Preparation, Characterization and Deoxygenation Performance of Modified Sponge Iron

Abstract

A modified sponge iron was prepared by chemical replacement copper plating using hydroxyl ethidene phosphonic acid (HEDP) as Cu(II) complexing agent in this paper. The morphology, chemical composition and surface area were characterized by scanning electron microscopy, energy dispersive spectrometer and Brunauer–Emmett–Teller area test, respectively. The results show that the sponge iron deoxygenation performance can be improved obviously by modifying with chemical replacement copper plating. The deoxygenation performance at first increases, and then reaches a maximum before decreasing as the modifying condition. Generally, the residual dissolved oxygen levels decrease with increased copper content rather than surface area. The maximum performance correlates well with maximum copper content, a condition which is realized when selecting optimal values of concentrations, temperature and contact time during the copper plating procedure with the aid of orthogonal experiments. The optimum modifying conditions are [CuSO4] 40 g/L, [HEDP] 80 g/L, [H2SO4] 10 ml/L, modifying times 15 s and plating bath temperature 30 °C. In addition, the copper content on the optimum modified sponge iron is up to 44.22 %.