Cement analysis

Carbon, analysis, 217, 318, 319 Carbon brushes, examination by x-ray absorptiometry, 97 Cathode follower, 60 Cauchois arrangement, 119, 120, 123 Caustic circle, 119, 120 Cells for liquids, 191, 194 Cements, analysis in Applied Research Laboratories PXQ, 260, 261 Ceramics, analysis by x-ray emission spectrography, 222-224 Cerenkov radiation, 43 Cesium, determination by x-ray emission spectrography, 328 Characteristic-line generator of Eng-strom, 144... 

N. Moroni, G. Calloni, and A. MarcotulUo. Gas impermeable carbon black cements analysis of field performances. In Proceedings Volume, volume 2, pages 781-792. E P Forum et al Offshore Mediter Conf (OMC 97) (Ravenna, Italy, 3/19-3/21), 1997. 

CAC require large industrial facilities, similar to those used to make ordinary Portland cement. The raw materials for CAC are typically bauxite and limestone, which are ball-milled and mixed together to form a feed of appropriate composition, which is fed into rotary kilns to form a calcium aluminate clinker. The clinker is ball-milled to produce the cement. Analysis for composition and mineralogy at various stages of manufacture are essential to ensure a consistent product, see for example Chakraborty and Chattopadhyay [32] for a discussion of the bulk processing of high alumina CAC. 

The ability of X-ray fluorescence to analyze complex solid samples without recourse to time-consuming wet chemical methods has considerable advantages for metallurgy, mineral and cement analysis, as well as petrochemical products. 

Finishing cements and raw mixes typically contain Ca, Si, Al and O at high concentrations, plus Fe, K, Mg and Na at low concentrations. One of the major problems in accurate cement analysis is homogeneity, particularly in the case of raw mixes, where the source of raw material may be variable. Most of the elements to be determined are of low atomic number, hence the penetration of their characteristic lines will be of the order of a few micrometres only. Careful grinding and pelletizing will suffice, but the fusion bead technique with Li3B04 is strongly recommended. Simultaneous multichannel WD systems are ideally suited for this kind of application. 

The data analysis of the XRD scan of the hydrated cement was carried out using Topas Academic v4.1 software. The data analysis departed from the results of the anhydrous cement analysis and moves through a series of steps as reflected in the following ... 

In addition to chemical analysis a number of physical and mechanical properties are employed to determine cemented carbide quaUty. Standard test methods employed by the iadustry for abrasive wear resistance, apparent grain size, apparent porosity, coercive force, compressive strength, density, fracture toughness, hardness, linear thermal expansion, magnetic permeabiUty, microstmcture, Poisson s ratio, transverse mpture strength, and Young s modulus are set forth by ASTM/ANSI and the ISO. 

The demand for cement was stimulated by the growth of canal systems ia United States duting the nineteenth century. Process improvements were made ia the calciaation of certain limestones for the manufacture of natural cements, which were gradually displaced by Pordand cement. This latter was named ia a 1824 patent because of its color and resemblance to a natural limestone quarried on the Isle of Pordand ia England. Research conducted siace that time has provided a clear picture of the composition, properties, and fields of stabiUty of the principal systems found ia Pordand cement. These results led to the widely used Bogue calculation of composition based on oxide analysis (1). Details beyond the scope of this article may be found ia the Hterature (2). 

An Analysis of Selected Trace Metals in Cement and Kiln Dust, SP109, Pordand Cement Association, Skokie, Dl., 1992. 

A wet-process plant maldug cement from shale and hmestoue has been described by Bergstrom [Roc/c Prod., 64—71 (June 1967)]. There are separate facilities for grinding each type of stone. The ball mill operates in closed circuit with a battery of Dutch State Mines screens. Material passing the screens is 85 percent minus 200 mesh. The entire process is extensively instrumented and controlled by computer. Automatic devices sample crushed rock, slurries, and finished product for chemical analysis by X-rav fluorescence. Mill circuit feed rates and water additions are governed by conventional controllers. 

Energy-dispersive X-ray spectroscopy has been used for quality control and test analysis in many industries including computers, semiconductors, metals, cement, paper, and polymers. EDS has been used in medicine in the analysis of blood, tis-... 

Rhodium-platinum alloys containing up to 40% Rh are used in the form of wire or ribbon in electrical resistance windings for furnaces to operate continuously at temperatures up to 1 750°C. Such windings are usually completely embedded in a layer of high-grade alumina cement or flame-sprayed alumina to prevent volatilisation losses from the metal due to the free circulation of air over its surface. Furnaces of this type are widely employed for steel analysis, ash fusions and other high-temperature analytical procedures. 

More detailed statistical analyses (chemical element balance, principal component analysis and factor analysis) demonstrate that soil contributes >50% to street dust, iron materials, concrete/cement and tire wear contribute 5-7% each, with smaller contributions from salt spray, de-icing salt and motor vehicle emissions (5,93-100). A list is given in Table VII of the main sources of the elements which contribute to street dust. 

Marland, G., Boden, T. A., Griffin, R. C., Huang, S. F., Kanciruk, P. and Nelson, T. R. (1989). Estimates of CO2 emissions from fossil fuel burning and cement manufacturing, based on the US Bureau of Mines cement manufacturing data. Rep. ORNL/CDIAC-25, NDP-030, Carbon Dioxide Information Analysis Center, Oak Ridge Natl. Lab., Oak Ridge, TN. 

X-ray diffraction shows that both the cement matrix and the salt are amorphous (Wilson, 1982 Smith, 1971 Steinke et al., 1988). On the basis of chemical analysis, Wilson (1982) assigned the following empirical formula to the zinc polyacrylate salt ... 

Bertenshaw, B. W. Combe, E. C. (1972a). Studies on polycarboxylates and related cements. I. Analysis of cement liquids. Journal of Dental Research, 1, 13-16. 

Cook, W. D. (1983c). Degradative analysis of glass-ionomer polyelectrolyte cements. Journal of Biomedical Materials Research, 17, 1015-27. 

Swift, E. J. Dogan, A. U. (1990). Analysis of glass-ionomer cement with use of scanning electron microscopy. Journal of Prosthetic Dentistry, 64, 167-74. 

Komrska Satava (1970) showed that these accounts apply only to the reaction between pure zinc oxide and phosphoric acid. They found that the setting reaction was profoundly modified by the presence of aluminium ions. Crystallite formation was inhibited and the cement set to an amorphous mass. Only later (7 to 14 days) did XRD analysis reveal that the mass had crystallized directly to hopeite. Servais Cartz (1971) and Cartz, Servais Rossi (1972) confirmed the importance of aluminium. In its absence they found that the reaction produced a mass of hopeite crystallites with little mechanical strength. In its presence an amorphous matrix was formed. The amorphous matrix was stable, it did not crystallize in the bulk and hopeite crystals only grew from its surface under moist conditions. Thus, the picture grew of a surface matrix with some tendency for surface crystallization. 

The action of heat on these cements is complex (Abdelrazig Sharp, 1988). The principal sequence based on XRD and thermal analysis is shown in Figure 6.10. 

These cements were the earliest of the oxysalt bonded cements to be prepared (Sorel, 1855) and their chemistry has been the subject of numerous investigations over the years. There are considerable difficulties associated with such investigations. Not only does the cement contain a complex mixture of different crystalline precipitates but it is unaffected by boiling water and dissolves only slowly in strong acids. Consequently separation or analysis of any of the phases which may be present is difficult. Nonetheless, as early as 1925 at least 17 crystalline compounds were claimed to occur in the zinc oxychloride cement (Mellor, 1925). 

A detailed study of the phase relationships in the magnesium oxysulphate cement was carried out by Urwongse Sorrell (1980b). They used X-ray analysis to examine the phases present in the cement, and established the composition of the invariant liquids after equilibration by measuring specific gravity with the aid of a pycnometer. Specific gravities were related to concentration by means of a calibration exercise in which 30 stock solutions of sulphuric acid at concentrations between 0 and 79-5 wt % were prepared with distilled water. 

Bagby, M. Greener, E. H. (1985). Infrared spectral analysis of EBA-hexyl vanillate-ZnO cement. Dental Materials, 1, 86-8. 

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