US1231260A - Process of producing ferro-silicon of high silicon content in blast-furnaces. - Google Patents

Description

ll FATE zrosnrn n. aonnson', an, or HARTSDALE, new YORK.

Li h u PROCESS OF PRODUCING FERRO-SILICON OF HiIGI-I SILIGON CONTENT IN BLAST- FURNACES.

No LQrawing.

To all whom it may concern:

Be it known that l, Josnrn E. JOHNSON, J12, a citizen of the United States, residing at Hartsdale, in the county of lVestchester and State of New York, have invented certain new and useful Improvements in Processes of ProducingFerro- Silicon of High Silicon Content in Blast-Furnaces, of which the following is a specification.

This invention relates to a process of smelting ores in the blast furnace, and aims to produce in an economical manner, ferrosilicon containing a high percentage of silicon.

,There are at present in common use two varieties of commercial vir'erro-silicon, one produced in the blast furnace, and the other produced in the electric furnace. variety, while comparatively inexpensive to The first produce, is low in its percentage of silicon,'

and the second variety while very high in silicon content, commonly 50% or more, is expensive to produce on account of the high electric current consumption.

It is the object of my invention to produce in the blast furnace, ferro-silicon containing a high percentage of silicon, thereby securing the advantage of the electric furnace in respect to the high silicon content, and the advantage of the blast furnace with respect to economy of production.

With this object in View, my invention consists of an improved method of smelting, in which a blast is employed rich in oxygen, whereby the temperature of combustion is increased to such degree that the silica will be reduced on a scale which will produce ferro-silicon containing a high percentage of silicon and equahng the product commonly produced in the electric furnace.

In carrying my improred method into ellect. I make use of a form of blast furnacc, in a general way similar to that now 1l11l"1:5l\ll employed for smelting ores, and I charge the sam with ore and fuel in-the usual and well known manner. 1 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 resultof which 1s the production of a much higher combustion temperature than is available in the furnace as ordinarily operated, and a correspondtion.

vto be incorporated.

Specification of Letters Patent. Pafhgnfiafi June 26, 1-917 Application filed June 20, 1916. Serial NO. 104,779.

ingly increased reduction of the silica. The reactions 1n this operation may be expressed by the following formula:

S10 +20 xFeZiFe Si 2C0.

Where atmospheric air is employed in the blast there is about 3; tlmes more by weight of nitrogen than there is of oxygen, and

- since, other things being equal, the temperaas a dead weight on the combustion and keeps the temperature down to such point that the reduction of silica is confined to limits in which the final product contains a comparatively small per cent. of silicon, rarely above 16%.

By my invention, by employing a blast rich in oxygen the increased temperature of combustion is Very marked, and if pure oxygen were employed the gain would be so enormous that it would greatly exceed the requirements for the end in View, and since .the increase of temperature need be only about higher than is now obtainable with the use of atmospheric air, I find 1t sullicient for my purpose to employ a blast in which the oxygen and nitrogen will boot equal.

weights, or in approximately that propor- A mixture of this character is more economically produced commercially than pure oxygen, and such'mixture is sul'licicntly 'rich in oxygen to obtain the temperature required, for the reduction of the silica on the deslred mcreased scale, and for the crcation of the amount of heat available at that temperature to bring about such reduction.

Ferro-silicon .as most generally employed in metallurgy,contains about equal proportions of iron and silicon in order to enable it to combine under the most favorable conditions with the molten metal in which it is A blast in which the nitrogenand oxygen are mixed inequal or substantially equal proportions I have found admirably adapted for producing that temperature of combustion which will bring about the reduction of the silica and iron in the proportions mentioned. and a blast mixture of this character may be economically and conve'i'iientlyproduced and with a far smaller plant than is required for a richer mixture or for pure oxygen.

nace, which-consists in chargingthe furnace with ore and fuel, and supplying a blast rch in oxygen to reduce the slhcaon a scale-topro'cluce, ferrosilicon containing a high percentage of silicon. r

2. The process of producing ferro-silicon of substantially 50% silicon in a blast furn ace, which consists in charging the furnace with ore and fuel, and supplying a blast containing equal" or substantially equal parts by weight of oxygen and nitrogen to reduce the silica on a scaleto produce a ferro-silicon containinga high percentage .of silica.--

In testimony Whereof, I have affixed my signature. 7 r.

' JOSEPH E. JOHNSON; JR.