Magnetite-water

Fortier SM, Cole DR, Wesolowski DJ, Riciputi LR, Paterson BA, Valley JW, Horita J (1995) Determination of the magnetite-water equilibrium oxygen isotope fractionation factor at 350°C a comparison of ion microprobe and laser fluorination techniques. Geochim Cosmochim Acta 59 3871-3875 Friedman I, O Neil JR (1977) Compilation of Stable Isotope Fractionation Factors of Geochemical Interest. US Geol Surv Prof Paper 440-KK... 

Wada S, Ichikawa H, Tatsumi K. Removal of phenols with tyrosinase immobilized on magnetite. Water Sci Technol 1992 26(9-11) 2057-2059. 

The situation for other minerals at low temperature is less satisfactory - as in the case of the iron oxides. Several fractionation factors proposed for magnetite-water exhibit an extremely wide range (Fig. 18). Empirical-theoretical calculations (Becker and Clayton 1976 Rowe et al. 1994) and empirical calculations by the increment method (Zheng... 

Based on microbial siderite-water and magnetite-water... 

HTS catalyst consists mainly of magnetite crystals stabilized using chromium oxide. Phosphoms, arsenic, and sulfur are poisons to the catalyst. Low reformer steam to carbon ratios give rise to conditions favoring the formation of iron carbides which catalyze the synthesis of hydrocarbons by the Fisher-Tropsch reaction. Modified iron and iron-free HTS catalysts have been developed to avoid these problems (49,50) and allow operation at steam to carbon ratios as low as 2.7. Kinetic and equiUbrium data for the water gas shift reaction are available in reference 51. 

Caustic corrosion (gouging) occurs when caustic is concentrated and dissolves the protective magnetite (Fe O layer. Iron, in contact with the boiler water, forms magnetite and the protective layer is continuously restored. However, as long as a high caustic concentration exists, the magnetite is constantiy dissolved, causing a loss of base metal and eventual failure (Fig. 4). 

Ferric and ferrous hydroxide usually contain water of hydration. A layer of hydrated magnetite sometimes forms between the ferric and ferrous hydroxides (see Fig. 3.2). The threefold layer of corrosion products is usually called rust. The bulk of rust is the ferric hydroxide layer. (In tubercles, however, ferrous hydroxide often is the major component see Chap. 3.)... 

Four magnetite rod anodes (All to A14), each weighing 9 kg, in perforated polypropylene protection tubes were used to protect the box headers, the in-flow hood and inlet housing as well as the CrNi steel oil cooler. Protection tubes keep out solid matter carried in the river water. The oil cooler was connected to the protection equipment with its own cathode conductor. 

The first use of new plant, or start-up after a shutdown, poses corrosion hazards additional to those encountered in normal operation. New plant such as boilers requires special water treatment, involving boil-out, passivation and possible chemical cleaning. Actual requirements depend on the boiler type, the proposed service, the quality of water available during commissioning and the internal condition of the boiler. The condition of the boiler depends on for how long and in what conditions it has been stored. The presence of any salts, dirt or rust is harmful. An adherent, protective layer of magnetite in normal operation... 

Reaction of iron containing a discontinuous magnetite scale with oxygenated water, crevice corrosion, water-line attack, long-line corrosion of buried iron pipes, etc. — separable A/C type. 

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