Copper recommendations

Unfortunately, there are no modern-day uses of copper complexes for this purpose. It is likely that copper complexes representing less than the amounts of copper recommended as safe daily intakes will eventually be found to be useful in successfully treating human seizure states. 

Copper. Some 15 copper compounds (qv) have been used as micronutrient fertilizers. These include copper sulfates, oxides, chlorides, and cupric ammonium phosphate [15928-74-2] and several copper complexes and chelates. Recommended rates of Cu appHcation range from a low of 0.2 to as much as 14 kg/hm. Both soil and foHar appHcations are used. 

Iron. As with copper, some dozen or more materials are used as fertilizer Hon sources. These include ferrous and ferric oxides and sulfides and ferrous ammonium phosphate [10101 -60-7] ferrous ammonium sulfate [10045-89-3] frits, and chelates. In many instances, organic chelates are more effective than inorganic materials. Recommended appHcation rates range widely according to both type of micronutrient used and crop. Quantities of Fe range from as low as 0.5 kg/hm as chelates for vegetables to as much as a few hundred kg/hm as ferrous sulfate for some grains. 

Bronze disease necessitates immediate action to halt the process and remove the cause. For a long time, stabilization was sought by removal of the cuprous chloride by immersing the object in a solution of sodium sesquicarbonate. This process was, however, extremely time-consuming, frequentiy unsuccesshil, and often the cause of unpleasant discolorations of the patina. Objects affected by bronze disease are mostiy treated by immersion in, or surface appHcation of, 1 H-henzotriazole [95-14-7] C H N, a corrosion inhibitor for copper. A localized treatment is the excavation of cuprous chloride from the affected area until bare metal is obtained, followed by appHcation of moist, freshly precipitated silver oxide which serves to stabilize the chloride by formation of silver chloride. Subsequent storage in very dry conditions is generally recommended to prevent recurrence. 

Handling and Safety Factors. Oxygen difluoride can be handled easily and safely in glass and in common metals such as stainless steel, copper, aluminum. Monel, and nickel, from cryogenic temperatures to 200°C (4). At higher temperatures only nickel and Monel are recommended. The compatibihty of OF2 with process equipment depends largely on the cleanliness of the equipment contaminants such as dkt, moisture, oil, grease, scale... 

Methacrylate monomers are shipped in bulk quantities, tank cars, or tank tmcks. Mild steel is the usual material chosen for bulk storage faciUties for these monomers, although stainless steel (Types 304 and 316) is also recommended for the esters and is a necessity for the acids. Moisture must be excluded to avoid msting and contamination of the monomers. Copper (qv) or copper alloys (qv) must not be allowed contact with acryUc monomers intended for use in polymerisation because copper is an inhibitor (28). 

Equipment for storing and handling methanol may be made of carbon or stainless steel. Methanol is aggressive toward copper, zinc, magnesium, tin, lead, and alurninum, which should therefore be avoided. Gasket materials must also be chosen carefiiUy, because some elastomers swell and deteriorate when exposed to methanol. Similarly, the use of plastics for storage is not recommended. 

Aniline is slightly corrosive to some metals. It attacks copper, brass, and other copper alloys, and use of these metals should be avoided in equipment that is used to handle aniline. For appHcations in which color retention is critical, the use of 400-series stainless steels is recommended. 

The vapor-phase conversion of aniline to DPA over a soHd catalyst has been extensively studied (18,22). In general, the catalyst used is pure aluminum oxide or titanium oxide, prepared under special conditions (18). Promoters, such as copper chromite, nickel chloride, phosphoric acid, and ammonium fluoride, have also been recommended. Reaction temperatures are usually from 400 to 500°C. Coke formed on the catalyst is removed occasionally by burning. In this way, conversions of about 35% and yields of 95% have been reported. Carba2ole is frequently a by-product. 

Ammonia is corrosive to akoys of copper and zinc and these materials must not be used in ammonia service. Iron or steel should usuaky be the only metal in ammonia storage tanks, piping, and fittings. It is recommended that ammonia should contain at least 0.2% water to prevent steel stress corrosion. Mercury thermometers should be avoided. 

The metal parts of the injection molder, ie, the liner, torpedo, and nozzle, that contact the hot molten resin must be of the noncatalytic type to prevent accelerated decomposition of the polymer. In addition, they must be resistant to corrosion by HCl. Iron, copper, and zinc are catalytic to the decomposition and caimot be used, even as components of alloys. Magnesium is noncatalytic but is subject to corrosive attack, as is chromium when used as plating. Nickel alloys such as Duranickel, HasteUoy B, and HasteUoy C are recommended as constmction materials for injection-molding metal parts. These and pure nickel are noncatalytic and corrosion-resistant however, pure nickel is rather soft and is not recommended. 

Assay of beryUium metal and beryUium compounds is usuaUy accompHshed by titration. The sample is dissolved in sulfuric acid. Solution pH is adjusted to 8.5 using sodium hydroxide. The beryUium hydroxide precipitate is redissolved by addition of excess sodium fluoride. Liberated hydroxide is titrated with sulfuric acid. The beryUium content of the sample is calculated from the titration volume. Standards containing known beryUium concentrations must be analyzed along with the samples, as complexation of beryUium by fluoride is not quantitative. Titration rate and hold times ate critical therefore use of an automatic titrator is recommended. Other fluotide-complexing elements such as aluminum, sUicon, zirconium, hafnium, uranium, thorium, and rate earth elements must be absent, or must be corrected for if present in smaU amounts. Copper-beryUium and nickel—beryUium aUoys can be analyzed by titration if the beryUium is first separated from copper, nickel, and cobalt by ammonium hydroxide precipitation (15,16). 

Methyl bromide, when dry (<100 ppm water), is inert toward most materials of constmction. Carbon steel is recommended for storage vessels, piping, pumps, valves, and fittings. Copper, brass, nickel, and its alloys are sometimes used. Aluminum, magnesium, zinc, and alloys of these metals should not be used because under some conditions dangerous pyrophoric compounds may be formed. Many nonmetallic materials are also useful for handling methyl bromide, but nylon and polyvinyl chloride should be avoided. 

This reaction is favored by moderate temperatures (100—150°C), low pressures, and acidic solvents. High activity catalysts such as 5—10 wt % palladium on activated carbon or barium sulfate, high activity Raney nickel, or copper chromite (nonpromoted or promoted with barium) can be used. Palladium catalysts are recommended for the reduction of aromatic aldehydes, such as that of benzaldehyde to toluene. 

An acidic solvent is recommended for use with palladium. Other catalysts that have been used for this reduction include copper chromite and any of the three Raney catalysts, cobalt, iron, or nickel. 

As for storage tanks, stainless steel and lacquer-lined mild steel are suitable materials of constmction for pipe lines. For pumps, valves, etc, various alloys are suitable, including phosphor bronze, gun metal. Monel, stainless steel, and certain nickel steel alloys. Alloys with high proportions of ziac and tin together with copper and aluminum are not recommended. 

Corrosion. Copper and selected copper aHoys perform admirably in many hostile environments. Copper aHoys with the appropriate corrosion resistance characteristics are recommended for atmospheric exposure (architectural and builder s hardware), for use in fresh water supply (plumbing lines and fittings), in marine appHcations (desalination equipment and biofouling avoidance), for industrial and chemical plant equipment (heat exchangers and condensers), and for electrical/electronic appHcations (coimectors and semiconductor package lead-frames) (30) (see Packaging). 

The nominal chemical composition and identification of the most important copper castiag alloys are Hsted ia Table 7. These alloys are ideatifted by name and by the Unified Numbering System. The use of names is not recommended. 

Copper is one of the twenty-seven elements known to be essential to humans (69—72) (see Mineral nutrients). The daily recommended requirement for humans is 2.5—5.0 mg (73). Copper is probably second only to iron as an oxidation catalyst and oxygen carrier in humans (74). It is present in many proteins, such as hemocyanin [9013-32-3] galactose oxidase [9028-79-9] ceruloplasmin [9031 -37-2] dopamine -hydroxylase, monoamine oxidase [9001-66-5] superoxide dismutase [9054-89-17, and phenolase (75,76). Copper aids in photosynthesis and other oxidative processes in plants. 

Stainless steel or epoxy-lined tank cars and tank tmcks are recommended for shipping. Aluminum also has been used. The tank can be flushed with carbon dioxide before loading and blanketed with nitrogen after loading. Dmm shipments are recommended in epoxy-lined open-head dmms fitted with a bung. Dimer acids and their by-products contaminated with iron or copper show accelerated color deterioration. Exposure to these metals or their salts should be minimised. 

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