US805834A - Furnace for refining copper. - Google Patents

Description

No. 805,834. PATENTED NOV. 28, 1905. R. BAGGALEY.

FURNACE FOR REFINING COPPER.

APPLICATION FILED APR.8. 1903.

5 SHEETS-SHEET 1.

WITNESSES INVENTOR Z I ,Q W

No. 805,834. PATENTED NOV. 28, 1905.

R. BAGGALEY.

FURNACE FOR REFINING COPPER. APPLICATION FILED mm 1903) 5 SHEETS-SHEET 2.

WITNESSES INVENTOR No. 805,834. PATENTED NOV. 28, 1905.

R. BAGGALBY.

FURNACE FOR RBFINING COPPER.

APP LICATION FILED APR 8 1 903.

5 SHEETS-SHEET 3 PATENTED NOV. 28, 1905.

R. BAGGALEY.

FURNACE FOR RBFINING COPPER.

APPLICATION FILED 533.8, 1908.

5 SHEETS-SHEET 4.

INVENTOR No. 805,834. PATENTED NOV. 28, 1905. R. BAGGALEY.

FURNACE-FOR REFINING COPPER.

APPLICATION FILED APR.8, 1903.

a sums-sum 5.

WITNESSES INVENTOR UNITED STATES PATENT OFFICE.

FURNACE FOR REFINING COPPER.

Specification of Letters Patent.

Patented Nov. 28, 1905.

Application filed April 8, 1903- Serial No. 151,636.

To all whom it may concern.-

Be it known that I, RALPH BAGGALEY, of Pittsburg, Allegheny county, Pennsylvania, have invented a new and useful Furnace for Refining Copper, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming partof this specification, in which- Figures 1 and 2 show in elevation the opposite ends of my improved refining-furnace. Fig. 3 is a vertical section on the line III III of Fig. 1. Fig. 4: is a vertical section on the line IV IV of Fig. 3. Fig. 5 is a sectional View showing a modified apparatus, and Fig. 6 isa planview of the means shown in Fig. 5 for introducing the hydrocarbon gases.

The purpose of my invention is to provide means for the refining of copper and to effect very rapidly and by mechanical means a refining operation which heretofore has required many hours and has been accomplished only by difficult and expensive hand-labor.

The invention consists in a copper-refining furnace (preferably a tipping furnace) having twyers opening into the furnace below the copper-level and connected with a supply of reducing-gas, means for heating above the copper-level, and a water-jacket by which the furnace is cooled and saturation of the lining with metallic copper is prevented. The refining of copper as practiced from ancient times at Swansea, Wales, consists in treatment in a reverberatory furnace and by flapping the molten copper into the air with a suitable hand-tool in order that the rapidly-passing air-current through the furnace may oxidize the various impurities such, for instance, as arsenic, antimony, bismuth, selenium, tellurium, &c. Since the application of the Bessemer converter to the treatment of copper, or since the year 1880, this stage of the refining process has been more cheaply accomplished in the converter by driving air underneath and through the molten bath instead of allowing it to flow over the surface of such bath, as is the case in the reverberatory furnace.

The purification of copper consists simply in bringing oxygen into contact with it While molten. As the impurities above referred to are more rapidly oxidized than copper, gold, silver, nickel, cobalt, &c., they are consumed and expelled before those metals havebeen seriously attacked by the oxygen, so that the latter remain in a practically pure state after the treatment described has been completed. Some of the impurities cling to the copper with great resistance as, for instance, antimony and bismuthand as even one-half percentum of either of these has the effect of injuring or destroying the ductility of the copper, particularly when cold, and inasmuch as the market price of the copper is injuriously aflected if it contains even an appreciable percentage of such impurities it is of great importance that they be completely oxidized and expelled. It is impossible, however, to carry the oxidation to this extent without at the same time producing a small percentage of suboxid in the copper itself. Such suboxid does not float on the surface of the copper, as is the case with the oxidized impurities, but the surface of the molten copper remains clean and pure and bright, and the suboxid is absorbed by and becomes an integral part of the copper itself.

Copper contaminated with suboxid is brittle and its ductility is injured or destroyed, particularly when cold, so that when rolled it acts in, many respects like copper containing appreciable percentages of objectionable impurities, such as antimony or bismuth. For these reasons copper that contains even a small percentage of suboxid must be re-treated while in the molten state in order to restore its ductility. This work has been done wherever copper has been produced by a process which consists in submerging poles of green wood, preferably hard wood,in the molten copper, the heat of which generates from the wood great volumes of hydrocarbon gases, which rise through the copper and exerta refining and a purifying influence upon it, expelling all the suboxid and restoring the ductility and value of the metal. The objections to the poling method are many and they are serious. Some of them are as follows: The workmen command very high Wages. The copper at this stage has a great tendency to chill on the bottom and the sides of the furnace. The losses of metal by saturation of the masonry of the present refining-furnaces are enormous. The copper is diflicult to tap and to keep flowing when tapped owing to its tendency to chill. It is often necessary to drive with sledge and steel bars through from eight to twelve inches of pure solidified copper in order to open the tap-hole, and the process of tapping causes many burns and sacrifices many eyes among the workmen. To produce satisfactory re too suits, the process must be carried on with large charges, varying from eight to fifty tons, and such large charges require from three to four hours time or more in which to treat them. The process often requires, in addition to the men who fire and tap the furnace, three high-priced workmen at one time to submerge and to handle the large green poles or trunks of trees which are used in,

large furnaces. As the charge approaches the proper pitch it is extremely difficult to stop the process at the exact point desired. When the butt-end of a tree is submerged in the bath, the fumes and hydrocarbon gases produced by the heat are enormous, and as the trees are of different dimensions and contain different percentages of moisture it is impossible to regulate these things to the exact point where the perfect pitch of the copper is reached and is not exceeded. Of course samples and test pigs are continuously taken; but with the utmost care overpoling, as it is called in the trade, is almost inevitable.

Such over-poling produces in the copper almost the same effect as insufficient poling. It reduces or destroys its ductility when cold. Fresh green poles are sometimes difficult and expensive to obtain and to retain in the green state until required for use, and only a small percentage of each pole can be used effectively.

At many establishments the copper is ladled out of the refining-furnaces by hand. To so ladle out a charge of from ten to twelve tons and to cast it into the ordinary sixteen-pound ingots of commerce requires four men from three and one-half to four hours. It requires somewhat less time for four workmen to ladle the same tonnage into two-hundred-pound anodes, such as are usually made for the separation of the contained precious metals at the electrolytic works. Of course one man cannot lift more than fifty pounds in a ladle. Hence to pour a two-hundred-pound anode the work must be regulated so that an even stream is constantly running into the mold until the casting is completed. The charge in a single furnace is often forty to fifty tons, and to ladle this tonnage by hand requires time and labor. While this work is being done, owing to the great time required, the copper is constantly changing in pitch, so that one force of workmen is required to do the ladling, while a separate force is required to hold the copper at the proper temper, a most intricate and difficult piece of work.

In my improved method of refining copper in lieu of the present poling process I am able ,to eliminate the expenses, dangers, and difliculties above enumerated.

The red ucing-gas which I employ is derived, preferably, from an auxiliary gas-producing plant, in the kilnsof which I make fixed ligneous hydrocarbon gases and charcoal very cheaply and in a continuous process, out of any description of waste wood, slabs, sawdust,

the trunks and branches of trees, the underbrush and waste materials of the forest, or indeed of ligneous material of any description. I maypump such gas by a suitable pump first into an ordinary gasometer, where it can be stored and used, as desired, or I may pump it directly through suitable twyers into the furnace, where at a pressure of six pounds to the square inch it is forced underneath and into the molten copper. It is desirable to deliver these gases at the temperature at which they are taken from the kiln, as this will materially increase the efficiency of the process.

The gases may be delivered beneath the molten copper through ordinary convertingtwyers at the end or sides of the furnace, and similar in many respects to the twyers now used for admitting the bessemerizing blast into the ordinary converter, or they may be delivered through a hand-pipe attached to a pliable hose, through which the hydrocarbon gases may be forced by an airpump from the kilns or gasometer. For this purpose I may use a large overhead swinging hand-pipe which may be inserted into the furnace through the end door, its refractory tip being submerged in the molten copper to any desired extent. When such refractory tip is moved by the operator backward and forward through the molten bath, it will distribute the purifying-gases thoroughly through every portion of the charge under treatment. Exactly uniform and predetermined quantities of refining hydrocarbon gases can thus be delivered into the copper and without-any waste whatever of the material from which the gases-are made. The operator is free to take frequent and continu ous test samples as the bath approaches the critical point, and when the exact pitch has been finally reached he can instantly shut off the supply by means of a hand-cock provided for the purpose, and thus prevent overpoling.

The molten copper while in the furnace undergoing treatment is preferably kept covered with a thick layer of powdered charcoal in order to prevent it from absorbing additional oxygen from the atmosphere. A suit able test sample of refined copper on cooling will indicate its exact pitch. If this is correct, the surface will remain smooth and level. If it is underdonez'. a, if it still contains suboxidthe surface will sink. If it is overpoled, the surface will expand and will show a tendency to form arborescences. When the test samples have shown that the charge is thoroughly refined and that the pitch is exactly right, the furnace is tilted by the operator through the use of machinery, and the refined copper is poured from the furnace into a ladle that is also provided with a covering of charcoal, whence the copper is immediately poured into pigs or slabs. By tipping the furnace for the purpose of withdrawing the copper I avoid the difliculties of chilling and clogging which would attend the use of a station- 'ary furnace provided with the usual tap-hole.

In the drawings the body of the furnace is shown as composed of a refractory lining 2,'

inclosed within l'lOllOW water-jackets3 3, made in sections and provided with water-pipes 1 4:, by which cooling-streams of water may be caused to flow through them. The cooling of the lining by circulation of water not only preserves the furnace, but also prevents the saturation of the furnace-Walls with metal, which heretofore has constituted a serious element of loss in the operation of the furnace.

The waterjacketed sections are held together by bolts'5, passing through flanges on the sections. The furnace is supported by a strong metal shell 6 of circular outline and is adapted to be rotated and tipped, preferably by being mounted on rollers 7 7, and provided with a rack 8, reciprocated by acylinder 9 or other suitable motor, the rack being in gear with a segmental pinion 10 on the furnaceshell. To permit of rotation of the furnace, the water-outlet pipes 4 are provided with flexible connections 11, and the water-inlet pipe 1 extends from the axis of the convertershell and is swiveled thereto, as shown in Fig. 2. At the end or ends of the furnace, preferably extending through the roofsection thereof, is a burner-pipe 12 for the introduction of gas or oil by which the furnace may be heated, and at the other end of the furnace is a working opening 13, adapted to be closed by a door 1 1, which may be operated by a cylinder or motor 15. The roof-section 16 of the furnace is preferably connected telescopically, as at 17, with a stack 18, and lifting devices 19 are provided by which it may be raised preparatory to tipping the furnace.

20 is the discharging-spout of the furnace. 21 is the pipe by which the hydrocarbon gas is supplied. It has a swivel-joint 22 at the axial line of the furnace and communicates with a box or chamber 23, from which and is continued until the proper pitch is' reached, whereupon the furnace may be tilted and the copper discharged into a ladle for casting into molds, as desired.

In Figs. 5 and 6 I show a modification of the means for introducing gas into the molten copper. This device consists of a pipe 26,

which may be supported by a hanger 27 and provided with a counterweight 28 and an op- Valve-concrating-handle 29. The end of this pipe which is to be introduced into the furnace terminates in a refractory nozzle 30, having gas-passages 31 extending therethrough and communicating with the pipe 26, which derives its supply of gas from a pipe 32, controlled by a valve 33. The gas-passages 31 preferably extend from end to end of the nozzle, having removtool 26 is inserted, is at the end of the furnace,

and thus affords means of easy access with the tool to all parts of the molten charge. Other refining instruments, such as poles of green wood, may be inserted through said door.

It will be understood from the foregoing description that by the use of the water-jacket the lining of my furnace is protected against the saturation with metals which results in other refining-furnaces. The furnace enables me to refine copper in small charges and to cast the metal at a uniform pitch, since the reducing-gas is entirely under control, and the variations in quality of the metal which have often occurred heretofore are prevented. The temperature of the furnace can be controlled so completely that the metal can be kept fluid without chilling, and loss of metal is thus avoided.

Within the scope of my invention as defined in the claims the apparatus may be modified in form and construction, since What I claim is 1. An oscillating, water-jacketed furnace adapted to refine copper, having a removable roof-section, means for heating the furnace, a working door at one end thereof suitable for the insertion of a refining instrument, a twyer below the surface level of the charge to be refined, means for supplying a hydrocarbon gas to said twyer, and means for oscillating the furnace to empty the refined charge; substantially as described.

2. An oscillating furnace adapted to refine charges of copper, having a removable roofsection, a working door at the end of said furnace suitable for the insertion. of a refining instrument, means for heating the furnace, a water-jacket and flexible supply connections therefor, a gas-twyer below the level of the working door, and means for supplying a hydrocarbon gas to said twyer; substantially as described.

In testimony whereof I have hereunto set GEO. B. BLEMING, H. M. CoRWIN.

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