US1747740A - Ore-reduction furnace - Google Patents

Description

Feb.- 18, 1930.

J. M- SMITH ORE REDUCTION FURNACE Filed June 1928 INVENTOR.

B ATTORNEY.

Patented Feb. 18, 1930 v PATENT OFFICE UNITED STATES JOSEPH M SMITH, OF SAN FRANCISCO, CALIFORNIA ORE-REDUCTION FURNACE Application filed June 5, 1928. Serial No. 283,041.

efficient retort for the roasting and reduction of these ores, comprising a furnace consisting of a lower circular chamber surmounted by a cupola. Inside the lower circular chamber is a circular table of slightly frusto-coni- 1 cal form covered with a refractory material,

the table being mounted to revolve in a horizontal plane. The cupola is also lined with a refractory material and supports a plurality of hollow frusto-conical battles arranged to continuously feed and distribute the ore to the revolving table. The space between the top of the table and the lower portion of the cupola forms a fire-box for the heating or roasting of the ore, the walls of the lower circular chamber being pierced to allow the insertion of burners to this fire-box. There are open spaces between the walls of the cupola and the baffles, as well as the circular open space through the center of the baflies, through which the heat may come in contact with the ore as it is being fed into the furnace and through which the vaporized metal may be drawn and conducted to conveniently arranged condensers, of such type as may be selected.

In operation the ore is fed into the hopper on top of the on 01a and slides downward and around the wal s of the baflies in a thin continuous stream until it reaches the revolving table. Here by means of rabbles with deflecting portions, 1t is spread evenly over the entire surface of the table and gradually worked toward the edge where it falls into a circular trough and moves to the discharge opening, where it is received by cars, or other receptacles, as waste. The trough for collecting and dischargin the spent ore has a pipe laid therein upon w ich the hot spent ore is held momentarily on its travels to the discharge opening. The function of this 1 pipe is to supply hot. air for the burners in the firebox. Thus the ore from the time it enters the eupola is distributed in a thin sheet over and around the baflies and is dried and thoroughly heated by the time it reaches the revolving table in the fire-box, where the direct heat from the burners vaporizes the metal, the

vapors being drawn oif to condensers while the spent ore heats the air for the burners.

The most important improvements in the metallurg of mercury, as here presented, are the intro uction of a furnace that feeds the or'e continuously, through gravity,to a revoluble distributing table, where the more refractory ore that has thus far escaped yielding up all its mercury is subjected to an intensified heatfor its further-and complete reduction, and the provision for the complete oxidization of the furnace gases through gas firing, so necessary to effective condensation.

In theaccompanying drawing formin a part of this specification and in which simi ar 4 refer to like parts 'tional view respectively, of the upper frustoconical bafile;

Figures 6 and 7 are a sectional and a top view, respectively, of the lower bafiie;

Figures 8 and 9 are the sectional and plan views, respectively, of the means for table adjustment; and

Figures 10 and 11 are a side elevation and a bottom View, respectively, of the rabble bars. Referring with greater articularity to the drawings, in which a pre erred construction is shown, my invention will beseen to comprise acylindrical base 1 interiorly lined with a refractory material 2 and having cent-rally a edestal 3 revolubly supporting an adjustab y mounted vertical shaft 4 resting upon ball-bearings 5 borne by a plate 6supported by a threaded member 7 movably supported within a sleeve 8 having an enlarged section 9 recessed within the pedestal and bearing a threaded nut 10 carried by the threaded member 7, through which this member -may 'be given the'required movement for raising or lowering the supporting shaft 4, this shaft having slidably keyed to it a gear 11 1n mesh with a,worm 12 borne by a shaft 13 extending through and beyond the walls of the cylindrical base 1 to a source of power, not shown, wherethrough the necessary rotary movement is imparted to the conoidal table 14, which is supported and borne by this shaft, as indicated at 15, Figure 1, the table being further supported upon rollers 16 borne by the members 16, which are secured to the member 19 resting upon the plate 20 and braced additionally thereby, these being provided with brace-rods 17 bearing turnbuckles 18 for tauting these members, which extend to and are secured to the member 19 resting upon the cap-plate 2O borne integrally by the sleeve 8, which, in turn, rests upon the upper base 21 of the pedestal 3.

Rabbles 22 are so arranged as to sweep the surface of the table 14 and distribute evenly the ore thereover, the table being further pro- 'the valves 23, the fuel used eing either gas or oil.

Surmounting the cylindrical base 1, and supported thereby through an arch 29, is a cupola 30, likewise lined with a refractory material 31, provided centrally thereof with a vertically arranged chute forore feeding, consisting of a plurality of pairs of revert invert hollow frusto-conical members 32-33, constituting bafiies, the-smaller, or revert, 32 of these having the upper bases provided with flue openings 34 and the lower bases with supporting lugs 35 to provide clearance between their bases and the inner surface of the invert members 33 for the passage of ore, while the larger or invert members 33 have the larger bases flanged, as indicated at 33, and supported by brackets 36 carried by the cupola walls, their inner surfaces being indentured, as indicated at 37, Figure 7 to provide foot-rests for the lugs 35 and additionally so peripherally, as indicated at 37 in the same figure, for the accommodation of the brackets 36. The ore is supplied to the furnace from a hopper 38 arranged to discharge upon the topmost member of this chute or bafile system, passing successively over an outer surface of a revert member and the inner surface of an invert member until the table 14 has been reached, where it is'thinly distributed thereon and thereover by means of rabbles 22, subjected to the direct heat from the burners 23, gradushaft 4. All products of combustion, mercurial vapors included, pass upward through the cupola and outward to the condenser, not shown, through the pipe 39.

Since the ore reduction process is distinctively one of distillation, in which the roasting serves but to volatilize the mercury content of the ore, freeing it from the gangue, it becomes of the utmost importance that the fuel used in the reduction furnace be of a character admitting of the readiest and most complete combustion, as, otherwise, soot and other impurities will be carried over and render impure the condensed mercurial vapors. Owing to the low temperatures required to volatilize the mercury in the ores, varying from'far below redness with some ores, to a red heat with cinnebar, it is apparent that the fuel best adapted to the purpose is either that of gas or a vaporized oil supplied with sufiicient oxygen to insure perfect combustion-reguirements that have been perfectly provided or. Additional to the foregoing is that of providing for a free circulation of heated gases throughout the cupola and the ore-feed ing chute members to the point of exit to the condenser, insuring perfect heat treatment to all particles of ore in their passage from the ore hopper to their exit after passing from the rotating ore table to the car awaiting the waste without the furnace walls.

Means providing conditions for effective condensation have not been shown in connection with the furnace for the reason that those of present practice are sufliciently satisfactory tomeet all requirements. Having thus described my invention, I claim, and desire to secure by Letters Patent: 1. In the herein described ore reduction furnace, the combination, a cylindrical firebox and a cupola surmounted thereon, a table revolubly mounted within said fire-box and adapted for rotation in a horizontal plane, means for the rotation of said table, means borne Within said cupola for feeding ore to said table, means operable through the adjustment of said table relative to height for regulating said ore feed, means for the even distribution ofsaid ore upon said table, means for directing heat upon said ore, a circular trough in near juxtaposition to the circumfere'nce of said table and adapted to receivetherefrom the spent ores, an air pipe laid Within said trough to receive the heat from said spent ores to heat the airinpassage through said pipe, means operable throu h the movement of said table whereby sai spent ores are forced around said trough, and means wherethrough said spent ores are finally discharged from said trough without said fire-box.

2. In an ore reduction furnace of the char acter described, a verticall disposed orefeeding chute constituted 0 pairs of baflles having a flue extending centrally therethrough, said pairs comprising an invert hollow frusto-conical member provided with a flange having spaced recessed sections adapted for the accommodation of supporting brackets and interiorlyspaced depressions adapted for the reception of supporting lugs, and a revert frusto-conical member provided with spaced supporting lugs and adapted to rest within and be supported by said invert member with said lugs resting within said spaced depressions.

3. In an ore reduction furnace of the character decribed, an ore dispersive member comprising a horizontally arranged conoidal table having therebeneath roller-bearing supporting means provided with tensioning rods bearing turnbuckles, a pedestal adapted for the revoluble support of said table, said pedestal having interiorly a sleeve hearing integrally an enlarged section accommodating a threaded nut and exteriorly a plate adapted to rest upon the upper base thereof, a threaded member adapted to travel within said sleeve through the action of said nut,

a plate resting upon the upper end of said threaded member and adapted to be moved therewith, a shaft within said sleeve having its lower end supported by ball-bearings resting upon said last mentioned plate, means for securing said shaft centrally to said table, roller-bearin bracing members extending from the un er surface of said table to and connected with a member supported by said integrally borne plate, and means for impartlng rotary movement to said shaft and therethrough to said table, comprislng a shaft bearing a Worm meshing with a gear.

slidably keyed to said shaft.

In the herein described ore reduction for supplying ore to said series of bafiies,

means for the regulation of the ore feed from said series of bafiles to said table, and means constituting rabbles for distributing ore evenly over the surface of said table.

5. In the hereindescribed ore reduction furnace, the combination, a cylindrical firebox having centrally therewithin a conoidal table, a means for rotatablysupporting said table, comprising a pedestal bearing an actuating mechanism, a cupola surmounting said fire-box and supported thereb a series of baffles within said cupola, sai baffles being constituted of pairs of oppositely disposed hollow frusto-conical members adapted to feed ore and provided centrally therethrough with a flue, means for the support of said members, both as to said pairs and as to said vertically arranged series of bafiles, means for supplying ore to said series of baifles, means for the regulation of the ore feed from said series of baffles to said table, means constituting rabbles for distributing ore evenly over the surface of said table, means in the form of gas flames for applying heat to said ore, and an ore discharge trough circumfer entially arranged relative to said table and adapted to receive the spent ore therefrom. 6. In the herein described ore reduction furnace, the combination, a cylindrical firebox having centrally therewithin a conoidal table, a means for roatably supporting said table, comprising a pedestal bearing an actu ating mechanism, a cupola surmounting said fire-box and supported thereby, a series of baflles within said cupola, said baflies being constituted of pairs of oppositely disposed hollow frust'o-conical members adapted to feed ore and provided centrally therethrough with a flue, means for the support of said members, both as to said pairs and as to said vertically arranged series of baflies, means for supplying ore to said series of bafiies, means for the regulation of the ore feed from said series of baflles to said table, means constituting rabbles for distributing ore evenly over the surface'of said table, means in the form of gas flames for applying heat to said ore, an ore discharge trough circumferentially arranged relative to said table and adapted to receive the spent ore therefrom, and means carried peripherally by said table and adapted to move said spent ore in said trough through a discharge chute.

7. In an ore reduction furnace of the char acter described, the combination with a firebox and its supported cupola, of an ore hopper, a series of vertically arranged pairs of baflies constituting an ore chute and adapted to receive ore from said hopper, said pairs comprising an invert hollow flanged frustoconical member adapted to be supported by brackets borne by the cupola walls and having its interior surface spacedly indentured, and a revert hollow frustro-conical member provided with a flue opening in its lesser base and with supporting lugs for its larger base and adapted to rest within and be supported by said revert member with said lugs resting in said indentures, causing said members to be retained in spaced relation, means com 5 municating with the interior of said cupola for the passage of vapors therefrom, a conoidal ore table rotatively and centrally sup ported within said fire-box, said table being co-operatively associated with the base of said ore chute and adapted to be fed with ore therefrom, means for evenly distribut ing ore over the surface of said table, means for supplying fuel to said ore, means for heating the air supplied to said fuel, means for regulating the ore-feed to said table from said chute, said means comprising a mechanism adapted to raise and lower said table to decrease and increase the space between said table and the base of said chute, and means for conveying the spent ore from said table to a point without said fire-box Walls.

In testimony whereof, I hereby affix my signature this 31st day of May, 1928. JOSEPH M. SMITH.

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