DE175814C

DE175814C -

Info

Publication number: DE175814C
Application number: DENDAT175814D
Authority: DE

Description

KAISERLICHESIMPERIAL

PATENTAMT.PATENT OFFICE.

PATENTSCHRIFTPATENT LETTERING

KLASSE 18 h. GRUPPECLASS 18 h. GROUP

WALTHER MATHESIUS in BERLIN.WALTHER MATHESIUS in BERLIN.

aus Metall-, besonders Eisenbädern.from metal, especially iron baths.

Zusatz zum Patente 165492 vom 15. Oktober 1903.Addendum to patent 165492 of October 15, 1903.

Patentiert im Deutschen Reiche vom 17. Januar 1904 ab. Längste Dauer: 14.Oktober 1918. Patented in the German Empire on January 17, 1904. Longest duration: October 14, 1918.

In dem Hauptpatent 165492 ist ein Verfahren ■ beschrieben worden, nach welchem durch Einführung von Calcium oder Calciumlegierungen Roheisenbäder entphosphort werden sollen, indem der in den Bädern gelöste Phosphor, bezw. die Phosphide, an Calcium gebunden und mit ihm zum Aufsteigen im Bade gebracht werden. Der Erfinder hat weiter, gefunden, daß diese Reaktion noch einer weiteren, wesentlich umfangreicheren Anwendung fähig ist, um diejenigen Schlacken, welche sich besonders im flüssigen .schmiedbaren Eisen in feiner Emulsion befinden und infolgedessen kaum zur Abscheidung zu bringen sind, zu entfernen.In the main patent 165492 there is a method ■ has been described after which by the introduction of calcium or calcium alloys Pig iron baths are to be dephosphorized by the phosphorus dissolved in the baths, respectively. the phosphides, in calcium bound and made to rise with him in the bath. The inventor has further found that this reaction still occurs is capable of another, much more extensive application in order to remove those slag, which are found in fine emulsion especially in liquid, forgeable iron and consequently can hardly be brought to the deposition, to be removed.

Es ist durch die neueren Eisenuntersuchungsmethoden nachweisbar geworden, daß alle Sorten schmiedbaren Eisens noch erhebliche Mengen von Eisenfrischschlacke enthalten. Diese Schlacken bestehen im allgemeinen aus Eisen- und Manganoxyden mit einem wechselnden Gehalt von Kieselsäure. Selbst edelster Tiegelstahl enthält noch ziemlich bedeutende Mengen solcher Reste, welcheIt has become detectable through the newer iron examination methods, that all types of malleable iron still contain considerable amounts of fresh iron slag contain. These slags generally consist of iron and manganese oxides a changing content of silica. Even the finest crucible steel still contains quite a bit significant amounts of such residues, which

a5 sogar durch stundenlanges Kochen, dem der Tiegelstahl unterworfen wird, nicht vollständig aus ihm entfernt werden können. Diese Schlacken sind indessen, wie aus anderen Analogien geschlossen werden muß, auch in flüssigem Zustande des Stahles in ihm nicht gelöst, sondern in der Form einer Emulsion darin enthalten. Diese Emulsion ist sehr beständig, wahrscheinlich infolge der nahen chemischen Verwandtschaft der Schlacke mit dem Eisen, während andere Fremdkörper, z. B. Schwefelmangan, sich aus eigenem Antriebe während einiger Stunden ruhigen Stehens aus dem Eisenbade nach oben hin absondern. Man hat den Versuch gemacht, diese Oxyde durch Sauerstoffentziehung mit Aluminium aus dem Eisen zu entfernen. Die Versuche sind aber negativ ausgefallen, weil man durch sie an Stelle der Metalloxydschlacken Tonerde gesetzt hat, welche noch viel strengflüssiger ist als diese Metalloxyde, und welche deshalb zu ihrer Abscheidung aus dem Eisen eine viel höhere Temperatur erfordert als bei diesem Verfahren zur Verfügung steht. Es ist allein gelungen, in den hohen Temperaturen des Thermitverfahrens diejenige Flüssigkeit der Tonerde und des Eisens zu erzielen, welche es den Tonerdemolekülen ermöglicht, infolge der Verschiedenheit des spezifischen Gewichtes rasch aus dem Eisenbade sich nach oben abzusondern. Es kommt hierbei hinzu, daß die geschmolzene Tonerde ein in chemischer Beziehung außerordentlich indifferenter Körper ist, der z. B. auch mit Kieselsäure nur sehr strengflüssige Verbindungen bildet.a5 even through hours of cooking, which the Crucible steel is subjected to it cannot be completely removed from it. These However, as must be inferred from other analogies, slags are also in In the liquid state of the steel, it is not dissolved in it, but in the form of an emulsion included in it. This emulsion is very permanent, probably due to the close proximity chemical affinity of slag to iron, while other foreign bodies, z. B. Sulfur manganese, on its own initiative during a few hours of quiet standing from the iron bath upwards secrete. An attempt has been made to use these oxides by removing oxygen Remove aluminum from the iron. The attempts were negative because they have replaced alumina in place of the metal oxide slag, which is still there is much more viscous than these metal oxides, and which is why they are used to separate them from the iron requires a much higher temperature than is available with this process stands. It was only possible to use the high temperatures of the thermite process to remove the alumina and the To achieve iron, which allows the clay molecules, due to the diversity of the specific weight to separate quickly from the iron bath upwards. It Added to this is the fact that the molten alumina is extraordinary in chemical terms is indifferent body that z. B. only very strict liquid with silica Forms connections.

Verwendet man nun aber zu diesem Zweck an Stelle des Aluminiums das metallischeBut if one uses the metallic instead of the aluminum for this purpose

Claims

Calcium, first of all, instead of the relatively low-affinity alumina, there is the highly basic calcium oxide, which in its compounds is considerably more fluid than alumina, and which in the molten state has a considerably lower specific weight than corundum. Second, the chemical relationship between calcium oxide and iron is considerably less ίο than that between clay and iron. For this reason, too, it becomes that. Calcium oxide may be inclined to separate itself from the iron bath more quickly than the molten clay. It therefore appears in itself. It is much more advantageous to use calcium than aluminum for these purposes. Calcium also has an effect that is not at all or almost completely absent from aluminum, namely to immediately convert the iron phosphides and sulfides present in the iron bath into the corresponding calcium compounds and again in the same way to rapidly dissolve the emulsion from the iron bath for separation bring. The use of calcium carbide has already been proposed for the same purpose, but without achieving the desired success with it. The difference in effectiveness can be explained as follows. The calcium metal is easily soluble in iron, therefore diffuses relatively quickly through the iron bath and now combats the above-mentioned foreign bodies in all places, while calcium carbide is not or only slightly soluble in iron and is therefore not able to deal with the in extremely fine distribution of foreign bodies contained in the iron bath to react. The metallic calcium can be incorporated into the bath in two ways, either by adding the metal as such to the bath, or by adding the calcium to the iron bath by electrolysis of the slag, provided that the iron bath is covered with a lime-rich slag. For this purpose it is only necessary that the metallic iron of the bath is made into the cathode, while one or more anodes are brought into conductive connection with the slag layer. In this case, the formation of ions brought about by the electric current also causes a much more rapid migration of all slag parts from the inside of the molten iron to the surface. Since metallic calcium is not very resistant to atmospheric influences, it seems advisable in practice to use an alloy of calcium with aluminum instead of pure calcium, which also appears harmless in view of the aspects developed above, since the molten liquid of calcium oxide and its Compounds is favorably influenced by the addition of a few percent alumina. It will be understood that the same procedure can be used for the purpose of cleaning all other metal baths. It is also already known to use alkaline earth metals, possibly also in conjunction with aluminum, to obtain bubble-free cast steel by binding gases dissolved in the steel. This process, in which the aluminum alkaline earth alloys are to be added at the moment of casting, can of course not be used to remove emulsified slag, since it is absolutely necessary to give the metal baths sufficient time to separate the slag freed from the emulsion, i. H. so to give to stone formation. Godfather ν T-A ν Proverbs:

1. Application of the method according to patent 165492 for the separation of impurities made of metal, especially iron baths, characterized in that the fresh slag residues, iron phosphides, Baths containing sulphides etc. as long as they are in furnace ladles or mixers, located, metallic calcium or an alloy of calcium and aluminum is added, whereupon the metal bath is left to separate sufficiently before it is further used for casting.

2. Embodiment of the method according to claim 1, characterized in that that the introduction of calcium by means of electrolysis happens in such a way that the λίε-tallbad the cathode and lime-based slag baths located above the metal represent the electrolyte, with at the same time the separation of the suspended slag residues from the metal is promoted by ionizing the baths will. no