US1398572A - Process of and material for reducing ore and making gas - Google Patents

Description

J H/REID.

PROCESS OF AND MATERIAL FOR REDUCING ORE AND MAKING GAS.

APPLICATION FILED JULY 16,1'920.

Patented N0v., 29, 192 1.

I To all whom it may concern:

Wir were @ATENT Fries.

f s- J'AMES HENRY REID, 0F READSZBORO, VERMONT, ASSIGNOR T0 THOMAS I. HOGAN, 0E

nosron, MASSACHUSETTS.

' rnocnss or AND MATERIAL FOR REDUCING ORE Am) MAKING. GAS. I

Application filed J'u1y 16, 1920. Serial No. 396,762

Be it known that I, JAMES HENRY Rnn), a citizen of the United States, residing at Readsboro, in the county of Bennington and State of Vermont, have invented acertain' new and useful Improvement in Processes of and Materials for Reducing Ore and Mak ing Gas, of which the following is afull, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to a process for reducing ore and for the production of gas; also to materials for realizing such processes.

It isthe general object of theinvention to reduce such ore in a more 'eflicient' manner than has been accomplished heretofore; to

make it possible to utilize-in the reduction- .of such ore (and especially of iron ore in a. blast furnace) certain grades of coal the sulfur content of which has excluded them heretofore from consideration; to increase the output of the iron or other metal from blast furnaces; and to reduce the proportion of coke required for the reduction of the ore.

A further object of the invention is to obtain in a novel manner a large-volume of gas of a heating value useful in the arts and in excess of that ordinarily obtained from the. distillation of coal in retorts and in the operation'of blast furnaces. Further and more limited objects of the invention will appear hereinafter and will be realized through the steps and ingredients and the combinations thereof, respectively, embodied in the claims hereto annexed. The invention will be de scribed in connection with the reduction of iron ore, for which it is especially adapted;

and the drawing shows diagrammatically an apparatus or system for realizing such in.

bon, yielding CO in accordance with the hearth furnace. The invention will be described with reference to such ordinary steel plant equipment.

For the reduction of the iron ore and the production of gas, I first intimately mix iron ore, coking coal, and limestone (CaCO in about the following proportions by weight Iron ore, 100 lbs.; limestone, 42 lbs.; coal, about 80 l-bs.sufiicient to produce about lbs. of coke.

The limestone will first be reduced to afineness of about forty mesh, the coal to a.

fineness of about eight mesh, and the iron I Specification of Letters Patent.

Patented Nov. 29,

1n which it is ordinarily supplied to blast furnaces. Where the ore is coarse or contains nodules, it is ground to a fineness of about elght mesh. These, ingredients, havlng been lntnnately mixed, are charged into the by-product coke oven or ovens or other retort 1 and are there retorted at a temperature of from 2600 F. to 2800 F. until v the .coal is completely coked.- By reason of the ingredients employed andthe mode of treatment, all of the gases ordinarily obtamed by the distillation of bituminous coal are secured; moreover,'the finely divided cond tions of the heated mass of limestone, ore, and coal enables me to crack into gas the liquid tarry constituents of'the coal, this cracking being secured by bringing the liq- .uid tarry material into contact with a myriad of incandescent bodies or points, due to the finely divided'condition of the ingredients,

particularly of the limestone and iron ore. As a result, the tarry constituents are removed 1n the retort and are recovered in the form of gases which serve to enrich the the. recovery of ammonium. sulfate from the,

gas liquor and makes it unnecessary to preheat the gas or gases delivered from the retort before introducing the same into the saturater. A

At the end of the retorting operation, the ore will have been partly reduced by the carequation Fe O +C:2FeO-|-CO, this, reduc:

:tion being facilitated by the presence of hydrogen in the liberated gases. The ingredients-will have been formed into a cemented or coked, mass wherein the iron ore, the carbon, and the limestone will be in most intimate contact; every small particle of ore has inclose contact with it a particle of car-' bon and a particle 0f limestone, which renders the mass delivered from the retorts 'ideal for the'reduction of the ore in the blast furnace.

Among the advantages,'from a gas-mak ing standpoint, which my rocess, as thus far described, possesses are t e follow,ing;-

(a), The recovery of a larger proportionof gas from the coal than has be plished heretofore by the methods ordic viy employed, this additional recovery be d to the conversion of the tarry products into gas andthe production of CU through the partial reduction of the The saving of ieat necessary for the retorting operation, d to the conductivity of the mass therein; also due to-the fact that the reaction occurring within the retort is exothermic to some extent. This will result in a shorter period of time for the coking operation, offsetting largely, if not entirely, the heat required for the great 1 bulk of material over the use of coal alone;

() The saving in the recovery of the by products (such asannnonium sulfate) re of the limestone.

sulting from the gas production, due to the elimination of the tar or tarry constituents.

In the reduction of the ore to pig iron in the ordinary blast furnace, indicated at 2, a great saving in fuel may be accomplished by charging the said furnace with the coked or cemented mixture in a hot condition, direct from the by-product oven or ovens. The saving of fuel because of this sensible heat in the charge will be enormous.

The advantage in the intimate mixtureof the ingredient-s which enter the blast furnace has already been pointed out. The flux and the reducing agent do'not have to find their way around and to the ore, but are in contact with it at the very start. Furthermore, a partial reduction of the'ore in the coke oven has already been accomplished. This results in a quicker fusion and a quicker reduction of the ore, thus greatly increasing the output of iron from the ,furnace over the output secured by ordinary methods. There is also a saving in the amount of coke required, since the reduction which occurs in the coke oven has been accomplished in the absence of air, and hence without the production of 00 as is the case to some extent in the bla t furnace.

Reference has been made heretofore to the practicability of using coal containing aportion of sulfur which has hitherto ex cluded the same from consideration in connection with blast furnaces. the coke and limestone into intimate contact, .so that every small particle of coke has next to it a similar particle of limestone, the sulfur in the coke will beabsorbed by the lime and will not enter the iron. While it is true that iron at a White heat will absorb sulfur from calcium sulfate, in the reducing atmosphere of the furnace calcium sulfate Will not be formed, but rather calcium sulfid. and the sulfur constituent of the coal will be absorbed by the calcium constituent In the operation of the blast furnace, the ore will not only be quickly reduced, With the advantages hereinbefore described, but

By bringing,

volume of carbon monoxid "will be d which may be mixed with the V ed in and discharged from the coke oven; and the resultant mixture of these :y s used for the open hearth furfor various commercial purposes. drawing, the gas the retort -product coke oven or ovens) 1 and i blast furnace 2 conducted by the pipes 3 and at to a hydraulic main 5, as

2 1 through the usual purifiers and scrubbers (not shown), being finally delivcred to a gas holder 6.- From this holder, such proportion of the gas as may be desirable may be supplied to an open hearth furnace or furnaces 7 by a pipe or pipes 8.

From charge of about lbs. of coal, 100 lbs. iron ore, and lbs. limestone, there will be recovered in the coke oven about 600 cu. ft. of 500 T. U. gas. or a total of 300,000 T. U. In addition, the reduction of the l c 'Q, to FeO will yield about 182 cu. ft. of 323 B. T. ll. gas, or a total of 58,786 B. T. U, making a total B. T. U. recovery from the 80 lbs. of coal in the coke oven of 358,786 B. T. U.

In the blast furnace, the ore, coke, and limestone will yield approximately 5000 cu. ft. of gas with a total B. T. U. value of 475,000. Thetotal B. T. U. recovery from the 80 lbs. of coal first introduced into the coke oven will amount to 833,000, or 10,400 B. T. U. per pound of coal. The recovery of useful gas by the process herein described represents more than 70 per cent. of the potentialenergy of the coal employed in the process. The limestone serves as a gas activating agent in the retort and as a fluxing agent 'and a gas-activating agent in the furnace.

Having thus described my invention, what I claim is:

1. The process which comprises rctorting a mixture of ore with cokable carbonaceous material and material capable of acting-as serve as a gaseous activating agent and as a fluxingagent, and smelting the coked aggregate.

4. The process Which comprises coking a mixture ofapproxiruately 100 parts by 130 weight of ore to 40 parts by weight of limestone to 80 parts by weight of bituminous coal, and without substantial conversion or reduction of the limestone, whereby the limestone may serve as a gas-activating'agent and a fluxing agent, and smelting the resultant aggregate.

5. Theprocess of reducing ore which comprises smelting a coked mixture of ore and carbonaceous material with limestone, the limestone being present in proportion to constitutea fluxing agent and a gas-activating agent. i

6. The process of reducing ore which co'mprises treating in a blast furnace a coked mixture of iron ore, carbonaceous material and limestone in about the following proportions by weight: 100 parts ore, 60 parts coke, 40 parts limestone, whereby the limestone is capable of acting as a fluxing agent and a gas-activating agent.

1 7. The process of reducing ore which comprises treating in a blast furnace a coked the production ofgas comprising a coked mixture of iron ore and carbon with limestone, the limestone being present in proportion to constitute a fiuxing and a gas-activating agent,

10. Material for the reduction of ore and the production of gas comprising a coked mixture of iron ore, carbon and limestone in about the proportions by weight of 100 parts ore, 60 parts carbon and 40 parts limestone, whereby the limestone may serve both as a fluxing agent and a gas-activating agent.

In testimony whereof, I hereunto alfix my signature.

JAMES HENRY REID.

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