US1365113A - Process of and apparatus for reducing and smelting ores - Google Patents

Description

.J. LUND. PROCESS OF AND APPARATUS FOR REDUCING AND SMEL'HNG ORES.

APPLICATION FILED JUNEZG. I916.

Patented Jan. 11, 1921.

4 SHEETSSHEET 1.

P. 0 ma N W L J" LUND.

PROCESS OF AND APPARATUS FOR REDUCING AND SMELTING ORES. APPLICATION FILED JUNE 26, 1916.

1 35 1 13 Patented Jan. 11, 1921.

4 SHEETS-SHEET 3- J. LUND. PROCESS OF AND APPARATUS FOR REDUCING AND SMELTING ORES.

" APPLICATION FILED JUNE 26. ms.

1-;365,113. Patented Jan. 11,1921.

4 SHEETS-SHEET 4.

.J. LII/VD cisco, in the county of'San UNITED STATES PATENT OFFICE.

JOEL mum, on san raaucisco, camroimm.

PROCESS AND APPARATUS FOR REDUCING AND SMELTING ORFS.

To all whom it ma y concern:

Be "it known that I, JOEL LUND a citizen of the United States, residin at San F ranrancisco and State of California, have invented new and useful Improvements in Processes of and Apparatus for Reducing and Smelting Ores,

of which the following is a specification.

The object of the present invention is to provide a process of, and apparatus for, re-

ducing and smelting ores,by means of which ores can be reduced and smelted continuously by the use of fluid fuel or finely divided solid fuel, and without the necessity of forming the ores into briquets. A further objectis to provide an apparatus for this purpose which will enable me to introduce fuels and gases under pressure for the purpose of accomplishing the above result and by which the gases so mtroduced may be maintained in a reducing condition.

In the accompanying drawing, Figure 1 is a vertical section on the line 1-1 of Fig. 2; Fig. 2 is a verticalsection on the line 2-2 of Fig. 1; Fi 3 is a' broken side view of the apparatus; I ig. 4 is a broken end view thereof; Fig. 5 is a horizontalsection thereof on the line 5-5 of Fig. 2; Fig. 6 is a horizontal section on the line 6-6 of Fi 1; F i 7 is a vertical section on the line --7 of ig. 2; Fig. 8 is an enlarged sectional view of a detail; Fig. 9 is a broken perspective view of a detail.

Referrin to the drawing, 1 indicates a conveyer o ordinary construction, by means of which ore is conveyed to a chamber in the upper portion of an ore stack 3 divlded into compartments 2, 4, 6, 7 by a screen 8 and movable slides 9, 11. Said ore stack container is preferably made of sheet metal of sufiicient stren h to stand the pressure of the material wlthin the same, as well as the gaseous pressure comin from a tubular reduction chamber '12.- T e sheet metal screen 8 is hinged in the top of the ore stack and is pressed forwardly against the side through.

which the conveyer' enters by a spring 13.

The object of said screen is to preventa too.

rapid escape of such compressedgases as may have collected in the chamber 6, ashere-Q inafter explained, when the shdell 1s open to permit material to enter the compartment 7 Said gases are permitted'to escape gradually from the compartment 4 by the arrangement shown, the edges of the screen 8 not Specification of Letters Patent. P te ted Jan, 11, 1921; Application filed June 26, 1916. Serial No. 105,859.

- fitting closely against the sides of the stack 3,

but against partitions 14, between which partitions and the sides of the stack are artitions 16, shown in dotted lines'in Fig. 1, forming chambers 17. .As said gases escape into the chambers 17 (Fig. 1) it will be seen that whatever material may have been'carried with them will again descend into compartment 6 when the slide 9 is closed.

Said slides are operated to close or open said compartment by wheels 18, (see F i 1 and 3), these being secured to nuts 19 w ich rotate in brackets 21 and engage screws 22, which are secured to the slides 9, 11, so that, asthe wheels 18 are rotated by pulling on cables or chains 23 around the. wheels, and the nuts-19 are rotated with the wheels, the

screws 22 move longitudinally therethrou gh and the slides 9, 11 are opened or closed. relieve the slides 9 and 11 of excessive friction and pressure, the openings closed by said slides are reduced in size by the inwardly converging projections 24 from'the sides of the ore chamber, between which said stationary cap 32, which is connected with a water-tight joint to a movable collar 33 secured to the tube 30, the pipe 29 extending within the screw to a short dlstance from its lower end, and the pi e 31 conducting ofl the-water within the tu 30. On the upper end of the feed screw is secured a worm wheel 34, which is rotated b means of a worm 36 on a shaft 37 (see carries a differential speed mechanism 38 driven b a motor (not shown). In a supporting racket 39 is formed a bearin in which the feed screw is fitted, and a ho low collar 42 is filled with some resilient'refractor material 43, such as mineral wool, and

ig. 2 which is tted over the stem of the feed screw inside of the bearing to rotect the parts. f

" the entrance of grit. he bracket 39 is made iiof (ill

. its.

in sections, removable on opposite sides of the bearing, to facilitate the positioning and removal of the screw when necessary.

A rotary device 150, turned by a weight 160 when the chamber 8 is empty of ore, indicates whether or not the chamber is empty.

Said feed screw feeds the ore into the reducing chamber or tube 12, which is constructed of refractory material and inclose l by a metallic casing 46 of suflicient strength to withstand the gaseous pressure generated within the tube, and made in sections held together by bolts 17, so as to facilitate its construction and repair and the structure rests on a heavy metallic plate 48, the whole being supported by screws 49. Said chamber is cooled by a cooling medium injected through pipes 51 and circulates in an annular space around said tube and contained between the inner metallic casing 46 hnd an outer metallic casing 52.

Also to facilitate repairs the chamber 12 is made removable, and, when a continuous operation is desirable, a duplicate chamber is provided, so that one is always in working order while the other is undergoing repairs. \Vhen it is desired to remove said chamber, a carriage 53, running on a track 51', and rotatable on a turn-table 56, is run under the chamber 12. The carriage 53 consists simply of flanged wheels connected in pairs by stout axles 57, across which are loosely laid metallic cross bars 58, which are notched, as shown at 59, to fit over the axle. To place the carriage under the chamber 12, as shown in Fig. 2*, one pair of wheels is rolled up to the side of said chamber, the cross bars 58 being under the bottom of the chamber, and then ends of the cross bars are lifted up and the acent notched parts are fitted over the axle of said wheels. The straps and turnbuclrles 61, 62, 63, which hold said chamber against the slag hopper 6a and smelting chamber 66, hereinafter described, and against tie ore stack 3 are loosened and the blast and fuel pipes 67, 68, hereinafter described, are raised and swung out of the way on telescope oints 69, 71, thus permitting the chamber 12 to be rolled out of the way on the tract: 54:. The chamber 12 is then raised by means of the screws 49, so that the other ends of cross bars 58 may be similarly placed on the axle of the other wheels on the opposite side of the furnace. Said chamber 12 is then lowered and made to rest shown} In said chamber 73 is a coil of cast iron pipe 76 leading from an air compressor and communicating at the other end with the hot blast pipe 67. Said blast pipe 67 is provided with a valve 77, by which the quantity of air passing through said pipe may be regulated or entirely shut off. A branch pipe 79, regulated or shut off by a valve 81, leads from the blast pipe 67 to the ore compartment 7. The fuel supply pipe 68, when oil or gas is used, enters the blast pipe through a reducer 83, which 'may be of different sizes, interchangeably used, and varied according to the fuel used, whether gas or oil. The oil in the pipe 68 is heated by passing the supply pipe through a steamheated compartment. To the discharge end of said pipe 68.is connected an atomizer 84 c of any suitable construction which will break up or atoniize the oil as it enters the furnace. The amount of oil entering in a given time is regulated by the pressure on the source of supply and also by a valve 86.

The lower end of the reducing chamber 12 communicates through a port 87 with the smelting chamber 66, which is constructed of refractory material and is provided with a removable cover 88. In the wall of said chamber 66, next to the reduction chamber 12, is located a slide valve 89 made of refractory material, and moved vertically by a screw 91 screwed through the top of a standard 92. The object of this slidevalve is to regulate the pressure in the reducing chamber 12 regardless of the quantity of molten metal in the smelting chamber 66, as will hereinafter be more fully set forth. A spy hole 93 provided with mica windows is placed in a cover 88. j

The smelting chamber 66 communicates with a settling or collecting chamber 96 through two ports 97 and 98 in the adjacent walls of the smelting and collecting chambers respectively, and through a port 99 in a. gate 101. Said gate is constructed of refractory material set in a metallic frame 102 provided with tie bolts 103, and raised or lowered by means of a screw 104i screwed through a supporting frame 106, which rests upon the chambers 66 and 96. The ports 97 and 98 in the walls of the chambers 66 and 96 are of the same width as the pbrt 99 in thedam or gate 101 but sufiiciently high so as to provide a passage through said walls, even when the gate 101 is raisedto its highest position. Under the port 99 in the gate 101 is located a pipe 107 provided with perforations 108 communicating with the port 98, so that steam, gas or air may be forced into and through the molten matter as it flows through said port. .To prevent overheating of said pipe 107, a cooling medium is circulated through an adjacent pipe 109, cast in one piece with the pipe 107. Finely ground refractoryjmaterial is placed in recesses 111, so as to keep the joints tight be fill! tween the chambers 66 and 96 and the gate 101 at the points where the molten metal flows over from the chamber 66.

In the chamber '96 the metal separates from the slag and settles to the bottom. Said chamber is provided with a door 113 in which is located a mica-covered spy hole 114, throu h which the action in the interior may be observed. Gas and air or superheated steam are conducted by pipes 116, 117 connected with suitable sources of supply and may be blown on to the slag-covered metal below, for the purification of said slag, so that it may be returned to the furnace for fluxing and heating purposes. Waste gases escape by a pipe 110. v

The chamber 96 is placed on rollers 118 in order that it may have freedom to move somewhat as the parts are expanded through heat, and thus the gate 101 is prevented from being jammed in too tight between the two chambers should they expand. 112'are heavy tension springs fastened adjustably to chambers 66 and 96, and which hold said chambers together, pressing against the sides of the gate 101. The chamber 96 is also provided with metal and'slag outlets 119, 121 (see Fig. 3). 122 is a tap hole at the lowest point of chamber 66 and through which said chamber may be drained when desired.

By the slag outlet 119 the slag is discharged into a slag truck 123 (see Fig. 3)

' i at truck 123 is elevated by means of a cable which runs on a track 124 to a position between standards 126 and guide rails 127c0nnected at the top bya cross bar 129. The

131 attached to a bail 132, the ends of which are attached to the sides of the truck, said cable running over a pulley 133 and attached to a hoisting engine (not shown). The truck in its upward movement engages the spring-actuated catches 134 having hookshaped portions 136 which hold down a hinged cover 137 for a slag hopper 64. The engagement of said truck With said catches causes them to be spread apart and to draw the hooks 136 from said cover. As the truck moves upward, the hook member 128, extending from the rear end of the truck, engages the above-mentioned cross-bar 129, stopping the rear part of the truck in its upward movement, tipping the truck, and causing the truck 123 to open the cover 137. When the truck is sufficiently tlpped, the slag runs out into the hopper 64, and when the slag truck has descended the cover 137 again closes and. the spring catches 134 hook over and hold the same-closed. The slag hopper 64 is provided with a d1scl a1'ge'copduit 139 opening into the reductlon chan'l-g ber at substantially the same level as the opening thereinto of the ore feeder conduit. Said conduit 139 may be closed by agate 141 which is operated by a lever 142 supported by a standard 143 and connected to a rod altogether, as is done when the hopper is being filled with slag. The hopper 64 is lined with non-conducting refractory material and .is closed to the atmosphere except at such times when it is being filled with slag. Into said hopper lead valve-controlled branch pipes 149 and 151, from the fuel and blast main pipes respectively. The ore stack, slag hopper and the like are erected on the platform 148, preferably of steel girder and reinforced concrete construction, said platform and superstructure being supported on suitable standards 152, the whole being securely fastened together and braced. Around the platform extends a suitable hand .rail 153, and the tie rods 154, which hold the ore stack in position, are securely fastened, their upper ends to the ore stack and their lower ends to the platform, said rods being also provided with turn-buckles 156 for the proper adjustment of the rods.

The furnace being first heated up gradually in the usual way, a bath of molten metal and flux is supplied to the chamber 66, either by chargingthe material in molten condition into said chamber, or by first charging ore and fiux and carbon into the chamber 66 through the top, the cover 88 being removed while this is being done, and then melting down the ore and flux in the chamber 66 by the combustion of solid carbon, such as coke or charcoal. An air blast is supplied through the main 67 and passes down through the chamber 12, but the supply of oil or gaseous fuel may be-diminished or even shut off during the preparation of this bath by the combustion of solid carbon, as heat and reduction are produced thereby. The union of combustible materials under pressure, which takes place when their expansion is resisted, results in increased chemical action and heat, and, as this invention contemplates the reduction of ores under such conditions, the bath in question is established for the purpose of creating and maintaining a resistance to the flow of the gas through the chamber 12 and also within the bath itself, thereby increasing the pressure of said gas. as the gas has to pass through said bath on its way into the chamber 96. It is evident that this resistance or back pressure against said gaseous current, moving as stated, will, generally speaking, be in proportion to the depth of molten matter in the chamber 66. The quantity of molten matter which may remain continuously in the chamber 66 is determined by the adjustment ofthe gate 101, and as said gate may be moved up or down, it is seen that as some ores are more refractory than others,

and as fuel oil and gases vary in composition and heating value, the process of reduction, in order to become successful and economical, has to be considered, and the various mechanical adjustments have to be regulated, with these factors in view. Ores of copper, for instance, not requiring so high a temperature as iron ores to smelt, the resistance need not be so high; in other words, the gate 101 may be held'lower, and less depth of molten matter maintained in the chamber 66 in the former case than in the latter. It is also evident that, where the resistance to the gaseous current is great, as will be the case when the gate 101 is raised, or the gate 89 lowered, and the depth of the molten bath is increased, a greater amount of fuel and blast, and a greater initial pressure on the same, must be provided in order that said current shall be able to pass through said bath, there being necessarily a limit of pressure below which, if the gaseous current is sufliciently resisted in this direction, its heat would be conducted away through the walls of the furnace 'or escape back into the ore stack. What is aimed at is'to maintain the mass boiling in the chamher 66, and, as the action may be observed through spy holes 93 in the cover 88, the pressure on the blast and fuel may be regulated accordingly. The pro ortion of fuel to air in order to produce per ect combustion being known, or since said proportion in reference to any particular fuel may be determined experimentally before it is used in the furnace, the relative amounts of fuel and air and the pressure on the same, are determined correspondingly. The initial pres-. sure on an and fuel malns must, however,

in all cases, be sufficiently powerful to overcome the resistance of the bath in the chamher 66 through which the gases have to pass.

The action of the expanding gases in the tube or chamber 12 is somewhat similar to that of a solid piston moving against and through the molten bath in the chamber 66.

T here is this difference, however: Since the gas diffuses in all directions through the molten bath in the chamber 66, its action,

when it reaches the funnel-shaped entrance to said chamber, is not so violent or localized as if a solid piston were moving through the bath. Owing to the chamber 66 having a larger cross-sectional area than that of the chamber 12, the gases are allowed to difiuse I while yet in the metal, but, as it is the depth of the molten bath in the chamber 66 over and above the point where the gases enter saidv chamber, and not its horizontal area, that determines the resistance and heating value of said bath, these factors are kept in mind in the construction of the furnace. The cross-sectional areas of the chambers 12 and 66, as shown, are as 1 to 10 respectively, this being a convenient not wish to limit mysel to this proportion, seeing that the same depth of bath may be kept in a chamber proportionally larger than the one here shown. The gaseous pressure in the chamber 12 may also be increasedregardless of the depth of the molten'bath in the chamber 66, this being accomplished by lowering the gate 89. There must, however, always be a sufiicient amount of molten matter in the chamber 66 so that the gases must ass through the same in their progress rom the chamber 12 to the chamber 66. As the inner walls of the chamber 66 taper gradually, reducing the cross-sectional area of said chamber until itbecomes equal to that [of the chamber 12 at the junction of the two chambers, it will be seen that the gases diverge from the point of junction. In this manner will the whole of the molten bath in the chamber 66 be moved and acted upon by the hot expanding gases from the chamber 12 diffusing through the mass.

Having prepared the bath in the chambe 66, as stated, and of a depth suiiicient to close the port between the chambers 12 and 66' and to extend above said port about twelve inches, I open the valve to the fuel main so as to admit the proper mixture of gas or gasified oil and air under pressure into the chamber 12. The feedscrew 27 is now set in motion on slowest speed so as to force material from the ore compartment 7 into the chamber 12.

The slag hopper 64: having been filled with the same material as is prepared in the chamber 66, or, if preferred, with a molten flux prepared separately, this material is now also admitted to the chamber 12 by opening the gate 141. The speed of feed'in the ore into the chamber 12 is determine by the speed-of reduction, and this is ascer tained by noting the boiling in the chamber 12 and also by examining samples of the molten material as it flows into the chamber 96, The speed of the feed screw 27 is regulated by dlfi'erentialspe'ed mechanism 38 or equivalents. The amount or flow or flux is regulated by raising or lowering the gate 141 and is otherwise roportioned to the ore charged, but, as this ux is" used in a molten condition, it wil be seen that its heatpas well as its chemical composition, aids in the re duction of ore, and the only drawback, therefore, tothe use of a liberal allowance continuously is that the slag hopper 59 has to be replenished oftener. I

Should the material, when the process is fully established, be found to boil violently, reduce well, and run freely into the chamber 96, under slight initial ress ure on fuel and air, this indicates that may speedup the process by raising the gate 101, forcing in. the-ore faster, and admltting more blast and fuel under greater pressure. On the, other hand, should the material in the cham ber 66, fed in slowly, as before mentioned, not a pear to reduce well and flow into the chamber 96 freely, then this is an indication of a refractory ore requiring moreheat' and a" somewhat longer treatment for reduction.

In such case, the dam 101 is raised, so as to providafor adeeper bath and more resistance to the current, the fuel and blast supply being regulated to suit this condition, that is, to cause'a brisk boiling of the mass, but the charging of ore is not increased under these circumstances.

A small quantity of solid'carbon is added to the ore charged, all being in. pulverized form. Said carbon, being in finely divided state, is immediately heated to incandescence as it enters the reduction chamber 12, and,

in this condition, it unites with the oxygen of the steam formed through the combustion of the hydro-carbons supplied. The gases are thus kept in the necessary reducing condition throughout said chamber, and this condition is further enhanced as said gases are forced through the permanent molten bath. in the chamber 66. As both CO and CO may be neutral to molten iron provided the temperature of the above-mew tioned gasesand-the bath through which they pass is sufiiciently high, this high temperature is produced by the high gaseous pressure in the chamber 12 and the resistance to the gaseous current maintainedby the molten bath in the chamber 66. The

greater the initial pressure and resistance, as before mentioned, the greater will be the heat in the elements involved, and the less free carbon is necessary to maintain a reducing atmosphere toward the oxid in the chamhere 12 and 66, and the less carbon will there involved in the process are preferably kept in separate bins, placed so as todeliver into the moving conve'yer buckets through spouts provided with adjustable shutters, it is seen that the various ingredients ofthe charge, both as to fluxing and carbon content, may readily be changed .as occasion requires. The speed of delivery of said material into the ore stack may be regulated by any well known differential speed mechanism arranged on the axle of the drum which carries the belt on which the conveyer buckets are placed. Said speed may also be regu- As the materials same a reducing gas, said gas being supplied through the pipe 107 in the dam 101, said gas being forced through the small holes 108 into and through said molten matteilas this flows over into the chamber 96. ir and superheated steam are forced through pipes 116, 117 on to the accumulating slag and metal in'the chamber 96 and the object of this treatment is in the main to purify the slag so as to make it fitto return to the furnacefor fluxing purposes. Should it be necessary to further heat the slag in the hopper 64, this may be done by means of a lighted burner projecting into said hopper and supplied from the fuel and air mains 149 and 151. Before opening the cover gon the hopper 64 in order to charge the same, the grate 101 is closed by raising the rod 1&4, said rod acting on the lever 142 and on the gate 141 to close the same. this is to relieve the'cover of the interior pressure before it is opened. 7

The movement of the material in the stack 3 and the operation of the slides 9 and 11 are as folloWs:--The conveyor being in motion and-supplied from suitable" bins, as

mentioned, with the pulverized material to be treated, the slides 9 and 11 are open sobegins.- The slides 9 and 11 are opened and closed alternately, in order to prevent the pulverized material and ases from blowing out through the stack. l hus while the slide llis closed, the slide'9 is open, until the com .artment 6 is filled, or until the supply in t e compartment 7 has run down, as

shown by the indicator 150, then the slide 9 is closed and the slide 11 opened so that the. material in the compartment 6 may descend into the compartment 7. This being done, the1 slide 9 is again closed to begin a new cyc e. v

The speed of ore deliver into the chamber 12 is determined mec anically by the differential speed mechanism, and' otherwise by the rapidity of the reduction which is taking place,*as previously mentioned, care being taken not to charge ore faster than it is reduced. Brisk boiling in the chamber 66 and a regular overflow of molten reduced matter into the chamber 96 indicate re lar workin The mechanism involved eing adjusta le, both as to supply of fuel and air, the initial pressure on the same, the

The object lof speed of the feed screw and the depth of the pressure-producing bath in the chamber 66, all these factors are to be considered together, with reference to. the nature of the ore treated, in order that a successful reduction of the same may be obtained. Should it be desired to change from liquid to gaseous fuel or vice versa, this may readily be done by change of supply pipe, the connection 83 in the blast main being of sufficiently large outside diameter to admit pipes of difierent sizes, such as may be required for different fuels. At the time of tapping the furnace, or oftener if necessary, the hopper 64 is replenished with molten slag from the chamber 96 by means of the slag truck 123 and accessories, as shown. The pressure on the blast and fuel is produced and gaged in the usual way, being further re ulated as to amount by valves, as shown. S ould it be desirable to maintain a more oxidizing atmosphere in the chamber 12 than is otherwise produced, the valve 81 on the branch 7 9 of the blast pipe is opened, thus admitting air to the compartment 7, said air forcing its way into the chamber 12 and producing the afore-mentioned effect.

In the reduction and smelting of oxide of iron or ores of a similar nature, it is necessaryv to maintain a hot reducing atmosphere in the furnace. nature of the fuel where solid carbon is used exclusively in that a large part of the gases generated by the use of such fuel will re main sufiiciently reducing, where enough fuel is supplied to 'deoxidize the ore and reduce it to metal, even thou h atmospheric air be freely admitted. Wlrere hydrocarbons, or gases containing a considerable portion of hydrogen, are used in furnaces of the ordinary construction, the action is somewhat different in that the atmosphere produced is more oxidizing than in the former case, especially so in reference to ores such as mentioned.

Various expedients, such as electric heating or heating of the gases prior to their in ection into the furnace have been suggested, or resorted to, in order to produce the desired effect, but so far as I know, without any practical success.

My invention contemplates the production and maintenance of the necessary reducing character of the hydrocarbons involved and other features for the purpose stated First. By manipulating the gases involved in a reduction chamber so constructed and operated that the atmosphere of the entire chamber may be maintained uniform, said chamber being practically closed to the outside air.

Second. By admitting air and gas or atomized oil into the reduction chamber of the furnace under pressure-and maintaining a certain pressure within said chamber.

This is provided for by the 'in conjunction with suitable fluxinf Third. By the immediate superheating of the gases as they come in contact with the incandescent walls of the reduction chamber, the construction of said chamber being such as to admit of close contact with the gases.

Fourth. By the introduction of molten flux or slag into the reduction chamber where the gases and other material involved mix and come in intimate contact with said slag.

Fifth. Through the dissociation of the steam formed by means of the pulverized solid carbon of the charge as mentioned, since said carbon, being in a finely divided state, is immediately heated as it enters the reduction chamber, sufliciently to cause said dissociation.

Sixth. By the further heating and carbonization of the gases involved as they are forced through the molten bath in the chamber 66.

Seventh. By the establishment and maintenance of a continuouslyincreasing reductive action in the elements involved as they are moved under pressure against the resistance' of the molten bath inthe chamber 66.

Eighth. By causing all the elements involved in the process to travel in the same direction through the furnace in gaseous and finely divided state and under pressure, thus insuring intimate contact, rapid reduction and chemical combination of said elements.

Ninth. By causing the gaseous elements involved to pass through a certain depth of molten matter containing a metal, thus superheating and boiling said matter to the extent that disassociation and recombination may take place of the gases and metallic elements respectively.

Tenth. By such construction 'of the furnace that there shall be, within the reduction chambelyof the same, a space practically closed to the outside atmosphere, and through which space all the elements of the process may travel freely under pressure toward a molten bath forming a seal to said chamber, and through which bath the gases 'involved are made to pass.

In the operation of my invention I donot wish to confine myself to the return of slag only to the furnace as mentioned, for, in certain instances, it may be more advantageous to return a partly reduced metal, or matter in molten condition, which then acts elements in the charge to produce the esired results. -As the molten slag acts not only as a flux'but also as a heating agent to quickly fuse the ore and keep it in motion, it is evident that, where proper fluxes are added to the charge, any other part of said charge in molten condition will act in the above-mentioned capacity as well as the slag, and the 1,ses,ua

operation thus modified will have a concentrative effect on the metal involved, as, for instance, in cop er smelting. If, for any reason, it should anything through the slag hopper into the furnace, said hopper may be closed by shutting the gate 141 asbefore mentioned. As the molten matter accumulates in the chamber 66, it runs over into the chamber 96 where metal and slag Separate and rare tapped as occasion requires.

11 case solid carbon is used exclusively as fuel it is fed into the reducing chamber by means of the feed screw 27.

By the term purified slag as herewithin used is meant a slag from which phosphorus and sulfur have been separated by forcing gaseous oxidizing agents on to the slag whlle it has been maintained in a molten condition and preferably resting on a metallic bath.

I claim 1. An ap aratus comprising a furnace having a re ucing chamber, means for feeding ore and fuel into said reducing chamber, means for supplying compressed air thereinto, means for preventing the free escape of gas therefrom, a smelting chamber and a communication between it and the reducing chamber so constructed that a liquid resist ance to compressed gases may be maintained between said chambers.

2. An apparatus comprising afurnace having a reducing chamber, an ore stack, the inner portion of which is closed to the external atmosphere but always incommunication with the furnace, means forfeeding ore from the stack and fuel into said reducing chamber, means for su plying compressed air thereinto, a sme tlng chamber and a communication between it and the reducing chamber so constructed that a liquid resistance to compressed gases may be maintained between said chambers.

3. An apparatus comprising a furnace having a reducing chamber, means for feeding ore and fuel into said reducing chamber,

means forsupplying compressed air there-. into, means for preventing the free escape of gas therefrom, a smelting chamber and a communication between it and the reducing chamber so'constructed that a liquid resistance to compressed gases may be maintained between said chambers, and means for varying the size of said communication.

4. An apparatus comprislng a furnace having a reduced chamber, means for feeding ore and fuel into said reducingchamber, means for supplying compressed air thereinto, means for preventing the free escape of gas therefrom, a smelting. chamber and a communication'between it and the reducing chamber and so constructed that a liquid re: sistance to compressed gases may be maintained betweefi said chambers, means for be desirable not to charge varying the size of said communication, and means for varying the depth of said resist.- ance.

5. An apparatus comprising a furnace having a reducing chamber, an ore stack, the inner portion of which is closed to the external atmosphere but always in communication with the furnace, means for feeding ore from thestack and fuel into said reducing chamber, means for indicating the quantity of ore in said stack, means for supplying compressed air thereinto, a smelting chamber and a communication between it and the reducing chamber so constructed that a liquid resistance to compressed gases may be maintained between said chanibersl 6. An apparatus comprising a furnace having a reducing chamber, an ore stack, the

inner portion of which is closed to the external atmosphere but always in communication with the furnace, means for feeding ore from the stack and fuel into said reducing chamber, revoluble means for indicating the quantity of ore in said stack, means for supplying compressed air thereinto, a smelting chamber and a communication between it and the reducing chamber so constructed that a liquid resistance to compressed gases may be maintained between said chambers.

, 7 An apparatus comprising a furnace having a reducing chamber, means for feeding ore and fuel into said reducing chamber,

means for supplying compressed air there-- into, means for preventing the free escape of gas therefrom, a smelting chamber and a communication between it and the reducing chamber so constructed that a liquidresistance to'compressed gases may be maintained between said chambers, said reducing chamber being removable frommthe smelting chamber. l

48. An apparatus comprising a furnace having a reducing chamber, means for feeding ore and fuel into said chamber, means for supplying compressed air, thereinto, means for preventing the free escape of gas therefrom, a smelting chamber, the reduction chamber being removably attached to the smelting chamber and the smelting chamber and reduction chamber communicating with each other, the communication being such that a liquid resistance to compressed gases may be maintained between said chambers, a settling chamber flexibly attached to and in communication with said smelting chamber and means for injecting steam and air upon themolten material in said settling chamber.

' 9. "A reducing and smelting apparatus having a chamber closed to the'external atmosphere, means for continuously and simultaneously passing fuel, air, and material to be treated through said chamber, means for forming and malntaining a liquid resistance in said chamber, means for forcing gases under pressure through said resistance and ma.

terial to be treated into said resistance, means for predetermining the pressure in said chamber, and means for drawing off the material treated.

10. An apparatus comprising a furnace having a reducing chamber, means for feed ing ore and fuel into said reducing chamber, means for supplying compressed air thereinto, means for preventing the free escape of gas therefrom, a smelting chamber and a communication between it and the reducing chamber, so constructed that a liquid'resistance to the passage of compressed gases may be maintained between said chamber, and means for establishing resistance, a settling chamber flexibly attached to, and having communication with, said smelting chamber, means to adjust said communication and means whereby gases may be forced through the molten material as it flows through said communication.

11. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other.

12. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for maintaining the resistance in a definite position relative to the two chambers.

13. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and thronghwhich they can communicate with each other, and means for maintaining said resistance at a constant level.

14. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for moving into the material offering the resistance the material to be treated.

15. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, and means for automatically regulating the rate of supply of material to said resistance.

16. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material ofi'ering the resistance the material to be treated,

and means for adding material as desired to the resistance.

17. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for moving heated reduced material into the material otlering the resistance.

18. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, and removable means for preventing the material in the resistance coming into contact with the outside atmosphere.

19. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, and means for superheating the molten matter in the resistance.

20. An apparatus comprising a furnace having reducing and smelting chambers constructed to form a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, said re ducing chamber being closed to the external atmosphere whereby said gases are heated.

21. An apparatus comprising a furnace having reducing and smelting chambers constructed to form a liquid resistance to the passage of gases and'through which theycan communicate with each other, means for moving into the material ofiering the resistance the material. to-be treated,

means for producing pressure by a hot gas on said resistance, and means for varying said pressure.

22. An apparatus comprising a furnace having reducing and smelting chambers constructed to form a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, means for producing pressure by a hot gas on said resistance, and means for maintaining the pressure on the resistance constant notwithstanding variations inthe amount of material fed into saidreducing chamber.

23. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, means for producing pressure by a hot gas on said resistance, and means for maintaining the pressure within the resistance constant notwithstanding variations in the amount of material fed into said reducing chamber.

24. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistvance the material to be treated, and means for forcing gases through the resistance.

25. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means "for moving into the material offering the resistance the material to betreated, and means for diffusing said gases through the molten matter of the resistance.

26. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for varying the level of the resistance.

27. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, means for difiusing said gases through the molten matter of the resistance, and means for bringing the gases toa reducing condition before they enter the resistance.

28. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquidresistance to the passage of gases and through which they can communicate with each other, means for moving into the material oflering the resistance the material to be treated, means for diffusing said gases through the molten matter of the resistance, and means for maintaining a reducing condition of the elements in contact with, and entering, the resistance. r

29. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold -a liquid resistance to the passage of gases and through which they can communicate with each other, means for moving into the material offering the sistance the material to be treated, means for difiusing said gases through the molten matter of the resistance, and means for car bureting' the gases before they enter the -re+ sietance.

32. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance. to the passage of gases and through which they can communicate with each other, and means for causing ebullition of the molten matter constituting the resistance.

33. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for preserving the gases escaping through the material offering the resistance.

34:. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, means fer moving into the material offering the re.- sistance the material to betreated, means for diffusing said gases through the molten matter of the resistance, and means for reducing the overflow from the resistance.

35. An apparatus comprising a 'furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage ofgases and through which they can communicate with each other, means for moving into the material offering the resistance the material to be treated, means for diffusing said gases through the molten matter of the resistance, means for main taining a reducing condition of the elements in contact with, and entering the resistance, means for purifying slag overflowing from the resistance, and means for conveying said purified slag to a point convenient for dis charging it into a succeeding body of ma terial to be treated. I

36. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for separating slag and metal flowing from the resistance.

37. An ap aratus comprising a furnace having reducln and smelting chambers con etructed to ho d a liquid resistance to the passage of gases and through which they constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for blowing gases on to the surface of material which has passed through the resistance.

39. An apparatus comprising a furnace having reducing and smelting chambers constructed to hold a liquid resistance to the passage of gases and through which they can communicate with each other, and means for draining the resistance.

40. In an apparatus for the reduction and smelting of ores, the combination of a reduction chamber, a smelting chamber and a settling chamber, means in said settling chamher for the purification of metal and slag and means for the return of said purified molten slag to the reduction chamber for fluxing and heating purposes.

41. In an apparatus for the reduction and smelting of ores, the combination of a reduction chamber, a smelting chamber, and a settling chamber, means in said settling chamber for the purification of molten metal and slag, means for the return of said purified molten slag to the reduction chamher and means communicating with said reduction chamber wherein said purified molten sla may be stored.

42. ii an apparatus for the reduction and smelting of ores, the combination of a reduction chamber, a liquid resistance in a smelting chamber and a settling chamber, means in said settling chamber for blowing air and steam on the molten material in the same, means for the return of said molten slag to the reduction chamber, means for holding said slag and adjustable means for regulating the flow of said molten slag into the reduction chamber.

43. in an apparatus for the reduction and smelting ofores, the combination of a reduction chamber, a smelting chamber, a Eiquid resistance in said chamber, a settling chamber, adjustable means between said settling and smelting chambers forming a communicating port between said chambers, means for forcing gases through the molten material. as it blows through said port, means for blowing steam and air into the molten material in the settling-chamber, means'for the return of the molten slag to thereduction chamber, means in communication with said reduction chamber for storing said molten slag and means for regulating the dew of said blown molten slag into the reduction chamber.

ae. in an apparatus for the reduction and smelting of ores, the combination of a reduction chamber, a smelting chamber, a liquid resistance to gases between the two chambers and a settling chamber, means adjacent to said settling chamber for the blowing of gases through the molten material flowing into said chamber, means for blowing air and steam into the molten slag and metal in said chamber, means for the return of the blown slag to the reduction chamber, means in communication with said chamber to hold said slag, adjustable means for regulating the flow of said slag into the reduction chamber, and means for keeping said slag in a heated molten condition prior to its entering the reduction chamber.

45. In an apparatus for the reduction and smelting of ores where the slag resultant from the process is purified and used repeatedly as a flux, the combination of a reduction chamber, a smelting chamber, a

liquid resistance to the passage of gases between said chamber, a settling chamber, adjustable means forming a communicating port between said settling chamber and the smelting chamber, means whereby gases may be blown through the molten material flowing through said port, means for blowing air and steam into the molten slag and metal in said settling chamber, means for the return of the blown molten slag to the reduction chamber, means in communication with said reduction chamber to hold said molten slag, adjustable means for regulating the flow of said slag into the reduction chamber, means for keeping said slag in a heated molten condition prior to its entering said reduction chamber, means whereby a pressure at least equal to that within the reduction chamber of'said apparatus may be maintained within said slag holding communicating means, and means for releasing the aforesaid pressure.

46. in an apparatus for the reduction and smelting of ores, the combination of a reduction chamber, a smelting chamber, a liquid resistance between said chambers, and a settling chamber, means for draining" said chambers and resistance and means for moving, substituting and making ready repairs to said chambers.

47. In an apparatus for the reduction and smelting of ores, a reduction chamber, a

smelting chamber, a liquid resistance be tween said chambers and a settling chamber, and flexible means to compensate for expansion and contraction connecting said smelting and settling chambers.

48. In apparatus for the reduction and smelting of ores, a reduction chamber, a liquid resistance to the passage of gases, a smelting chamber, constructional means in the reduction chamber whereby the fuel involved may be quickly heated to incandescence comprising a very gradually flar- 49. The method of reducing and smeltingores which consists in first smelting the ores and maintaining the smelted ores in such form as to offer a liquid resistance to the passage of gases, passing gases through said liquid resistance, and carburizing the material ofthe resistance.

50. The process of reducing ore which consists in feeding the ore into a closed chamber, supplying fuel and compressed air to said chamber to reduce and melt the ore, preventing the escape of gases from the feed end of said chamber, maintaining at the discharge end of said chamber a column ofmolten ore of a suflicient height to oppose the escape of gases at said dischargeend, and drawing off the molten ore at said dis charge end.

51. An apparatus comprising a furnace having reducing and smelting chambers constructed to operate by the use of fluid fuel and to hold a liquid resistance to the passage of gases, through which liquid resistance they can communicate with each other, said reducing chamber being provided with means whereby the fluid fuel passing therethrough may gradually expand'and be highly heated and maintained in the reducing condition before coming into contact v with the ores tobe treated.

52. The process-of reducing ore which consists in feeding the ore into a closed chamber, supplying fuel and compressed air to said chamber to reduce and melt the ore, preventing the escape of gases from said feed end of said chamber, maintaining at the discharge end of said chamber a column of moltenore of a sufficient height to oppose the escape of gases at said discharge end, drawing off the molten material, and utilizing the heated slag as a flux and to heat the reducing chamber.

53. The process of reducing ore which consists in continuously feeding the ore into a closed chamber, supplying fuel and compressed air to said chamber to reduce and melt the ore, preventing the escape of gases from the feed end of said chamber, maintaining at the discharge end of said chamber a column of molten ore of a sufiicient height to oppose the escape'of gases, and drawing 0d the molten material at. said discharge end.

54. The process of reducing ore which" consists in feeding theore into the upper end of a vertical chamber having a liquidseal, supplying fuel and compressed air at the same end as the ore to said chamber to 'retime and melt-the ore, preventing the escape of gases from the feed end of said chamber, maintaining at the other end of said chamber a column of molten ore of a sufiicient height to prevent the escape of gases at said discharge end, and drawing off the molten material at said other end.

55. The process of reducing ore which consists in feeding the ore into a closed chamber, supplying fluid fuel, .acir, solid carbon and molten slag to said chamber to reduce and melt the ore, and drawing off the molten material.

56. The metallurgical process which consists in forcing hot gases under predetermined pressure and of predetermined carbon content through a furnace chamber and through a molten bath of metalliferous material and flux, said bath, forming a" seal to said chamber, supplying additional material to said bath to facilitate chemical action in the same, and withdrawing the excess of said molten material.

57. In metallurgical processes, the steps which consist in forcing oxidizing gases on to slag produced in said processes while said slag is maintained in a molten condition and resting on a metallic bath, and returning said molten slag in a purified condition to the furnace for heating and fluxing purposes.

58. The method of reducing and smelting ores which consists in forcing said ores into and through a furnace chamber filled with reducing gases under pressure, said gases being heated by the resistance of a molten bath through which they must pass and into contact with which bath said ores are carried.

59. The method of reducing and. smelting ores which consists in moving all the material involved in the same direction in a gaseous or finely divided state through a reducing chamber sealed to the outside atmosphere, an automatically regulated gaseous pressure being maintained in said chamher, said gases under pressure being made to pass into another chamber through a molten bath.

a 60. The process which consists in forming and maintaining a 1i uid resistance to the reducing throughouuand under airegulated gaseous pressure, employing said pressure to move the ores into contact with a molten bath in the smelting chamber, and confining the molten bath to form a liquid seal between the two chambers.

62. The continuous method of reducing and smelting granulated ores with hydrocarbons or gaseous fuels which consists in forcing said ores and a regulated amount of flux into and through a highly heated reduction chamber under a predetermined pressure into a molten bath in which bath the ore and flux are agitated by the ebullition of the gases assing through the same.

63. he continuous method of reducing and smelting granulated ores with hydrocarbons or gaseous fuels which consists in forcing said ores and purified heated slag into and through a highly heated reduction chamber under a regulated pressure into a molten bath in which bath the ore and slag are maintained in ebullitio'n by the gases passing through same.

fi l. The continuous method of reducing and smelting finely divided ores under blast pressure by the use of liquid fuel which consists in forcing said-ores, a small amount of carbon, and a molten dun into and through a highly heated reduction chamber into contact with a purified molten slag.

65. The process which consists in forming a metallic bath in a furnace chamber by means of metalliferous material smelted with solid carbon, maintaining said bath of sufiicient depth to form a liquid resistance to the passage of gases through said chamber, feeding metalliferous material and flux into said bath, forcing hot carbureted -gases through said bath to reduce, smelt and carburize said material, and drawing off the excess of molten material.

66. The process of reducing ores which consists in feeding the ore into a closed chamber, supplying fuel, air, solid carbon and molten purified slag to said chamber to reduce and melt the ore and drawing off the molten material.

67. The process of reducing ore which consists in feeding the ore into a closed chamber supplying fiuid fuel, air, a small amount of pulverized carbon, molten purified slag and material to chemically qualify said molten slag for during purposes, to reduce and melt the ore and drawing ofi the material.

68. The process of reducing and smelting finely divided ores under a gaseous pressure, which consists in feeding said ores into and through a closed reduction chamber filled with highly heated gases under predetermined pressure commingling said ores in their passage through said chamber with a molten purified slag fed simultaneously therein, moving said ores, molten slag and gases into and through a bath of molten metal and slag to reduce and melt said ore and drawing off the molten material.

69. The process of reducing and smelting ores which consists in moving all the induced being purified by forcing suitable gases through the same as said metal and slag passes through said aperture.

v 70. The process of reducing and smelting ores which consists in moving said ores, a highly heated purified molten slag, material to chemically qualify said slag for fiuxing purposes and the fuel involved into and through a reduction chamber filled with highly heated gases under pressure, the reducing quality of said gases being further augmented by the addition of a small amount of pulverized carbon; said material being further moved into contact with and through a bath of molten metal and slag to smelt said ore, the metal and slag produced being still further moved through an adjustable aperture into a settling chamber, a suitable gas bein forced through said metal and slag in their passage through said aperture for purification purposes.

71. The process of reducing and smelting ores which consists in commingling and moving in the same direction all the elements of the charge and the gases involved into and through a reduction chamber filled with highly heated carbureted gases under pressure, said pressure being adjustable from both ends of the reduct1on chamber, said charge and the gases involved being further moved into contact with and through a bath of molten metal and slag to smelt the ore, the metal and slag produced" being still further moved through an aperture adjustable in reference to the depth of said bath and into a settling chamber, the

molten metal and slag being blown. in passage by a suitable gas and still further blown with steam and air in said settling chamber.

72. The -method of treating ores which consists in causing the ores and fproducts thereof to flow in a continuous stream, continuously feeding ores at one end of said stream, continuously drawing away the products from the other end thereof, reducing and smelting the ores in one portion of said stream and simultaneouslypurifying the molten metal and slag derived from ores in another portion of said stream.

73. In a process which includes the heating of metalliferous material, the step which consists in adding to said material purified molten slag, and fluxing and heating thereby,

sesame "M, la processes which include lithe heating of metalliferous material, the seeps Which consisa in repeatedly purifying, chemically ualifyirig; and returning to saiol processes it e slab; produced and heating thereby.

75. he methocl of reducing and smelting ores which consists in feeding said ores, molten slag, material to increase the firming properly of said slag, and "the necessary fuel ln'lo a compressed heated reducing [atmosphere in a chamber having a liquid seal, ancl gradually expanding, gasilying, heating aml mains-aiming in reducing condition the said ii uel in said chamber before said fuel comes iii. comfiaol, with said ore:

78. eoriifiinaous methorl of reducing and sreeliaiagg by use oi fluid luel which consists in feeding said fuel, finely rliviclecl ores and granulated carbon into a com pressed, healed reducing atmosphere "within a chamber having a liquid seal and. cans ing said fuel to gradually expand, to be fully gasiiieol and to be highly heated and maintained in reducing condition in said. chamber before coming into Contact with said ores. I

In testimony whereof I have hereunto set my hand in the Witnesses.

JOEL LUND.

Witnesses: I M. rarer-m Do llreeseesu presence of'two subscribing

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