Converter steel production with the use of fluoritized limestone and a combination blow

Autor: Yu. A. Pak, V. D. Kuleshov, V. S. Kolpakov, A. K. Smirnov
Rok vydání: 1989
Předmět:
Zdroj: Metallurgist. 33:199-199
ISSN: 1573-8892
0026-0894
Popis: Bottom-blowing converter steelmaking makes it possible to intensify mass transfer and the refining of the metal. However, such a practice also entails an increase in the consumption of expensive and scarce fluorspar, which is used to thin the slag. The Cherepovets combine made heats of steels 2sp and 3sp in 350-ton converters in which the slag was thinned with fluoritized limestone instead of a mixture of fluorspar and bauxite (the fluoritized limestone is a by-product of fluorspar production and contains 92.5% CaF2). In the trial heats, the consumption of inert gas through the bottom was 12-13 m3/min (0.030-0.045 m3/min.ton). The bath was blown from below for 1-3 min after the end of the top oxygen blow. We used pig iron containing 0.45... 1.18% Si; 0.17...0.24% Mn; 0.009...0.038% S; 0.037...0.057% P, while the slag-forming materials were partially burnt lime and dolomite. The fluoritized limestone was added in batches. It was established that with a consumption of fluoritized limestone of 1.11 tons per heat (versus 0.69 tons of the fluorspar-bauxite mixture), the steel has nearly the same contents of sulfur and phosphorus. With satisfactory slag formation, the slag at the sampling point was sufficiently fluid and was easily removed. No metallization of the lance or deterioration in the performance of the converter lining were observed.
Databáze: OpenAIRE
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