US1491960A - Apparatus and process for reducing and refining ores - Google Patents

Description

April 29 1924. 1,491,960

E. MILL APPARATUS AND PROCESS FOR REDUCING AND REFINING ORES Filed Sept. 28 1920 IIII/IIIIII l INVENTOR, 1? M1115 Q ATTORNEY Patented Apr. 29, 1924.

NITED; STATES PATENT OFFICE.

EIIL HILL, 0!- ANGELES, CALIFORNIA, ASSIGNOB OF ONE-HALF TO ALTHEBTON L.

GRAY; OF L08 ANGELm, CALIFORNIA.

APPARATUS AND FOR REDUCING AND BEFINING ORES.

7 Application flledSentember 28, 1820. Serial No. 418,852.

To all whom it may concern:

Be it known that I, EMIL MILL, a c1t1zen of the United States, residing at Los A11- geles, in the county of Los Angeles and State of California, have invented new and useful Imfprovements in A paratus and Processes or Reducing and fining Ores,

of which the following is a specificatlon.

. able to ores mined in Western States. 'It

has been found that European ores and ores found in Eastern States sometime require particular methods in refining and reducing same. The invention has for an obf'ect the turning of oxides of iron into metal ic iron. Another object is the production of an a paratus and process forproducing metal 1c llOIl in a more direct, inexpensive and quick manner than is now possible by existing known means. a y

In racticing theinvention I provide a suitab e hopper or container into which iron ore, broken into small pieces, may be placed. Associated with the lower portion of said hopper are valve means spacedly dis osed within a duct, which duct joins, wit the chamber of a retort. c The iron ore is rmitted' to pass through the duct and into the chamber and thence through pipes-joining the lower 'wall of said retort with a further retort spaced from said upiper retort. Surrounding both the upper an lowercretort members is a wall of fire clay orother heat resisting means, and playin through apertures within the fire c ay we 1 or heat resisting wall are nozzles through which gas may be assed. Said gas when'ignited allows a ame to play on the outer surface of the lower retort and by conduction allows the heat to pass within the retort. Within the lower retort are spacedly arranged a plurality of electrodes. Said electrodes depend through apertures in the upper wall of said lower retort. The electrodes are preferably made of graphite and are provided with a longitudinal bore through.

which bore a carbonaceous gas is assed; The electrodes are likewise provide with electrical contacts and electrical circuit paths connect with said contacts. The bottom wall of the lower retort is provided bonaceous gas is bein with depending pipes having spaced valves therein, the stretch between the upper valve and lower valve being provided with means for feeding a-carbonaceous as therein. The division etfected between t eupper retort and lower retort by pipes joining the same in spaced relation to each other is necessary in order that an operator may remove any ofthe lower retort may also heat'the upper retort, conducting pipes extend between the er baflie plate and lower bafile plate;

'l us method of heating the upper retort allows for a gradually increasing heat, as any ore contained within the upper retort passes downwardly through the pipes above mentioned into the lower retort. The articular arrangement of the electrodes al ows for a heating within the lower retort, and

when a low potential current is effected be-' tween theelectrodes an arc appears, which arc is not sufiicient to in any wayfuse the me within said retort. Inasmuch as a carheated electrodes, I be ieve that the gas will tend to absorb more carbon and thus when discharged from the openin in saidelec trodes, the as will be in a ighly nascent state, readi combining with any oxygen confined wit in the ore and formin a carbon dioxide gas, and leaving metal 1c iron,

which is coated with carbon deposit throughout the voids of said iron.

Ordinarily inreducing iron ore, a blast of air is forced throu h the ore when the ore is heated, but in t is invention all air is excluded from the retorts. I believe that it is a commonly known fact that ore of all forms, and particularly iron ore, has a great deal of air confined within the same, and by heating the ore as has been described, the ore W111 crack, similar to the method of cracking" oil to produce gasoline. This cracking of course allows the im risoned oxygen and other ses confined within the ore to escape an immediately upon its escape the car naceous gas which is introduced within the retort may combine with passed through the the same forming another gas of some complex chemical composition and allow carbon to be deposited over the iron and in all interstices, pores and voids of the iron.

It is a so known that any iron when heated to a high temperature and exposed to the atmosphere before allowing it to cool, the same may immediately oxidize. However, by the method just described theiron may be removed from the retort, and due to the fact that it is covered throughout with carbon the metallic iron will not rust or oxidize. Obviously the metallic iron removed from said retort will not require further carbon in the making of the same into steel. In fact, the ore removed may be again heated to the desired temperatures and the carbon present will be sufiicient for steels of various forms. It will immediately be seen that this eliminates two operations ordinarily incident to the making of steel.

The invention has for further objects to provide a process as well as apparatus of the character above mentioned which will be relatively simple and inexpensive in carr'y ing on or practicing or furtherance, taken in conjunction with efiiciency and expediency and general adaptability.

The invention consists in the novel and useful means and process hereinafter disclosed, and finally pointed out in claims.

It will be understood that many variations in detail may be made in departure from the specific definition of the rocess as well as the apparatus about to disclosed.

In the drawing:

Figure 1 is a cross sectional view of a furnace which may be utilized in reducing and refining ores;

Figure 2 is a fragmentary cross sectional view of an electrode used in practicing the invention;

Figure 3 is a fragmentary perspective view of a valve used in connection with the invention;

Figure 4 is a fragmentary cross sectional view of a trap door used in the ducts; and

Figure 5 is a fragmentary view of a filtering device used in practicin the invention.

Corresponding parts in al the figures are designated by the same reference characters.

Referring with particularity to the drawing, A designates the completed furnace of which 1 is a hopper into which the broken pieces of ore such as iron oxide a may be introduced. The hopper has its bottom wall member I) slanting downwardly, so that the ore a within the hopper 1 will tend to move toward one point as 0. At said point there is an opening provided with a duct 3. The duct 3 has adjacent the opening 0 a sliding door valve- 2 which is illustrated in Figure 3, in

which figure it will be observed that the surface thereof and which boxing 2 is a part of the valve 2. Passing through said oxing is a hand screw 2" provided with threads, the lower stretch of which as 2 has connected therewith a circular door 2". The duct 3 is slotted as at 3 a sufficient width so as to permit the door 2 to be drawn through the same upwardly or downwardly dependent upon rotation of the means 2". This arrangement permits closing the duct 3 at its upper end and prevents any of the ore (1. within the hopper 1 from entering said duct. The duct 3 asses through a plate (1 into the interior 0 a retort 5. Just above said assage into the retort 5 is located a furtlier valve 4 which in all particulars is similar to the valve 2 just described. It will thus be seen that in order to properly introduce any ore a from the hopper 1 into the retort 5 and the chamber 5 thereof, it will be necessary first to raise the valve 2 allowing the ore to pass into the space 3' between the valves 2 and 4, at whichtime the valve 2 has its gate 2 screwed downwardl so as to close the opening in the duct 3, an then the valve 4 is so screwed that the gate of the same will be raised and the contents within the space 3" allowed to ass into the chamber 5 of the retort 5. e purpose of all this is to prevent the atmosphere from directly entering the retort 5. It will be noticed upon reference to the drawing that the retort 5 is provided with openin s5" through its lower wall 5, and into said 0 enings 5" are passed and confined pipes 6. he pipes 6 are of extended length and communicate with a lower retort 7 through openings 7 in the upper wall 7 of said retort 7. Pipes 6 likewise pass through what may be termed bafile plates e and f. The upper plate 6 joins the bottom plate of theretort 5 on the exterior thereof as at 5 and the bottom late f joins with the top wall on the exterior t ereof as at 7 of the retort 7. These plates 6 and f are preferably circular in formation, although I do not wish to be restricted to this particular contour. The lower retort wall 7 of the retort 7 has dependent through holes 7 therein pipes 9.

The pipes 9 are similar to the duct 3 previously described, and said pipes 9 are provided with upper and lower valves 8 and 11 arranged in spaced relation each to the other. The valve 8 is arranged a short distance below the opening 7 and the valve 11 is arranged adjacent an end 9 of the pi s. The space confined-intermediate the valifes 8 and 11 as 9" has communicating therewith a pipe 10. Said pipe 10 normally conducts a carbonaceous gas to the space 9 of the pipes 9. The lower end of each of the pipes 9 is provided with trap doors 12. Said tra doors are illustrated in Fi re 4, in whic it will be noticed that the 001' 12 is hinged duct 3Thas a boxing 2 formed on the outer to the pipe 9 as at 12 by means of a strap 1 i which hook projection engages with a leaf thereof an spring 12' attached at one end as 12' to the 1pc 9. Thus the trap door may beopened y releasing the spring 12? from the projec'tion 12, or the "tra door 12 vmay be readily snapped into position. Surrounding the outer periphery of. the plates e and f as well as the retorts 5 and 7 and the pipe6, is a circular wall 13. Said wall 13 extends upwardly and joins with the late (1 -as shown at g. A lower portion said wall 13, as 13 does notcompletely endose the retort 7 but allows a. lower stretch of the same as 7 to be exposed. The retorts and 7 are each in spaced relation to, the inner wall surface of the wall 13.v The wall 13 is preferably made of fire clay rovided with a tile lining, although the wal may be made of any heat resistant material. Extending between the plates e' and f and communicating with the s ace between the wall 13 and i the outer sur ace of each of the retorts 5 and 7, are pipes 14. Passing through perforations 15 located as at 16 in the wall 13 are nozzles 17 through which is conducted by means of pipes 18, a gas of some form suitable, when ignited to heat the outer wall surface of the retort 7. Obviousl the gas flowing within the space confine between the retort 7 and the wall 13 will tend, when ignited, to present a solid flame completely around the retort 7. Of course oxygen for roper combustion will be drawn upwardly into thespace for thereason that the wall 13 terminates so as to permit air to be drawn u wardly into said space, as shown at 19.

e heated air and ases will surround the chamber 5 and heat t e same. From thence the heated gases are allowed to pass upwardly throu h a stack 20 confined within a hole 21 in the wall at as at 22. A damper 23 regulates the out-ward flowof the heated gases to -,the atmosphere. It will seen that the retort 5 is really pre-heated and does not have a flame playing against the same. i

Depending within the lower retort 7 through a ertures in the upper wall 7" through apertures 'in the wall 7 are electrodes 24. Said electrodes 24 are arranged in a spaced relation each to the other as shown in the drawin Referrin to' Figure 2 it W1 1 be seen that the electro cs 24 are tubular information or provided with a lon itudinal bore 25 concentric within said e ectrodes 24. The electrodes are preferably made of graphite, and

surrounding an upper stretch of said electrodes as zit-26 is a cop n band 27 provided with ears 28 for c amping the band to the electrodes 24. Through said ears a screw 29 is passed for firmly securing the band 27 to the electrodes 24. A short pipe 30 communicates with the bore 25 as'at 31. Said pipe is likewise attached by suitable means as 32 to a non-electrical conducting tube or ipe 33. Referring to igure-l the non-con ucting tube or pipe 33 passes upwardly and is capped or closed as at 34. Likewise it is joined to the wall e as at 34 so that the electrodes 24 may be retained in position. A pipe 36 passes through perforations in the walls 13 and 37 and connects with an enclosed box-like structure 45. Said pi e 36 likewise connects with each of the tuhes 33 as "at 36. The boxdike structure is suitably supported by means of a bracket 46. Said bracket 46 is located exteriorly of the wall 37-and is held to same by means of rivets. A further pipe 47 communicates with the interior of' the box 45 as at 48. Within'the box 45 are small carbon granules 49. Where the ipes 36 and 47 enter the box is placed a brous cloth 50. The pipe 47 connectswith the source of supply for a carbonaceous gas. Beneath the bracket 46 is a heatins. means 51 provided with a jet. A pipe 52 connects said jet with a source of gas supply. It is the intention to light the jet 51 and heat-the box 45. It will thus be seen thatthe carbonaceous gas first passes throu h the'pipe 47, through the cloth 50, then t rough the carbon granules 49 within the box 45, then through a further cloth, and then into the pipe 36 and down through the bore in the electrodes 24 into the retorts 7.

Electrical conducting paths such as wires X are joined to each of the electrodes 24 at the ears 28 of the band 27. The electrical conducting wires X are connected with a source of electrical supply 35 of low potential. Two parallel walls 37 arranged in spaced relation each to the other, normally support the wall (1, the wall 13. and the hopper 1. support the entire furnace, inasmuch as'the plate members e and are embedded within the wall 13. When t 1e furnace is in operation a gas such ascarbon dioxide is driven oif from the oreand said gas is allowed to pass through a pipe 38 communicating with the interior 5 of the retort 5. 'Sa-id pipe has at an upper end as at 39 an automatic pressure valve 40 which allows the burnt or waste gases to escape through the same and into the-pipe 41 passing withinthe stack 20 as at 42. The automatic pressure valve 40 permits any: gas to escape from the retorts 5 and 7, but does not permit any air passing back into the'same.

The walls 37 are supported as at 43 upon a suitable foundation 44.

The operation is as follows:

Thus the parallel walls 37 tend to The ore is first introduced in small chunks is then closed and the valve 4 opened and the ore passed into the chamber 5% of the retort 5. From thence the ore passes through the pipe 6 into the retort 7 and then the same may be passed through the pipe 9 by opening the valves 8 and 11.

First the gas used for heating the exterior of the retort 7 is ignited at the nozzle 17 and as the flame plays around the retort 7 the retort is heated, and the heated gases allowed to pass upwardly through the pipes 14 and heat the retort 5. Ore is introduced within the retorts 5 and 7 so as to completely fill the same, and as it is necessary that each piece of ore go through the same operation it is essential that the ore confined within the retort 7, to begin with, be drawn off through the pipes 9 and again placed in the hopper 1. Obviouslycthe ore already within the retort 5 will not be again placed in the hopper 1. As the flame plays around'the retort 7 electricity is passed through the electrodes 24. and while so-passing an arc will be formed between the electrodes. This are is of low potential and not sutiicient to fuse any ore within the retort 7. Obviously the arc will tend tolieat the interior of the retort 7- and while the electrodes are so heating the ore in combination with the heat being absorbed through the wall of the retort, a carbonaceous gas is passed through the bore of the electrodes. The temperature within the retort 7 is preferably maintained at 1100 degrees and this amount of heat I believe tends to cause the electrodes 24,

which as has heen stated, are .formed of graphite, to be in a state-of agitation; that is, the molecules of carbon making up the electrodes 24am in a vibratory state, and as the carbonaceous gas passing through the same is heated by the electrodes the gas I 'believe tends to absorb more carbon and thus becomes satu'rated. with carbon and in a highly unstable'and nascent state.

It will be seen that as the ore asses'from the chamber 5* of the retort 5 ow'nwardly into the chamber portion of the retort 7, that the ore will ggadually become heated more and more, andwhen in the" retort .7 thehept issufiicient to crack the ore.- It wilt now be obvious why a double system-of; valves as 2, 4, 8 and 11- is employed. They are employed in order to keep out the atmosphere from the retorts 5 and 7. I am of the opinion that all ores contain a certain numberof gases and when the ore cracksthe gases are released and which gases immediately combine, I believe, with the carbonaceous gas and in so combining carbon is deposited in the voids of the ore, effectively sealing the ore against a re-introduction or re-oxidization of the ore. Obviously when the furnace is in o ration the valve 2 is first lifted, the ore al owed to pass in the space 3 of the duct 3, the valve 2 closed, and the valve 4 again in case the same has not ore.v is practically fact, by using the h ter a more perfect product ofiron is produced.

been reduced and refined may not oxidize en properly covered with carbon throughout its voids. further carbonaceous gas is introduced into the space 9 through the pipes 10. Upon opening the valve 11 the ore may be permitted to drop downwardly and into the open when the trap door 12 is released.

Obviously any impurities within the iron ore would be burnt by the heat within the retort 7 and the burnt gas allowed to escape upwardly through the pipe 38 and then into the stack 20. g

It will be noted that the wall 13 is cut out between the plates 6 and In actual practice of the invention a plurality of furnaces similar to that shown in Figure 1 is included between the parallel wall members 37. Inorder that an operator may successfully replace worn-out electrodes 24 it is essential that the operator be permitted to pass within the space confined between the plates 6 and f to further similar spaces in duplicate furnaces.

It has been found that little slag is formed when a filter means such as the box 45 containin carbon granules 50 therein is employe The inventor is not sure as to the exact chemical re-action occurring within the retorts 7 and 5. However, when the carbonaceous gas is passed, throu h what is termed the filter, thence throug the electrodes 24 and then into the retorts 7 and 5, thegas in some manner is more active, and any silicon or sulphur within the iron is immediately burned out and the resultant ure metallic iron. In

' It is manifest that man variations and changes may be made wit respect to the disclosure of the foregoing furnace in connection with the particular method of refining ores such as iron ores, just described,

within a fair spirit of interpretation of the invention. I

Having thus disclosed my invention, I claim and desire to secure by Letters Patent: i

1. The. herein disclosed method of reducin and refining iron ore within the workho ding retort of a furnace, which consists inintroducing heat exteriorly jand interiorly of the retort so as to heat the ore and crack same; passing a carbonaceous as within the retort and preventing access 0 other oxygen than that already present within the retort and ore.

2. The herein disclosedmethod of reducin and refining iron ore within a workho ding retort of a furnace, which consists in introducing heat exteriorly and interiorly of the retort so as to heat the ore and crack the same; passing a super-heated carbonaceous gas within the retort and preventing the access of other oxygen than that already resent within the retort and ore, thus alowing the carbonaceous gas to combine with the oxygen resent and at the same time to fill all the interstices and voids of the ore with a deposit of arbon, thereby preventing re-oxidization of idiaore,

3. The art of reducingand refiningores, which consists in placing ore in a retort, heating the ore by application of heat both exteriorly and interiorly of the retort, injecting a carbonaceous as into the retort, and preventing access 0 other oxygen than that in the ore during the process.

4. The art of reducing and refining iron ore, which consists in placing the ore in a retort, heating certain portions of the retort both exteriorly and interiorly so as to subject the ore from a known minimum to maximum heat suflicient to crack the ore, preventing the access of oxygen within the retort and introducing a carbonaceous gas within the retort.

5. The art of reducin and refining iron ore, which consists in p acing the ore in a retort, heatin certain portions of the retort both exteriorfy and interiorly so as to subject the ore from a known minimum to maximum heat suflicient to crack the ore, preventing the access of oxygen within the re tort and introducing a carbonaceous gas within the retort which has first been allowed to flow through heated carbon.

6. A furnace forreducing and refining ores, comprising an upper and a lower retort spaced from each other; ipes communicatin with the chambers 0 said retorts, means for directly heating the lower retort and indirectly heating the upper retort so that there is a progressively varying heat upwardsin the, chambered portion of the lower and upper. retorts; means for introducing a carbonaceous gas into the upper retort, and means forpassin said gas in a superheated condition into t e lower retort chamber.

' 7. A furnace, comprising upper and lower retorts in spaced relation to each other,

intercommunicating means joining the chambers of said retorts, an outer refractory wall spaced from the retort walls, said lower retort wall and refractory wall forming between them a continuous combustion space, means for supporting combustion in said combustion space, whereby the lower retort wall is heated; and means for supplying a carbonaceous gas to the space confined by said upper and lower retort walls.

8. A furnace, comprising upper and lower retorts in spaced relation to each other, intercommunicating means joining the chambers of said retorts, an outer refractory wall spaced from the retort walls, said lower retort wall'and refractory wall forming between them a continuous'combustion space, means for supporting combustion in said combustion space, whereby the lower retort wall is heated, means for conducting the heated gases of combustion to the space confined by the upper retort wall and refractory wall so as to heat-the upper retort wall,

and means for supplying a carbonaceous gas, etc.

9. A furnace, comprising an outer wall of refractory material, an inner retort wall spaced. therefrom, said walls forming between them a combustion space; means for supporting combustion in said combustion space; means within said retort for heating said retort; and means for supplying a carbonaceousgas to the space confined by said retort wall.

10. A furnace, including upper and lower retorts in spaced relation to each other; an outer refractory wall spaced from the retort walls, said lower retort wall and refractory wall forming between them a continuous combustion space; a plate joined with the upper wall of the lower retort and embedded in the refractory wall dividing the lower retort from the upper retort; means for supporting combustion in the combustion space, and means for supplyinga carbonaceousgas to the space confined by said upper and lower. retort walls; there being intercommunicating means joining the chambers of said retorts.

11. A furnace, including an outer wall of refractory material; plate members arranged in spaced relation embedded in said wal and dividing same into compartments; a retort interposed between two of. said plate members with the walls of said retort spaced from said outer wall, a lower retort dependent from another of said plate members, said last named retort being in spaced relation to the outer wall; interco nmunicating means joining the chambers of said retorts, and means for heating said retorts.

12. A furnace comprising an outer wall of refractory material, an u p'er and a'lower retort confined within said outer wall and in spaced relation thereto, inter-communicating means joining the chambers of said with said last named means for preventin access of any air while passing said worfi to said retort.

13. A furnace comprising an upper and lower retort, intercommunicating means joining the chambers of said retorts; a hopper located above said upper retort and means joining said hopper and chamber of said upper retort whereby any work within said hopper may be passed into said upper retort; said means joining the hopper an upper retort being provided with means for preventing the access of air from the outside into the sand retort; means likewise being provided for introducing a carbonaceous gas within the chambered portions of said retorts.

14.- A furnace comprising an upper and lower retort, intercommunicating means joining the chambers of said retorts; a hopper located above said upper retort and means joining said hopper and chamber of said upper retort whereby any work within said hopper may be passed into said upper retort; said means joining the hopper and upper retort being provided with means for preventing the access of air from the outside into the said retort; means likewise being provided for introducing a carbonaceous gas within the chambered portions of said retorts; means likewise being provided dependent from a bottom wall of said lower retort for removing any work contained within said retort and means associated with said last named means for preventing the ingress of any air while removing any work from the retort.

15. A furnace, comprising a work-holding retort, means within said retort for heating the same, means for introducing a carbonaceous gas within said retort, and means for filtering said gas before its introduction within the retort.

16. A furnace, comprising a work-holding "retort, means within said retort for heating the same, means for introducing a carbonaceous gas within said retort, and means for filtering said gas before its introduction within the retort; said means for filtering said gas comprising a container filled with carbon granules, around which granules the gas first passes before its introduction into the retort.

17. A furnace, comprising a work-holding retort, means within said retort for heating the same, means for introducing a carbonaceous gas within said retort, and means for filtering said gas before its introduction within the retort; said means for filtering .said gas com rising a container filled with carbon granu es, around which ranules the EMIL MILL. Witnesses i Mimnm Luca, J, CALVIN Brown.

furnace, comprising a work-holding

Images