Chromium combustion methods

Analysis of Size-Fractionated Particles. A series of samples was analyzed by both methods of analysis, and the results of two samples that were collected on different days are shown in Tables III and IV. The data shown in Table III illustrate that there are probably two origins of the elements. Vanadium, bromine, manganese, copper, mercury, chromium, and zinc increase in concentration as the particle size decreases. This inverse relationship is expected if these particles are emitted by high-temperature combustion processes such as automobiles and power plants (which are the major sources in this area). Sodium, aluminum, iron, scandium, and cobalt were present in an approximately uniform distribution throughout the particle size range. This relationship results... 

In the present work the causes oi the deactivation of alumocopperchroniLum and aiumoniagnesiuci chromium catalysts for fuel combustion have been investigated by a variety of instrumental methods IR-spectroscopy electron diffuse reflectance spectroscopy (EDRS), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD) and a pulse microcatalytic method. 

Comparison of chromium exposed to atmospheric air at 1600°C with chromium exposed to combustion chamber solicitations (figure 8) permitted to conclude that mechanisms responsible for the material failure were similar for both cases so testing in high temperature air is a representative method to obtain qualitative results on chemical resistance of Cr-based alloys to combustion chamber gasses. 

Abbas ZA, Steenari BM and Lindqvist O (2001) A study of Cr(VI) in ashes from fluidized bed combustion of municipal solid waste leaching, secondary reactions and the applicability of some specia-tion methods. Waste Manag 21 725-739. Accominotti M, Bost M, Haudrechy P, Mant-ouT B, CuNAT PJ, Comet F, Mouterde C, PiANTARD F, Chambon P and Vallon JJ (1998) Contribution to chromium and nickel enrichment during cooking of foods in stainless steel utensils. Contact Dermatitis 38 305-310. 

The release of trace elements, associated with the combustion of coal, to the environment and disposal of coal ash, which often contains a wide range of trace elements, has become a matter of concern. The determination of these elements in coal (and coke) ash is a very important aspect of coal analysis and involves the use of atomic absorption (ASTM, 2011x). The methods cover the determination of beryllium, chromium, copper, manganese, nickel, lead, vanadium, and zinc. The use of x-ray fluorescence (Prather et al 1979), the electron probe microanalyzer (Raymond and Gooley, 1979), for determination of trace elements in coal has also been reported. 

While not pyrophoric, the porous copper metal monolith is readily combustible by the application of a flame in air. In addition to copper, this method has been appUed to prepare other nanoporous metals such as iron, cobalt, nickel, and tin, as well as carbides of chromium, titanium, and hafnium (Chap. 14). This method is especially powerful as it appears to be applicable to a wide variety of metals and affords articles that are mrmolithic. 

As yet no heats of combustion have been reported for any of the chromium carbides. Nevertheless, measurements have been made using gas-phase equilibria which can be used, with some reservation, to obtain heats of formation. To provide a common basis, all of the following values were recalculated by the third law method using the data listed at the bottom of Table 42. 

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