Sponge iron oxide

In atomization, a stream of molten metal is stmck with air or water jets. The particles formed are collected, sieved, and aimealed. This is the most common commercial method in use for all powders. Reduction of iron oxides or other compounds in soHd or gaseous media gives sponge iron or hydrogen-reduced mill scale. Decomposition of Hquid or gaseous metal carbonyls (qv) (iron or nickel) yields a fine powder (see Nickel and nickel alloys). Electrolytic deposition from molten salts or solutions either gives powder direcdy, or an adherent mass that has to be mechanically comminuted. 

The iron sponge process is very old (introduced in England in the mid-19th century) and very simple. It removes only H S and mercaptans. It is good only for streams containing low H2S concentrations at pressures of 25 to l,200psig. Hydrated iron oxide containing water and of proper pH is supported on wood chips or other material. Water is injected with the gas. 

The ferric oxide is impregnated on wood chips, which produces a solid bed with a large ferric oxide surface area. Several grades of treated wood chips are available, based on iron oxide content. The most common grades are 6.5-, 9.0-, 15.0-, and 20-lb iron oxide/bushel. The chips are contained in a vessel, and sour gas flows through the bed and reacts with the ferric oxide. Figure 7-3 shows a typical vessel for the iron sponge process. 

Iron Sponge Also called Dry box. An obsolete process for removing hydrogen sulfide from gas streams by reaction with iron oxide monohydrate. The ferric sulfide that is formed is periodically re-oxidized to regenerate ferric oxide and elemental sulfur. When this process becomes inefficient because of pore-blockage, the sulfur is either oxidized to sulfur dioxide for conversion to sulfuric acid, or is extracted with carbon disulfide. 

Eriedrich, K., Kordesch, K., Simader, G., Selan, M. 1995. The process cycle sponge-iron/hydro-gen/iron oxide used for fuel conditioning in fuel cells. Proceedings of International Symposium on Fuel Cell System, New York. 

Iron oxide, spent, or Iron sponge, spent obtained from coal gas purification 1376... 

Let us take the example of iron oxide reduction in solid state by carbon monoxide, as it happens in the sponge iron making process. 

Breulmann, M., Colfen, H., Flentze, FI.-P Antonietti, M., Walsh, D. and Mann, S. (1998) Elastic Magnets Template controlled mineralization of iron oxide colloids in a sponge-like gel matrix. Advanced Materials 10 237-241. 

Sulfinol Shell-Paques Iron sponge, zinc oxide, mol sieve, activated carbon... 

See iron oxide process iron sponge, spent. 

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