Method of producing non-pyrophoric metallic iron
AssigneePremier Enviro Services, Inc.
InventorsJames L. Coburn, John L. Sullivan
Life of this patent
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Abstract
A method for producing a substantially metallic iron-containing product from iron oxide. The metallic iron produced according to the invention is non-pyrophoric and may be safely shipped and handled without additional process steps. The method of the invention is simple, economical, and produces high quality metallic product which may be used as a feed for Electric Arc Furnace (EAF), Blast Furnaces and Cupolas among other applications.
Claims35
A method of producing a substantially non-pyrophoric metallic iron-containing product from virgin and waste iron oxide sources, said method comprising the steps of:
- (a) agglomerating slag components:
- (i) iron oxide,
- (ii) zinc oxide,
- (iii) calcium and/or magnesium oxide, and,
- (iv) a finely divided low volatile carbon source,
- adjusting the slagging components to form a slag with a melting point exceeding the kiln treatment temperature by at least 100° C. to avoid kiln ring formation, and, forming a bonded agglomerate thereof by curing and drying the agglomerates to form a calcium and/or magnesium-zincate bond;
- (b) heating the bonded agglomerate of step (a) to temperatures above 900° C. to reduce and evaporate the zinc;
- (c) further increasing the temperature to reduce the iron oxide to metallic iron, wherein about 50 to 100 percent of the iron in the bonded agglomerate is metallized such that a metallic iron containing consolidated product is formed;
- and
- (d) controlling the heating time, heating rate, and temperatures such that the consolidated product is formed with low specific surface to render the product substantially non-pyrophoric.
A consolidated metallic iron pellet suitable for use in a blast furnace, said pellet comprising a metallic iron-containing interior produced by way of reducing an iron oxide agglomerate bonded with calcium oxide and zinc oxide, wherein the pellet is substantially non-pyrophoric.
A method for producing bonded iron oxide-containing agglomerates, comprising the steps of:
- (a) providing an iron oxide source with sufficient carbon for self reduction,
- (b) blending the iron oxide source with a source of calcium oxide, and a source of zinc oxide, such that the resulting mixture of slagging components forms a slag with a melting point exceeding the treatment temperature by at least 100° C. to avoid kiln ring formation;
- (c) compacting the blended composition into a plurality of agglomerates;
- and
- (d) curing the agglomerates at temperatures of less than about 450° C. and pressures of less than about 50 psig, to produce the bonded agglomerates.
A method of producing a substantially non-pyrophoric metallic iron-containing product, said method comprising the steps of:
- (a) agglomerating slag components:
- (i) iron oxide,
- (ii) silica or zinc oxide
- (iii) calcium oxide and/or magnesium oxide, and
- (iv) optionally a finely divided particulate carbon source,
- adjusting the composition of the slagging components such that the melting point of the slag is at least 100° C. above the kiln treatment temperature to form a bonded agglomerate thereof;
- (b) heating the bonded agglomerate of step (a) to temperatures of at least about 900° C.;
- (c) reducing the iron oxide to metallic iron, wherein about 50 to 99 percent of the iron in the bonded agglomerate is metallized such that a metallic iron containing consolidated product is formed;
- and
- (d) controlling the heating time, heating rate, and temperatures such that the silica, calcium oxide, and/or magnesium oxide form a fused outer layer on the consolidated product effective to render the product substantially non-pyrophoric.
A method for producing bonded iron oxide-containing agglomerates, comprising the steps of:
- (a) providing an iron oxide source;
- (b) blending the iron oxide source with a source of calcium oxide, a source of zinc oxide, and a source of silica;
- (c) compacting the blended composition into a plurality of agglomerates;
- and
- (d) curing the agglomerates at temperatures of less than about 300° C. and pressures of less than about 50 psi, to produce the bonded agglomerates.
Dependencies are inferred from the claim text.