Utilization of Waste Copper Slag to Produce Directly Reduced Iron for Weathering Resistant Steel

• Xian-Lin Zhou

  School of Mineral Processing and Bioengineering, Central South University

• De-Qing Zhu

  School of Mineral Processing and Bioengineering, Central South University

• Jian Pan

  School of Mineral Processing and Bioengineering, Central South University

• Teng-Jiao Wu

  School of Mineral Processing and Bioengineering, Central South University

抄録

Waste copper slag is a refractory material with high iron content, but it is difficult to recovery iron minerals from the slag because the iron mainly occurs in fayalite. A new technology of coal-based direct reduction-magnetic separation process was developed to recover iron from the slag assaying 39.85% Fe_total and 0.33% Cu. The results show that the final iron concentrate, assaying 90.68% Fe_total, 94.01% metallization degree, 0.66% Cu and 0.058% S with overall iron and copper recoveries of 90.49% and 79.53%, respectively, was manufactured under the optimized conditions as follows: balling the mixture of copper slag with 20% compound additive at 0.3 of basicity, preheating the green pellets at 1000°C for 9 min, then reducing the preheated pellets at 1200°C for 70 min with coal to dried pellets mass ratio of 2, grinding the reduced pellets up to 95% passing 0.074 mm, and magnetically separating the ground product in Davi Tube at 0.08 T magnetic field intensity. The observation of the reduced pellets microstructure shows that the additive plays a role of nucleating agent, which enhances metallic iron grains migrating and coarsening during reduction process. The process is probably one of efficient ways to recover iron from copper slag to produce directly reduced iron (DRI), which can be used as the burden to produce weathering resistant steel by electric arc furnace to replace sponge iron or scrap steel. The process reduces the secondary environmental pollution of copper slag and has been applied well in Tongling Nonferrous Metals Group Holding Co., Ltd in China.

収録刊行物

• ＩＳＩＪ　Ｉｎｔｅｒｎａｔｉｏｎａｌ

  ＩＳＩＪ　Ｉｎｔｅｒｎａｔｉｏｎａｌ 55 (7), 1347-1352, 2015

  一般社団法人 日本鉄鋼協会

キーワード

• waste copper slag
• coal-based direct reduction
• directly reduced iron
• compound additive
• weathering resistant steel

詳細情報

• CRID: 1390282681465250560
• NII論文ID: 130005089776
• DOI: 10.2355/isijinternational.55.1347
• ISSN: 13475460
• ISSN: 09151559
• Web Site: https://www.jstage.jst.go.jp/article/isijinternational/55/7/55_1347/_pdf
• 本文言語コード: en
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