Iron reduction in aluminum by electroslag refining
(1. State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering,
Shanghai Jiao Tong University, Shanghai 200240, China;
2. Suzhou Zhenwu Electric Furnace Co., Ltd., Suzhou 215168, China)
Shanghai Jiao Tong University, Shanghai 200240, China;
2. Suzhou Zhenwu Electric Furnace Co., Ltd., Suzhou 215168, China)
Abstract: The effect of electroslag refining on iron reduction from commercial aluminum was investigated. Cast electrodes of commercial aluminum were electroslag refined using KCl−NaCl−Na3AlF6 slag containing Na2B4O7. Experimental results indicate that the iron content decreases with increasing Na2B4O7 addition and remelting time, and the iron content decreases from 0.400% to 0.184% under 9% Na2B4O7 addition for 30 min remelting. The elastic modulus, yield strength and ultimate tensile strength commercial aluminum are improved, and the tensile elongation is increased by 43% after electroslag refining. The chemical reaction between melt and slag to form Fe2B is the main reason for iron reduction and the thermodynamic calculation of the chemical reaction theoretically accounts for the formation of Fe2B.
Key words: aluminum; electroslag refining; iron; mechanical properties; thermodynamic calculation