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Reduction of oxides

For tire situation in figure C2.8.5 a), tire catliodic reaction is tire reduction of oxide/gas or... [Pg.2723]

The commercial production of silicon in the form of binary and ternary alloys began early in the twentieth century with the development of electric-arc and blast furnaces and the subsequent rise in iron (qv) and steel (qv) production (1). The most important and most widely used method for making silicon and silicon alloys is by the reduction of oxides or silicates using carbon (qv) in an electric arc furnace. Primary uses of silicon having a purity of greater than 98% ate in the chemical, aluminum, and electronics markets (for higher purity silicon, see Silicon AND SILICON ALLOYS, PURE SILICON). [Pg.535]

Fig. 1. The H. C. Starck pyrometallurgical upgrading process of Ta—Nb-containing tin slags where the soHd vertical bars represent electrodes. The product of (a) electrothermic reduction of Sn slag goes to (b) oxidation of Fe alloy 20—60 Ta + Nb and then to (c) electrothermic reduction of oxidized Fe ahoy. Fig. 1. The H. C. Starck pyrometallurgical upgrading process of Ta—Nb-containing tin slags where the soHd vertical bars represent electrodes. The product of (a) electrothermic reduction of Sn slag goes to (b) oxidation of Fe alloy 20—60 Ta + Nb and then to (c) electrothermic reduction of oxidized Fe ahoy.
Vapor—sohd reactions (13—17) are also commonly used ia the synthesis of specialty ceramic powders. Carbothermic reduction of oxides, ia which carbon (qv) black mixed with the appropriate reactant oxide is heated ia nitrogen or an iaert atmosphere, is a popular means of produciag commercial SiC, Si N, aluminum nitride [24304-00-3], AIN, and sialon, ie, siUcon aluminum oxynitride, powders. [Pg.306]

There have been many studies of the reduction of oxides and of oxy-acid salts with elemental carbon, some of which are of great technological importance. Although both reactants may be solids... [Pg.277]

In general, corrosion of metal is always accompanied by dissolution of a metal and reduction of an oxidant such as a proton in acidic solution and dissolved oxygen in a neutral solution. That is, metal corrosion is not a single electrode reaction, but a complex reaction composed of the oxidation of metal atoms and the reduction of oxidants. [Pg.217]

The second chapter is by Aogaki and includes a review of nonequilibrium fluctuations in corrosion processes. Aogaki begins by stating that metal corrosion is not a single electrode reaction, but a complex reaction composed of the oxidation of metal atoms and the reduction of oxidants. He provides an example in the dissolution of iron in an acidic solution. He follows this with a discussion of electrochemical theories on corrosion and the different techniques involved in these theories. He proceeds to discuss nonequilibrium fluctuations and concludes that we can again point out that the reactivity in corrosion is determined, not by its distance from the reaction equilibrium but by the growth processes of the nonequilibrium fluctuations. ... [Pg.651]

The T dependence of the solubility of CsH in Cs differs significantly from those for solutions of the hydrides in the other alkali metals. Distillation leaves behind involatile impurity salts, but oxygen transport from distilland to receiver has been observed. Oxygen can be carried over with the distillate in the form of COj or CO, the former being produced by decomposition of carbonate and the latter by reduction of oxides with a carbon impurity under dry conditions near the end of distillation. The identification of CO among the noncondensable gases during the distillation of Cs lends support to this. ... [Pg.350]

We should note that this effect of the hydrogen on electric conductivity is related neither to reduction of oxide nor to the volume dissolution of hydrogen in oxide. The first option was ruled out due to initial heating of adsorbent in hydrogen atmosphere up to establishing the stationary value of electric conductivity at the temperature exceeding the maximum temperature of experiment (Theati 400 420 C). The con-... [Pg.140]

The reduction smelting process involves the reduction of oxidic sources of metals with carbon in the presence of a flux. The process can generally be represented as ... [Pg.353]

Examples of metals which are prepared by the metallothermic reduction of oxides include manganese, chromium, vanadium, zirconium, and niobium. In a manner similar to the production of magnesium by the Pidgeon process, some of the rare earth metals have been produced by the metallothermic reduction-distillation process. [Pg.380]

The metallothermic reduction of oxides is essentially a reaction involving only condensed phases. It follows therefore, that the entropy changes in these reactions are small and that the differences in the heats of formation of the pertinent compounds determine the feasibility of a given reaction. Among the metallic reductants, calcium forms the oxide whose heat of formation is the most negative. As a first approximation, calcium may be considered to be the most effective reducing agent for metal oxides. [Pg.380]

One of the important differences between calciothermic and aluminothermic reduction of oxides concerns the interaction between the reduced metal and the reductant. Calcium does not form stable solid solutions or alloys with the reduced metals calcium contamination in the metal is, therefore, relatively small. Aluminum, on the other hand, readily forms solid solutions with the reduced metals, and the product generally contains appreciable quantities of residual aluminum. This is not a serious problem because in many cases either a certain aluminum content is desired in the reduced metal or the residual aluminum can be effectively removed in post-reduction purification operations. The extent of the contamination of a reduced metal with the reductant can be related to factors such as the reaction temperature, the standard free energy change associated with the reaction, and the slag composition. Let the following generalized reaction be considered ... [Pg.388]

Figure 11.8 Formation of ordered nanoparticles of metal from diblock copolymer micelles, (a) Diblock copolymer (b) metal salt partition to centres of the polymer micelles (c) deposition of micelles at a surface (d) micelle removal and reduction of oxide to metal, (e) AFM image of carbon nanotubes and cobalt catalyst nanoparticles after growth (height scale, 5 nm scan size, lxl pm). [Part (e) reproduced from Ref. 47]. Figure 11.8 Formation of ordered nanoparticles of metal from diblock copolymer micelles, (a) Diblock copolymer (b) metal salt partition to centres of the polymer micelles (c) deposition of micelles at a surface (d) micelle removal and reduction of oxide to metal, (e) AFM image of carbon nanotubes and cobalt catalyst nanoparticles after growth (height scale, 5 nm scan size, lxl pm). [Part (e) reproduced from Ref. 47].
The most important product of the hexose monophosphate pathway is reduced nicotinamide-adenine dinucleotide phosphate (NADPH). Another important function of this pathway is to provide ribose for nucleic acid synthesis. In the red blood cell, NADPH is a major reducing agent and serves as a cofactor in the reduction of oxidized glutathione, thereby protecting the cell against oxidative attack. In the syndromes associated with dysfunction of the hexose monophosphate pathway and glutathione metabolism and synthesis, oxidative denaturation of hemoglobin is the major contributor to the hemolytic process. [Pg.2]

Glutathione reductase (GR) catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) using NADPH provided from the hexose monophosphate pathway. GR, a ubiquitous flavoenzyme, maintains a high value of two for the GSH/GSSG ratio in the red blood cells. l,3-Bis(2-chloroethyl)-nitrosourea (BCNU) selectively inhibits cellular GR. GR is composed of two identical subunits, each of molecular mass 50 kDa (S8). The three-dimensional structure and mechanism of catalysis have been established for human GR (K17). [Pg.27]

The pseudo solid-solid reduction of oxidic iron ores with solid carbon is known to proceed through the gaseous intermediates, CO and C02, according to the following mechanism ... [Pg.553]

III. Glutathione reductase (EC 1.6.4.2) It is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG) to glutathione (GSH). This enzyme is essential for the GSH redox cycle which maintains adequate levels of reduced cellular GSH. A high GSH/GSSG ratio is essential for protection against oxidative stress. [Pg.141]

In this section we review research on biocatalytic cathodes for oxidant reduction. The biocatalytic reduction of oxidants has only recently attracted renewed attention, with... [Pg.412]

Verhagen H, Poulsen HE, Loft S, Van-Poppel G, Willems MI and Van-Bladeren PJ. 1995. Reduction of oxidative DNA-damage in humans by Brussels sprouts. Carcinogenesis 16(4) 969—970. [Pg.50]

Thompson and others (1999) measured urinary F2-iP as a marker of the reduction of oxidative cellular damage by consumption of fruits and vegetables. Stewart and others... [Pg.278]


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See also in sourсe #XX -- [ Pg.11 , Pg.12 , Pg.13 , Pg.14 , Pg.15 , Pg.16 , Pg.17 , Pg.18 ]

See also in sourсe #XX -- [ Pg.11 , Pg.12 , Pg.13 , Pg.14 , Pg.15 , Pg.16 , Pg.17 , Pg.18 ]




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A Preview of Oxidation and Reduction

Amino alcohols via reduction of cyclohexene oxide

Auto-inhibition of oxide mineral reductive capacity toward

Calciothermic reduction of electrically isolated oxide

Catalytic Reduction of Nitric Oxide

Catalytic reduction of nitrogen oxides

Co-reduction of mixed oxides

Detection of the end point in oxidation-reduction titrations

Electricity of a Battery Comes from Oxidation-Reduction Reactions

Electrocatalysis of Cathodic Oxygen Reduction and Anodic Hydrogen Oxidation in Fuel Cells

Electrochemical Reduction of Chromium(VI) Oxide

Electrochemical Reduction of Oxide Layers

Electrochemical oxidation and reduction of complexes using inert electrodes

Equilibrium constant of oxidation-reduction reactions

Experiment 8 Determination of Concentration by Oxidation-Reduction Titration and an Actual Student Lab Write-Up

Formation and reduction of nitrogen oxides

Introduction - The Meaning of Oxidation and Reduction

Iron oxides and reduction performance of catalysts

Metallothermic reduction of actinide oxides

Niels Formulation of Photosynthesis as an Oxidation-Reduction Process

Nitric Oxide Reduction, Oxidation, and Mechanisms of Nitrosation

Oxidation and Reduction of Aromatic

Oxidation and Reduction of Aromatic Compounds

Oxidation and Reduction of Ascorbate

Oxidation and Reduction of CO

Oxidation and Reduction of Carbonyl Compounds

Oxidation and Reduction of Co-ordinated Ligands

Oxidation and Reduction of Cr(III) Complexes

Oxidation and Reduction of Heterocyclic Rings

Oxidation and Reduction of Iron by Bacteria

Oxidation and Reduction of Substituted Benzenes

Oxidation and reduction of heterocycles

Oxidation of Organic Matter and Sulfate Reduction

Oxidation or reduction of central atoms

Oxidation-Reduction Balances of the Earth System

Oxidation-Reduction Conversion of Transition Metals

Oxidation-Reduction of Organic Compounds

Oxidation-Reduction of Sulfur

Oxidation-reduction potentials of pyridine nucleotide system

Oxidation-reduction reactions of iron

Oxidation-reduction reactions of iron-sulfur clusters

Oxidation-reduction state of tissue mitochondria

Oxidations and Reductions of Diazo Compounds

Oxidative Addition and Reductive Elimination of Alkyl Halides

Oxidative and reductive dissolution of ionic semiconductors

Oxidative reduction, of mucobromic acid

Oxidative, Reductive, and Hydrolytic Metabolism of Drugs

Oxidative-reduction, of mucobromic

Oxidative-reduction, of mucobromic acid and sodium nitrite

Oxides, reduction of refractory

Oxides, reduction of refractory metal

Periodate Oxidation of Glycoproteins Followed by Reductive Conjugation

Potential oxidation-reduction, of ion radicals

REACTIONS WITH CHANGE OF VALENCY OXIDATION AND REDUCTION

Reactions of Metals with Nonmetals (Oxidation-Reduction)

Reduction and Oxidation of Metallocorroles

Reduction mechanism of oxides

Reduction of Doped Tungsten Oxides

Reduction of Germanium(IV) Oxide

Reduction of Main Group Oxides via Metal Carbonyls and Carbonylate Anions

Reduction of N-oxides

Reduction of Nitric Oxide with Ammonia

Reduction of Tungsten Oxides by Hydrogen

Reduction of Uranyl(VI) species by low oxidation state niobium ions

Reduction of actinide oxides

Reduction of iron oxide

Reduction of lead oxides

Reduction of metal oxides

Reduction of metal oxides with carbon

Reduction of nitric oxide

Reduction of nitric oxide by carbon

Reduction of nitric oxide by carbon monoxide

Reduction of nitrogen oxides

Reduction of nitrogen oxides by hydrogen

Reduction of nitrogen oxides emissions

Reduction of nitrogen oxides with ammonia

Reduction of nitrogen oxides with carbon monoxide

Reduction of nitrous oxide

Reduction of phosphine oxides

Reduction of pyridine N-oxides

Reduction of tin oxides

Reduction of tungsten oxides

Reduction of uranium oxide

Reduction, Oxidation, and Control of Stereochemistry

Reductions of Heterocyclic N-Oxides and Aromatic Nitro Groups

Reductions of carbon oxides

Reductive Dissolution of Metal Oxides

Reductive Dissolution of Oxides by Organic Reductants

Reductive Release of Nitric Oxide from Nitrosothiols

Reductive dissolution of iron and manganese (oxy)(hydr)oxides

Reductive oxidation of />-nitrotoluene

Review of Oxidation and Reduction

Simultaneous Accomplishment of Water Reduction and Oxidation

Specific Adsorption of Oxidants and Reductants

Standard Solutions of Oxidation and Reduction Reagents

THE REDUCTION OF HIGHER OXIDATION STATES

The Chemical Mechanism of Pyridine N-oxide Reduction

The Electricity of a Battery Comes from Oxidation-Reduction Reactions

The Reactions of Hydrocarbons Oxidation, Reduction, Substitution, Addition, Elimination, and Rearrangement

The Stabilization of Oxidation States, and Reduction Potentials

The reduction of oxides and halides by reactive metals

The reduction of stable oxides in carbon arc furnaces

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