US1690820A - Reduction of metals from ores - Google Patents

Description

Nov. -6, 1928; 1,690,820

J. w. HORNSEY BEDUCT ION OF'METAI JS FROM ORES Filed Nov 25, 1925 2 Sheets-Shee't MMMMMMMMM 4 l Th mmmm 1 Emma f W 7. WWW

ATTORNEYS Patented Nov, 6, 1 928.

UNITED STATES JOHN WILLIA HORNSEY, or NORTON BY SHEFFIELD, ENGLAN D, ASSIGNOR 'I 'O GRANITE LAB IIQON COMPANY, A CORPORATION OF MICHIGAN,

REDUCTION or METALS .FBOM onns.

Applicationlled November as, 1925. Serial No. 71,442.

This invention relates to the-reduction of metal from ores and it is particularly useful for the reduction of iron ore in connection with which it will be described.

One of the primary objects of my invention is to simply and effectively reduce ores without going thru the molten state, that is to say to solidly reduce the metal and to lessen the cost of producing the same. in More particularly my invention consists in the special features of construction and the general arrangement and combination of parts hereinafter to be described,

In general, my invention contemplates the provision of means'whereby the process of solid reduction may be carried out.

How the foregoing, together with such other ob'ects as may hereinafter appear, or are inci ent to my invention, are realized,

is illustrated in theaccoifipanying drawings inrpreferred form, .wherein ig. 1 is a'diagrammatic side elevation of "the apparatus I employ in carrying out my invention. j

Fig. 2 is a section ofF1g.1. F

Fig. 3 is a section taken on the line 3-3 of Fig. 1-, and ig. 4 is a vertical section thru a portion of the apparatus illustrating details of my invention.

Referring now to Fig. 1, I take suitable state of sub-division say', for exam ple, crushed so as to pass thru a 4-inch mesh screen, and deliver it from the hopper 7 into a preheating cylinder 8. The material is fed from the hopper into the heating cylinder by means of the screw conveyor 9 and the pipe 10, the screw conveyor preferably terminating short of the inner end of the'pipe 10 so that the ore piles p beyond the end of the screw and is pus ed in the form of a plug which excludes air from entering thru the feeder. mechanism into the cylinder 8. The feeder pipe projects thru a stationary chamber11 which has a seal ,12 to be more particularly described hereinafter, whereby a substantially gas tight connection is had between taken on the line 2-2 the revolving cylinder 8 and the stationary 5 .chamber 11. Leading from the chamber 11 is a damper controlled stack 13 for carrying ofi' the said gases.

The material in passing thru the cylinder 8 is heated substantially to the temperature of reduction, the heat being preferably supthe ore in a plied by the' hot gases leaving the succeeding cyl nder 14,.supplemented by the introduction' of such additional fuel as may be required thru the burner 15 which "passes thru the stationary casing 16 at the right hand end of the 'cylinders8 and 14. The cylinder 8 has a seal 12, as above, aflt'ordinga substantially; gastight connection as between the cylinder and the casing 16. Thus no air can enter into the cylinder 8 except such as may be deliberately supplied under control thru the pipe 17 and the burner 15 passing thruthe 'casing 16. Air required for burning the fuel admitted tothe cylinder 8 is supplied thru .this pipe 17 and the burner 15, and I find it 7" desirable to maintain a reducing atmosphere 7 at the discharge end ofthe cylinder 8. and a slightly oxidizing atmosphere at the feed end. The cylinder 8 is revolved by any suitable driving mechanism such asthatindicated and it is to be noted that the inclination of this cylinder, as well as all other cylinders employed in my apparatus, is very slight in order that the grosser particles of the ore shall not move too rapidly in advance of the fine particles, the object being to cause the gross and fine particles to, move as nearly as possible together. This, I have found, materially increases the capacity and as a desirable degree of inclination I mention l-inch to four feet. 1

The heated material discharging out of the cylinder 8 into the casing 16 falls by avity thru the casing 16 and into the right and I end of the cylinder 14, which cylinder has a seal 12 in the casing 16 as'above. The ma-.

' terial as it falls into the cylinder 14 meetswith reducing agent introduced thru the pipe 18, such reducing agent being preferably granulated coal. The advantages of intro-' ducing the reducing fuel at this point will be hereinafter pointed out. Reduction nowv takes place and the material gradually moves toward the lower end of the cylinder 14 from. which it 'iseventually discharged into the 10K casing 19 constructed substantially the same as the casing 16, there being a seal 12 between the cylinder 14 and the casing 19. As the reaction of reduction with coal as the reducing agent is endothermic, there is a $1 tendency for the temperature to become-too low and, therefore, I introduce fuel, such as pulverized .coal, thru the "casing 19 into the cylinder 14 by means of the burner 20. This burner is preferably constructed as to sub I an annular space 23 thru which the coal and carrying air must pass. The coal and carry air is thus caused 'to assume-a cyllndrical' form, the air admitted thru the nozzle filling the' center of the cylinder of coal and air. Immediately beyond the end ofthe nozzle 22 I provide a Venturi like portion24. I prefer a pressure of about 40-pounds per square inch in the nozzle 22 and about a 2-ounce pressure in the burner pipe 21. By virtue of these pressures the controlled admission of air and the arrangement shown. the coal very largely surrounds the central core of air and the flame may be causedto travel a substantial length and the airfor combustion to have an o portunity to combine with the combustible 25 e ements of the fuel before the gases so formed come into' contact with the material being treated also, the air itself cannot come into detrimental contact with the material being reduced which is indicated at 25 in Fig. 2.

It will also be seen on inspection of this figure that the burner 20 is located well toward t e .wall of-the cylinder, that is to. say, re-

l moved from the material within the cylinder. Thus,-as is the case with cylinder 8, air is I excluded from the cylinder 14 with the exceptionof such air as is retiuired for burning the fuel for heating the cy' is admitted under contro from as casing19 into the cooling cylinder 26, there being a seal 12 between such cylinder and the casing 19. The; cylinder 26 is sub-- jected to a cooling means such as water dis-' dharge from-the ipe 27, the length of the cylinder being sac that the material is cooled below the point atwhich any. ap reciable oxidation can occur before itjis discharged to the atmo here. The lower end .of the cylinder 26 'scharges into the 0 cas 28, there being'a seal 12 between the I cylin' er and the casing. The discharge end of the cylinder 26 is perforatedor foraminous, .the siZe'of the holes 29 being such as to only permit the material being treated to pass llI-therethru.-' This materialdischarg es on to the plate or chute 30,thelowe1;.end of which is curved to provide a trough, in which works a conveyor screw 31'. This conveyor screw 31 terminates short of the end of the discharge orms a Jplu "for such pipe, actin as. a' excluding st ir. whi h would oth erwise be drawn into the cylinder 26 and thence into theother cylinders. I Y. J If for any reason bricks iorming' the phragm 39 to the shoe 38, studs 44 being em I ployed for this purpose. By this arrangebeing sub'ect to the pressure of the sp der and this air is provided between the shoe 38 and t The material leaving the cylinder 14 falls a slide one way or another on the fla g timatelyrea y be ap recia stood that the 'aphrstgm and connected pa ts 1 ,reducing pipe 32 o; the casing-28 so that the'material r of being of the cylinders 8 and 14 should become dis-' lodged an work down thru the cylinder 26, they can 11 t discharge onto the plate 30 but pass beyond and fall on to the plate 33 for subsequent removal thru the door 34. Thus the conveyor screw31 is protected.

The materialdischarged'from he pipe 32 consists of the metal and the ga gue. The metal may be separated in any desired way, as for example, b magnetic separation as diagrammatically indicated at 35 in Flg. 1.

Referring now to Fig. 4, this is a vertical section thru the casing 16 and illustrates the construction of the seal 12.v Secured to the cylinder '14 is a ring 36, rivets 37 or other suitable fastening means bein employed. This ring, therefore, revolves w1th the cylmder. Concentric with the ring. 36, but spaced away therefrom, is a wearing ring or shoe 38 and connecting these two rm is a corrus gated metallic diaphragm 39, this diaphragm being held to the ring 36 by means of a r1ng 40 anda stud 41 with lock nut 42. A similar ring 43 secures the outer edge of the (ha-.-

ment there is a tight joint between the diaphragni and the ring 36 and between the diaphragm and the ring 38. The ring 38 bears upon the annular flange 45, forming a part of the casing 16. A plurality of yokes 46 hold the shoe .38 against the flange 45, these yokes 47 carrie by the stu s41. The pressure 0 the springs may be adjusted by the means indicated and I have found from practical ex perienee thata substantially air tiglhtfiioint 45. If the cylinder 14'shouldshift longitu I nally of its axis 'th respect to the casing 16,

the diaphrag'm SQ will merely flex, the shoe 38'bein firmly held against the flan 45 not wi 'n'din that it revolves wit the cylinder. If the ongtudinal axis of the cylinder should shift, 'eshoe 38 willm seal is-a very important part 0t my inventio'n and I have found it entirely reliable in o eration. The sim licity of the seal It is to be under-.

may be fastened to e' stationary chamber '16 and the'shoe38' made to contact with a ring I similarjto ring 45 attached to the cylinder. 1 Bevertingnow to thedesirability of introducing the reducing fuel atthe point where the material discha ,from the 16 into the cylinder 14, it will the is immediately brought into contact wi the material and is entrained withit,sotospeak,beco emheddedtherein and thoroughly mixed erewith instead a ted.. Redu actionistlm's f immediate initiated and e 'ectively continned at points thruout the materialso-jlao that not only the time of reduction but also the quantity of reducing material employed is reduced to a minimum. Since the ore is not melted and the temperatures employed are .this art. At the temperatures which exist and other conditions and the general environment, no iron cyanogen compounds can be formed or absorbed and hence the iron contains no ferrite dissolved nitrides, which are objectionable. In'any event the iron is rust resisting to a most remarkable degree and when it is used in the making of steel it produces a steel, the properties of which are far in excess of steel containing iron produced in the usual ways.

What I claim is 1. Apparatus for the solid reduction of ores including a cylinder, means for rotating the cylinder, a stationary casing into which an end of the cylinder projects, an annular flexible diaphragm rotatable with the cylinder, an annular shoe rotatable with the diaphragm, a plate on the casing against which the shoe bears for sliding movement thereover, and means for holding the shoe in engagement with said plate.

2. Apparatus for the solid reduction of ores including a cylinder, a stationary casing into which an end of the cylinder projects, a ring on the cylinder and rotatable therewith,

a flexible diaphragm secured at its inner periphery against said ring, a shoe secured against the diaphragm at its outer periphery and'rotatable therewith, a plate on the casing on which the shoe slides, and means yieldingly pressing the shoe against said plate.

3. Apparatus for the solid reduction of ores including a rotating cylinder member, a casing member for an end thereof, and a seal thcrebetween including a flexible diaphragm carried by one member, and annular shoe carried by the other member and slidably engaging the first member.

In testimony whereof, I have hereunto signed my name.

' J ()HN W. HORNSEY.

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