創新轉爐熱渣吹氧改質安定化製程研究

The Study of Molten BOF Slag Modification and Stabilization Technology by Oxygen Blowing Treatment

曾耀弘(Y.H. Tseng) ； 翁丁財(T.T. Weng) ； 李育成(Y.C. Lee) ； 郭煜賢(Y.H. Kuo)

《鑛冶：中國鑛冶工程學會會刊》 66卷3期 (2022/09) Pp. 25-35

https://doi.org/10.30069/MM.202209_66(3).02

摘要

世界商轉之轉爐熱渣改質安定化製程多利用矽砂作為調渣劑，將矽砂吹入轉爐渣中以達成轉爐渣安定化，惟矽砂改質需再額外吹入矽砂造成物料成本上升、爐渣量增加，熔解矽砂之熱能損失。針此，本研究發展創新轉爐熱渣吹氧改質安定化技術，製程中不加矽砂以減少熱能損失及大幅減少渣量增加，同時可以降低物料成本。轉爐熱渣吹氧改質安定化其原理乃利用渣中自身FeO氧化成Fe_2O_3再與游離氧化鈣結合成鐵酸鈣，以達到安定化。經於中鋼改質站進行試驗，探討攪拌時間、吹氧量及氧氮比與改質成功率之關係，再搭配轉爐渣渣性預測技術，完成吹氧改質製程優化，改質成功率可達91%。吹氧改質轉爐石具有三降特質，包含（1）降膨脹率（＜0.5%）、（2）降鹼功效（pH：10.6～10.8）及（3）降白濁（鈣離子不易溶出），可有效化解一般轉爐石之使用疑慮，另，因其富含鐵酸鈣之特性，後續有機會應用於燒結原料及煉鋼輔料，為轉爐石開創多元資源循環及利用途徑。

關鍵字

熱渣改質 ； 吹氧改質 ； 轉爐石 ； 安定化 ； 資源循環利用

並列摘要

The strategy of injecting silica sand into molten BOF slag is normally used in traditional molten BOF slag modification. However, the addition of the silica sand causes the increase in cost, slag amount produced and heat loss of the treatment. Herein, we developed an innovative technology for BOF slag stabilization. In this new technology, oxygen was blown into molten BOF slag without adding silica to achieve slag stabilization, which results in lower cost, slag amount produced and heat loss. The stabilization is achieved through FeO oxidation of BOF slag, which forms Fe_2O_3 to react with f-CaO, and finally forms stable calcium ferrite. Together with the prediction technology of BOF slag property, the operation conditions of stirring, oxygen blown amount and O_2/N_2 ratio in slag modification station of CSC was optimized to yield a success rate of 91% of slag modification. With the superior properties of low expansion (＜0.5%), low pH(10.6-10.8), low turbidity (low calcium ions dissolution) and high calcium ferrite amount found in modified BOF slag, it is believed that various applications such as engineering materials, sintering raw materials and steelmaking flux can be developed.

並列關鍵字

molten slag modification ； oxygen blowing modification ； BOF slag ； stabilization ； Resource recycle and utilization

參考文獻

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Y.H. Tseng, Y.C. Lee, and B.L. Sheu, 2015, Proceedings of the 8th European slag conference, Linz, Austria.

Y.H. Tseng, T.T.Weng, and Y.C. Lee, China Steel Technical Report, (2019), 32, 39-43.