電爐高效冶煉技術開發

Development of Efficient Electric Arc Furnace Smelting Technology

黃宥綸(Y. L. Huang) ； 曾名輝(M. H. Tseng) ； 邱永麟(Y. L. Chiu) ； 劉永章(Y. C. Liu) ； 張顧齡(K. L. Chang) ； 林常盛(C. S. Lin)

《鑛冶：中國鑛冶工程學會會刊》 63卷4期 (2019/12) Pp. 69-78

https://doi.org/10.30069/MM.201912_63(4).06

摘要

中龍擁有全台灣唯一可添加鐵水製程的電爐，具備熱能高且稀釋有害元素之優勢，但在中鋼集團自我回收煉鋼爐渣的政策下，中龍電爐肩負回收脫硫渣鐵的任務，根據以往冶煉數據，電爐回收脫硫渣鐵會產生許多負面效應。研究為提升電爐冶煉效率、提高產品品質、及促進循環經濟效益，開發脫硫渣鐵高效熔化技術、保碳吹煉技術及泡沫渣冶煉技術。脫硫渣鐵高效熔化技術以渣化取代熔化，提升脫硫渣鐵回收效率；保碳吹煉技術則是由前期軟吹、末期保碳，促進脫磷及提高產率；泡沫渣冶煉則是透過第二相固態粒子的控制提高爐渣黏度，藉爐渣泡沫化包覆電弧以節省電力。技術落實於現場產生五大效益：（1）鋼液產率提升3.27%，大幅降低冶煉成本；（2）環保減渣貢獻：冶煉渣量減26.9%，同時脫硫渣鐵回收去化量從5%提高至10%，使渣鐵回收達平衡；（3）能源效率提高：電耗每年節省34Gwh；（4）鋼液品質提升（磷不合格率7.2%降至0.6%、氮78ppm降至65ppm）；及（5）接續製程改善:包含降低精煉製程合金量及提高鋼胚清淨度。估算整體年效益約10億元。以上技術皆可應用在國內電爐廠，及拓展到其他煉鋼渣的回收去化，達煉鋼爐渣循環回收及製程節能減廢的效益。

關鍵字

電弧爐 ； 冶煉 ； 渣鐵回收 ； 泡沫渣

並列摘要

The electric arc furnace in Dragon Steel Corporation (DSC) is the only one in Taiwan that is charged with molten iron. This furnace has the advantages of high thermal energy input and being able to dilute harmful elements. Recently, this process is used to recycle desulfurization slag in CSC Group. However, the process efficiency becomes poor when charging desulfurization slag to the furnace; this includes lower iron recovery rate and higher energy consumption. In order to improve the efficiency of smelting and product quality, and to promote the economic benefits of the recycle, three smelting technologies have been developed. The first one is the high-efficiency melting technique for recycling desulfurization slag, which is to substitute slagging process for melting process to improve the melting efficiency of de-sulfurized slag. The second one is the EAF catch-carbon gas blow technique, it is the ＂soft blow＂ in the early period and the ＂catching carbon＂ in the final period of the smelting process. The last one is the EAF foamy slag smelting technique, it is to increase the slag viscosity through the control of solid particles in the slag, and to create foamy slag for saving electric power. Major benefits found from the implementation of these technologies in practice are: (1)EAF yield was increased by 3.27%, which significantly reduced the cost; (2) the smelting slag was reduced by 26.9%, and capacity for recycling desulfurization slag was increased from 5% to 10%; and as result of that, the desulfurization slag in CSC Group can be fully recycled; (3)Energy efficiency was improved by saving 34Gwh of electric power each year; (4)The quality of molten steel is improved by reducing phosphorus rejection rate from 7.2% to 0.6% and nitrogen content in the steel from 78ppm to 65ppm, and (5)The ensuing processes was able to be improved by reducing the amount of alloys in the refining process and increasing the cleanliness of steel. The overall annual benefit of these smelting technologies is nearly 1 billion TWD. The developed technologies can be applied in domestic electric arc furnace plants for the treatment of steelmaking slag and achieving slag recycling, saving energy and reducing by-products from steelmaking plants.

並列關鍵字

electric arc furnace ； smelting ； recycle slag ； foamy slag