US1587600A - Method of introducing additional agents into matallurgical baths - Google Patents

Description

June 8 1926. 587,600

0. NIELSEN METHOD OF INTRODUCING ADDITIONAL AGENTS INTO METALLURGICAL BATHS Filed Dec. 4, 1924 Jmverzfor n L P '5 3 oaired dune i3,

My inventionreiates to new method introducing additional agents into gical baths, and more especially to method of addin chemical substances to inert metallurgical baths, for instance in tionwith the refining process for copper, and the chief object my invention is to obviate the disadvantages of the so-cailed poling recess, that is the process of refinin w ich essentially consists in adding o les of green wood to the metallurgical ath, in order to bring about the refining. According to my invention the process of refinin is carried out in two successive steps, viz in first introducing into the molten mass of the bath an agent in gaseous form or a stream of oxidizing gas, and thereupon introducing a reducing agent, which may be gaseous, liquid or also solid, in the latter case in round or crushed condition.

In or er to explain my invention more fully, I'may refer, for example to the refining process for copper by treating the same in raw condition in a reverberatory furnace. This process, as known, is carried out by blowin compressed air through a tube mto the ath of molten copper. In modern practice the tube serving for the introduction of the compressed air terminates below the surface of the bath, in order to have the oxidation proceed most eifectively. The entire copper bath will thus be mechanically a itated, as if being in a state of boiling, by the action of the gas rising from the end of the tube; the motion of the bath thereby will greatly assist the gas introduced thereinto in bein distributed all over the mass contained in t e bath. If thus the impurities contained in the latter have been removed, the copper will take up ox gen as if in solution, and it will at this time ein an intermediate condition, in which it is only partly or imperfectly refined. In this case the percentage of oxygen contained in the copper will amount to about 0.6 percent. In or or to complete the process of refining, this amount of oxygen must also be removed from the bath and this had heretofore been effected by the above-mentioned process of poling, that is by introducing poles of green .wood into the bath. The steam and hydrocarbons thus introduced will act on the bath in such a way, that the steam will cause the bath to be greatly agitated and the hydrocarbons wil take up the oxygen contained in the bath, thus'exerting a reducing eflect bath is very crude volition is provide a efiicient of refining. I am aware of as a substitute for the poiing process there had been proposed to empoy tar-oil or petroleum, that is liquid fuels. This prom ess, however, has been utterly unsuccessful for two reasons. Firstly, to introduce a substance of the kind mentioned into the bath is connected with danger, and secondly, the liquid fuel thus introduced into the bath will only to a small extent be utilized for the pur ose of reduction, so that the efiiciency of t is process will necessarily be very poor. By t e refining method according to my invention, the introduction of the liquid fuel as a reducing and refining agent may be carried out absolutely without danger and a complete reduction of the bath will be at- 39 tained with a very small quantity of oil or other reducing agents. The process accordmg to my invention, as may be mentioned by the way, has been employed in actual practics and has met with a complete success. Inorder to properly meet the conditions existmg in the bath, when the refining is intended, the fact must be taken into consideration, that the temperature of the fur-- nace amounts to from 1200 to 1300 degreesoo centlgrade. By introducing the oil or'other: reduclng agent into the bath through the tube, even if terminating above the level of the bath, there will be heavy puflin not to say an explosion, and the oil will be burnt up-by the oxygen of the air and thus be utilized only to a very small extent for the i desired purpose of bringin about a reduction of the co per. In ad ition to this, if the orifice of t e tube terminates below the level of the bath, the tube would either melt away or become clogged u so that it will be unable to perform the esired functions.

My invention will be more fully understood by reference to the accompanyin 106 drawing, which represents diagrammat1cal ly an exam 1e of an arrangement. and combination' 0 parts, by which my invention may be carried out in practice.

In the drawing D designates the furnace 110 containing the metallurgical bath, for instance molten copper containing oxygen.

The coritainer A is filled with a suitable reducing a out, which in the present case may be an oi, or also a reducm substance in round or crushed solid con ition, such as or instance calcium carbide charcoal, or the like. The steel-bottle l3 contains a comfpressed gas of suitable character, such as or instance carbonic acid, nitro en, or the like, or also steam which may e substituted for these gases. The bottle B is provided with a valve e, which is connected with the container A by the tube f. The container A'is rovided with a safet valve 9 at its top and with an outlet pipe at its bottom, the outlet pipe h being provided with a cook or valve 77., by means of which it may be connected with the pipe The latter is connected to the pipe f at t e point f indicated in the drawin The junction f, of the pipe I and the pipe f, as well as the junction 7, of the outlet ipe h of the container with the horizontai part of the pipe f, serves for the successive introduction of the two reducing agents into the bath according to my invention, said agents being contained in the bottle B and the cor. tainer A respectively. A further valve or cock 2' is provided in the pipe f between the junctions f and i The device described will operate as follows. Supposing the copper-bath be in proper condition in the furnace D for commencing with the process of refining, the device may be put in operation by opening the valve 6, the valves 2 and it, being closed at this time; the gas contained in the bottle B will now be able to pass into the container A. in order to facilitate the passage of gas from the bottle B into the container A, the safety valve 9 rovided on the latter may be lifted for a s ort time. The end of the pipe 0, which joins the outlet pipe it and the pipe f, at the point of junction f is introduced at its orifice into the bath contained in the furnace D, as shown in the drawing and thereu on the valve 2' is opened for some time. A'ter a certain time the valve 6 is again closed, thus preventing an immediate supply of gas from the container 13 to the bath of the furnace D, and the valve h, is now opened. By this a part of the liquid agent contained in the container A will be forced through the outlet pipe it into the pipe C and through the orifice of the same into the bath of the furnace D.

The inert gas for instance carbonic acid;

diately.above.the level of the bath. Carbonic acid will thus enter the bath and move therein in upward direction. By reason of the fact, that the gas dischargin from the orifice of the ipe G is in cold condition, the orifice of t e pipe, 0 will not be damaged by the temperature of the bath, and no 0 oggingaip of the orifice ormelting of the same can thus take lace. inthis manner carbonic acid is supp ied to the'hath' only for such a time as will be HGCGSSEL? to carry on this phase of the process accord ing to my invention; At the proper time, therefore, the valve a is closed and the valve h, o ened, so that now a part oi the agent in t e container A will be forced into the bath. The carbonic acid during this phase ofthe process merely serves for the purpose of pressing liquid from the container A into the pipe C and therewith into ti o bath. By pro erly adjusting the valve c at the top of t ebottle B it will of course be possible to regalate the amount of gas passing from bottle '3 to the conta n-er A during his of the process.

E wish it to be understood, that in tead oi the liquid agent in the container A there may also be employed an agent in gaseous form or in ground or crushed solid condition as above mentioned. Also the container A should in such case he properl constructed in order to serve for the reception of an agent gaseous or solid condition.

The process according to in may also be employed with a montage in connection with other metalurgical processes, whereby easily oxidizable substances are introduced into the bath.

My present process may furthermore be advantageously employs with the process of remelting copper in crucibles, such as is ordinarily done in foundries. In this case the process of pol'ing could only be applied, if certain substances, such as phosphorous, are added to the copper, which as a rule is not practicable in foundry work.

I claim:

The method of introducing a refining agent into a metallurgical bath, which consists in first introducing -ani inert gas into the bath, for the purpose of removing the air contained in the conduits to the bath and invention in connection ing the refining agents to said hath,

" thereupon introducing into said hath the reducing agents in liquid, gaseous or solid condition, substantially as described and for the purpose set forth.

in testimony whereof I hereunto aiiix signature.

OTTO NIELSEN.

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