US578271A - Furnace for reducing ores - Google Patents

Description

(No Model.)

E. A. F. SOHULTZE. PURNAGE POR REDUGING DRES.

No. 578,271. Patented Mar. 2, 1897.

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UNITED STATES PATENT OFFICE.

EMIL A. F. SOHULTZE, OF BALTIMORE, MARYLAND.

FURNACE FOR REDUCING ORES.

SPECIFICATION forming' part of Letters Patent No. 578,271, dated March 2, 1897.

Application led February 24, 1896. Serial No. 580,456. (No model.)

To all whom it may concern.'

Be it known that I, EMIL A. F. SCHULTZE, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented a new and useful Improvement in Furnaces for Reducing Ores; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in furnaces for the reduction of ores, and especially ores containing the precious metals associated with iron, zinc, copper, or other of the baser metals.

The primary object of the invention is to provide an improved furnace for the reduct-ion of ores by chemical action whereby the rocky and earthy constituents of the ores are oxidized and rendered pulverulent without crushing or stamping by the usual mechanical means; and the invention consists in the irnproved furnace hereinafter described, an d defined in the appended claims. y

My improved furnace is illustrated in the accompanying drawings, in which- Figure l is a sectional elevation, and Fig. 2 a top or plan view.

rlhe reducingfurnace comprises a jacket A, of fire-brick, provided with an outer metallic casing B, mounted upon a foundation O. A heavy base-plate D, of iron, is secured by bolts d to the foundation O, and above said plate D is supported the grate E.

The furnace is provided at about the center of its height with a transverse partition F, dividing the interior into an upper compartment Gand a lower compartment H, connected by lateral passages I. The lower compartment I-I constitutes the fuel-chamber7 and the upper compartment G is the ore-chamber. The fuel-chamber II is provided with a charging-door h and an ash-pit h', closed by a door h2. Surrounding the fuel-chamber a coil of pipe J is arranged in the furnace-wall, the upper end of the coil Aconnecting with an inlet-pipe K, leading` from any suitable steamgenerator, while the lower end of the coil terminates in the ash-pit h below the grate.

An air-blast L is arranged at the base of the fuel-chamber to supply a blast of air below the grate. The ore-chamber G is also provided with an air-blast M, having a series of branches m, leading to the space m at the base of the chamber. VThe blast-pipe M is connected by a vertical pipe N (shown in dotted lines in Fig. l) with the lower blast L, suitable cut-offs being employed, so that the two blasts may be used either together or separately.

The upper end of the ore-chamber is provided with charging chutes O, a top plate P, and stack Q, controlled by a damper R. The charging chutes or inlets .O are closed by clamped cover-plates S.

The ore is supplied to the ore-chamber as it is mined,without regard to size of the lumps.

The operation of the furnace is as follows: After charging the respective chambers of the furnace with ore and fuel the fuel in the fuel-chamber is heated to incandescence by the aid of the lower blast-pipe L. Steam is introduced through the pipe K at a pressure of from eighty to ninety pounds per square inch.v In its travel through the coil .I the steam is converted from wet to dry steam audthen passes up through the incandescent fuel, mingling with the products of combustion and finally escaping through the passages I to the ore-chamber G. The steam is decomposed by contact with the heated fuel into its elementary constituents, hydrogen and oxygen. The oxygen combines with the carbon of the fuel to form carbonic oXid, while the hydrogen remains free, excepting a small portion which combines with the carbon to form carbureted hydrogen. The use of dry steam I regard as important, as wet steam would restrict the heating power of carbon and thus entail a loss. The lower blast-pipe L is employed primarily to effect the required incandescence of the fuel, the upper blast-pipe being at that time closed. The upper blast-pipe assists the combustion of the gases, which are ignited in contact with the ore. Both the upper and lower blastpipes may, however, be employed simultaneously. The ores are distintegrated, first, by elim in ating all volatile products, such as sulfur, mercury, &c., by the action of the heat;

secondly, depriving them of their oXids,`which leaves the metals in a highly-porous state,

IOO

and finally by the continued reduction reducin g them to an anhydrous hghly-pulverulent state.

The steps more in detail are as follows: The ores coming directly from the mine are placed in the apparatus in pieces as large as will pass through the ingress (pieces weighing one hundred pounds or more) and the interstices filled with fragments or smaller pieces. The gases generated from the fuel by action of atmospheric oxygen admitted by the lower blast pass into the ore-chamber in contact with the ore which it contains. Here this gaseous fuel is supplied again with atmospheric oxygen and burned. The products of this Iinal combustion pass up through and in contact with the whole body of ore. By this means the ore is subjected to the whole of the heat evolved by the fuel. IVhen the fuel in the lower chamber has been made incandescent by use of the blast, the latter is discontinued and the ore is subjected to the action of the combustible gases. After sufficient length of time the ore is examined, and should oxidation be not far enough advanced the upper blast is turned on and after further examination of the ore both blasts are turned on until the ores are completely oxidized and the ore examined. Should oxidation be not far enough advanced, the upper blast is turned on, and after further examination of the ore both blasts are again turned on until the ores are completely oxidized. Both blasts are now shut off. Dry steam or dry water-vapor is again admitted, which, coming in contact with the incandescent fuel, is decomposed into its elements, hydrogen and oxygen. The oxygen combines with carbon to form carbonio oxid. The hydrogen remains free. Only a comparatively small part is converted into carbureted hydrogen. These two gases, carbonio oxid and hydrogen, areconveyed to the ore-chamber and burned. By these means (the burning carbonio oxid and hydrogen) a very high temperature is at once attained. Then the bottom blast is shut olf and the ore may be subjected to the iniiuence of atmospheric oxygen for as long a time as necessary, all at the will of the operator. Thus by the use of oxygen the sulids, sulfates, dto., are deprived of their sulfur and reduced to the state of oxid, and by the use of the unburned gases, carbonio oxid and hydrogen, deprived of the oxygen and re- 5 duced to the metallic state.

The apparatus can be discharged of its contents and recharged without interruption or cooling. The time required to effect complete reduction depends naturally upon the physical structure andthe chemical constitution of the charge and also upon the size of the apparatus.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. rI`he furnace herein described, comprising the structure A, a fuel-chamber in the lower part thereof provided with a grate and an ash-pit below the grate, a coil of steampipe about the fuel-chamber located within the furnace-wall and having its inlet at the upper coil and its exit at the lower coil beneath the grate, a transverse partition over the fuelchamber and constituting the floor of the orechamber, an ore-chamber above the fuelchamber, charging-chutes opening into the orechamber, a blastpipe opening into the ash-pit, a blast-pipe surrounding the orechamber and having branch blast-pipes leading therefrom through the walls of the orechamber and opening into the base thereof, and lateral passages leading from the top of the fuelchamber into the base of the orechamber.

2. The furnace herein described, comprising the structure A, a fuel-chamber in the lower part thereof, provided with a grate and an ash-pit below the grate, a coil of steampipe about the fuel-chamber located within the wall thereof and having its inlet at the upper coil and its exit at the lower coil beneath the grate, atransverse partition over the fuelchamber and constituting the floor of the orechamber, an ore chamber above the fuelchamber, charging-chutes opening into the ore-chamber, a blast-pipe opening into the ash-pit, a blast-pipe surrounding the orechamber and having branch blast-pipes leading therefrom through the walls of the orechamber and opening into the base thereof, lat-eral passages leading from the top of the f ucl-chamber in to the base of the ore-chamber, and a vertical pipe N, connecting the blastpipes of the fuel chamber and the orechamber. Y

In testimony whereof I affix my signature in presence of two witnesses.

EMIL A. F. SCHULTZE.

IVitnesses:

C. HENRY BIsoHoFF, B. A. SoHNEIDnRnrrI-I.

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