Oxidation FeOOH

The product, ferrous hydroxide, is commonly further oxidised to magnetite (Fej04) or a hydrated ferric oxide (FeOOH), i.e. rust. 

Ferrous oxide (FeO) and hydrated iron oxide (FeOOH) can be found as a bright red to red-brown, light and fluffy deposits under various conditions, such as in cold FW tanks and freshly acid-washed or wet laid-up boilers. 

In the goethite process, the precipitation of iron from solution occurs in the form of hydrated ferric oxide, FeOOH. The commercial development of the process was due to Societe de La Vielle Montagne. The process basically involves the reduction of iron to the ferrous state, and this is followed by oxidation by air at a temperature of around 90 °C and at a pH controlled at around 3.0. The reaction can chemically be shown as ... 

In this paper the extraction of gold chlorocomplexes on alternative metal oxide (FeOOH, Fe304 and AI2O3) sorbents was investigated. The investigations reported in this paper can be summarized as follows ... 

In this chapter, we discuss double layer theory and how it can be incorporated into a geochemical model. We will consider hydrous ferric oxide (FeOOH //IFO), which is one of the most important sorbing minerals at low temperature under oxidizing conditions. Sorption by hydrous ferric oxide has been widely studied and Dzombak and Morel (1990) have compiled an internally consistent database of its complexation reactions. The model we develop, however, is general and can be applied equally well to surface complexation with other metal oxides for which a reaction database is available. 

As an example of an equilibrium calculation accounting for surface complexation, we consider the sorption of mercury, lead, and sulfate onto hydrous ferric oxide at pH 4 and 8. We use ferric hydroxide [Fe(OH)3] precipitate from the LLNL database to represent in the calculation hydrous ferric oxide (FeOOH /1H2O). Following Dzombak and Morel (1990), we assume a sorbing surface area of 600 m2 g-1 and site densities for the weakly and strongly binding sites, respectively, of 0.2 and 0.005 mol (mol FeOOH)-1. We choose a system containing 1 kg of solvent water (the default) in contact with 1 g of ferric hydroxide. 

Contaminants in soils and sediments can be adsorbed on to inorganic minerals such as clays and metal oxides, notably hydrated iron oxide, FeOOH and manganese dioxide, Mn02, or adsorbed on to organic matter such as humic... 

From a mineralogical perspective, Fe-Mn nodules are composed of layers of manganese oxides (vernadite, todorokite, and birnessite), hydrous Fe oxide FeOOH H2O), aluminosilicates, quartz, and feldspar. Like the rest of the Fe-Mn oxides, the nodules... 

Iron oxides are used as the flux in smelting of nonferrous metals (e.g. lead) (Pettifer, 1981). The oxide removes the siliceous and other impurities and also serves to keep the slag fluid. A further use of iron oxides (FeOOH) is in the removal of H2S from coal gas, i. e. 

The presence of hydrous ferric oxide (FeOOH) has been confirmed by X-ray diffraction, Mossbauer spectroscopy, and magnetization measurements (7). Figure 11 shows the X-ray diffraction patterns for the region of 20 between 14 and 18°. The two peaks at 15.2 and 16.3° are diffractions from a-Fe203, but the large background is from the various forms of hydrous ferric oxide. The lack of fine structure excludes the possibility of identifying... 

Reduction of iron oxide (FeOOH) is a potential source of arsenic to groundwater because it releases arsenic adsorbed to the oxide surfaces. A representation of this process might be ... 

In the cable industry, plasticization of CPVC by phthalates and phosphates improves the flexibility and processability of CPVC. However, the addition of plasticizer lowers the limiting oxygen index and increases smoke production. The schematic diagram below illnstrates the mechanism of degradation in the absence (A) and the presence (B) of the smoke-suppressing componnd - basic iron oxide, FeOOH. " ... 

It has been found that incorporating modest amounts of hydrated iron(m) oxide (FeOOH) into ABS/PVC blends increases char formation significantly when compared with equivalent formulations containing no iron. The formation of large amounts of char in the presence of basic iron(m) oxide results in a reduction in the amount of smoke produced when the polymer blend bums in air. In addition to the formation of char, it has also been found that this iron(iii) compound improves the flame resistance of the blends and also stabilizes them against decomposition by both heat and light (Table 1). 

If the scale is mostly ferric oxide (FeOOH or red "rust"), a safe solvent using HEDTA and the reducing agent erythorbic acid can be used to clean cooling water systems at temperatures at or below 150°F (65°C). 

The surface of the unreduced catalyst consists of a mixture of basic ferric oxide ( FeOOH ) with aluminum oxide and the basic carbonates of potassium and calcium. The constitution of this layer is considered to be similar to rust, since it is the product of the reaction of magnetite with air during catalyst storage. This layer is seen in the intergranular spaces and is also present in the cracks between the polycrystalline particles. 

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