Nickel special-purpose

Nickel Special-purpose heat exchangers, caustic handling... 

Marsh, J. S., The Alloys of Iron and Nickel Vol. I Special-purpose Alloys, McGraw-Hill, New York and London, 495 et seq. (1938)... 

The Raney nickel process applied to alloys of aluminum with other metals produces Raney iron, Raney cobalt, Raney copper and Raney zinc, respectively. These catalysts are used very rarely and for special purposes only. 

Chemical pumps are available in a variety of materials. Metal pumps are the most widely used. Although they may be obtained in iron, bronze, and iron with bronze fittings, an increasing number of pumps of ductile-iron, steel, and nickel alloys are being used. Pumps are also available in glass, glass-lined iron, carbon, rubber, rubber-lined metal, ceramics, and a variety of plastics, such units usually being employed for special purposes. 

A number of copper alloys have been developed for special purposes. For example, gun metal is an alloy used to make guns. It contains about 90 percent copper and 10 percent tin. Monel metal is an alloy of nickel and copper that is resistant to corrosion (rusting). Coinage metal is a copper alloy from which U.S. coins are made. 

Catalytic reductions have been carried out under an extremely wide range of reaction conditions. Temperatures of 20 C to over 300 C have been described. Pressures from atmospheric to several thousand pounds have been used. Catal3rsts have included nickel, copper, cobalt, chromium, iron, tin, silver, platinum, palladium, rhodium, molybdenum, tungsten, titanium and many others. They have been used as free metals, in finely divided form for enhanced activity, or as compounds (such as oxides or sulfides). Catalysts have been used singly and in combination, also on carriers, such as alumina, magnesia, carbon, silica, pumice, clays, earths, barium sulfate, etc., or in unsupported form. Reactions have been carried out with organic solvents, without solvents, and in water dispersion. Finally, various additives, such as sodium acetate, sodium hydroxide, sulfuric acid, ammonia, carbon monoxide, and others, have been used for special purposes. It is obvious that conditions must be varied from case to case to obtain optimum economics, yield, and quality. 

Mold tool steels P These are special-purpose tool steels containing chromium and nickel as major alloying elements. They exhibit low hardness and low resistance to work hardening when annealed. 

Cadmium is a soft, ductile, bluish white metal. It may be alloyed with lead, tin and bismuth in the manufacture of fusible metals for automatic sprinkler systems, fire alarms and electrical fuses. Cadmium has been used as a control or shielding material in atomic energy plants because of its high absorption of low-energy neutrons. Nickel-cadmium batteries are in common use for specialized purposes, but intensive research is going on in order to develop a more ecofriendly anode material as an alternative to cadmium. 

The principle of the heterogeneous catalytic hydrogenation of unsaturated acylglycerols was outlined under 3.2.3.2.4. The most widely used catalyst is carrier-bound nickel. Raney nickel, copper, and noble metals serve special purposes. The choice of catalyst is made according to ... 

Special-purpose sealed nickel-cadmium batteries are manufactured with specifically designed characteristics, overcoming some of the limitations of standard batteries, to meet the requirements for certain applications. Manufacturers recommendations should be followed because of the specific performance characteristics of these batteries. 

The specific purpose of this chapter is to describe the chemical and physical pretreatment methods required for nickel-chromium plating wastewater, to describe the upgrades needed by a municipal wastewater treatment system to manage this waste, and to relate the methods and upgrades to the operation of the total treatment system. Special emphasis is placed on presentation of the following ... 

The term major active component may be used to describe the active component, the proportion of which greatly exceeds that of the others. Secondary components added on purpose may be described as additives, whereas the term impurities should be reserved for trace amounts of other elements, over which the investigator (manufacturer) has little control. The use of the word promoter implies that the additive improves some particular property of the catalysts, and it is desirable to indicate this property when known (e.g. activity, selectivity, textural properties, resistance to sintering). The term modifier is used sometimes in this context, but is not recommended. The term modifier is used in a special and proper sense in the context of asymmetric hydrogenation when, for example, Raney nickel is modified by optically active tartaric acid in order to impart the property of asymmetry to hydrogenation reactions over the catalyst. 

Nickel yields a considerable number of alloys, some of which are of great technical importance. Chief amongst these are the alloys of nickel and iron, known generally as nickel steels and special ferroalloys. At least half of the world s nickel production is employed in ordinary peace times in the manufacture of these, whilst during the Great European War of 1914 to 1918 probably three-quarters were consumed for this purpose. 

Preparation of Nickel Salts free from Cobalt.—As has already been mentioned, nickel closely resembles cobalt in many of its properties, and for many purposes it is quite unnecessary to effect a complete separation of the metals. When, however, pure salts of either metal are required, several convenient methods are to hand for effecting the removal of the unwanted element. In order to remove small quantities of cobalt from nickel salts any of the methods suggested for the removal of nickel from cobalt salts may be utilised. Of these, Fischer s nitrite process is specially convenient. 

Stainless steels are in a special class, differing from other steels in being nonmagnetic and essentially free from rusting and corrosion. A typical stainless steel (type 316) contains 17 percent chromium, 12 percent nickel, and 3 percent molybdenum. The chemical resistance of stainless steel makes it very attractive for many purposes, but its cost and the difficulty of machining it limit its use somewhat. It can be silver-soldered or welded soft soldering is difficult. 

A radical species may also be generated by reduction of an electron-deficient compound and a classical entry to 4,4 -bipyridines is the reduction of a pyridine by sodium and subsequent rearomatization. Figure 8a illustrates the use of such a reduction in order to prepare the precursor of a sodium-ion molecular switch [30], A more general route, derived from the ancient copper-catalyzed Ullmann coupling, is the metal-induced dimerization of an aryl halide. The key step is a reductive elimination within the coordination sphere of the metal. A nickel(O) complex, in stoichiometric quantities, is usually selected for this purpose. Constable and Ward have used such a reaction to prepare a bis-terpyridine from an interesting synthon, which would have otherwise required a more specialized strategy with dedicated intermediates (Figure 8b) [31]. 

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