Nation chromium oxidants

The use of chromium(III) oxide as a pigment for toys, cosmetics, and in plastics and paints that come in contact with food is permitted in national and international regulations [3.62] -[3.68]. Maximum limits for heavy metals or their soluble fractions are usually a prerequisite. Because pure starting materials are used, these limits are satisfied by most types of chromium oxide. 

Source National Bureau Standards Monograph (1977). Notes Identification lead chromium oxide ... 

N. Sutin, Brookhaven National Laboratory The 16% decrease in the rate of oxidation of reduced plastocyanin by Co(phen)33 resulting from the attachment of the chromium(III) label seems rather small if the chromium is indeed bound at or near the protein site used for electron transfer to Co(phen)33. ... 

Environmental Protection. Since alkali dichromates or chromic acid anhydride are used as starting materials for the production of chromium(III) oxides, occupational health requirements for the handling of hexavalent chromium compounds must be observed [3.59]. The sulfur dioxide formed on reduction with excess sulfur must be removed from the flue gases according to national regulations, e.g., by oxidation to... 

As can be seen from Table 3, the product distribution is different due to the catalyst. Chromium(III) oxide leads, in the case of l,l,2-trichloro-l,2,2-trifluorocthanc and 1,2-dichlo-ro-l,l,2.2-tetrafiuoroethane, to products with roughly the same amounts of fluorine atoms attached to both carbons whereas aluminum trifluoridc leads to products with a high fluori-nation degree on one carbon and a low one on the other carbon. Similar results are obtained with an aluminum trifluoride catalyst prepared from aluminum oxide and chlorofluoroethanes.25... 

National Emission Standards for Coke Oven Batteries National Perchloroethylene Air Emission Standards for Dry Cleaning Facilities National Emission Standards for Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks Ethylene Oxide Emissions Standards for Sterilization Facilities... 

Several samples from Jonuta, of the Altar type of Fine Orange, have been analyzed by NAA at the Brookhaven National Laboratory and the results have been published. One sample is from a figurine named XCII by Goldstein (30), another is named sample 53 by Sayre et al. (34), and the last two are identified as samples 4 and 6 by SablofiF(43). The elements analyzed by both NAA and AAS were potassium, iron, chromium, manganese, and cobalt. The concentrations of these elements expressed as oxides, are given in Table III for all the samples analyzed by NAA and AAS. Again, recall that the concentrations of the elements analyzed by AAS do not represent absolute values they are only used for comparative purposes. 

Metal oxides, sulfides, and hydrides form a transition between add-base and metal catalysts. They catalyze hydro nation-dehydrogenation as well as many of the reactions catalyzed by adds such as cracking and isomerization. Their oxidation activity is related to the possibility of two valence states which allow oxygen to be released and reabsorbed alternately. Common examples are oxides of cobalt, iron, zinc, and chromium and hydrides of predous... 

Vapor-phase fluori nation using hydrogen fluoride and, for example, a chromium or aluminum oxide/fluoride catalyst (i.e., the procedures used for manufacture of fluorochloroalkanes ) has also been applied (Eq. 7). ... 

The effectiveness of modern masks depends on both physical adsorption and chemical inactivation of the threat agent. For example, in the M17 protective mask the adsorbent, known as ASC Whetlerite charcoal, is charcoal impregnated with copper oxide and salts of silver and chromium.6 The M40 protective mask uses an ASZ impregnated charcoal, which substitutes zinc for the hexavalent chromium (CrVI). The Centers for Disease Control and Prevention and the National Institute for Occupation... 

The sodium salts Na2[Cr(CO)5] and Na2[Cr2(CO)jo] are yellow solids. Due to the low formal oxidation state of the chromium atom, they are extremely sensitive to air oxidation and must be handled in an inert atmosphere with rigorous exclusion of air. As might be expected from itscoordi-nation number of five, the mononuclear [Cr(CO)s] anion is decomposed by water... 

Mikkelsen, L. (2003). High Temperature Oxidation of Iron-Chromium Alloys, (Ph.D. Thesis, Riso National Laboratory Roskilde, Denmark, Date of access 20 of August 2011, Available at http //130.226.56.153/rispubl/reports/ris-phd-2.pdf... 

The oxides of 48 metals were screened by the Ttacor Co. in a project conducted for the U.S. National Air Pollution Control Administration to determine which were best suited for the removal of sulfur oxides from flue gases by chemical reaction (Thomas et al.. 1969). The screening was accomplished by consideration of the thermodynamic requirements for efficient sulfur oxide removal and product regeneration. Sixteen potential sorbents were selected as a result of this screening process. These were the oxides of titanium, zirconium, hafnium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, aluminum, tin, bismuth, cerium, thorium, and uranium. 

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