US1164653A - Process of smelting ores. - Google Patents

Description

l. H. KLEPINGER, M. W. KREJCI & C. R. KUZELL.

PROCESS OF SMELTING ORES.

APPLICATION men MAR. 3. 1915.

1,164,653. Patented Dec.21,1915.

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PROCESS OF SME'LTING ORES.

APPLICATION r1120 MAR. s. 1915.

Patented Dec.21,1915.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

JOHN H. KLEPINGER, MILO W. KREJ'GI, AND CHARLES R. KUZELL, OF GREAT FALLS,

MONTANA.

PROCESS OF SMELTING ORES.

Application filed March 3, 1915.

To all whom it may concern:

Be it known that we, JOHN H. KLEPIN- can, MILO WV. KnEJcI, and CHARLES R. KUZELL, citizens of the United States, residing at Great Falls, in the county of Cascade and State of Montana, have invented certain new and useful Improvements in Processes of Smelting Ores, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

Our invention has relation to improve ments in processes of smelting ores and metalliferous material generally; and it consists in the novel features. more fully set forth in the specification and pointed out in the claims.

The present invention is directed to the smelting of ores and metalliferous material requiring oxidation to generate the heat of fusion, the process being particularly applicable to compounds containing oxidizable constituents serving as fuel, although it may be applied to material to which extraneous fuel may be added if the compound does not naturally contain such constituent in proper proportions to bring about the results here contemplated. The prevailing combustible constituents availed of under our process are sulfur, iron, arsenic, zinc, and the like, although as above stated, the process is apapplicable to the treatment of any material in which the element of oxidation inheres, irrespective of the character of the oxidizable constituent present. The chief application of our process is in the smelting of metallic sulfids (particularly those of copper and iron) with a View of forming matte without the preliminary step of roasting, the matte under our process being formed in one operation and in one and the same furnace. As well understood in the art, the prevailing practice of matte making contemplates a preliminary roasting to expel excess of sulfur where the percentage of this element is too high for matte purposes, preceded by concentration where the ore is low grade, the roasting being followed by treatment in a smelting furnace to produce the matte. The old method requires therefore at least two distinct steps, whereas under our process a single operation (in which these steps are combined) will suffice. Our improved process is eminently adapted for the treat- Specification of Letters Patent.

Patented Dec. 21, 1915.

Serial No. 11,769.

ment of fines and dust, whether such fines arethe result of grinding without concen tration, or whether the fines constitute a product of concentration (it being understood that concentrates are ores from which the gangue has been wholly or partly removed). In treating fines and dust under prevailing methods. where such fines are fed to fuel-fired smelting furnaces, they are in a large measure either blown out of the furnace when subjected to a blast, or, where treated in a reverberatory, they tend to pack or form an impervious bed of which only the particles lying on the outside are exposed to the action and influence of the heating medium, the under layers being entirely out off from both the heat and the reaction gases. Under our process each individual particle no matter how fine, is directly and independently exposed to the heat and reaction gases, being at once surrounded by the heating medium the moment the particle enters the furnace or reaction and smelting chamber. It follows therefore that our process is eminently economical of fuel, the heat units be ing made available the moment the combus tion gases and air come in contact with the ore particles in the combustion chamber. To bring about the beneficial results of our process, we contemplate the introduction of the finely divided ore or material into the furnace chamber in the form of a spray or a cloud, said spray being accompanied by a proper proportion of air (preferably heated) to support combustion, or effect oxidation of the combustible constituents of the ore, and of any extraneous fuel which it may be found necessary to add, the heat of combustion being sufficient (under proper regulations of air and combustibles) to smelt the charge of suspended ore particles, each particle being surrounded by the heating and oxidizing medium so that it is virtually fused or smelted while still in suspension in the furnace chamber. Over-oxidation may be corrected by introducing unoxidized material (coarse if desired) into the furnace on the hearth of which the smelted material collects.

Our process is eminently adapted to the oxidation and smelting of concentrates of oil flotation processes.

As a specific illustration of our process now to be described, we may cite the production of copper matte, it being convenient to describe the details of the same in connection with the accompanying drawings illustrating more or less conventionally one form of furnace capable of carrying out our process, in which- Figure l is a top plan of a reverberatory furnace and appurtenances showing the method of application of our invention; Fig. 2 is av middle vertical longitudinal section thereof; and Fig. 3 is a vertical transverse section on the line 3-3 of Fig. 1.

Referring to the drawings, F represents a reverberatory furnace having an elongated combustion and settling chamber C provided at one end with a slag tap-hole it and at the side with a tap-hole h at a lower level for the discharge of the molten ore or matte. Leading from one end of the furnace is a waste-gas flue 1 which discharges into a distributer casing 2 provided with a valve or damper V, the casing being connected by a pipe 3 to a suitable blower or air pump P, and by short pipes 3, 3', with the preheating stoves S, S, from which lead the conduits 4, 4, which discharge into a second distributer or casing 5 provided with a damper or valve V. From the casing 5 leads a waste-gas flue 6 discharging into a main 7, a portion of the gases being shunted through shunts or pipes 8, 8, 8", leading to suitable driers 9, 9, 9 respectively, awaste pipe 10 from the driers discharging 1nto the main 7. The driers are supplied with raw ore, powdered fuel and flux respectively, which when dried is delivered into the hopper 11 mounted at the charging end of the furnace chamber. The hopper 11 in thepresent instance is shown as divided into three c0m-' a down-take. 13 discharging into a mixing chamber 14.- across the path of discharge of a blast nozzle 15 through which air under ressure is delivered by a hot air flue or conuit 16 leadin from the casing 5, the several nozzles 15 lea ing from the discharge end of said conduit. The latter is provided with a controlling valve 17 each of the nozzles 15 being provided with a valve 18, the discharge ends of the nozzles terminating a trifle short of the inner walls of the downtakes'l3 as shown, so that the blast from any nozzle may instantly pick up the material as it drops from the downtake, and project the same through the mixing chamber 14 into the treatment chamber C of the furnace, in the form of a spray or cloud. Any one or more of the nozzles'may be set in operation by a proper manipulation of the valves, and

any one or more of the conveyer screws 12 may be actuated to deliver the material to the nozzles which are active, the proportions of the materials delivered to the nozzles being regulated by imposing any desired speed of rotation on the conveyers. In this way the exact qLiantities of ore, fuel and flux may be projected into the treatment or combustion chamber (.7 to produce the desired product, which in the present case is copper matte. Disposed on the sides of the furnace are a series of hoppers 19 for holding raw ore or concentrates, calcines, or flue dust, or any material which when fed into the furnace will neutralize the effect of over-oxidation of the material which has settled on the hearth of the furnace.

The present is an oxidizing process, the heat of combustion being derived either from the oxidation of combustible elements entering into the composition of the charge, where such elements are in sufiicient quantity, or from the combustion of extraneous fuel added to the'charge where such element is absent or is in insuflicient quantity. the object sought being to'bring about o; :idation and fusion or smelting of the cl'airgc delivered in the form of spray or a cloud into the treatment chamber, while the particles are still in suspension. In the production of matte from sulfid ores of copper for example, the process eliminates one of the steps practiced separately by the old method. to wit, the step of roasting. By the old method, the ore is first roasted (or calcined) in one furl. ace and subsequently smelted in another; whereas under our new process the oxidation of the fine particles (which corresponds to the roasting step) and the fusion (which corresponds to the smelting step) take place almost simultaneously, or in such rapid sequence that the particles are oxidized and fused while still in suspension in the furnace chamber.

That the general character of our invention may be fully comprehended we will describe its operation in connection with the drawings, confining our description by way of example, to the production of copper matte, assuming that we are treating concentrates high enough in sulfur as not to require extraneous fuel to keep up the combustion. The furnace is first brought up to a smelting temperature by means of fuel other than the ore, delivered in the form of spray into the chamber C where it is ignited through a torchhole O. This fuel may be coal, fuel oil, gas or the like, but preferably fine coal derived from the hopper compartment a, and blown into the furnace by the air from the blower or fan P operating through the pipe 3. casing 2, pipe 3, stove S, pipe or conduit 4;, casing 5, flue or pipe 16, and blast nozzle 15 beneath the compartment a, as indicated by the feathered arrows in Fig. 1. as the furnace heats up one of the stoves will become heated by the waste gases, after which by a proper manipulation of the valves V, V, the air may be forced through the heated stove and-the waste gases caused to pass through the first stove and thence through the casing-5, and waste flue (S to the main 7, as clearlyobvious from the drawing, the stoves serving alternately to receire the hot waste gases from the furnace whereby they become heated, and to receive cold air whereby the air is preheated, this result being brought about by a simple turning of the valves V. V, as clearly obvious from the drawings. Once the furnace is brought to the proper working temperature, the flue 16 will deliver hot air to the nozzles 15, because by that time the stores S, S. are being alternately heated,- and the pump l drives the cold air first through one stove and then the other. The ore having sufiicient sulfur as a fuel element, no further extraneous fuel need be injected into the furnace once the latter is heated to proper working temperature, and the fuel from the hopper compartment at is discontinued. and (if desiredl. the

blast through the particular nozzle 15 identified with said fuel compartment may be cut off by a proper manipulation of the valve or damper 18 of said nozzle.

The furnace being brought to proper working temperature, the conveyers 12 of the'compartments b and 0 (when flux is necessary) are started, and the blast turned into their corresponding nozzles 15, whereupon there is projected into the chamber 0 a spray or cloud of sulfid ore and fluxing material. the sprayed particles intermingling in the furnace chamber, a portion of the sulfur component of the ore (and the iron which is usually present) being oxidized, the oxidized iron combining with the fluxing material to form slag, and the resulting matte (copper sulfid) being fused while the particles are still in suspension, after which the fused particles of matte and slag are caused to be precipitated to the bottom or hearth of the treatment chamber, where they separate according to their specific gravity, the matte sinking to the bottom where it may be tapped through the hole h, and the slag floating on top where it may be tapped through the hole It;

If the fuel content (sulfur, iron) of the ore is insufiicient to generate the heat and the necessary temperature to bring about fusion of the matte or product desired, ex-

traneous fuel may be blown into the furnace from the fuel compartment (2, the same as when the furnace is first started. If for any reason over-oxidation of the ore particles resulted in the treatment chamber, this may be neutralized or corrected by discharging into and distributing through, the fused At first the air will be cold, but

ng ores generally and in all cases where oxidation enters as one of the necessary steps to bring the charge to the condition at which fusion or smelting is desired. The raw materials are preferably dried by the Waste gases as hereshown, the material being taken from the driers and charged into their respective compartments (a, 5, 0) of the charge hopper 11.

We do not wish to be understood as limiting ourselves to any special construction of furnace or instrumentalities by means of which our process may be carried on. fact, the apparatus herein illustrated is more or less conventional and diagrammatic, no

details being attempted to be shown, the purpose of the drawing being to convey to the skilled metallurgist the generic features of a desirable form of apparatus, from which he can depart at pleasure to meet various conditions, according to the material to be treated, and the environments under which it is treated. lin some cases cold air may suffice to produce the blast for the nozzles; a different form of furnace may be used; an oil or fluid hydro-carbon fuel may be substituted; a special design of blower may be necessary; it might be desirable to mix the fuel with the ore and blow the mixture from a single nozzle in lieu of blowing the components independently from separate nozzles as here shown. All such matters are within the purview of the skilled metallurgist and need not be dwelt on to any great length in the present connection.

It may be added that where hot air is blown into the furnace for the burning of concentrates containing combustible constituents, the air should be preheated to about one thousand degrees Fahrenheit to insure the burning of the concentrates. This initial temperature is desired where no extraneous fuel is added to the ore charge.

Having described our invention what we claim is:

1. In the treatment of ore and other material, the process of subjecting a charge of the material in a finely divided state to the action of an oxidizing atmosphere in the presence of a combustible component, maintaining the temperature of the reaction at a point to efiect fusion of the charge while in suspension, and distributing a suitable quantity of unoxidized raw material through the ing iron, and fluxing material in the pres- 1o,

ence of a supporter of combustion, i iting the charge in said chamber, continuing the introduction of fresh particles of ore and flux after ignition, regulating the air supply to maintain oxidation of the sulfur and iron, and the slagging of the iron thus oxidized, and at a rate to raise the temperature to the point of fusion of the matte-forming copper sulfid and slag while the particles are in suspension in the treatment chamber, collecting the fused matter and slag, and dis tributing therethrough a suitable component of raw material to neutralize the effect of any over-oxidation while the mass is still under the influence of the reaction temperature.

In testimony whereof, we affix our signatures in presence of two witnesses.

JOHN H. KLEPINGER.

MILO V'KREJCI. CHARLES R. KUZELL.

Witnesses M. A. PESTANA, R. A. LA MoT'rE.

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