USRE14547E - Joseph e - Google Patents

Description

't invgclited certain new and useful Improvements in Processesof Producing Ferro-Sllr UNITED STATES ra'rnnr one JQSEPHE. Jonnsomaa, or HAETSDALE, new ironies 'rnocnss or rnonucmo rnimo-srmoonrn BLAsr-rnnneons' an. Qriginal no ham itmay concern: I

citizen of the United'States of Amer-.

ica,

'tch'ester and 'State of New York, have pheric air, as a result of whichI am en abled-to produce low grade ferro-silicon such as is produced in the standard blast furnace, but at much less expense; and am also enabled to; produce at-compa-rativeiy small expense, high grade ferro-silicon such as can now onlybe produced in the electricfurnace at great expense.

There are at present in common use, two

varietiesof commercial ferro-silicon, one produced in the blast fnruace and the other produced in the electric furnace. The first variety, while comparatively inexpensive to produce, is low in its percentage of, silicon, and the second variety, wh1le very high in silicon content, commonly or more, is. vexpensive to produce on'acc'ount or the high 818013110 current consumption.

By the em ployment ofmy improved process, by properly propoition ing the amount of oxygen used in the blast-,1 can produce either a low grade ferro-silicon at much less expense than it is now produced in the standard blast furnace employing the usual blast of atmos-' pheric air, or I canproduce a ferro-silicon containing a high silicon content, and at far less expense than the same can be produced in the electric furnace. I p i In carrying my improved method into effeet, I make use of a form of blast furnace, in a general way similar to that now universally employed for smelting ores, and I charge the same with ore and fuel in the usual and well known manner. I introduce at the base of the charge, through the usual twyers', a blast which is rich in oxygen as compared with the usual blast of atmospheric air, the ,result of which is the-pro- 5 duction of a'highercombustion temperature known that I, JOSEPH E. Join won,

residing at Hartsdale, in the county of metal in which it is incorporated.

Specification of Reissued Letters Iatent. Rgigsued N31, 12, 1918,

1,231,260, dated June 26, 1917, Serial 80. 104,779, filed one 20, 1916. application I for reissue filed October 8, 1918. 7 Serial No. 257,427.

than is available in the furnace as ordinarily operated, and a correspondingly in- The reaccreased reduction of the silica. v tions n this operation may be expressed by the following formula:

Sit), so FeT Fe Si 200. lVhere atmospheric air is employed in the blashthere is about S g-times morehy weight of n trogen than there is of oxygen, and

since, other things being equal, -the tempera ture obtainable 1s inversely proportional to the weight of the products of combustion, the temperature produced is only about 5 as high as would he produced by blast of pure oxygen. In other words, the nitrogen in sucklarge proportions in the blast acts as a dead weight on the combustion anti keeps the temper that'tlie redu ion of silica is confined to limits in Whit the final product contains a comparatively small per cent. of silicon, rarely above 16%. a

By my invention, by employing a: blast rich in oxygen, the increased temperature of combustion is very-marked, and if lure oxygen were employed the gain woul b so enormous that it would greatly exceed-til requirements for the end in view, and since the increase of temperature need he only about 1096 to 15% higher than new ohtainable with the use of atmospheric-air, I find. it sufficient for my purpose in pro: ducing term-silicon of high silicon center 5," to employ a blast-in which the oxygen and nitrogen will be of equal weights, orjnap proximately that proportiozr- A mixture of this character is more economically pro dueed connnercially than pure oxygen, such mixture is sufficiently rich inoxygenito obtain the temperature required, for the re* duction of the silica. on the desired increased scale, and for the creation of the amount of heat available at that temperature to bring about such reduction. 1

Form-silicon of high percentage as most, generallyemployed in metallurgy, contains ture down to such point about equal proportions of iron and silicon in order to enable it to combine under the most favorable conditions with. the molten in which the nitrogen and oxygen are mixed i inequal or substantially equal proportions I have found adnnrahly adapted for producing' that temperature of combustion which will bring about the reduction of the 'silira and iron iii-the proportions mentioned. 'and a blast mixture of this eharacter'niay be economically and eonveniently produced L and with a far smaller plant than is required for a richer mixture or for pure I't will-be. manifest that I may employ oxygen in the blast in lower proportigns 1) than that mentioned. in cases where the silicon content is not to be so high, say, in cases where the silicon content is 12% or thereabouts as is now produced in thestandard blast furnace einplo \'ing a blast of atmos- 15 pheric air.

Having thus described my invention. what .I claim is: l. The process of producing ferro-silieon of high silicon content in a blast furnace, which consists in charging the furnace with oreand fuel. and supplyinga blast rirh'in oxvgen to reduce the silica on a" scale to ])1()( are ferro-silieoncontaining a high per-i centage of silicon.

2. The processof producing a ferro-silicon of substantially 530% silicon in a blast furnace, which consists in charging the furnace with oreJand fuel, and supplying a blast containing equal or substantially equal parts by weight of oxygen and nitrogen t0 reduce the silica on a scale to produce a ferro-siheon containing a high percentage of slllcou.

' The process of producing ferrorsilicon.

in a hlasr'furnaee. which conQiste-inghalgmg the furnace with ore and fuel, and sup.- plyuig a blastmntauung oxygen in :greater proportion thanin atmospheric air.

In testimony whereof Ilmve afiixedrny signature hereto.

JOSEPH E. JOHNSON, JR.