Brass and Bronze

The electrical industry is one of the greatest users of copper. Iron s alloys -- brass and bronze --are very important all American coins are copper alloys and gun metals also contain copper. 

Zinc consumption is categorized in five semifabricating markets (see Table 15). Galvanizing was the main market for zinc in the 1970s followed by zinc-base casting alloys and brass and bronze. Depressed constmction and automotive industries caused a decline from 1979 to 1980 of ca 18%, and the die-casting business declined 34% and galvanizing 24%. 

AQ grades of zinc slab are used to some degree in brasses and bronzes. In many leaded brass-mill products, the lead originates from the slab zinc the accompanying cadmium is usually acceptable. 

Dispersed mixtures of boron and another metal are used as deoxidizing and degassing agents to harden steel (qv) (5,6), to increase the conductivity of copper (qv) in turbojet engines, and in the making of brass and bronze (see Copper alloys). Two examples are alloys of ferroboron and manganese boron. 

Secondary Recovery. Metal returning from the store of metal in use is referred to as old scrap, in contrast with scrap generated within the copper fabrication process, which is called new scrap (see Recycling). In 1990 the amount of the U.S. copper supply derived from old scrap was 24% of the total copper consumed. About 40% of old scrap is used for producing refined copper most of the remainder is used in the production of brass and bronze ingots (see Copper alloys). About 75% of new scrap is consumed by brass mills, with most of the remainder used in the production of refined copper. Some estimates suggest that as much as 60% of the copper produced is ultimately recycled for reuse. Old scrap combined with new scrap from fabricating plants accounts for about 40% of the metallic input to domestic copper furnaces. 

Red-brass and bronze valves are available with female solder-joint ends for soldered copper-tubing piping systems. 

Secondary Brass and Bronze Production Plants Primary Emissions from Basic Oxygen Process Furnaces for Which Construction Commenced after June 11, 1973... 

The simplest and most thoroughly studied solutions are those based on phosphoric acid at low temperatures (<35°C) which alone can fulfil all three requirements of acid solvent, film former (as metal phosphate) and diffusion agent by virtue of its viscosity. Thus copper and its main alloys of brasses and bronzes can be very effectively electropolished in 60-70% orthophos-phoric acid with the temperature maintained below 35°C under other conditions copper passivates or dissolves freely under mass transfer controlled conditions, but by varying the conditions appropriately polishing can be continued under mild agitation. An annotated polarisation curve is given in Fig. 11.7 readers are referred to recent studies for more detailed 2ispects " . 

Copper alloys such as brass and bronze, which are harder and more resistant to corrosion than is copper, are important construction materials. Copper corrodes in moist air in the presence of oxygen and carbon dioxide ... 

Zinc is aiso combined with copper and tin to make brass and bronze. Finally, large amounts of zinc are used to make severai types of batteries, as discussed in Chapter 19. 

Silicon s atomic structure makes it an extremely important semiconductor. Highly purified silicon, doped with such elements as boron, phosphorus, and arsenic, is the basic material used in computer chips, transistors, sUicon diodes, and various other electronic circuits and electrical-current switching devices. Silicon of lesser purity is used in metallurgy as a reducing agent and as an alloying element in steel, brass, and bronze. 

Copper is attacked by mineral acids, except cold, dilute, unaerated sulphuric acid. It is resistant to caustic alkalies, except ammonia, and to many organic acids and salts. The brasses and bronzes have a similar corrosion resistance to the pure metal. Their main use in the chemical industry is for valves and other small fittings, and for heat-exchanger tubes and tube sheets. If brass is used, a grade must be selected that is resistant to dezincification. 

The U.S. is the world s largest recycler of lead scrap and is able to meet about 72% of its total refined lead production needs from scrap recycling. The secondary lead industry consists of 16 companies that operate 23 battery breakers-smelters with capacities of between 10,000 and 120,000 t/yr five smaller operations with capacities between 6000 and 10,000 t/yr and 15 smaller plants that produce mainly specialty alloys for solders, brass and bronze ingots, and miscellaneous uses. 

The domestic use pattern for lead in 1990 was as follows lead-acid storage batteries, used for motor vehicles, motive power, and emergency back-up power, accounted for 80% of total lead consumption ammunition, bearing metals, brass and bronze, cable covering, extruded products, sheet lead, and solder, represented 12.4% the remaining 7.6% was used for ceramics, type metal, ballast or weights, tubes or containers, oxides, and gasoline additives (USDOC 1992). 

In the United States, primary tin consumption in 1990 remained about the same as in the prior year. Only the category of solder and tinning increased significantly, and only the category of brass and bronze declined significantly. The USA consumption of finished... 

Werner, O. (1980). Composition of recent reproduction castings and forgeries of Mediaeval brasses and bronzes. Berliner Beitrage zur Archaeometrie 5 11-35. 

Brass and bronze castings that are polymer impregnated should not be used. 

Soft metal excellent conductor of electricity name derives from the Latin cuprum, meaning from Cyprus, where it was mined by the Romans alloys are brass and bronze. 

Although there is no ASTM specification for gasoline mercaptan or hydrogen sulfide levels, a copper corrosion specification does exist. Since mercaptans and hydrogen sulfide attack copper and copper-containing alloys such as brass and bronze, it is important to minimize fuel mercaptans and hydrogen sulfide concentrations. 

Copper, brass, and bronze compatibility Poor ethanol is pure Poor... 

Although the majority of the elements are metals, not all the metals we meet are elements. Steel is basically iron to which other elements, including carbon, have been added. Brass and bronze are mixtures of copper with other metals, such as zinc and tin. Before the elements were known about, it was thought to be possible to make gold by mixing other metals together. Many a lifetime s work was wasted looking for the secret recipe. 

Frost RL, Martens W, Kloprogge JT, Williams PA (2002) Raman sepctroscopy of the basic copper chloride minerals atacamite and paratacamite implications for the study of copper, brass and bronze objects of archaeological significance. J Raman Spectrosc 33 801-806. 

Prior to the Civil War, engineers were pretty well limited to working with only a few materials, such as iron, copper, tin, zinc, brass and bronze and, of course, wood. Steel became more readily available shortly after the Civil War through the wider use of the recently discovered Bessemer and open-hearth processes and the subsequent discovery of alloy steels. And around the turn of the century, aluminum was becoming available in commercial quantities. 

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