US918381A - Metallurgy of iron. - Google Patents

Description

UNITED STATE Parana? @FFIQE.

WILLIAM SPEIRS SIMPSON AND HOWARD OVIATT, OF LONDON, ENGLAND.

Ii [ETALLURGY OF IRON To all whom it may concern:

Be it known that we, WILLIAM Srnins SIMPSON, a subject of the King of Great Britain, and HOWARD OviA'rT, a citizen of the United States of America, both residing at London, England, have invented certain new and. useful Improvements in Connection with the Metallurgy of Iron, of which the following is a specification.

This invention has for its object the reduction of iron oxide and the production of metallic iron from various ores in which iron occurs as an oxid; especially such ores as hematite or magnetite and their compounds.

The method or process is adaptable to any form of iron oxid capable of being crushed or ground for mixing purposes as hereinafter set forth, but it is peculiarly adapted to the treatment of concentrates or of ores already existing as natural products, in a line state of division, such as magnetic iron sands or partially decomposed ores containing sesquioxid of iron.

In carrying out the purposes of the invention we thoroughly mix any convenient uantity of suitable iron ore which if not a ready in a comparatively fine state of division has been so prepared, with an aqueous solution suflicient in quantity to form a stii'l' paste suitable for being placed in or packed mto a receptacle prepared for the purpose and made ready (as a furnace or crucible charge) for being subjected to heat. This solution is composed of water and a carbohydrate such as sugar or other saccharine substances or compound, or such as starch, flour, or other starchy substance or com pound. It is advisable (but not necessary) that the solution should be made with hot water in order to more perfectly dissolve the carbo-hydrate employed. The quantity of such carbohydrate required to efl'ect the desired result in respect to the reduction of the metallic oxids under treatment, varies according to the character of the carbonaceous substance so employed and according to the character of the ore to be reduced. Thus if magnetic iron sand (which contains but a small proportion of gangue) represents the ore to be reduced and if ordinary brown sugar represents the carbo-hydrate to be employed the quantity of sugar should be approximately equal to four or five per cent. of the weight of the ore to be treated. The em loyment of an excess of such carbohy rate is not detrimental to the accom- Specification of Letters Patent.

Application filed. November 16, 1908.

Patented April 18, 1909.

Serial No. 462,905.

I plishment of the desired result and in some cases if an excess of sugar is employed the water may be omitted. In some cases when the iron ore contains a considerable percentage of silica, alumina, lime or other gangue the carbo-hydrate employed may with advantage be considerable increased. In almost every case unless already present in the crude ore, there should also be intimately and thoroughly mixed with the ore charge, suflicient lime, alumina, silica or other convenient fluxing material which has been suitably crushed or ground for the purpose, in proportions suitable to form, during the process of heating and reduction, a liquid slag, which may be either acid or basic as may be best suited to the ore under treatment.

The ore charge having been prepared in the manner hereinbefore described may be placed in any suitable receptacle or vessel (with or without a cover) and subjected to heat in any convenient manner or in any convenient form of furnace wherein it is practicable to create and maintain a heat equal to or somewhat higher than the melting point of steel. Or the prepared ore charge may be packed into or suitably placed mens open hearth regenerative furnace fired with producer gas. The hearth of such furnace should be provided with a suitable lining composed of such material as ganister or magnesite or a refractory carbonaceous compound. hen subjected to a heat varying from 2600 F. to 3000 F. according to the ore-charge under treatment and the result desired, for a period of time ranging from two hours to iive hours and upward, according to the magnitude of the charge, there is pro duced (at the will of the operator) either (a) sift malleable pig or cast iron, of remarkable purity in that it is practically free from graphitic carbon or silicon, or (b) a fine quality oi spongy iron suitable for the manufacture of wrought iron bar. The result depending chiefly upon the temperature to which the ore has been subjected during or after reduction and whether such temperature has been high enough to melt the reduced iron or otherwise.

In some cases and with some ores it is desirable to augment the action of the carbo-hydrates mentioned (sugar, starch etc.) by associating with the ore and fluxes a small quantity of ground coke, coal, charcoal, or other form uithin the hearth of a furnace such as a Sie- Q of carbon, not exceeding 10 or 15 per cent. of the Weight of the ore and which may or may not be intimately mixed therewith. And in some cases Where a considerable proportion of lime is to be employed for fiuxing purposes the same may be introduced in the form of calcium carbonate, the same having been mixed with about 12 per cent. of its "Weight of charcoal or other carbon (both finely ground) it may be placed in the bottom of the receptacle or furnace hearth before the ore charge is placed therein; which mixture when heated,

yields active reducing gases.

'W nat We do claim as our invention and desire to secure by Letters Patent is 1. A process of producing iron directly from the ore which involves mixing the ore in a iine state of division with a carbo-hydrate associated with Water, and subjecting the same to heat to ei'i'ect the reduction of the metallic oxids.

2. A process of producing iron directly from the ore which consists in associating a carbo-hydrate with the ore in a finestate of division, and heating the charge to effect its reduction.

3. The herein described process for the reduction of iron oxids to metal which consists in associating water and a carbo-hydrate With the ore together With fluxing materials suitable to form a liquid slag, all in a fine state of division, and heating the ore charge to effect its reduction.

i. A process of reducing iron oxids to metal Which consists in intimately associating a carbo-hydrate dissolved by Water, with the ore in a fine state of division, and subjecting the ore charge to heat to effect its reduction.

5. A process of reducing iron oxids to metal which consists in mixing a carbo-hydrate augmented by another carbonaceous material with the ore in a fine state of division to form an ore charge to which heat is applied to etl'ect its reduction.

6. An improvement in the art of reducing iron oxids to metal Which consists in associating a carbo-hydrate with the ore in a fine state of division, mixing therewith suitable liuxing materials to produce a liquid slag, and subjecting the mass to heat adequate to effect a complete reduction of the ore.

In testimony whereof We have hereunto set our hands in presence of two subscribing nitnesses.

WILLIAM SPEIES SIMPSON. HOWARD OVIATT.

vVitnesses RICHARD CORE GARDNER, LYNWOOD F. GARDNER.