LU82813A1 - METHOD FOR STEEL PRODUCTION FROM SOLID, METAL IRON CARRIERS - Google Patents

Description

D. 51.226 ___ U Ίε. Ο I # AND-DUCHÉ DE LUXEMBOURG Brevet N ° ....................................... ......

you 3o. septembre 193 D Monsieur le Ministre de l’Economie et des Classes Moyennes

Titre délivré ................................... 2¾¾¾ Service de la Propriété Intellectuelle

"- \ t0 LUXEMBOURG

% Demande de Brevet d’invention ΐ 'I. Requête. La. société ... dite: ...... KLÖCKliER-IfSRKE AKTIENGESELLSCHAFT, ..... Klöckner- (1)

Street 29., ...... à ..... 41 ..... DUIS3UR.G., ..... Allemagne. Fédérale., ...... représentée .......................

. par..I4onsie-ar .... Jacques. de .... Muy.ser, ..... agissant ...... en ..... qu.alité ..... de. manda- (2) ^ - ... taire -----------.-.......................... .................................................. ..................... — ............................ .................................................. .................................................. ...............

- déposent) ce. — trente ... septembre 19oo .quatre-vingt .................................. ...... (3) à ...... 15_______________heures, au Ministère de l'Économie et des Classes Moyennes, à Luxembourg; 1. la présente requête pour l'obtention d'un brevet d'invention concernant: "Procedure ... for steelmaking, from. £ esten-t -raetall isehen ............. ........ (4) ........ iron beams "............................. .... ................... ........................... ......... ......................................... .........................................— 2. la délégation de pouvoir, datée de DUISBURG ............................. le 12 ..... juin. .198 O ......

3. la description en langue ........... allemande ._____________________ de l’invention en deux exemplaires; 4 ......... // ............... planches de dessin, en deux exemplaires; 5. la quittance des taxes versées au Bureau de l'Enregistrement à Luxembourg, le ......... 3o ..... septembre ..... 12-Sun ......... .................................................. .................................................. .................................................. ...........................

déclare (nt) en assumant la responsabilité de cette déclaration, que l ’(es) inventeur (s) est (sont): .1 * -..... Ludwig. ..from. ..EÛGDAI'îD.Y, ..... Eirsehkaapstxasse 12, .à ... OBERHÄUSER, .... (5) .................... Allemagne .. Fédéra le ............................................. .................................................. .................................................. ....................................

. .2: .. .Karl .... BROTZMANK ... .Fentsch.er.str.asse .6., ..... à. -SULÉBACH-ROSElïBERG r ...........

................... Allemagne ..... Fédérale -....................... .................................................. .................................................. .................................................. ...

revendique (nt) pour la susdite demande de brevet la priorité d'une (des) demande (s) de (6) brevet ....................... .............................. déposée (s) en (7) ... Allemagne ..Fédérale ..... .......................................

le. .. 2 octobre .. 19.7 9 ........... (Ho .. P 29 3.9 859 .. 2 ^ 24} ................. .................................................. ...................... (8) au nom de. ..La .... d.êpQs.anfce ......... .................................................. .................................................. .................................................. ..................... (9) t élit (élisent) pour lui (elle) et, si désigné, pour son mandataire, à Luxembourg ..... ...............................

..3.5. / ..... bld ....... Royal ............................... .................................................. .................................................. .................................................. ......................... (10) sollicite (nt) la délivrance d'un brevet d'invention pour l'objet décrit et représenté dans les »Annexes susmentionnées, - avec ajournement de cette delivrance à. ..... // .............................. ............. .mois. (11) '1' f. rrf îLe ... bandataire ........... », ......... t ... \ - v: ...........- w. .................... v "'v II. Procès-verbal de Dépôt

La susdite demande de brevet d’invention a été déposée au Ministère de l’Économie et des Classes Moyennes, Service de la Propriété Intellectuelle à Luxembourg, en date du: ^ / · **. g ar.j 1 O g q

Pr. Le Ministre p T_5 heures / de l’Économie et des Classes Moyennes, p. d.

C ii c

A 6SWVT

ί D. 51,226

I DEMANDING PRIORITY

! . the patent / öft / rrf / - application

! IN: THE FEDERAL REPUBLIC OF GERMANY

'From: 2. OCTOBER 1979 ________ jl- I * ---- i% * I * * * r Γ '' X. \ Λ \ λΛ1. \ Ι *; *

PATENT APPLICATION

in

Luxembourg v,

Applicant: KLÖCKNER-WERKE AKTIENGESELLSCHAFT

ι * i

Re: "Process for the production of steel from solid, metallic ^ iron beams".

: f: ü / _! '’’ L: **! *; * ·! $ \\ \ ί l 1 ι. 1 j i * * - * Λ> * <i

Steel Bristle Closure Process. from solid, metallic iron carriers i The present invention relates to a method for the steel manufacture from solid, metallic iron carriers, in particular scrap, pest iron, pellets, sponge iron or any mixtures thereof, in an oxygen blowing converter, which at the same time via oxygen inflators and inlet nozzles for ground, carbon-containing fuels below the steel bath surface.

\ '· ’

Steel production from scrap, without the use of molten pig iron, is preferred today carried out in electric arc furnaces. The cost-effectiveness of this process largely depends on the price of electrical energy. The known converter processes, in which oxygen is blown on or through the melt, work faster and more cost-effectively than the electric arc furnace. To steelmaking | In the converter, however, liquid pig iron is required, to which scrap is added as a coolant in relation to its composition during the fresh process. Usually * f Î the scrap content is up to approx. 30 based on the steel weight.

t! . Converter methods for steel production are now known.

t j, which allow the scrap to steel

J

I - increase production from solid iron carriers. The required heat is brought in by preheating the scrap and adding carbon-containing fuels to the melt. The thermal efficiency of the fuels used essentially determines the economic efficiency with this procedure. · • »/ ~ · ·« • »·, * ..... · - 2» · ·· '· already in the old German patents 508 966 and 537 781 from 1924 and 1929 describe a converter process for melting ore ore, in which coal dust and oxygen or oxygen-enriched air are fed into the melt.

The supply of the fuels and the required heat to the melt seemed to be difficult, because in the additional patent 537.781 it is proposed that the method according to patent 508 966 in an electrically heated con. 1

> I

verter. ·>. - - - - The German patent application r P 28 38 983 - "Process for supplying heat during steel production in the converter" describes an advantageous method of working to increase the scrap rate in the converter as desired and finally to produce a steel melt from solid iron carriers. Following the procedure of this patent application, the scrap is charged into the converter and preheated for about 10 minutes. During the preheating phase, the oxygen inlet nozzles arranged in the converter bottoms work as burners. After the preheating, either liquid pig iron is charged into the converter or work is continued without adding pig iron. As soon as there is melt in the converter, ground, carbon-containing fuel, mainly coke or coke powder, and oxygen with a coating of a hydrocarbon-containing protective medium are injected through the nozzles below the bath surface. Approximately the same amount of oxygen that is introduced below the surface of the bath is simultaneously blown through the free converter space onto the Dad surface.

In the practical application of this method, it has been shown that with a sharp reduction in the amount of pig iron, defined as the amount of pig iron in relation to the steel weight, and when used, only solid iron carriers, the gating time for the fixed iron girders increases proportionally. The batch! Olgo time increases accordingly. Furthermore, the energy consumption fluctuates during this melting phase and rises somewhat on average. The • · known method can consequently not be carried out with as little reliability in terms of its economic efficiency as with the use of a minimum amount of pig iron without the use of molten pig iron. An extended batch sequence time is to be expected and there are fluctuations in the thermal efficiency of the fuels used during the scrap. melting time. .. · * ’. :

The object of the present invention is now to provide a steelmaking process which enables steel to be made from solid iron carriers without the need for liquid pig iron with high energy utilization, that is to say in a reliable manner. with an energy requirement such as when using a minimum amount of molten pig iron, in a relatively short batch time and thus in a more economical manner than previously known.

The invention solves this problem in that 10 to 30% more steel is produced in the converter than the desired tapping amount and that after the tapping of this desired tapping amount, the additional amount of steel is tapped into a separate vessel, preferably a corresponding steel transport pan, a so-called auxiliary pan. 1

The method according to the invention is preferably carried out in a further developed oxygen blow-through converter, according to German patent application P 28 38 983. This converter has oxygen inlet nozzles below the steel bath surface, which serve to add oxygen-containing fresh agents, preferably conventional oxygen, with a hydrocarbon coating to protect the nozzles To conduct melt. At the same time, the converter has oxygen injection devices above the Dad surface, through which oxygen is blown onto the bath. The oxygen scavengers can be nozzles in the refractory lining in the upper convergent area, or they can be the known water-cooled lances. Between 20 to 80% of the total amount of oxygen, the fresh process is led from above through one or more gas jets directed onto the surface of the bath, which over a substantial part of the fresh process; This acts as Frcis rays blowing in a gas space, according to German Offenlegungsschrift 27 55 165. Furthermore, the converter also has inlet nozzles for carbonaceous | Fuels below the bath surface. These nozzles are like | operated according to the procedure of the previously unpublished German i, i patent application P 29 3 333 »7. The fuels are i ·; Coke, brown coal coke, graphite, coal of various qualities and mixtures thereof.

: 'The solid, metallic iron supports used, in particular

Scrap, solid pig iron, pellets, sponge iron or any mixture thereof are first preheated in the converter mentioned. During this preheating phase, the nozzles are operated beneath the steel bath surface as a burner, according to the German j

Patent application P 28 16 5 ^ 3-7 * Liquid and / or gaseous hydrocarbons, preferably natural gas or 01 · dienen are used as fuels. Surprisingly, it has been shown that the melting time and the thermal efficiency of the fuels used for melting scrap at a Increase the stake Λ. e solid, metallic iron carrier in a 30 t converter up to “a share of approx. 30 $ melt, in a 60 t converter up to a liquid part of approx. 20% and in a 200 t converter! ter remain approximately constant up to a weight of the charged melt of approx. 10%. For batches made of 100% solid iron carriers, e.g. Scrap, the melting rate increases, i.e. the time after preheating until there is melt in the nozzle area on the converter bottom, more than expected, and the energy! . * * m- m Λ -5- '.

• · # • * ·

Utilization of the fuels used scatters during this. .

Time relatively strong and is on average lower than in comparison melts with a portion of liquid use · \ There is probably an explanation for this extension of the melting phase and the partly increased energy requirement when working without the use of liquid is that the transition from the pre-warmed scrap to a liquid sump with sufficient yo-lumen, in which the carbonaceous fuels are dissolved and burned to CO under heat generation, due to the relatively widely scattering operating conditions during this process phase. The changing operating conditions can be caused by different types of scrap, for example

Packing in the converter, the degree of oxidation achieved when the solid iron carrier is passed and the resulting changes in heat transfer Ij. In addition, • fluctuations in the melting and the initial position of the bath in the converter are to be expected, particularly with regard to the nozzle arrangement. · ’

According to the invention, 10 to 30% more steel is produced in said converter than for the tapping weight, i.e. for further processing in the steel mill. For example, in a 100 t converter, about 120 t of steel are freshly blended and 100 t of which are tapped for further processing in the steel mill.

According to the invention, the additional steel quantity of approximately 10 to 30% is emptied into a storage vessel, for example into a corresponding steel pan, after the steel melt has been tapped, hereinafter referred to as the auxiliary pan. The steel residue is initially stored in this auxiliary pan and the next melt is fed in again after the preheating of the scrap.

It is important both for the practical implementation and for the economical operation of the new process that the liquid steel quantity ß m intended for the next melt! '· V. '* *, • »- 6 - * · removed from the converter and, after charging and preheating the scrap, the following batch is returned to the converter. A remaining amount of steel remaining in the converter would have two decisive disadvantages. If there is a liquid amount of steel in the converter, it is not possible to preheat the scrap by means of burners in the bottom of the converter. Then, however, the required amount of liquid steel must be at least twice as large as when working with preheated scrap. In addition, it is always problematic in a molten steel, especially if this

There is a lot of bulk to load scrap, because emptying the scrap usually involves manipulation of the converter and additional reactions between the scrap and the liquid bath can also occur.

According to the invention, it has proven advantageous to repair the steel residue to be repeated, i.e. the amount of additional steel from 10 to 30%, carburized to a carbon content> 1%, preferably between 2 to 3. The carburization causes the amount of steel in the auxiliary ladle to cool down, but the lowering of the solidification temperature of the more carbon-rich melt reduces the risk that the repetitive melt will partially solidify as soon as it comes into contact with the scrap during the charging process. Ultimately, by blowing oxygen through the combustion of the carbon contained in the melt, energy is obtained which leads to a desired Ç. contributes to the rapid heating of the sump in the converter and the

Share of melt in the converter increased ·

In order to achieve the best possible thermal efficiency when preheating the solid, metallic iron carriers, for example scrap, charged in the converter, efforts are made to leave no steel residue in the converter. If the molten steel is completely emptied out of the converter, C3 is, however, inevitable that a portion of liquid slag will run along. Between this iron oxide-rich slag and the carburized molten steel, undesired, «- 7 - #

Reactions come. For this reason, inventions are de-oxidized, e.g. Silicon up to a content between 0.1 and 1.5 added to the steel frame. This allows the »

Mostly suppress reactions between slag and steel residue.

9

According to the invention, it has proven to be particularly economical to have all or part of the coal already in the converter; Add liquid steel residue before emptying it into the auxiliary pan. Carburization is carried out in a simple manner by the carbon-containing, ground fuels, for example t

Coke, which is blown in through the existing inlet nozzles in the converter bottom.

The carburizing of the steel residue in the converter according to the invention has particular advantages if the steel is refined according to the so-called two-slag practice. With the two-slag technique, the first slag is removed as completely as possible after the main fresh season. This slag contains the essential parts of the elements to be removed during the fresh process, such as phosphorus and sulfur. In so-called post-blowing or finishing blowing, a second slag is formed in the converter, the ice oxide content of which is normally between 15 and 20%, i (If coal is then blown into the steel residue to be repeated in the converter, the ice oxide solution k «: _ of this second slag is reduced at the same time which is still in the converter. The slag becomes viscous to crumbly and can therefore be retained in the leichter state more easily if the rest of the steel is tapped into the auxiliary pan. This slag is left as a lime carrier for the next melt In this way, the lime consumption is reduced, and at the same time the heat balance is improved, since less lime has to be heated up. Furthermore, it has been shown that this is partly crumbly. ,..

»» I I I

' - 8th - "

Slag improves the degree of thermal engineering during preheating compared to a liquid slag. The reason probably lies in the fact that liquid slag is easier on the me%; ‘Metallic use, for example scrap, solidifies and the heat transfer deteriorates. As already mentioned, it is also difficult to completely empty the steel residue out of the converter as long as the slag is thin. A steel residue in the converter in turn leads to a significant reduction in the thermal efficiency of the fuels used during preheating.

i /;. It is in the spirit of the invention to adapt its essential feature, namely the repetition of a residual steel quantity for the next batch, to the operating conditions in the various steelworks. Both the amounts of residual steel, the time of addition and the alloy rates, in particular carbon and

Silicon, within wide limits while maintaining the inventive concept, the production of steel without molten pig iron, can be varied.

«(*

Claims (5)

1. A process for the production of steel from solid, metallic \ iron carriers, in particular scrap, solid pig iron, pellets, v iron sponge or any mixtures thereof, in an oxygen-blowing converter, which at the same time uses oxygen inflators and inlet nozzles for ground, carbon-containing fuels below the Steel bath surface /, characterized in that 10 to 30% more steel is produced in the converter than the desired steel tapping quantity and that after tapping this desired steel tapping quantity, the additional steel quantity is placed in a separate vessel, preferably a corresponding steel transport pan, a so-called Auxiliary pan, is tapped. 2. The method according to claim 1, characterized in that the said amount of additional steel with or without alloy additions is charged in the next batch after preheating of the solid metallic iron carrier used in the converter. 3. The method according to claim 1 or 2, characterized in that after the tapping of the desired tapping amount, the additional steel amount is carburized in the converter. 4. The method according to claim 3, characterized in that * after the main refining, the slag is largely removed from the converter. 5. The method according to one or more of claims 1 to 4, characterized in that the steel residue to be repeated (additional steel quantity) is adjusted to silicon values between 0.1 to 1.5% with silicon-containing alloying agents. t '!>} ·,) Λ ·