Decuprization and Purification of molten steel by ammonia gas

氨气脱铜净化钢水

• 批准号: 08555179
• 负责人: SUZUKI Ryosuke O.
• 金额: $ 2.56万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08555179/
• 关键词: Ammonia; Decuprization; Scrap; Recycle; Evaporation; 清浄化; スプラッシュ; 窒化物

The purpose of this research is to recycle the steel scrap and to pbtain the cold-rolling grade steel by the secondary refining with copper removal. We confirmed an industrial applicability from the technical view by some experiments that the ammonia nustavle at the higher temperatures was blown to the molten steel. After blowing against the normal steel SS41 containing 1.0%Cu, for example, for 30min. under the continuous evacuation (about 10Torr) and strong stirring condition, copper was removed to 100mass ppm, carbon to 10ppm, oxygen and sulfur to a 10ppm level, and phosphor to 150ppm. However, nitrogen content was so high as 150ppm that we judged that a post-vacuum treatment was required. Accompanying degassing after ammonia top blowing, nitrogen decreased to 5ppm. The ammonia decuprization proceeded at 10 times faster rate than vacuum treatment. It reached to a limit when the present small crucible was used at the laboratory scale, because the effect of interface area on the reaction rate was large. Arranging the rate determine equation to adjust the industrial operation, a good calculation result was obtained that it is possible to remove copper and purify the molten steel within the same time as the present secondary refining process, assuming the wider reaction interface at RH method.The evaporation phenomenon by ammonia from pure copper liquid was visualized by the laser flash method to discuss the mechanism. Abnormal evaporation by ammonia gas blowing on molten pure Cu, Ge and Sn was recorded. The mechanism was discussed that the unstable hydride or nitride is produced by the interaction between these metals and the decomposing ammonia gas. In the high concentration of alloys, in addition to this mechanism, the splash forming introduced by over-saturated nitrogen in the alloy melts was largely contributed.

本研究的目的是利用废钢进行二次精炼除铜，获得冷轧级钢。我们通过一些实验从技术角度证实了将氨吹到钢水中在较高温度下的工业实用性。对含1.0%Cu的SS41钢吹炼30min后，在连续抽真空（约10Torr）和强烈搅拌条件下，铜被除去至100质量ppm，碳被除去至10ppm，氧和硫被除去至10ppm水平，磷被除去至150ppm。然而，氮含量高达150ppm，我们判断需要进行后真空处理。顶吹氨后伴随脱气，氮降至5ppm。氨脱粗以比真空处理快10倍的速率进行。由于界面面积对反应速率的影响很大，目前的小坩埚在实验室规模上使用时已达到极限。通过调整反应速率方程来调整工业操作，得到了较好的计算结果，即在RH法较宽的反应界面下，可以在与现行炉外精炼工艺相同的时间内实现除铜和净化钢水的目的，并利用激光闪光法对纯铜液中氨的蒸发现象进行了可视化观察，探讨了其机理。在Cu、Ge、Sn熔液中，用氨气吹扫，发现了异常蒸发现象。讨论了这些金属与分解的氨气相互作用生成不稳定的氢化物或氮化物的机理。在高合金浓度下，除此机制外，合金熔体中过饱和氮引入的飞溅形成也起了很大作用。

项目成果

Toshitsugu Hidani: "Copper Removal from the molten steel by ammonia gas blowing" Tetsu-Fo-Hagane. Vol.82. 135-140 (1996)

Toshitsugu Hidani：“通过氨气吹炼从钢水中去除铜”Tetsu-Fo-Hagane。

Katsutoshi Ono: "Elimination of copper from the molten steel by NH_3 blowing under reduced pressure" Steel Research. Vol.66. 1-5 (1995)

Katsutoshi Ono：“通过减压下吹NH_3从钢水中消除铜”钢铁研究。

鈴木 亮輔: "アンモニアによる鉄スクラップからの銅の除去" 金属. 8. 55-66 (1996)

Ryosuke Suzuki：“用氨从铁废料中去除铜”金属。 8. 55-66 (1996)

鈴木亮輔,日谷知嗣,竹村康司,小野勝敏: "アンモニアによる鉄スクラップからの銅の除去" 金属. 8月号. 55-66 (1996)

Ryosuke Suzuki、Tomoshi Hiya、Koji Takemura、Katsutoshi Ono：“使用氨从铁废料中去除铜”金属，8 月号。

Katsutoshi Ono: "Elimination of copper from the molten steel by NH_3 Blowing under reduced pressure" Steel Resenrch. 66. 1-5 (1995)

Katsutoshi Ono：“通过减压下的 NH_3 吹炼从钢水中消除铜”《钢铁研究》。