Copper-nickel-zinc

Some metals used as metallic coatings are considered nontoxic, such as aluminum, magnesium, iron, tin, indium, molybdenum, tungsten, titanium, tantalum, niobium, bismuth, and the precious metals such as gold, platinum, rhodium, and palladium. However, some of the most important poUutants are metallic contaminants of these metals. Metals that can be bioconcentrated to harmful levels, especially in predators at the top of the food chain, such as mercury, cadmium, and lead are especially problematic. Other metals such as silver, copper, nickel, zinc, and chromium in the hexavalent oxidation state are highly toxic to aquatic Hfe (37,57—60). 

Examples of plating solutions having good throwing power include cyanide plating baths such as copper, zinc, cadmium, silver, and gold, and noncyanide alkaline zinc baths. Examples of poorer throwing power baths are acid baths such as copper, nickel, zinc, and hexavalent chromium. 

The transport of pre-boiler corrosion debris to the boiler section includes the oxides of iron, copper, nickel, zinc, and chromium and results from the corrosion of pre-heaters and condensers, and the like. Specifically, equipment components variously fabricated from admiralty brass, aluminum brass, cupronickels, and stainless steels are most affected. 

Corrosion of condensate lines is a serious problem. It is compounded where both oxygen and carbon dioxide are present because it causes considerable quantities of hematite (Fe203) to develop. Corrosion of other boiler plant components, such as FW heaters, adds more metals to the mix, and corrosion debris typically includes iron, copper, nickel, zinc, and chromium oxides. 

The chemical supplier can also identify any regulated pollutants in the facility s treatment chemicals and offer available substitutes. The federally regulated pollutants are cyanide, chrome, copper, nickel, zinc, lead, cadmium, and silver. Local and/or state authorities may regulate other substances, such as tin, ammonia, and phosphate. The current status of cyanide and noncyanide substitute plating processes is shown in Table 9.11... 

Beck et al. [61] used flow injection magnetic sector ICP-MS to determine cadmium, copper, nickel, zinc, and manganese in estuarine waters. The online preconcentration system used Toyopearl A-T Chelate 650 H as chelating resin, and was validated for an alkaline water standard reference material (SLEW-2). 

In fishes, additive or more-than-additive toxicity occurs with mixtures of salts of copper and mercury, copper-zinc-phenol, and copper-nickel-zinc (Birge and Black 1979). Accumulation of copper in gills of fathead minnows during exposure to 16 pg Cu/L is reduced by added ionic calcium, which competes with Cu for gill binding sites (Playle et al. 1992). 

Peters (5) Has reviewed the leaching of copper, nickel, zinc, lead and molybdenum concentrates in terms of the thermodynamic stability of the sulfide minerals of these metals. Process developments associated with the most favorable decomposition paths are considered. 

Cobalt is also found in seawater, meteorites, and other ores such as linnaeite, chloanthite, and smaltite, and traces are found mixed with the ores of silver, copper, nickel, zinc, and manganese. Cobalt ores are found in Canada and parts of Africa, but most of the cobalt used in the United States is recovered as a by-product of the mining, smelting, and refining of the ores of iron, nickel, lead, copper, and zinc. 

Phytoplankton particulate matter (organic and biomineralized) contains many trace elements. The most abundant are magnesium, cadmium, iron, calcium, barium, copper, nickel, zinc, and aluminum (Table 1), which are important constituents of enzymes, pigments, and structural materials. Carbonic anhydrase requires zinc or cadmium (Price and Morel, 1990 Lane and Morel, 2000), nitrate reductase requires iron (Geider and LaRoche, 1994), and chlorophyll contains magnesium. Additionally, elements such as sodium, magnesium, phosphorus, chlorine, potassium, and calcium may be present as ions... 

Use Analytical reagent for metal determination (cobalt, copper, nickel, zinc). 

Two special copper alloys, beryllium copper and nickel silver, although only used on a small scale, contribute valuable metal properties for special uses. Two percent beryllium added to copper gives greater fatigue resistance to the metal and confers a nonsparking (on impact) quality to tools made of this alloy, important for impact tools in flammable or explosive atmospheres. Nickel silver, a copper/nickel/zinc alloy with an appearance very like silver, is important as the strong base metal for silver-plated tableware. 

This makes the use of catalysts indispensable. Copper, nickel, zinc based systems are used in the vapor phase, promoted or not in metallic or oxide form, and possibly deposited on a support Tire lower temperature (S 150 Q reaction can be carried out in the liquid phase, in the presence of Raney nickel. Hie thermodynamic equilibrium in this case is shifted in the desired direction by the continuous removal of the hydrogen produced. It is also necessary to extract the acetone from the reaction medium upon its formation, by vaporization for example, owing to the inhibitory action it exerts on the activity of the catalyst... 

The X-ray measurements of Robertson and his co-workers were in all cases carried out on the more stable /3 modification, which is also the more crystalline modification. The a modification is unstable to transition to the 8 form in aromatic solvents (335). Ebert and Gottlieb have published (81) detailed methods by which the different polymorphs of copper, nickel, zinc, and metal-free phthalocyanine may be isolated. Phthalonitrile condenses in hydrogen-donor solvents, such as cyclohexylamine, to form metal-free phthalocyanine. The a metal-free phthalocyanine may be obtained from this reaction by milling the product in the dry with sodium chloride, the 6 form by milling in the presence of xylene. Solutions of metal-free phthalocyanine in sulfuric acid precipitate the a modification upon dilution (172). This may be sublimed below 200°C in vacuo, but is converted to the j8 modification above this temperature. Copper phthalocyanine behaves similarly. The 6 phthalocyanine may be reconverted to the a form by milling in the dry with sodium chloride or sodium sulfate. The y metal-... 

During the five decades since the Second World War, more metallic raw materials have been produced than over the entire history of mankind. While the Earth s population has almost doubled between 1959 and 1990, the advancement of the six most important base metals (aluminum, lead, copper, nickel, zinc, tin) has increased more than eight-fold. Contrary to the prognoses from the period between 1950 and the mid-1980s, no substantial bottlenecks have arisen with most ores. An important factor for the continuous availability of metallic raw materials however, is the strong increase in environmental awareness in the past three decades mainly in the industrialized nations, and to a certain extent in the developing countries (Hodges 1995). 

Buldini et al. ° developed a procedure for the ion chromatographic determination of total chlorine, phosphorus, and sulfur, and of iron, copper, nickel, zinc, cobalt, lead, and cadmium in edible vegetable oils and fats after the complete removal of the organic matrix by saponification followed by oxidative UV photolysis. The method was simple and required fewer reagents compared with other sample pre-treatment procedures. Saponification lasted for half an hour since the addition of ethanol and potassium hydroxide. 

Copper-nickel-zinc alloys Copper-nickel-zinc alloys (also known as German silver ), which have a high mechanical and corrosion resistance, are mainly used for machining of optical mold inserts for injection molding of plastics. 

The consumption of raw materials, already from the industrial revolution time, has been on constant increase worldwide. Available data, recorded and analyzed, mainly during the last 50-60 years, widely prove this fact for a number of materials being critical for manufacturing activities, such as steel, aluminum, copper, nickel, zinc, wood, etc. As far as steel is... 

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