Uses of Copper

Even ia 1960 a catalytic route was considered the answer to the pollution problem and the by-product sulfate, but nearly ten years elapsed before a process was developed that could be used commercially. Some of the eadier attempts iacluded hydrolysis of acrylonitrile on a sulfonic acid ion-exchange resia (69). Manganese dioxide showed some catalytic activity (70), and copper ions present ia two different valence states were described as catalyticaHy active (71), but copper metal by itself was not active. A variety of catalysts, such as Umshibara or I Jllmann copper and nickel, were used for the hydrolysis of aromatic nitriles, but aUphatic nitriles did not react usiag these catalysts (72). Beginning ia 1971 a series of patents were issued to The Dow Chemical Company (73) describiag the use of copper metal catalysis. Full-scale production was achieved the same year. A solution of acrylonitrile ia water was passed over a fixed bed of copper catalyst at 85°C, which produced a solution of acrylamide ia water with very high conversions and selectivities to acrylamide. 

Distillers employ a somewhat unique process to make various products and have tailored approaches to control and reduce ethyl carbamate to their own particular process. Some of the methods used are the use of copper packing in the rectifying section of stills, increased frequency of cleaning stills and other equipment, and using a cool-down period in the cleaning procedure. Increased rectification also reduces ethyl carbamate. Keeping the system clean is critical to minimising ethyl carbamate. 

Foliar Fungicides and Bactericides. Of the - 70,000 t/yr as copper in compounds used in agriculture, almost 75% is used in the control of fungi (see Fungicides, agricultural). The first reference to the use of copper as a fungicide dates to 1761 (83) where copper sulfate was used on wheat seed for the control of bunt. In 1807 (84) the discovery of copper as a fungicide was made and the discovery of Bourdeaux mixture (copper sulfate plus lime) followed in 1882. 

An example of the use of copper as a catalyst is Acid Blue 25 [6408-78-2] (Cl 62055) in which l-amino-2-sulfonic-4-bromoanthraquinone is condensed with aniline using copper salts (Ullmann reaction) (314). Another example is oxidation to the tria2ole of Direct YeUow 106 [12222-60-5] (Cl 40300) (315,316). 

A.STM. B503, Std. Practicefor Use of Copper and Hickel Electroplating Solutionsfor Electroforming, American Society for Testing and Materials, Philadelphia, Pa., 1984 Ref 57, Chapts. 13, 14, and 15. 

The most notable part of the traction engine made from copper is the boiler and its firetubes (see Fig. 1.1). In full size this would have been made from mild steel, and the use of copper in the model is a nice example of how the choice of material can depend on the scale of the structure. The boiler plates of the full-size engine are about 10 mm thick, of which perhaps only 6 mm is needed to stand the load from the pressurised... 

Amongst heat stabilisers are copper salts, phosphoric acid esters,phenyl-3-naphthylamine, mercaptobenzothiazole and mercaptobenzimidazole. Of these, copper salts in conjunction with halides have been found particularly effective, and some automotive specifications require the use of copper for heat stabilisation. Light stabilisers include carbon black and various phenolic materials. 

Avoid fitting copper alloy pipes upstream of carbon steel equipment. Salts of carbon from copper-base pipes can dissolve in solution and pose problems to carbon-steel components and vessels downstream. If the use of copper alloy pipes is unavoidable, sacrificial sections of mild steel pipe can... 

The true, all-aromatic system (see 18, below) described by Kime and Norymberski is unusual in the sense that all of the ether linkages bridge aromatic carbons ". Synthesis of 18, therefore, required extensive use of copper mediated coupling reactions. As expected for such reactions, yields were generally low. The aromatics such as 18 were ineffective at binding either alkali metal or ammonium cations ". ... 

Estimates of the earliest use of copper vary, but 5000 BC is not unreasonable. By about 3500 BC it was being obtained in the Middle East by charcoal reduction of its ores, and by 3000 BC the advantages of adding tin in order to produce the harder bronze was appreciated in India, Mesopotamia and Greece. This established the Bronze Age , and copper has continued to be one of man s most important metals. 

With the discoveiy of electricity, the evolution of communications occurred at a rapid rate. Smoke signals that were used for hundreds of years to convey information at a word or two per minute were first replaced by the use of copper-based conductors, such as the telegraph, that transmitted twenty to forty words per minute. By the end of the twentieth century, lasers with fiber optic wires transmitted an entire book around the world in under a second. 

The water supply authorities normally insist that (for uses other than drinking-water taps) their main should discharge into a break-pressure vessel, after which the water quality becomes the consumers responsibility. The water tank should be covered against tramp dirt and access by birds, etc., and it must be shielded from sunlight to avoid the growth of algae. Nevertheless, access must be maintained for easy inspection. The distribution pipework is preferably all plastic and lead must be avoided altogether. The use of copper is doubtful with some corrosive waters, and soldered joints in it can lead to unacceptable concentrations of lead in the water. 

Copper and its alloys in certain fresh waters give rise to a form of localised attack that is referred to as nodular pitting in which the attacked areas are covered by small mounds or nodules composed of corrosion products and of CaC03 precipitated from the water. This is a serious problem in view of the extensive use of copper pipes and tanks for water supplies, and in aggressive water these may perforate in a relatively short time. 

When contemplating the use of copper-base materials for industrial purposes it is necessary to bear in mind that even though a satisfactory life of the component may be obtained, trouble can arise from other causes ... 

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