Krupp race procedure
The Krupp racing process is an iron reduction process carried out in a rotary kiln, in which the iron is extracted in the form of compact, low-carbon pellets . It is used to process acidic and low- Fe ores that cannot be smelted in the blast furnace.
History of origin
The Krupp racing process was developed in the early 1930s by the metallurgist Friedrich Johannsen in the Fried. Krupp AG in Magdeburg-Buckau ( Grusonwerk ). It partly represents a transfer of the old racing work to the rotary kiln and thus to an ongoing large-scale operation.
The words “racing work” and “running”, which are derived from “getting into the gutter”, refer to processes in which the iron is extracted directly from the ore as low-carbon and therefore malleable iron. In contrast to the blast furnace process, there is no liquefaction of the reduced iron in these racing processes. Rather, solid iron flakes are produced by a welding process, which are usually stored in a semi-liquid slag and are only separated from it when it is cold.
The racing fire for thousands of years the only method for iron extraction and was widely applied in almost the same way. The first racing ovens were made as early as 1500 BC. Built. They were clay ovens into which charcoal and iron ore were placed in layers. Temperatures between 1200 and 1300 ° C arose in the racing furnace. The disadvantage of the racing fire operation was that it could only be carried out in small businesses and with interruptions and, despite the high fuel consumption, only had a low iron output: With the old racing fire, for example, only an iron output of 30 to 60% compared to 90 to 96%. achieved in the Krupp racing process.
The regular operation of the Krupp racing procedure began in Essen-Borbeck in 1935. Almost at the same time, the race course of the Schlesische Nickelwerke in Frankenstein, which in 1915 became the property of Fried. Krupp AG had gone over to their work. Further plants were commissioned worldwide:
Works
| Number of ovens | place | builder | Inner diameter (m) | Length (m) | Capacity (t ore / day) | Start of production | End of production | notes |
|---|---|---|---|---|---|---|---|---|
| 1 | Steelworks and mines in Rheinhausen | F. Krupp | 0.9 | 14th | 1 | Rheinhausen ironworks abandoned in 1993 | Demonstrator | |
| 1 | Essen-Borbeck | F. Krupp | 3.6 | 50 | 275-300 | 1935 | 1945 | Dismantling -> USSR |
| 2 | Frankenstein ( Silesia ) | Silesian nickel works | 3.6 | 50 | 275-300 | 1935 & 1941 | Dismantling -> USSR processing of garnierite |
|
| 2 | Salzgitter-Watenstedt | F. Krupp | 4.2 | 70 | 2 × 500 | 1943-1945 | 1945 | Dismantling in 1950 |
| 1 | Royal Court (Czechoslovakia) | F. Krupp | 3.6 | 60 | 300-325 | 1943 | 1945 | |
| 1 | Salzgitter-Watenstedt | F. Krupp | 4.2 | 70 | 1 × 500 | Still under construction at the end of the war | 1945 | |
| 8th | Anshan (Manchuria) | Shōwa side sushi | 3.6 | 60 | 8 × 300 | 1939 | Ore containing 35–36% Fe and 40–48% SiO 2 | |
| 4th | Seishin (Korea) | Mitsubishi Corporation | 3.6 | 60 | 4 × 300 | Ore with 55-60% Fe | ||
| 2 | Kuji (Japan) | Kawasaki shipyard | 3.6 | 60 | 2 × 300 | 1967 | Ore containing 34–35% Fe and 5–8% TiO 2 | |
| 4th | Oeyama (Japan) | Nippon Yakin Kogyo | 3.6 | 70 | 500-600 | 1940-1942 | ||
| 1 | Avilés (Spain) | 3.6 | 60 | 250-275 | 1954 | Ore with 30–40% Fe and 20–30% SiO 2 | ||
| 1 | Larymna (Greece) | Hellenic Company of Chemical Products & Fertilizers Ltd. | 4.2 | 90 | 400 | 1956 | Ore containing 35% Fe and 1.5-1.75% Ni | |
| 2 1 |
Salzgitter-Watenstedt | Rennanlage Salzgitter-Ruhr GbR. | 4.2 4.6 |
95 110 |
2,000 | 1956-1957 | 1963 | Acid ore with 28 to 34% Fe |
| 6th | Essen-Borbeck | Rennanlage Rhein-Ruhr GbR. | 4.6 | 110 | 4,200 | 1959 | 1963 |
Description of the procedure
The iron-containing ores to be processed are, if they are delivered in lump form, crushed to about 10 mm and then mixed with reducing substances of about the same size. Low-quality fuels such as coke dust or anthracite dust are particularly suitable as reducing agents. Usually about 90% of the fuels are added to the ore and about 10% are introduced as flame heating at the outlet end of the furnace. The mixture of ore and fuel is fed into the slightly inclined rotary kiln and runs through it at temperatures of 600 to 1100 degrees Celsius for up to 12 hours. The discharge from the furnace consists of a semi-soft slag with embedded lobes that are up to about 200 mm in size. The discharge, cooled by air or water, is ground in a comminution plant. The flakes are freed from the externally adhering slag, which is finely ground to about 1 mm, without being crushed. While the removal of the slag from the old racing fire had to be promoted by manual labor, in the Krupp racing process the rotary motion of the furnace supports the separation of the slag from the pellets and the formation of large pellets through the constant rolling of the semi-soft loading. The whole grain over 1 mm represents the lump product, while the grain under 1 mm consists of slag and the smallest lobes. A final slag is produced from this undersize and a magnetic concentrate is produced as the middle product. The pellets produced in this way are particularly suitable as raw material for steel production, the fine-grained slag is mainly suitable as a base for road construction, the middle product is returned to the furnace.
Practicality and economy
In the immediate pre- and post-war period, the long-term securing of supplies of ferrous raw materials turned out to be a desideratum of the German steel industry. The German ores were by no means sufficient for domestic steel production. In addition, they only had a low iron content compared to high-quality foreign ores. In addition to ore, scrap was used for steel production. However, scrap was an extremely cyclical commodity and subject to constant speculation. As the scrap supply - according to the assessment at the time - would become a serious bottleneck with increasing steel production, the iron and steel works on the Ruhr looked for a "scrap substitute"
The solution was seen in the development of the Krupp racing process, which gained renewed - also international - importance just a few years after the dismantling of German systems as part of the reparation payments. In 1956 the Salzgitter-Ruhr GbR racing facility was put into operation in Salzgitter-Watenstedt , followed by the Rhein-Ruhr GbR racing facility in Essen-Borbeck in 1959 . Both plants were able to process the low-iron ores from the ore deposits in the Salzgitter area. But the market suddenly changed. The Swedish mine owners had meanwhile increased their capacities considerably and had been offering their higher-quality ore at ever lower prices since 1958. When the steel industry collapsed in the summer of 1961, the seven largest ironworks in the district agreed in 1962 that from the beginning of 1963 onwards they would no longer purchase ore from Salzgitter and only smelt foreign ore. Their western coal and steel partners had already decided not to use Salzgitter ores any more. This also sealed the end of the racing facilities in Salzgitter-Watenstedt and Essen-Borbeck. They were shut down in 1963 and then dismantled.
The Krupp racing process was further developed into the Krupp iron sponge process for the use of iron-rich ores. The SL / RN process is also a further development of the Krupp racing process. It is named after the companies Stelco , Lurgi , Republic Steel and National Lead and also works with rotary kilns to produce sponge iron .
literature
- Jürgen Ruge: Technology of materials: manufacture, processing, use; with 68 tables . Vieweg, Wiesbaden 2007, ISBN 978-3-8348-0286-6 .
- Entry on Krupp-Renn-Proceedings. In: Römpp Online . Georg Thieme Verlag, accessed on 2014-11-17.
Individual evidence
- ^ Friedrich Johannsen, The Krupp race procedure, in: Steel and iron . Journal of the German Ironworks , Volume 54, Issue 38 (1934), pp. 974, 976
- ↑ For the biography cf. Marc Zirlewagen, Biographical Lexicon of the Associations of German Students , Volume I, Norderstedt 2014, p. 381.
- ↑ Johannsen, op.cit., P. 969
- ↑ Felix Sykorra, that time at Krupp at the Bottrop street: Borbecker News / food from 2 November 1979 to November 9, 1979
- ↑ Communauté Européenne du Charbon et de l'Acier (ed.): Procédé de réduction directe des minerais de fer . 1958, p. 130 ( PDF ).
- ↑ a b Akira Kudō: Japanese-German business relations cooperation and rivalry in the inter-war period . Routledge , 1998, ISBN 0-203-01851-6 , pp. 93 ff.
- ↑ a b Song of the Archangels . In: Der Spiegel . No. 29 , 1962, pp. 31-32 ( online - 18 July 1962 ).
- ^ Borbecker Nachrichten / Essen, February 8, 1963
- ↑ Johannsen, op.cit., P. 969
- ↑ Johannsen, op.cit., P. 970
- ^ DIE ZEIT , No. 46, November 13, 1958
- ↑ Hamburger Abendblatt, June 4, 1957
- ↑ DIE ZEIT No. 23 of June 6, 1957
- ^ Hermann Schenck , Werner Wenzel, Heinrich Gudenau: Reduction of iron ores with oil and natural gas . Westdeutscher Verlag , Opladen 1972, ISBN 978-3-531-02228-4 , pp. 12 .