Iron titanates

One member of this family BisTisFeOis (with a bandgap of about 2-2.5 eV) has been reported to have photocatalytic activity for the decomposition of rhodamine B and acetaldehyde under visible light irradiation [84] or isopropyl alcohol photodecomposition [85]. 

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Iron Titanates. Ferrous metatitanate [12168-52-4] FeTiO, mp ca 1470°C, density 472(0), an opaque black soHd having a metallic luster, occurs in nature as the mineral ilmenite. This ore is used extensively as a feedstock for the manufacture of titanium dioxide pigments. Artificial ilmenite may be made by heating a mixture of ferrous oxide and titanium oxide for several hours at 1200°C or by reducing a titanium dioxide/ferric oxide mixture at 450°C. 

Fig. 5. A 90° polished cross section of a production white titania enamel, with the microstructure showing the interface between steel and direct-on enamel as observed by reflected light micrography at 3500 x magnification using Nomarski Interface Contrast (oil immersion). A is a steel substrate B, complex interface phases including an iron—nickel alloy C, iron titanate crystals D, glassy matrix E, anatase, Ti02, crystals and F, quart2 particle.

The technology for the production of titania slag by direct reduction smelting in electric arc furnaces (particularly for smelting of iron titanates and ilmenites having lower amounts of titania) is very old and the process has been in vogue in Canada, Norway, South Africa,... 

Iron Titanate Brown, pigment for plastics, 7 369t... 

Iron titanates, 25 46 47 Iron titanium brown spinel, formula and DCMA number, 7 348t Iron trimer, 16 62 Ironworks, early American, 14 492 Iron/Zinc/Magnesium Oxide Tan pigment for plastics, 7 369t Irradiated uranium, plutonium separation and purification from, 19 674-675 Irradiation... 

Ihncnitc. FeTiOi, corresponding io 36 8 7 Fe. 3l,69f Ti. and s 6 3 Os. iron-black, opaque, generally mined for titanium with iron as a byproduct, also called iron titanate. 

Due to the formation of a potassium iron titanate, simple addition of potassium promoter does not improve the performance of the titan i a supported system. The potassium ferrite KFe02 which is observed in, e.g. MgO supported catalysts, is less stable than the compound incorporating Fe, K and Ti02, so the formation of the ferrite is not possible. The well developed interaction obtained during preparation is less beneficial for a good performance under dehydrogenation conditions. 

Kisch et al. reported photoreduction of N2 at iron titanate films with a Ti Fe molar ratio 1 1 [21, 22], The postulated new semiconducting phase Fe2Ti2Q7... 

Rusina O, Eremenko A, Frank G, Strunk HP, Kisch H. Nitrogen photofixation at nanos-tructured iron titanate films. Angew Chem Int Ed 2001 40 3993. 

Other iron titanates Fe2Ti04 (Eg= 2.12 eV) and Fe2TiOs (Eg = 2.18 eV) also examined. 

Sample 1 is from the whole particles and Sample 2 mainly consists of kernels. Silica is the only element that has a high concentration in the kernel. Most metals are of higher concentration in the whole particle, indicating that they are enriched in the shell. Iron, titan, nickel and lead are those with the largest differences in concentration in shells and kernels. However it should be pointed out that these results were obtained from only one randomly chosen sample and the concentrations were in some cases very low. Therefore, the test needs to be repeated to confirm the above observations. 

Types Properties Aluminium oxide 21iFconium oxide 2 j iconium silicate Aluminium silicate Titanium dioxide Cbronium oxide Iron titanate Rare earths (50% cerium oxide)... 

D.S. Ginley, M.A. Butler, Photoelectrolysis of water using iron titanate anodes. J. Appl. Phys. 

Linnik O, Kisch H On the mechanism of nitrogen photofixation at nanostruc-tured iron titanate films. Photochem Photobiol Sci 2006, 5(10) 938-942. 

Rusina O, Linnik O, Eremenko A, Kisch H Nitrogen photofixation on nano-structured iron titanate films. Chemistry-a European Journal 2003, 9(2) 56l— 565. 

The most important natural source of titania is iron titanate, known as the mineral ibnenite. Titanium oxide occurs also in its pure form, as the mineral rutile. Titanium dioxide is produced industrially via the sulfate process, whereby Umenite (Fe Ii03) is hydrolyzed with sulfuric acid at >95 ° C, after which Ti02 is obtained by calcination at >800 °C. Rutile is purified by treatment with hydrochloric add gas and conversion into titanium tetrachloride Ti02 is produced by treating the TiCU with oxygen at >1000 °C. 

Ilmenite il-no- nIt [Gr llmenit, fr. Ilmen range, Ural Mts., Russia] (ca. 1827) n. Fe0 Ti02. Natural iron titanate. It is an iron-black mineral and is one of the main sources of titanium dioxide. 

Examples The roasting of ores, the chemical adsorption of hydrogen sulfide by metal oxides (forming sulfides), the conversion of a metal oxide with a volatile non-metal oxide into a salt (e.g., the chemical adsorption of sulfur dioxide and oxygen by calcium oxide), the reductive chlorination of ilmenite (iron titanate) whereby iron chloride and titanium oxide are formed. In some processes a second solid reactant is present (e.g., carbon) that also reacts with the gaseous reactant, forming another gaseous reactant (e.g., carbon monoxide). 

Titanates are inverse spinels, where a number of the +2 ions occupy octahedral coordination sites in the lattice. Commercially important grades are the cobalt titanate greens and iron titanate browns. 

Iron titanates are formed from combinations of iron(II) oxide and Ti02- These formulations are commonly modified by additions of iron(III) oxide, zinc(II) oxide, and aluminum(lll) oxide. Like the cobalt titanates, these are inverse spinels stmc-tures. Iron titanate pigments yield light yellow-brown to dark reddish-brown hues. In many cases these pigments exhibit greater heat stability than zinc ferrite or iron oxide browns, and are generally used in applications for this purpose. 

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