Metal-graphite combinations

Strontium metal is responsible for the red color in fireworks. Fireworks manufacturers use strontium carbonate, which can be produced by combining strontium metal, graphite (C), and oxygen gas. The formation of one mole of SrC03 releases 1220 X 103 k) of energy. 

Gingerich 1989) and La2C n = 1-6, 8) (Pelino et al. 1984, Pelino and Gingerich 1989), as well as ScC (n = 2-6) (Haque and Gingerich 1981), have been observed in the equilibrium vapor above the metal graphite systems at high temperatures. Their thermodynamic characterizations, such as atomization energies etc., have been determined by the Knudsen effusion technique combined with mass spectrometry. The structure of the molecules have been inferred from the assumed models and consistency of the thermodynamic results based on various methods of evaluation. 

This unique combination of physical and chemical properties has resulted in numerous applications. Among them lighting carbons carbon-graphite and metal-graphite brushes for motors and generators welding... 

Atomic absorption spectroscopy is more suited to samples where the number of metals is small, because it is essentially a single-element technique. The conventional air—acetylene flame is used for most metals however, elements that form refractory compounds, eg, Al, Si, V, etc, require the hotter nitrous oxide—acetylene flame. The use of a graphite furnace provides detection limits much lower than either of the flames. A cold-vapor-generation technique combined with atomic absorption is considered the most suitable method for mercury analysis (34). 

Because of their unique combination of physical and chemical properties, manufactured carbons and graphites are widely used in several forms in high temperature processing of metals, ceramics, glass, and fused quartz. A variety of commercial grades is available with properties tailored to best meet the needs of particular appHcations (45). Industrial carbons and graphites are available in a broad range of shapes and sizes. 

Rupture Disks A rupture disk is a device designed to function by the bursting of a pressure-retaining disk (Fig. 26-15). This assembly consists of a thin, circular membrane usually made of metal, plastic, or graphite that is firmly clamped in a disk holder. When the process reaches the bursting pressure of the disk, the disk ruptures and releases the pressure. Rupture disks can be installed alone or in combination with other types of devices. Once blown, rupture disks do not reseat thus, the entire contents of the upstream process equipment will be vented. Rupture disks are commonly used in series (upstream) with a relief valve to prevent corrosive fluids from contacting the metal parts of the valve. In addition, this combination is a reclosing system. 

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