The influence of electroslag refining on removal of iron from commercial purity aluminum using KClNaCl-Na

3

AlF

6

slag containing Na

2

B

4

O

7

was investigated.The results reveal that iron content is decreased with the decrease of the remelting speed

and the iron content can be decreased from 0.42%to 0.20%after electroslag refining under the remelting rate of 180 g·min

-1

and removal rate of iron impurities is more than 50%.The reaction of the molten slag to capture Fe

2

B formed in the chemical reaction between melt and molten slag is responsible for the reduction of iron content.Thermodynamic calculation of the chemical reaction theoretically accounts for the formation of Fe

2

B spontaneously in the electroslag refining process.The ultimate tensile strength and elongation of commercial aluminum are improved obviously after electroslag refining.