Miscellaneous Precious Metals

Titanium, tantalum and zirconium are used for construction in process plants. The principal physical and mechanical properties of these three metals are given in the Table 3.34. 

It is possible to carry out such oxidation processes as the conversion of acetaldehyde to acetic acid, or methyl alcohol to formaldehyde in aluminum plants, thus avoiding boiling anhydrous acids. The metal is especially valuable for handling delicate chemicals, which must not acquire metallic taste or color. For these reasons, aluminum has found extensive use in the food, dairy, brewing and fishing industries. 

Neutral salts and aqueous solutions of various acids generally follow the acid action. Aluminum has no apparent action or microbiological processes (i.e., the production of antibiotics by deep-vessel fermentation). Fermentation tanks, as well as various absorbing and extracting units, can be made from aluminum. 

Since aluminum is not attacked by hydrogen sulfide (HjS) solutions, it is used widely as a material in refineries for the handling of hydrocarbons made from sour crudes. In the strongly oxidizing conditions of manufacturing hydrogen peroxide, aluminum is one of the few materials that does not undergo decomposition. 

Steam-heated aluminum castings are used for the melt spinning of nylon and polyester fibers and have been used for storage of raw materials during manufacturing, as well as for storage of acetic acid in cellulose acetate plants. 

Thermal Yield Tensile Conductivity Strength Modulus Hardness OV/m°C) (N/mm2) (N/mm2) (DPN) 

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Miscellaneous Refinery catalyst regenerator Municipal incinerators Apartment incinerators Spray drying Precious metal refining... 

Aluminum and aluminum alloys Copper and copper alloys Rare-earth and rare-earth-like metals and alloys Low-melting metals and alloys Miscellaneous nonferrous metals and alloys Nickel and nickel alloys Precious metals and alloys Reactive and refractory metals and alloys... 

Miscellaneous Techniques. Lasers have been used for both electroless and electrolytic plating selective dissolution has hcen used from ancient times to give the appearance of a thin plated coaling nf precious metal and mercury layers plated onto the surface of analytical electrodes serve as liquid meial coatings... 

Miscellaneous bromine uses are in catalysts, fluxes, precious metal recovery, hair care products, food additives, flotation agents in ore treatment, solvents, refrigerants, quartz-halide light bulbs, some lasers, some photovoltaic batteries, and some electrically conductive polymers. 

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