Mechanically iron content

The resultant slag, a complex mixture of titanates, may contain 70—85% Ti02- The slag route is particularly useful when ilmenite is closely associated with haematite, from which it cannot economically be separated mechanically. Because the iron content of the slag is low, its use reduces the quantity of iron sulfate in the Hquid effluent of sulfate process plants. Slag used as a feedstock for TiCl production must be low in magnesium and calcium. A variety of other ilmenite beneficiation or synthetic mtile processes have been pursued, primarily to provide alternative chloride process feedstocks. Low grade ilmenite... 

Apart from the oxygen corrosion that results in HW and LP steam heating systems where water losses occur as a result of leaking pump mechanical seals, excess BD, faulty steam traps, and other sources, a subsequent effect is the development of fouling. This effect stems from the production of corrosion debris and (high iron content) sludge that eventually settle out in the boiler. This corrosion debris, sludge, and other foulants must be periodically removed from the boiler by BD, which merely adds to the water loss, and the cycle perpetuates. 

Table 5. Iron content in the C2-Ms and C2-Us/Ms catalysts found after different amounts of each catalyst were subjected to the digestion process. It is observed that relatively higher iron content was found in the catalyst prepared by mechanical stirring...

Study of the reaction mechanism of succinate dehydrogenase has. been complicated, partly because of the activation-deactivation properties of the enzyme, and partly because most of the early preparations studied had low iron content and low activities. Kinetic studies with activated, soluble preparations have led Zeylemaker et al. [215) to propose the fol-... 

The association pyroxene + olivine + cummingtonite + quartz, often encountered in highly metamorphosed BIF, is also very important for judging the thermodynamic parameters of mineralization. This association fixes the temperature at 700-720°C, which depends little on pressure and iron content of the silicates, while pressure can be estimated fairly precisely from the iron content of orthopyroxene. A decrease in partial pressure of water in conjunction with mechanical equilibrium P =Ff) due to dilution of the fluid by other volatiles, for instance carbon dioxide, can lead to some shift of the P-T curve into the lower-temperature region. However, the amount of such a shift, especially at high pressures (8-10 kbar) cannot be significant because Fe-Mg carbonates which are stable in carbon dioxide fluids already appear at 610-650°C (Fig. 93b), and their paragenesis with anhydrous silicates is not typical of iron formations. 

In general, it is recognized that there are multiple cellular and molecular responses to asbestos fibers, that no single mechanism is likely to account for all asbestos-related diseases, that the precise steps in pathogenic pathways leading to asbestos-related disease are not fiilly established, and that fiber structural and chemical properties (e.g., length, width, iron content, durability, surface areas) are important variables that play a role in the development of lung and pleural injury. 

Asbestos produces its toxic effects by direct contact with lung tissue or by stimulating an acute or chronic inflammatory reaction in the tissue (via active oxygen mechanism or other cell-mediated mechanisms). The important determinants of asbestos toxicity are fiber size, fiber durability, and iron content. 

In spite of extensive research efforts, the mechanism by which the body normally regulates its iron content remains a mystery. However, a considerable number of proteins that appear to play a role in iron homeostasis have been discovered mutations of these proteins in humans and/or their targeted disruption or overproduction in mice can be shown to result either in iron overload or in iron deficiency. Table... 

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