Sulfur atmospheric

Type J thermocouples (Table 11.58) are one of the most common types of industrial thermocouples because of the relatively high Seebeck coefficient and low cost. They are recommended for use in the temperature range from 0 to 760°C (but never above 760°C due to an abrupt magnetic transformation that can cause decalibration even when returned to lower temperatures). Use is permitted in vacuum and in oxidizing, reducing, or inert atmospheres, with the exception of sulfurous atmospheres above 500°C. For extended use above 500°C, heavy-gauge wires are recommended. They are not recommended for subzero temperatures. These thermocouples are subject to poor conformance characteristics because of impurities in the iron. 

Patterson, D. E., et al., Thermochemical Vapor Deposition of Diamond in a Carbon-Halogen-Oxygen and/or Sulfur Atmospheric Hot-Wall Reactor, in Applications of Diamond Films and Related Materials, (Y. Tzeng, et al., eds.), Elsevier Science Publishers, pp. 569-576 (1991)... 

Yellow to orange crystal occurs as two polymorphs, hexagonal alpha form and cubic beta form exhibits stable wurtzite structure at lower temperature, and zinc blende type structure at higher temperatures the beta form converts to alpha form when heated at 750°C in sulfur atmosphere sublimes at 980°C practically insoluble in water (1.3 mg/L at 20°C) Ksp 3.6x10-29 dissolves in dilute mineral acids on heating or concentrated acids at ordinary temperatures (decomposes with liberation of H2S). 

J Iron - Constan-tan (Cu-Ni) 0 to 750 0 to 200 Recommended for reducing atmosphere. Displays poor conformance characteristics due to poor iron purity. Above 538°C, oxidation of Fe in air is rapid so heavy-gauge wire is recommended for extended use. Should not be used bare in sulfurous atmospheres above 538°C. 

K Chromel -Alumel -200 to 1250 0 to 200 Recommended for clean oxidizing atmospheres. They can be used in reducing atmospheres, but they should not be cycled from reducing to oxidizing and back repeatedly. The higher temperature ranges can only be achieved with heavy-gauge wires. They should not be used in vacuums and should not be bare in sulfurous atmospheres. 

High temperature uses where high sulfur atmospheres make presence of nickel undesirable. 

Tume furnaces, flare stacks, materials in contact with high sulfur atmospheres... 

ARDS unit works as the springboard in the new scheme of Mina Abdulla Refinery operation Primarily a desulfurization unit, ARDS also reduces the metals, asphaltenes and nitrogen in the products, thereby, ensuring proper quality of feed for downstream conversion units. As an additional benefit, ARDS is also a mild hydrocracking process, partially upgrading high sulfur atmospheric residue to low boiling products like naphtha and distillate. 

Properties Offers good resistance to dilute acids and alkalies, seawater, and moist sulfurous atmospheres. D 8.53 (20C), liquidus temp 935C, solidus temp 900C. 

Use It is used principally for electric resistance purposes. It also offers good resistance to mine and seawaters and moist sulfurous atmospheres. 

Size-(submicrometer-sized) and rnoi phology-(spherical) controlled composite Gd—Eu oxalate particles were prepared by Hirai et al. [171] using W/O/W system. The oxalate particles thus prepared were calcined in air to obtain Gd2O3 Eu phosphor particles and in sulfur atmosphere to obtain Gd2O2S Eu phosphor particles. These submicrometer-sized spherical phosphor particles showed photoluminescence properties with emission peak at 614 nm for Gd2Oi Eu and 628 nm for Gd2O2S Eu. ... 

NP Same general use as type KP, except less affected by sulfurous atmospheres because of the... 

KN Can be used in oxidizing or inert atmospheres. Do not use unprotected in sulfurous atmospheres as... 

The first report of a CuInSe2/CdS heteroj unction solar cell-based on single-crystal CulnSe2-appeared in 1974 [72]. The cell achieved an efficiency of 5%. In 1983 the first electrochemical approach to produce a polycrystalline thin film of CuInSe2 was reported by Bhattacharya [73] in which Cu, In, and Se were deposited simultaneously from an acidic solution. Other approaches to the synthesis of polycrystalline CuIn(S,Se)2 thin films appeared quickly after the first report for example, Hodes et al. annealed an electrodeposited Cu-In alloy [74], Kapur et al. annealed stacked Cu-In layers [75], and Bhattacharya et al. annealed In-Se Cu-Se stacks [28]. The EDA routes which currently produce the most efHcient CuIn(S,Se)2 solar cells involve co-deposition of all of the constituent elements [76] followed by annealing in a sulfur atmosphere, and the electrodeposition of a Cu-In alloy with a small amount of Se, again followed by annealing in sulfur [34]. Both routes produce devices with around 11% power conversion efficiency. 

There are currently two basic approaches to fabricate GZTS layers by electrodeposition. In the stacked elemental (SEL) approach, the parent metals are electrodeposited sequentially to form a stack [35, 119] which is then annealed in a sulfur atmosphere to from CZTS. In an alternative approach, the parent metals are co-deposited to form a mixed metallic or alloy layer which is then annealed in the presence of sulfur [120, 121]. Both approaches have yielded cells with AM 1.5 efficiencies of over 3%. 

Above 900°C, the life of aluminized steel is limited, although extended over that of the bare metal (e.g., at 900°C-980°C, the life is increased 20 times, at 980°C-1000 C, five times). Below 750°C, the life of aluminized steel components can be considered to be indefinite. Results obtained between 750°C and 900°C are conflicting, although the presence of silicon has been shown to be detrimental (Figure 10.15) at all temperatures [135]. Aluminum-coated steels have also been shown to be particularly resistant to sulfurous atmospheres [131]. In this respect, such coatings are particularly useful for the protection of heat-resisting grades of steel. 

Nickel and high-nickel alloys tend to oxidize along grain boundaries when subject to alternate oxidation and reduction. Alloying with chromium reduces this tendency. Also, in contact with sulfur or sulfur atmospheres at elevated temperatures, nickel and high-nickel alloys are subject to intergranular attack. Consequently, nickel is not usefully resistant to such atmospheres above about 315 °C... 

Sulfur, sulfur atmospheres, and H2S. Aluminum is used for mining of sulfur. 

The heat-resistant steels are weldable by the usual processes, with arc welding preferred over gas fusion welding. For the ferritic steels, the tendency to grain coarsening in the heat affected zone has to be kept in mind. The application of austenitic filler metals will lead to better mechanical properties of the weld connection than those of the base metal (however, with respect to the scaling resistance, different thermal expansions of the ferritic and austenitic materials may be a problem). Filler materials should be at least as highly alloyed as the base metal. In sulfurizing atmospheres it is advisable to use ferritic electrodes for the cap passes only in order... 

Monel 400 is a nickel alloy containing 30-33% copper. The corrosion of Monel 400 is negligible in all types of atmospheres. When exposed to rain, a thin gray-green patina develops. In a sulfurous atmosphere a smooth, brown adherent film forms. Because of its low corrosion rate and the pleasing patina that forms. Monel 400 is used for architectural applications such as roofs, gutters, and flashings. 

Inconel 600 remains bright indefinitely in indoor atmospheres, even in damp sulfurous atmospheres that may fog nickel 200 and Monel 400. However, because of cost Inconel 600 does not find many indoor applications. 

The transformation of the cerium precursor into the colored sesquisulfide is carried out at high temperatures (between 700 and 1100 C) in a sulfurizing atmosphere. The resulting colored sesquisulfide is then cooled to room temperature. 

The corrosion of Monel is negligible in all types of atmospheres. When exposed to rain, a thin gray-green patina forms. In sulfurous atmospheres, a smooth brown adherent film forms. 

Zinc is exposed to the atmosphere in the form of galvanized sheet, as in flashings on roofs as die castings, and as coatings on steel, either hot-dipped or electroplated. The general behavior of zinc metal and zinc coatings is described in the ISO tables presented earlier. Note the particularly low rates of attack on zinc as compared with steel in marine exposures where chloride deposition is important. Such excellent resistance is acquired by the hard, dense, protective products of corrosion in a chloride atmosphere. Similar results cannot be obtained in a sulfurous atmosphere where the corrosion products are soft, voluminous, and non-protective. 

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