Iron oxide naming

Structural relationships exist between certain planes in the hematite structure and those in other iron oxides, namely magnetite and goethite (Tab. 2.6). There is, for example, a relationship between the (111) plane of magnetite and (001) plane of hema-... 

The gas product derived from reduction should be expelled from the reaction region along the same path. Here, the reducing agent contacts with iron oxide, namely, it is adsorbed on the surface of the solid and starts surface reactions. The reduction reaction includes seizure of oxygen from oxides, the formation and growth of crystal nuclei of the product. The continuous growth of product layer is maintained by solid state reaction and the diffusion in solid state. 

Aluminum. All primary aluminum as of 1995 is produced by molten salt electrolysis, which requires a feed of high purity alumina to the reduction cell. The Bayer process is a chemical purification of the bauxite ore by selective leaching of aluminum according to equation 35. Other oxide constituents of the ore, namely siUca, iron oxide, and titanium oxide remain in the residue, known as red mud. No solution purification is required and pure aluminum hydroxide is obtained by precipitation after reversing reaction 35 through a change in temperature or hydroxide concentration the precipitate is calcined to yield pure alumina. 

Synthetic red iron oxides are prepared in a variety of grades from light to dark. These are sold under a variety of names, eg, Indian red, Turkey red, and Venetian red. 

A frequently cited example of protection from atmospheric corrosion is the Eiffel Tower. The narrow and, for that age, thin sections required a good priming of red lead for protection against corrosion. The top coat was linseed oil with white lead, and later coatings of ochre, iron oxide, and micaceous iron oxide were added. Since its constmction the coating has been renewed several times [29]. Modern atmospheric corrosion protection uses quick-drying nitrocellulose, synthetic resins, and reaction resins (two-component mixes). The chemist Leo Baekeland discovered the synthetic material named after him, Bakelite, in 1907. Three years later the first synthetic resin (phenol formaldehyde) proved itself in a protective paint. A new materials era had dawned. 

Sauer-dorn, m. barberry, -dombitter, n. ber-berine (old name), -eisen, n. (Metal.) iron oxide, -futter, n. ensilage, sauerhaltig, a. acidiferoiis. 

With Guyton de Morveau, Lavoisier devised the system of chemical terms still used today. For the first time, the names of chemical substances described their constituents and proportions astringent Mars saffron became iron oxide, and philosophic wool became zinc oxide. Many contemporaries called Lavoisier s new chemistry The French Science. Today Lavoisier is regarded as the equal of Isaac Newton in physics, Charles Darwin in evolution, or Albert Einstein in relativity. 

In order to understand the general behavior of the tested materials, scoping tests were conducted in 25 mg/L gold(III)-chloride solutions at 25°C and 80°C with different initial pH values, namely 1.5, 4 and 8. After the start of the experiment the pH was not further adjusted, i.e., it could change freely. It remained similar to the initial pH in all cases. From these tests it was found that, in the case of the iron-oxide based adsorbents, dissolution of the solid took place at pHaluminum oxides and titanium oxide was observed at this pH. At pH>2 all adsorbents were found to be stable and did not dissolve during the experiment. 

Name of State Iron Oxidation States [Fe4S4] Core Oxidation State Total Spin... 

Apart from titanium oxide, two other carbon-modified semiconductors were studied in water photoelectrolysis due to their low band gap energy, namely iron (Fe203) and tungsten oxide (W03) [70,90]. Carbon-modified iron oxide demonstrated promising photoconversion efficiency, 4 % and 7 % for modified oxides synthesized in oven and by thermal oxidation respectively [90]. Also, carbon-modified tungsten oxide (C-W03) photocatalysts exhibited a 2 % photoconversion efficiency [70],... 

Table 16.3 Names, abbreviations, pseudo-first-order rate constants, and half-lives of polyhalo-genated alkanes in Fe(II)/goethite suspension. Experimental conditions 25 m L" goethite, pH 7.2, tgq>24 h. Fe(II) = 1 mM. b Standard deviation, c number of replicates, d t =5 h. Reprinted with permission from Pecher K, Haderline SB, Schwarzenbach RP (2002) Reduction of polyhalo-genated methanes by surface-bound Fe(II) in aqueous suspensions of iron oxides. Environ Sci Technol 36 1734-1741. Copyright 2002 American Chemical Society...

For iron oxides, IR spectroscopy is useful as a means of identification. Hematite crystals in films that were too thin (<70nm) to be characterized by XRD were shown by IR to be oriented with the c-axis perpendicular to the surface of the film (Yubero et al. 2000). This technique also provides information about crystal morphology, degree of crystallinity and the extent of metal (especially Al) substitution because these properties can induce shifts in some of the IR absorption bands. It is also widely used both to obtain information about the vibrational state of adsorbed molecules (particularly anions) and hence the nature of surface complexes (see Chap. 11) and to investigate the nature of surface hydroxyl groups and adsorbed water (see Chap. 10). Typical IR spectra of the various iron oxides are depicted in Figure 7.1. Impurities arising either from the method of preparation or from adsorption of atmospheric compounds can produce distinct bands in the spectra of these oxides -namely at 1700 cm (oxalate), 1400 cm (nitrate) and 1300 and 1500 cm (carbonate). 

The chemical name for rust is iron oxide. Normally, iron rusts more quickly if it is wet. However, iron can be kept underwater without rusting if the water is first boiled, to drive off its oxygen, and the container sealed with oil to prevent the oxygen from re-entering. 

Iron (III) oxide exists in mineral form as hematite. It is 70% iron and is the primary source of iron ore in the world. About 90% of the iron mined in the United States is hematite. World production of this ore is more than 1 billion tons. Magnetite and taconite are two other primary iron oxide minerals used as iron ore. The name hematite comes from the blood-red color of powdered hematite. The Greek word hematite means blood-like. Some ancients held the belief that hematite was formed in areas where batdes were fought and blood was spilled into the earth. Large deposits of hematite have been identified on Mars. 

Trade names and producers include Capelle (Gebroeders Cappelle N.V., Belgium), Fastona Transparent Iron Oxide (Blythe Colours Ltd., UK), Sicotrans (BASF and BASF Lacke + Farben, Germany), and Trans Oxide (Hilton Davis, USA). 

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