Bronzes, Ordinary

Copper bronze. Ordinary copper bronze does not give as satisfactory results in the Ullmunn reaction im bronze that has been activated with a 2% solution of iodine in acetone. ... 

Natur Kupfer C is a good catalyst, but ordinary copper bronze may be used. 

Copper was called cuprum in Latin, hence its symbol, Cu. It is used in the minting of one cent pieces and for pans, but an even more important use is in the wires and switches that carry electricity. Copper is the second-best conductor of electricity (silver is first). It is alloyed with other metals to make bronze and brass. The Cu+2 ion is necessary in the human body, in very small, or trace, amounts, as a catalyst in making blood. At ordinary temperatures, copper is the best conductor of heat. 

An unusual bronze skin color has been noted in some patients pigmentation of the skin and mucous membranes is more often described as ordinary jaundice and is seen in most poisoning cases. Oliguria or anuria, the most serious manifestation, may become manifest before the third day. In fatal cases, death... 

Ordinary copper bronze does not always give satisfactory results in the Ullmann reaction. More uniform results are obtained if the copper bronze is prepared as suggested by Kleid-erer and Adams.1 The copper bronze is treated with 2 1. of a 2 per cent solution of iodine in acetone for five to ten minutes. The product is then collected on a Buchner funnel, removed, washed by stirring into a slurry with 1 1. of a 1 1 solution of concentrated hydrochloric acid in acetone, and again filtered. The copper iodide dissolves, and the copper bronze remaining is separated by filtration and washed with acetone. It is then dried in a vacuum desiccator. It should be used immediately. 

Stannic sulphide, SnS2, is the higher sulphide of tin, and can be prepared by direct combination of the metal or, still better, of the lower sulphide, SnS, with sulphur. Under ordinary conditions these two substances will not react at a temperature below that which will decompose stannic sulphide. If, however, they are mixed with ammonium chloride the presence of this substance makes possible the combination at a lower temperature. The stannic sulphide formed in this way appears as soft, glistening, yellow crystals. It is used as a bronzing powder, and is known under the name of mosaic gold. In physical properties it is very different from the stannic sulphide which can be precipitated by hydrogen sulphide from a solution of stannic chloride. 

As you know from Chapter 4, solid solutions of metals are called alloys. Adding even small quantities of another element to a metal changes the properties of the metal. Technological advances throughout history have been linked closely to the discovery of new alloys. For example, bronze is an alloy of copper and tin. Bronze contains only about 10% tin, but it is much stronger than copper and more resistant to corrosion. Also, bronze can be melted in an ordinary fire so that castings can be made, as shown in Figure 8.3. 

Although, in the anhydrous condition, COFj is not corrosive to ordinary metals used for construction, when moist the compound behaves in a highly corrosive manner. In these circumstances, copper, nickel, "Monel, "Inconel, or "Hastelloy C are recommended. For ordinary temperatures, natural rubber, "Viton, Teflon and "Kel-F are compatible [277,1199]. Steel is acceptable at moderate temperatures [84a]. A corrosion-resistant distillation column made entirely from nickel, bronze and "Kel-F has been used to separate the corrosive gas mixture OFj, COF, CjFg, C F Cl, ClOj, CIO3, CIO3F, ClOjF and HF [1573]. 

All of these compounds are bactericidal and the ancients knew that they helped to prevent wounds from festering. Accordingly, Achilles has been represented in ancient pictures as scraping the rust or oxidation products from his bronze sword or spear into the wound of Telephusf. These oxidation products are frequently but incorrectly called verdigris, which latter is really a basic acetate of copper, and is not produced by ordinary atmospheric corrosion of the metal or its alloys. 

Brasses and bronzes, iron-base alloys, nickel, monel, magnesium alloys, hard rubber, plastics, tin, aluminum, and like metals must be added to ordinary gray and white cast iron as materials for pump construction. Practically any alloy or modern metal can be fabricated into pumps, and it remains only for the chemical engineer to stipulate the kind of solution he wishes to handle, or the kind of metal, and the pump manufacturer will attempt to construct a pump for the service demanded. (See Perry s Chemical Engineers Handbook, 3d ed., p. 1424.)... 

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