US1348470A - Process of and furnace for refining copper - Google Patents

Description

F. L. ANTISELL.

PROCESS OF AND FURNACE FOR REFINING COPPER.

APPL'CATION FILED JUNE 5. ma.

1 348,470, Patented Aug. 3, 1920 WITNE88E8 NVENTOR Z6 ZW 3% [y mum: n ANTISELL, or ram-n ma zmw messy.

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Specification of Letters Patent.

Patented Aug. 3, 1920.

Application filed June 6. 1918. Serial No. 772,038.

To all whom it may concern:

Be it known that I, FRANK L. ANTIBELL, a citizen of the United States, and a resident of Perth Amboy, Middlesex county, State of New Jersejy, have invented certain new and useful mprovements in Processes of and Furnaces for Refining Copper, of which the following is a specification.

One of the objects of the invention is to produce copper of a better grade and more economically than has been possible heretofore. Another object is to charge the copper into the furnace, melt it down and cast it continuously. Other objects will appear from the hereinafter description.

Before describing the invention in detail it may be well to briefly outline the prevailing process and operation of furnaces used for melting down electrolytically refined cathode copper sheets. will run in conductivity, atthissen standard, when refined in a solution of proper properties as high as 102%, and the cop or contents of such cathodes will run in 999i 0 copper. When cathodes are drawn from the refining vats there is a certain amount of copper sulfate on the surface thereof. It has been found impracticable to entirely eliminate the copper sulfate, and it has therefore been customary to give the sheets 'only a superficial washing and then charge them into a furnace, nerally of the reverberatory type, for tile purpose of melting the cathodes down into such commercial shape as the market demands. The cathodes besides being coated with copper sulfate are also coated to a greater or less extent with metallic arsenic which some copper in the cathode has thrown out of the solution. While the arsenic is necessarily small in amount, it has the characteristic of lowering the electrical conductivity if present as the metallic element in alloy with the copper, and when the copper is melted down in the furnace in the usualpractice', a greater or less amount of impurities, such as arsenic and antimony, are detrimental to the electrical properties of copper, so it has been customary after the charge has been melted, to flap it down, or in other words, oxidize the cop er either with compressed air, blowing wit a small pipe into the bath, or causing a large volume bath and agitate copper with suitof air to blow over the the surface of the molten able appliances.

Co per in this form forming eutectoids which.

During this operation some slag is produced and the copper sulfid which has been formed is disassociated by the well known formula of copper oxid acting on copger sulfid, forming metallic copper and 2 gas, which, by proper manipulation of the bath, will be mechanically driven off.

It has been generally customary to carry on this oxidization to a point where a sample of the copper will show large crystals of copper. Some refineries term this matrix a block, and they say a large block or a small block, thus in a rough way, indicating a greater or less amount of sub-oxid in solution in the copper. The greater the amount of arsenic in the copper up to a certain limit (100%) the more sub-oxid is necessary to introduce in the bath, for the reason of effecting oxidization of the arsenic, and it is necessary at times to introduce as much as 20% of the copper as sub-oxid. After the molten copper has been subject to this oxidizing treatment and the slag skimmed oil, which will contain iron, zinc., etc., (if present in the charge) the copper is subjected to another step in the art of refining known as poling or deoxidizing the cop er. This is generally effected by covering tl 'ie surface of the molten copper with charcoal, coke, or coal, and forcing a stick of wood under the surface of the bath. Some of the oxids of copper in this way are reduced to metallic copper and the re notion is carried on until a point is reached when the sub-oxid isreduced to a fraction of 1%. It is necessary thatthis deoxidization be not carried too far, otherwise, the arsenic and antimony which is present will be reduced to a metallic state alloying with the copper and thus reducing the electrical conductivity. At the same time, it is desirable to reduce the oxid of copper to the lowest percentage possible and still not reduce the other OXldS present. In this manner the highest electrical conductivity is obtained.

have overcome the objections to the prior process of refining and have simplified and cheapened the same by the process hereinafter described which may be carried out by different furnaces, but in the accompanying drawing I have shown a furnace especially adapted for carrying out said improved process.

This application is a continuation in par of my prior applications Serial No. 608,935,

filed Feb. 6, 1911, and Serial No. 728,984. filed November 1, 1912.

Referring to the drawing:

Figure 1 is a vertical section of a furnace for carrying out the improved process taken on line 1 of Fig. 2.

Fig. 2 is a horizontal sectional view on the staggered line 2-2 of Fig. 1.

Fig. 3 is a section through the shaft or chimney of the furnace showing the arrangements of the cathodes as they are charged into the furnace through the stack.

Fi 4 is a horizontal View showing a slight modification of the construction of the stack.

Fig. 5 is a top plan view of a modified construction of stack.

Fig. 6 is a sectional view on line 6 of Fig. 7 is a sectional view'on line 7 of Fig. 5.

eferring first to Figs. 1 and 2, the part marked A reprsents the furnace proper. B is the stack divided b the partition B to form flues B and B T he partition B extends nearly to the bottom of the stack and the two flues are connected to the furnace hearth G by the passageway D. The furnace A is divided by the partition E into a casting comgartment C 'and a melting compartment The object of the partition E is to baffle the currents of copper in the hearth as they pass from one compartment to the other.

F is an air cooled bridge wall and G is a fire box provided with grate bars H to sup port a bed of coal which is used in the furnace for melting down copper. J is an air pipe leading from a suitable source of sup ply and is connected to the stack 13 and is provided with a branch J, which leads to the fire box G. Each branch is controlled by suitable valves or dampers j and j.

The roof of the furnace is provided with a port or opening a, through which sticks of wood may be inserted for the purpose of poling or through which pipes for supplying crude oil may be introduced.

n Fig. 4 I have shown a slightly modified construction in which the stack is provided with only one flue and in this case, as in the prior described constructions, ,the

cathodes are charged crosswise in the stack as shown. Fig. 3 IS a perspective view to more clearly show the arrangement of the cathodes in the stack.

The operation of this improved furnace is as follows: Coal is placed on the grate bars H and the fire is started and the furnace is heated up to melting point of copper. When this temperature is reached the cathode copper is char ed into the stack as follows. A cathode p ate is charged diagonally across the flue and is lowered until the bottom edge rests upon that part of the furnace marked a. Another cathode 2 is then charged diagonally in the flue but crossing the first cathode, and this arrangement is carried out until the stack is full of cathode plates. By this arrangement of cathodes the products of combustion have free egress and the cathodes are heated by the outgoing products of combustion. As the lower cathode sheet melts or liquefies, the molten metal flows from compartment 0 and under the partition or baffle E into the compartment 0'. The charging and melting down is carried on continuously "until the metal in the hearth C reaches a predetermined point. During the melting down the charge has been sufiiciently oxidized through the agency of free oxygen introduced into the stack through the pipe and into the combustion chamber of the furnace through the pipe J.

After the copper has remained long enough in the compartment 0 to permit the necessary reactions to take place, for instance, the copper oxid acting on the coper sulfid forming metallic copper and 0 gas, it passes into compartment 0'. If an sulfid should be carried into the bath, which likelihood is reduced to a minimum owing to the thorough roasting of the cathodes during their descent in the stack and into the zone of the furnace, the copper in compartment 0 is thus automatically maintained at such a point of saturation of sub-oxid as will insure the presence of the im urities as oxid.

In t is furnace it is not necessary to introduce as much sub-oxid in the copper when melted down as is the case in'the ordinary reverberatory furnace heretofore used where the copper has been charged on the hearth. The molten copper from compartment flows under the partition or bafiie E into compartment 0' where it is further heated by the flame passing over the air cooled bridge wall F where it is de oxidized to the proper point with hydrocarbon gases derived from the combustion of green oles inserted through the opening a, or rom petroleum supplied through pipes inserted through said opening. Properly the deoxidized copper is then drawn out of compartment 0' through a suitable tap hole 0 to a casting apparatus,

where it is cast into suitable form for commercial use.

I wish it to be distinctly understood that I stack or flue marked B. In this construction the outlet end of the stack is tumbled in or contracted as shown at b with crissthe heat is retained in the stack somewhat lon er.

y this furnace and the described rocess I am able to produce better copper or the reason that such arsenic as is on the surface of the cathodes supplied through the stack is gradually heated by the outgoing products of combustion until it is partially volatilized and roasted to an oxid resultin in an elimination of about of the tot arsenic contents of the cathodes. The antimon carried by the cathodes is also partiall vo atilized, resulting in an elimination 0 about 20% of the antimony carried b the cathodes. It is to be understood that t ese figures apply to high grade cathode sheets, where the arsenic and antimony originally are present in both cases to about .0015%. As the o eration is carried on continuously t e economy is apparent when it is considered that the cold cathode plates are charged into the comparatively cold portion of the furnace and preheated by the products of combustion that have previously heated cop per lower down inthe stack, and as the as cending gases or outgoing roducts of combustion meet the incoming 0 ar e or cathode plates by reason of the lower s eet being in the melting zone of the furnace, and as the lower sheet dissolves or melts the upper sheet coming gradually into the heated zone on the counter current rinciple, the heat that would otherwise be 0st is utilized for heating, the copper.

In an ordinary reverberatory furnace the efliciency of the furnace is about 10%. With this furnace by actual practice, an eflicien of 45% has been affected and as the'hea is small in proportion to the amount of copper melted in a given period of time, the radiation losses are reduced. This fact artially accounts for the high efliciency ereinabove stated.

Then again, by maintaining a lar e proportion of impurities as oxid during the melting, it is not necessary to bring the copper down to as low a point in sub-oxid as if the arsenic had-been allowed in its metallic state and a large percentage of the cost of deoxidizing the copper. is therefore obviated.

The continuous o eration of the furnace is evident from the act that the furnace can be charged continuously at the top of the stack and the bottommost cathode be continuously melted and the molten copper in the hearth can be continuously removed from the compartment 0'. a

In the drawing only one cathode sheet to each layer is shown, but this is only su gestive, as the cathodes may be successful y melted down with as many as a dozen plates placed side by side, or in a single layer. It is only necessary that the plates should be placed so that there will be free exit of the products of combustion and a free circulation of said products against the surfaces of the cathodes.

It is evident that the source of heat is from the fire box G, and the flame passes over the bridge wall F and it raises the temperature of the metal in the hearth to the proper point as high above the melting temperature as desirable for casting, and the flame then ascendin the stack reheats the incomin charge 0 copper. he rate at which t e melting is carried on and the amount of oxid formed on the surface of the cathode depends to a great extent upon the amount of submergence that the bottom of the co per has in the bath and molten metal. he deeper the submergence the greater the rate of melting of t e copper and the less the submergence the eater the oxidization of the copper. In ot er words, if the copper melts at such a high rate that the oxidization has not been completed before the lowermost cathode enters the melting zone, the submergence is decreased. This means regulation is necessary for the reason that the cathodes charged are of varying weights. The heavier the cathode the slower it will melt, and to a very large extent the submergence is regulated by raising or lowering the metal line in the furnace.

It is to be noted that the copper plates are so arranged that they continuously and successively gravitate in series to the melting chamber, and the products of combustion continuously pass upward in a direction 'opposite to the movement of the plates so that the combustion products successively pass by and operate serially upon the said plates. I define this counter movement of the plates and the products of combustion as a counter current operation.

In carrying out my process, the Ste B of pro-heating and of roasting are each e ected by means of a heat which is not suflicient to melt the copper, and therefore the step of pro-heating and the step of roastin in my process are clearly distinguishable mm the initial action of the melting heat upon the copper. The pre heating and the roasting are never accomplished by the action of the melting heat, but are always accomplished by a heat which is always lam than the melting heat and insuflicient to accomplish the melting of the copper. It is in this sense that I have used the words pro-heating and roasting in the specification and claims.

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

1. The process of refining copper which consists in continuously, progressively and serially pro-heating, i-oastin and melting copper forms separately and individually.

2. The process of refining copper which consists in continuously, progressively and serially roasting copper forms and then subjecting the said copper forms separately and individually to a meltingtemperature.

The process of refining copper which consists in gradually feeding copper forms to the melting zone where they are melted separately and individually and progressively and serially pie-heating and roasting said copper while being so fed.

4. The process of refining copper which consists in continuously, progressively and serially pie-heating and roasting copper forms and then subjecting the copper forms to a melting temperature so that they are melted separately and individually.

5. The process of refining copper which consists in continuously feeding copper forms to a melting zone, melting the copper forms in said zone separatel and individually, preheating and roasting the copper forms serially by a current of products of combustion passing counterwise to the direction of the feed.

6. The process of refining copper which consists in progressively and serially melting copper forms separately and individually, roasting the copper to be melted and pre-heating the copper to be roasted.

7. The process of refining copper which consists in continuously feeding copper forms in series through a pre-heating zone then through a roasting zone and then to a melting zone so that said forms are melted separately and individually and then superheating the fused copper.

8. The rocess of refining copper which consists in continuously feeding copper blanks in series through a pre-heating zone, then through a roasting zone, then to a melt ing zone, melting the copper forms in said zone separately and individually and then super-heating the melted copper and then feeding the melted copper to a de-oxidizing zone.

9. The process of refining copper which consists in continuously feeding copper blanks in series through a pre-heating zone, through a roasting zone, to a melting zone, where said forms are melted separately and individually and then super-heating the melted copper and then feeding said melted copper to a de-oxidizing zone and then continuously removing the copper from the de oxidizing zone.

10. The process of refining copper which consists in progressively preheating and roasting copper forms in series, then progressively su jecting said forms to a melting temperature so that said forms are melted separately and individually, holding the copper at that temperature until the necessary reaction takes place, then raising the temperature to a casting heat and deoxidizing at that heat.

11. The process of refining copper which consists in preheating and roasting copper forms in series, then subjecting said copper forms serially to a melting temperature so that said forms are melted separately and individually, holding the copper at that temperature until the necessary reaction takes place, then raising the temperature to a casting heat, deoxidizing at that heat, and ltlhen removing the deoxidized copper at that eat.

12. The process of refining copper which consists in preheating and roasting the copper, then subjecting the copper to a melting temperature in a compartment with a suitable amount of sub-oxid present in the solution, holding it in that compartment" until the necessary reaction takes place, and transferring the copper to another compartment.

13. The process of refining copper which consists in preheating and roasting the copper, then subjecting the copper to a melting temperature in a compartment with a suitable amount of sub-oxid present in the solution, holding it in that compartment until the necessary reaction takes place, transferring the copper to another compartment,

and raising the temperature of the copper" in the second compartment to a casting point.

14. The process of refining copper which consists in preheating and roasting the copper, then subjecting the copper to a melting temperature in a compartment with a suitable amount of sub-oxid present in the solution, holding it in that compartment until the necessary reaction takes place, transferring the copper to another compartment and then partially deoxidizing the copper in the second compartment.

15. The process of refining copper which consists in preheating and roasting the copper, then subjecting the copper to a melting temperature in a compartment with a suitable amount of sub-oxid present in the solution, holding it in that compartment until the necessary reaction takes place, transferring the copper to another compartment, and then partially deoxidizing the copper in the second compartment by introducing hydrocarbon ases.

16. he process of refining copper which consists in charging plates of copper crisscross into a stack, preheating and roasting the copper, subjecting the lowest plate to a melting temperature, and holding the copper at that temperature until the necessary reaction takes place.

17. The process of refining cathode copper which consists in melting the cathodes and passing the products of combustion by which the melting is effected along the surfaces of a series of cathodes arranged in vertical succession in advance of the melting zone, each cathode resting upon and supported by the one next below, whereby the cathodes before being subjected to a melting temperature are caused to melt separately and individually to move gravitally and in series through zones of heat of successively increasing temperature derived from the products of combustion.

18. The process of refining cathode copper which consists in melting the cathodes and passing the products of combustion by which the melting is effected along the surfaces of a series of cathodes loosely arranged in vertical succession in advance of the melting zone, each cathode being in contact with and supported by the one next below, whereby the cathodes before being subjected to a melting temperature are caused to melt separately and individually to move gravitally and in series through zones of heat of successively increasin temperature derived from the products 0 combustion. I

19. The process of refining cathode copper which consists in melting the cathodes and passing the products of combustion by which the melting is effected along the surfaces of a series of cathodes arranged in criss-cross fashion in vertical succession in advance of the melting chamber, whereby the cathodes before being subjected to a melting temperature are caused to move gravitally through zones of heat of successively increasing temperature derived from the products of combustion.

20. The process of treating copper, which consists in continuously melting copper forms separately and individually by means of the highly heated products of combustion of a hydrocarbon burner regulated to produce an oxidizing atmosphere, thereby producing an amount of copper oxid in said copper, and liberating the oxygen from said oxid by commingling with the copper a reducing agent, and purifying said copper.

21. A furnace for treating copper comprising a hearth having melting and refining chambers communicating with each other, and a stack having communication with one end of said chamber and through which all the products of combustion pass and the material to be refined is introduced into the hearth.

22. A furnace for treating copper comprising a melting chamber, a stack having communication with one end of said chamber and through which all the products of combustion pass and the material to be treated is introduced then-into. grate bars arranged at the other end of the chamber, and a bridge wall between the grate bars and the chamber.

A furnace for treating copper comprising a melting chamber having means for supplying a melting flame thereto, a stack having communication with said chamber, said stack having its outlet end contracted and provided with an opening through which the material to be treated may be in troduced into the stack. the contracted end of the stack being otherwise closed to partially confine the products of combustion,

E24. A furnace for treating copper comprising a melting chamber having means for supplying a melting flame thereto, a stack having communication with said chamber, said stack having its outlet end contracted and provided with openings arranged in crisscross fashion for the introduction of the material to be treated. and to partially confine the products of combustion.

25. A furnace for treating copper comprising a melting chamber, a combustion chamber having communication with one end thereof, a stack having communication with the other end of the melting chamber, said stack serving to feed the material to be treated to the melting chamber, and valved means for supplying air, having one branch to the stack and another branch to the combustion chamber.

In witness whereof I have hereunto set my hand at Perth Amboy, county of Middlesex and State of New Jersey, this fourth day of June, 1913.

FRANK L. ANTISELL.

In presence of A. CLAYTON CLARK, FERDINAND ANnnEws.

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