Thermal analysis of clays

C. M. Earnest, Thermal Analysis of Clays, Minerals, and Coal, Perkin-Elmer Corporation, Norwalk, CT (1984). 

R. C. MaoKenzie, The Differential Thermal Analysis of Clays, Central Press, Aberdeen, Scotland, 1957. 

Mackenzie,R.C. The differential thermal analysis of clays. London Mineralogical Society, 1957. 

Dulong Pierre-Louis (1785-1838) Fr. chem., research on refractive indices and specific heats of gases, co-formulated Dulong-Petit s law, devised empirical formula for the heat Earnest Charles Mansfield (1941-) US chem., expert in geoscience and minerals (book Thermal analysis of clays 1984) Einstein Albert (1879-1955) Ger. phys., originator of theories of relativity, laws of motion and rest, simultaneity and... 

One of the first applications of thermal techniques was related to the characterization of clay minerals. Extensive work has been carried out on thermal analysis of clay products. Identification and characterization of clay raw materials and accessory minerals, reactions that occur during the firing... 

P. L. Arens, A Study on the Differential Thermal Analysis of Clays and Clay Minerals, Excelsiors Foto-Offsets, 1951. 

Allaway, W. H., 1949. Differential thermal analysis of clays treated with organic cations as an aid in the study of soil colloids. Proc. Soil Sci. Soc. Am. 13 183. 

Campbell, A.S. Schwertmann, U. (1985) Evaluation of selective dissolution extractants in soil chemistry and mineralogy by differential X-ray diffraction. Clay Min. 20 515-519 Campbell, A.S. Schwertmann, U. Campbell, P.A. (1993) Thermal analysis of ferrihydrite. 10 Int. Clay Conference, Adelaide, S.A., July 1993, Abstract, p. 0-26... 

White, E.A. 2004. Preparation and thermal analysis of cotton-clay nanocomposites. J. Appl. Polym. Sci., 92(4) 2125-2131. 

The techniques of DTA, and to some extent TG, have long been used by geochemists and others to study the thermal behavior of clays and minerals. Since many simultaneous reactions occur in clays, as well as solid-state reactions that alter the decomposition reaction, the use of other methods such as EGA, X-ray, IR. and so on, are used to supplement conventional thermal analysis techniques. Consequently, there has recently been an unusual amount of interest in the use of EGA (MS) in the study of these compounds. 

Figiire 4. Differential thermal analysis of the pillared clay GaAli2 STx-l. 

Morgan, D.J. (1993). Thermal analysis including evolved gas analysis of clay raw materials. Applied Clay Science, 8 81. 

C. B. Hedley, G. Yuan, and B. K. G. Theng, Thermal analysis of montmorillonites modified with quaternary phosphonium and ammonium surfactants. Applied Clay Science, 35 (2007), 180-88. 

Slates are related to clays. The DTA technique has been applied to study the weathering quality as well as an aid to the identification of slate of unknown origin. Figure 17 shows the differential thermal analysis of samples of roofing slate of three different qualities.The first curve represents a slate of excellent durability. The peaks at 610 and 850°C may be due to some type of chlorite. The inflection at 575 C is caused by the presence of quartz. In the calcined material (2 curve), the presence of quartz is more clear. The third curve is obtained with a slate that was found in practice to delaminate slowly on roofs under conditions of low atmospheric pollution. The poor durability may be caused by the slow oxidation of pyrite in the slate and subsequent reaction between the oxidation product and calcite to form calcium sulfate. The presence of pyrite and calcite is indicated by the peaks at 450° and 770°C, respectively. The fourth curve of slate of pure quality is dominated by the large calcite peak. The exothermic peaks at 930° and 420°C suggest the presence of chlorite and a small amount of pyrite, respectively. 

The thermal analysis of different archaeological samples of bricks, terra-cotta, and local clays provides useful information on the chemical composition of historical samples and can provide confirmation of specific sites of originJ ] The thermal characterization of local clays is valuable to assist the restoration of historical pottery materials. 

Kacker, K.P., and Ramachandran, V. S., Identification of Clay Minerals in Binary and Ternary Mixtures by Differential Thermal Analysis of Dye-Clay Complexes, 9 lnt. Ceram. Congr., Brussels, p. 483-500 (1964)... 

Thermal analysis of hexadecyltrimethyl quaternary ammonium ion exchanged onto montmorillonite [9] indicates that water could be present in the quat-clay gallery up to 130°C. Reviews of published studies [3] of the thermal stability of organoclays indicate that water could be present up to 200°C. These studies indicate that the addition of quat to montmorillonite past the exchange capacity compromises the thermal stability of the organoclay. Removal of quat from montmorillonite by solvent... 

Pask, j. a. Davis, B. 1954. Thermal arudysis of clays and acid extraction of alumina from clays. Differential Analysis, US Bureau of Mines, Denver. 

CARRADO ET AL. Thermal Analysis of Porphyrm—Clay Complexes... 

Jonas, E. C., and R. E. Grim, 1957. Differential thermal analysis using controlled atmosphere. In The Differential Thermal Investigation of Clays, R. C. Mackenzie, ed. London Mineralogical Society, p. 389. 

Speil, S., 1945. Applications of thermal analysis to clays and aluminous materials. Tech. Pap. Bur. Min (Washington) No. 664 1. 

The hydrated alumina minerals usually occur in ooUtic stmctures (small spherical to eUipsoidal bodies the size of BB shot, about 2 mm in diameter) and also in larger and smaller stmctures. They impart harshness and resist fusion or fuse with difficulty in sodium carbonate, and may be suspected if the raw clay analyzes at more than 40% AI2O2. Optical properties are radically different from those of common clay minerals, and x-ray diffraction patterns and differential thermal analysis curves are distinctive. 

Thermogravimetric analysis has also been used in conjunction with other techniques, such as differential thermal analysis (DTA), gas chromatography, and mass spectrometry, for the study and characterisation of complex materials such as clays, soils and polymers.35... 

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