US393553A - Process of manufacturing steel direct from the ore - Google Patents

Description

UNiTEn STATES PATENT OF ICE.

MATTHEW GRAFF, OF PITTSBURG, PENNSYLVANIA.

PROCESS OF MANUFACTURING STEEL DIRECT FROM THE ORE.

SPECIFICATION forming part of Letters Patent No. 393,553, dated November 27, 188 8. Application fi'ed January 4. 1888. Serial No. 259.795. (No specimens.)

To aZZ whom, it may concern: I integrated ore in suitable proportions-about Be it known that I, llIATTHEW GRAFF, a twenty'five to thirty-three per cent., more or citizen of the United States, residing at Pitts less, by weight,of the ore. The'mixed ore and burg, in the county of Allegheny and State of carbonaceous material are then charged into Pennsylvania, have invented or discovered a a suitable reverberatory furnace and there certain new and useful Improvement in the subjected to a sufficient degree of heat to lib- Process of Manufacturing Steel Direct from crate the oxygen groin the ore and also to melt the Ore, of which improvement the following the matrix in which the iron is held. The is a specification. I bottom of the reducing-furnace is formed first IO In the attempts heretofore made to manuofa layer of comparative] large lumps of carfacture steel direct from the ore the carbonabonaceous material and then with a layer of ceous material and the ore were crushed or smaller lumps, and finally with a layer of fine broken up,and after beingthoroughlymingled I material, which will iill the interstices bewere placed inasuitablefurnaee and subjected tween the lumps and formasmooth bed. The

15 to a reducing-heat. This method, however, material forming this bed is either coated has proved practically unsuccessful on ac with a wash of lime or loam prior to being countof the rapid combustion of the carbona placed in the fnrnacc,or else a quantity of the ceous material, which would be entirely conwash is poured over the bed after being formed. sumed before thorough deoxidation could be I In lieu of forming the bottom of carbonaceous 2c effected; and, further, the heat generated in material, as above stated, unwashed graphite the combustion of the carbonaceous material may be employed, if desired. The coating or would fuse the metallic iron,which would then wash will protect the carbonaceous material convert the phosphoric acid to its elemental to such an extent as to prevent a rapid com- 7 condition and then absorb it. bustion thereof, and hence there will be a 25 The object of the invention herein is to so slower generation of carbonic oxide. On acretard orlessen the combustionof the carbonacount of this slow generation the carbonic ceous material as to afford opportunity for the oxide will be enabled to form a chemical combination of the carbon with the oxygen of union with the oxygen of the ore, thereby So the ore and to prevent the generation of such forming carbonic acid,whereas if the carbona- 30 a heat as will fuse the metallic iron, which in ceous material were unprotected the oxygen its molten condition will readily combine with would not be given OE With sufficient rapidity the phosphorus. to combine in proper proportions with the In general terms, the invention consists in large volumes of carbonic oxide rapidly 8 the process or method, all as more fully hereevolved from the carbonaceous material. 3 5 inafter described and claimed. The charge is heated to about a cherry-red In the practice of my invention I take any heat and maintained thereat until the gangue is suitable form of carbonaceous material-hard melted into a fluid slag and until the oxygen coal,or coke produced in the usual manner or has been entirely removed, or practically so, 0 by the combustion of fluids or by the distillaand the metalliciron broughtinto an adhesive 40 tion of oils, such as petroleum. The carbostate.

naceous material is then broken up into small The fluid slag removes or takes up from the lumps and then ground up or reduced to about sponge a greater part of the impurities held the size of coarse sand preparatory to mixing therein, including phosphoric acid. When deit with iron ore similarly prepared. These oxidation has been efiected and the metallic 5 small lumps or particles of carbonaceous mairon is in an adhesive condition, it is bailed or terial are then coated or covered with a thin worked up into masses of a suitable size, relime or loam wash, which may be applied in moved from the furnace, and immediately any suitable manner-as, for example, pourcharged into an open-hearth furnace containing the wash over the carbonaceous material ing a bath of molten iron or steel. By balling 50 or by immersing the latter in a bath of the up the iron and working it as free as possible wash. The carbonaceous material thus profrom the slag, a comparatively pure mass of teeted or coated is mixed with the broken or d isiron is obtained for subsequent working,and by charging solved in the bath,and any impurities, includ ing phosphorus, which it may contain are liberated and rise up into the slag before the heat of the bath can so convert them as to permit of their absorption by the iron.

Any suitable material which will retard or lessen the combustion of the carbonaceous material may be employed in lieu of the lime or loam to form the wash.

In some cases it is preferred to mingle the carbonaceous material and the ore and to charge them into the furnace before the wash or coating has become dry, thereby prevent ing any loss of the ore and carbonaceous material in the form of dust.

I claim herein as my invention 1. As a step in the art of manufacturing steel direct from ore, theherein-described process, which consists in intimately mixing the ore with a carbonaceous material protected as while hot it is immediately dis-' steel direct from ore, the herein described process, which consists in intimately mixing the ore with a carbonaceous material protected by a coating of lime as against rapid combustion, and then subjecting the mixed ore and carbonaceous material to the action of the reducingflame in a suitable furnace, substantially as set forth.

In testimony whereofl have hereunto set my hand.

MATTHE\V GRAFF.

\Vitncsses:

W. B. CoRwIN, DARWIN S. Worico'r'r.