Copper metal dusts

SYNONYMS arwood copper, bronze powder, C.I. 77400, copper bronze, copper metal dusts, copper metal mists, raney copper. 

Synonyms/Trade Names Copper metal dusts, Copper metal fumes... 

A literature procedure for the preparation of the zinc-copper couple was followed except for the use of slightly more (28%) than the Indicated amount of copper sulfate. The checkers found that the kind of zinc used Is critical. Zinc dust, 325 mesh, from Aldrich Chemical Company, Inc. [catalog number 20,998-8] gave 7,7-d1chloro-l-methylb1cyclo[3.2.0]heptan-6-one in 80-89% yield. Zinc metal (dust) from Fisher Scientific Company (Lot 874394) gave the dichloro ketone In yields of 37-61% (five trials). The Fisher zinc was of unknown mesh, but was much more finely-divided than the Aldrich Chemical Company, Inc. zinc. 

The soil depth profile was sampled 600 m to the Southwest of the Hettstedt metallurgical works from a clayey soil (>35% clay) of the Wipper meadow. Fig. 9-12 shows that the heavy metal emission in the Hettstedt district originated from the copper metallurgical industry [UMWELTBUNDESAMT, 1991]. The heavy metal emission was at a maximum in 1983 and 1985 and is nowadays at a low level because of the closure of most of the emitters. As would be expected from the high values of heavy metal dust emission in recent years, high soil concentrations were found for the elements zinc, copper,... 

Cadmium oxide, calcined dolomite, calcium chloride, calcium oxide, carbomethylcellulose (CMC), carbonates, catalysts, cellulose acetate, ceramics, charcoal, clay, coal, cocoa powder, coffee powder, coke, copper, corn starch Detergents, dextrine, dimethylterephthalate (DMT), dolomite, ductile metals, dusts, dyes Earthy ores, eggshells, elastomers, emulsifiers, epoxy resins... 

The subsequent step of the reaction, hydroxylation, is carried out directly with the reaction mixture from iodination without any interme diate isolation or other processing of the reactants or by-products. Abase, such as an alkali metal hydroxide or a quaternary amine such as tetraalkylammonium hydroxide, is added directly to the reaction mixture to make a final concentration of 0.5 to 6 molar, with 0.1 to 20 mole % copper metal, or cuprous salts such as oxide, chloride or iodide, at temperatures of from 50°-120° C. The preferred conditions art-addition of sodium hydroxide to the iodination reaction mixture to give a concentration of 2-5 molar, then addition of 1-5 mole % copper dust, cuprous oxide or cuprous chloride, then allowing reaction at reflux (100°-120° C.) for about 18 hours. 

An easy synthesis of prenyl naphthoquinones, e.g. menaquinone-2 (205 n = 2), was achieved by coupling the appropriate prenyl halide with an organo-copper derivative of the electrochemically derived quinone bisacetal (216). Menaquinone-2 and phylloquinone (204) were also obtained in good yields by reaction of 2-methyl-1,4-naphthoquinone (205 n =0) with geranyl and phytyl halides in the presence of metal dust. A one-step method for the preparation of vitamin K analogues uses cyclodextrin inclusion catalysts.Thus reaction of the diol (217) with allyl bromide in the presence of oxygen and/3-cyclodextrin at pH 9 afforded the menaquinone analogue (218). 

ACIDE SULFHYDRIQUE (French) (7783-06-4) A highly flammable and reactive gas. Violent reaction with strong oxidizers, metal oxides, metal dusts and powders, bromine penta-fluoride, chlorine trifluoride, chromium trioxide, chromyl chloride, dichlorine oxide, nitrogen trichloride, nitryl hypofluorite, oxygen difluoride, perchloryl fluoride, phospham, phosphorus persulfide, silver fulminate, soda-lime, sodium peroxide. Incompatible with acetaldehyde, chlorine monoxide, chromic acid, chromic anhydride, copper, nitric acid, phenyldiazonium-chloride, sodium. Forms explosive material with benzenediazonium salts. Flow or agitation of substance may generate electrostatic charges due to low conductivity. Attacks many metals. 

Incompatibilities and Reactivities CuO Acetylene, zirconium [Note See Copper (dusts and mists) for properties of Copper metal.]... 

A particular type of carbon formation occurs on metals, known as carburisation, leading to spalling of metal in a phenomenon known as metal dusting . Again, it is important to reduce the risk of this in fuel cell systems, and some developers have used copper-coated stainless steel in their fuel gas preheaters to keep the risk to a minimum. 

Copper is thought to be noneatalytic to carbon deposition in all gas atmospheres, and owing to the extremely low solubility of carbon in copper, inert to the metal dusting reaction. Copper-based alloys have recently been reported in the patent literature [13, 14] to be resistant or immune to earburisation, metal dusting and coking. Thus, the addition of copper to niekel, which forms a near perfect solid solution, may be able to suppress or... 

Binary nickel-copper alloys have already been investigated as substitutes for nickel catalysts in order to reduce the amount of coking because of the noncatalytic nature of copper [15-18], Nickel-copper alloys, however, have never been tested for their resistance to metal dusting. The aim of this work was to study the effects of adding copper on the behaviour of nickel metal dusting and associated coking. 

Alloying with copper to reduce metal dusting rates 21... 

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