US1297641A - Electric furnace for smelting ores. - Google Patents

Description

A. E. BOOKWALTER.

ELECTRIC FURNACE FOR SMELTING ORES. I APPLICATION FILED APR.26. 1911. 1,297,641. Patented Mar. 18,1919.

4 SHEETSSHEET 1.

Skier/mega A. E. BOOKWALTER. ELECTRIC FURNACE FOR SMELTING ORES.

APPLICATION FILED APR.26. I91].

Patented Mar. 18, 1919.

4 SHEETS-SHEET -2 A. E. BOOKWALTER.

ELECTRIC FURNACE FOR SMELTING ORES.

APPLICATION FILED APR 26 19l]. 1,297,641. Patented Mar. 18,1919.

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ELECTRIC FURNACE FOR SMELTING OR'ES.

. APPLICATION FILED APR.26. I91]. 1,297,641.

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UNITED STATES PATENT OFFICE.

ALBERT E. BOOKWALTER, 0F GOEUR DALENE, IDAHO.

ELECTRIC FURNACE FOB, SMELTING ORES.

To all whom it may concern:

Be it known that I, ALBERT E. BOOK- WALTER; a citizen of the United States, re.

' siding at Coeur dAlene, in the county of which it appertains to make and use thesame.

This invention relates to a new and mproved process and apparatus for smelting ores.

One object of the invention is to provide a process for smelting ores whereby the ores are put through a calcining process in a furnace which causes them to be heated to almost the melting or fusing point, and then melting and fusing them by electric means, the current necessary to accomplish this being considerably less than is required in furnaces heretofore known by reason of the heating during this calcining step.

Another obj ect of the invention is to provide a process and apparatus for smelting ores in which there is practically no metal which is not recovered from the crude ores. A further object of the invention is to provide a dust chamber to be used in connection with the smelting furnace, said chamber being provided with suitable means for collecting the dust carried from the furnace by the strong draft through the same in order that it may be again treated in the furnace.

Another object of the invention is to generally improve upon apparatuses of this character by the provision ofan eflicient and reliable construction, and one which will be well adaptedto the'purpose for which it is designed.

With these and numerous other objects in view, the invention resides in certain details of construction, the combination and arrangement of parts as will be hereinafter fully described and claimed.

In the accompanying drawings forming a part of the application, and in which simiparts lar reference characters designate like throughout the several views;

Figure 1 is a view, partly in elevation and partly in section, of the complete apparatus constructed in accordance with this invention for carrying out the steps of the improved process; I.

Fig. 2 is a vertical sectional view of the smelting furnace taken on the plane of the line 22 of Fig.3;

Fig. 3 is a horizontal sectional view taken oFn' the plane indicated bythe line 33 of Fig. is a verticalsectional view taken pin the plane indicated by the line H of Fig. 5 is a vertical sectional view of the dust chamber taken on the plane indicated by the line 55 of Fig. 6 and showing the dust collecting means in front elevation;

, Fig. 6 is a vertical sectional view taken on the plane indicated by the line 6-6 of Fig. 5; I

Fig. 7 is a detail sectional view through one of the horizontal water pipes;

Fig. 8 is a horizontal sectional view of the dust chamber taken on the plane indicated by the line 8-8 of Fig. 6.

Referring more particularly to the drawings, and especially to Fig. 1, the letter A designates a smelting furnace in which the ores are calcined and smelted, B the smoke pipe connected with the upper end of-the furnace for conveying the smoke and other products of combustion to a. chamber 0 provided with a dust collecting means, and D a settling tank for separating the dust collected in the chamber C from the water used in the collecting step of the process.

The furnace A- is somewhat similar to smelting furnaces now in use in that it is. provided in its wall near its upper end with an opening 1 through which it is charged. This opening 1 is closed when not in use by a door or cover 2 which is hung or suspended by means of suitable cables passing over pulleys. However, it is to be understood that other means than this may be employed for closing the opening. The furnace A is substantially square in cross section and is provided at its lower end with a well 3 in which the molten metal collects and is drawn from the furnace. As clearly shown by Fig. 3 of the drawings the well 3 extends substantially horizontally across the bottom of the furnace midway between two opposite sides. The walls of the well 3 are substantially upright for a short distance, and then they are flared outwardly and upwardly on an incline to provide a hearth 3 for sup- Specification of Letters Patent. 7 Patented Mar, 18, .1919,

Application filed April 26, 1917. Serial No. 164,778.

, porting the ore and for directing the molten metal 1nto the well.

Adjacent the well 3 and fixed in the walls of the furnace A in any suitable manner are electrodes 4 and 5 composed preferably of a composition of graphite, iron shavings or' filings and silica clay. These electrodes 4: and.5 are substantially rectangular in configuration in lan View and extend parallel with the well 3 on opposite sides of the same. Conductors 6 and 7 connect the electrodes with a suitable'source of current in which is arranged a rheostat for controllin the same.

he furnace, A is preferably housed or in fact covered' by a suitable shed a having a flooring'b arranged substantially on a plane with the lower side of the charging open- Mounted upon the flooring b is a fan blower 8, and connected to the blower is a pair of bustle pipes 9 which are disposed on opposite sides of the furnace A and extend at right angles to the well 3, and are disposed in a plane slightly below the flooring 7). Connected to the lower side of each of the bustle pipes 9 is aseries of vertically disposed pipes 10, the latter being arranged on the exterior of the furnace A and having connected to their lower ends twyers 11. These twyersare all disposed in substantially the same horizontal plane which is spaced slightly above the plane ofthe electrodes tand 5, and as clearly shown in. Fig. 2 of the drawings they areprovided with removable and separable bushing members 12 to regulate the air supplied to the furnace.

The well 3 is provided at one endwith a spout 13 whereby the molten metal may be drawn from the furnace. It is to be understood that the well is slightly inclined from the spout 3 to cause. the metal to run from the latter when it is being drawn off.

At the other end of the well there is pro vided a slag spout 14 through which the slag and other refuse material is removed from the furnace.

The pipe B heretofore mentioned is of arched formation. One, of. the ends of this pipe is secured in a convenientmanner to the upper end or to .of the furnace A, while the other end of thepipe is mounted on or secured to the top of the chamber C; Arranged upon the lower side of thehorizontal portion or crown of the pipe B is a series of hoppers or pockets 15 which are capable of catching any mineral that may pass through therein. The lower ends of these hoppersare provided with suitable" closure members which may be operated to remove such mineral therefrom.

The connection of the pipe B with thechamber C is at one end of the latter. At the other end of the chamber is a vertical comthe pipe and which may, condense paratively high smoke pipe E. The ends of the chamber C below the pipes B and E are less in width than the intermediate portion ofthe chamber and communicate with this intermediate portion ,by openings 6.

Disposed across the opening 6 adjacent the troughs 18, the lowermost trough being disposed at the screen 16.

The numeral 19 represents a vertical water supply pipe to which are connected a series of vertically spaced horizontally extending pipes" 20 disposed on the side of the screen 16 adjacent the intermediate portion of the chamber C and arranged directlybeneath the troughs 18. ,The lower sidesof the pipes 20 are provided with a plurality of apertures or openings 21 throughwhich water is sprayed upon the screen. An additional spray pipe 22 bent into substantially semiextreme lower end of the circular shape to conform to the shape of the upper portion .ofthe opening 0 is also connected. to the supply pipe 19. The troughs l8 communicate with a vertically disposed collecting pipe 23, the lower end of which is connected to-a ipe 24 which conveys the water and other material to the settling tank D above briefly described.

This settling tank D may be of any suitable construction, and is here shown as being provided with a pipe through which the water is drawn 01f.

The ore to be smelted such as lead, silver or copper, is fed into the furnace through the opening 1. After a certain amount of it has been placed therein, a layer of fuel such as wood or coke is placed upon the ore. Another layer of ore is added, then another of fuel, and more layers of first ore and then fuel are added until the furnace is completely filled. The blower 8 is then started and a strong draft of air is thus sent through the material in the furnace from the lower end thereof.

will heat the ore to a drive off practically all of the volatile matter contained therein. The temperature of the ore will practically reach the melting point of v the metal contained therein. By this time the ore, almost'in a molten state, will be disposed at the bottom of the furnace and upon the hearth formed by the inclined edges of the wall of the well 3. The current of electricity is then turnedon, and this current will pass from one of the electrodes 4 and 5 through the ore to the other electrode, the resistance of the ore being a considerable amount will cause it to "become The fuel being ignited considerable extent and heated and quickly melt. When melted, the

metal will run into the well 3 from which it is drawn by the s out 13. Other ore will drop down upon t e hearth and thus the smelting operation is comparatively a continuous one, it being understood that the furnace is continuously charged. The slag and other refuse material is removed from The products of combustion and smoke pass vertically through the furnace to the pipe B, and thence 'to the chamber C. Ow-

ing to the very strong draft created through the furnace a large amount of dust containing minerals will be blown through the pipe tal portion of the pipe B, and some of the gases will condense and fall into these hop- B to the dust chamber. Some of this dust will collect in the hoppers 15 in the horizonpers. This material is removed from the hoppers and-again placed in the furnace to remove the valuable minerals therefrom.

As smoke and other gases pass through the chamber C and 'up the smoke stack E a great .amount of dust will be collected upon the screen 16'. This screen is continuously sprinkled with water from the pipes 20 and 22 so that the dust is caused to collect in the troughs 18. The water and dust will then be conveyed through the pipe 23 and pipe V2% to the tank D. Dust will settle to the bottom of this tank, and when a considerable quantity has been thus accumulated the water is allowed to drain off from the. tank and sediment is collected and pressed bricks and again fed to the furnace.

From the foregoing description it will be' seen that the ObJGCtS of the invention have been effectively carried out as an improved and practical furnace for smelting ores has been provided. Practicallyall of the min era-ls contained in the ores are collected, and hence there is very little waste or refuse material. The cost of smelting ores is reduced by the use of this'process, first by calcining the ores by heating them with wood or coke, and then allowing the metals to be completely melted orfused by the passage therethrough of an electric current when almost in a molten condition. A considerably less amount of current is required than is required in the furnaces heretofore known for there the current is passed through a comparatively cold ore.

As various changes in form, proportion and in the minor details of construction may be resorted to without departing from the principle of this invention it is to be understood that I do not wish tobe limited to the precise construction herein shown and de scribed.

I claim: "1

In a smelting. furnace, a furnace shell having a rectangular bottom and a polysided wall rising therefrom, said bottom having along its central portion a relatively narrow well provided with a-molten metal outlet, a pair of one piece electrodes extend ing from one side to the opposite side of the furnace and lying on said bottom on opposite sides of and parallel to said well, said electrodes abutting the remaining two opposite sides of said wall and being spaced from said well, said bottom of the furnace inclining downwardly from said electrodes to said well and forming means for supporting the ore to be melted by the electric current passing between said electrodes.

In testimony whereof I have hereunto set my hand in the presence of two subscribin witnesses.

ALBERT E. BOOKWALTER. Witnesses:

ELMEB C. RAUOH,

- W. J. BURNS.

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