and alumina are the major minerals. 

The chromite used in this study is imported from South African, and bentonite, chlorite, coke breeze were all from China. The industrial analysis of the coke breeze is shown in Table I, and the chemical composition of the other raw materials are shown in Table II. 

Table 8 contains chemical analyses representative of each of the nine species given by Foster [1962], plus analyses for kammererite, kotschubeite, the Mn-chlorite pennantite, the Li-Al chlorite cookeite, and a dioctahedral chlorite. The analyses have been allocated to structural formulas, based on 18 (O + OH) atoms, in Table 9. Small amounts of P2O5 and of the large cations K, Na, Ca, or Ba have been excluded from the allocation, where present, on the assumption that they represent impurities. CaO is found by analysis in small amounts in many chlorites, and Belov [1950] has suggested that the Ca might be incorporated in octahedral coordination between the silicate layer and the interlayer. Brown and Bailey [1963] found no evidence for this on electron-density maps of a particular chlorite they investigated.

In fact, if the analysis of the dehydrated mineral is solely taken into consideration, which is often necessary, given the uncertainty over the composition of the constituting water, the number of hydrogens present in the structure cannot be known. There exists, in fact, a process of chemical alteration well demonstrated in the case of chlorites (Brindley and Youell [1955]), whereby ferrous iron of the structure becomes ferric iron, the charge increase of this cation being compensated by a hydrogen loss. 

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