Iron preparative techniques

In slower production processes, atomic absorption can be used directly for production control of those processes for which rapid sample preparation techniques have been developed. One such example is the determination of magnesium concentration during the production of cast iron [70]. A further example is the determination of acid soluble aluminium in steel [147], where in large steel companies 100 samples or more per day may be required. (See also section II.A.)... 

The book opens with a short introduction into the nature of iron oxides. This is followed by a discussion of general preparative techniques (chapter 2). In chapter 3, techniques for characterization of the products - color measurement, electron microscopy. X-ray diffraction, infra red absorption spectroscopy, surface area measurement, thermoanalysis and Mossbauer spectroscopy - are briefly described with particular emphasis on their application to Fe oxides. 

The most popular and elegant specimen preparation technique introduced by Claisse 17] is based on fusion of solid specimens with lithium tetraborate. The method was used with great success in our laboratory for the rapid quantitative X-ray fluorescence analysis of silicates, bricks, refractories, limes, iron, and manganese ores. The use of lithium tetraborate and lithium fluoride flux systems was therefore examined first. 

PREPARATIVE TECHNIQUES Emulsion polymerization (a) 300-800 psig, perfluorinated surfactant initiator, 65-85°C, 2-6 h/ (b) 2001bin, 50-110°C, fluorinated surfactant, 17-21 h, iron powder. ... 

Through the achievements of the Hittites, the ground was prepared for the Iron Age and an everyday use of iron. Their technique is illustrated in Figure 8.7. 

Proven, industrially used catalysts are mostly based on either iron or cobalt. Ruthenium is an active F-T catalyst but is too expensive for industrial use. Both Fe and Co are prepared by several techniques including both precipitation and impregnation of (e.g. alumina or silica) supports. The more noble Ni catalyst produces nearly exclusively methane and is used for the removal of trace of CO in H2. 

A third way to increase both the active surface area and the number of oxygenated species at the electrode surface is to prepare alloy particles or deposits and then to dissolve the non-noble metal component. This technique, which is similar to that used to prepare Raney-type catalysts, yields very high surface area electrodes and hence some improvements in the electrocatalytic activities compared with those of pure platinum. However, it is always difficult to be sure whether the mechanism of enhancment of the activities is due to this effect or the possible presence of remaining traces of the dissolved metal. Results with PtyCr and PtSFe were encouraging, although the effect of iron is still under discussion. From studies in a recent work on the behavior of R-Fe particles for methanol electrooxidation, it was concluded that the electrocatalytic effect is due to the Fe alloyed to platinum. ... 

Alqudami, A. and Annapoorni, S. (2007) Fluorescence from metallic silver and iron nanoparticles prepared by exploding wire technique. Plasmonics, 2, 5-13. 

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