Bottom Blowing Research Articles

Improvement of the Heat Balance in the Combined Blowing Process

Thermal recovery processes in the STB (Sumitomo Top and Bottom blowing) process have been developed and the refining characteristics have been investigated. Postcombustion process in a STB converter has been developed, applying the results of fundamental tests by a 15t STB converter to a commercial scale 160t STB converter. And then coal injection process through a top lance was combined with postcombustion. The results are as follows:(1) A lance of the two-independent-flow type is essential to postcombustion.(2) The jet angle θ2 for postcombustion should be wide as 30-35 deg.(3) The oxygen flow rate through PC nozzles should be about 20% of the total oxygen flow rate.(4) The thermal recovery efficiency of postcombustion is very high, nearly 100% in a 15t STB converter and 70% in a 160t STB converter.(5) Although postcombustion causes no change in % (T.Fe) in the slag at the end point, it increases (Fe3+) in the slag and improves dephosphorization of the hot metal.(6) The large amounts of heat can be effectively used to improve the heat balance in a converter by using the TAPS (Triple Action Process of STB; coal injection from a top lance with postcombustion).(7) In the case of the TAPS, as the coal injection interferes with postcombustion, it is necessary to inject coal effectively within a short time.

酸素上吹き一アルゴン底吹き法によるステンレス鋼溶製法の開発

酸素上吹き一アルゴン底吹き法によるステンレス鋼溶製法の開発

Comparative tests of refractories in the tuyere zones of a converter with bottom oxygen blowing

For the purpose of investigation of highly resistant refractories for use in the tuyere zones of the bottoms of converters with bottom oxygen blowing after semiproduction tests, comparative tests were made of different domestic refractories under production conditions. Tuyere refractories in the form of 280x225x190 mm blocks with a center channel under the 30 mm diameter tuyere were produced for the investigation at Magnesite Combine in TsMI-2. Blocks of the type PKhK periclase-chromite composition, type PShGP periclase with a spinel binder, type KhM chromite-periclase, KhPT, and type MKhVP periclasechromite were produced. The chemical compositions of the mixtures for production of the parts are given. Vanadium iron was blown and the bottom fuel-oxygen blowing of the vanadium iron was done using two variations. The amount of wear of the blocks and tuyeres is presented and a chemical analysis of the samples of parts after service is shown. Under the conditions of the investigation conducted, KhM chromite-periclase refractories showed the greatest resistance.

Comparative tests of various forms of refractories in the bottom of a converter in the blowing of vanadium iron

Comparative tests have been made of different forms of refractories in the zone near the tuyeres of the bottom of a 300-kg converter in bottom blowing of vanadium iron into steel. The various types of refractories that were prepared for testing in the experimental converter were: KhM chromite periclase; PkhP periclase-chromite; PShV and PShPKhV, periclase-spinellide; fired fused periclase base experimental composition; and unfired type PGBP periclase-carbon based on fused periclase. The basic properties of the refractories used are shown.

ステンレス鋼における転炉複合吹錬法の冶金特性

ステンレス鋼における転炉複合吹錬法の冶金特性

上底吹き転炉特性のコールドモデルによる検討

上底吹き転炉特性のコールドモデルによる検討

予備処理溶銑を用いたクロム系ステンレス鋼の溶製

予備処理溶銑を用いたクロム系ステンレス鋼の溶製

上下吹き転炉における少量スラグ吹錬の精錬特性

上下吹き転炉における少量スラグ吹錬の精錬特性

底吹き取鍋,LD転炉およびRH脱ガス装置における混合特性の比較

底吹き取鍋,LD転炉およびRH脱ガス装置における混合特性の比較

コールドモデルによる底吹きガスの吹き抜け臨界条件の検討

コールドモデルによる底吹きガスの吹き抜け臨界条件の検討

上底吹き転炉の冶金反応特性に対する鋼浴攪拌強さの影響

上底吹き転炉の冶金反応特性に対する鋼浴攪拌強さの影響

底吹き転炉吹錬における脱燐挙動と溶銑脱燐法の開発

底吹き転炉吹錬における脱燐挙動と溶銑脱燐法の開発

底吹き転炉を用いる生石灰系フラックスによる溶銑脱燐の反応機構

底吹き転炉を用いる生石灰系フラックスによる溶銑脱燐の反応機構

Bottom Blowing with Oxygen

This article describes a new iron refining process which drastically reduces iron oxide fumes. Instead of the top lancing of the LD process, high-pressure oxygen is injected into the bottom of the metal bath through specially-designed injectors. The cooling effect of the oxygen flow itself eliminates the need for an external coolant.