Manufacture of wear-resistant cast iron and copper-bearing antibacterial stainless steel from molten copper slag via vortex smelting reduction

Recovery of Cu-Fe Alloy from Copper Smelting Slag

“…As the carbon addition increased to 16%, the copper and iron in the reduced slag decreased to 0.06% and 0.5%, respectively. The experimental results confirmed the reductant ratio predicted by FactSage and that reported by Hao et al [31]. The exact requirement of the reductant depends on the proportions of the reducible oxides in the slag, the types of the reductants and the reaction temperature.…”

“…The microstructures shown in Figure 4 confirm the observations shown in Figure 3 and the prediction shown in Figure 2. With the support of thermodynamic predictions, high temperature experiments show that only a 5% addition of CaO can decrease the liquidus temperature of the reduced slag to approximately 1300 • C. This result provides the possibility of lowtemperature smelting reduction compared to those (1450-1500 • C) previously reported in the literature [14,31]. 5% CaO addition not only decreases the flux cost but also reduces the volume of the reduced slag by approximately 30% compared to the previous studies [14,31] where 20% CaO was added.…”

“…This result provides the possibility of lowtemperature smelting reduction compared to those (1450-1500 °C ) previously reported in the literature [14,31]. 5% CaO addition not only decreases the flux cost but also reduces the volume of the reduced slag by approximately 30% compared to the previous studies [14,31] where 20% CaO was added. Figure 4a shows the typical microstructure of the quenched sample after reduction at 1250 • C. The black phase shown in Figure 4a is graphite, the grey phase is slag, and the white phase is alloy.…”

“…This result provides the possibility of lowtemperature smelting reduction compared to those (1450-1500 °C ) previously reported in the literature [14,31]. 5% CaO addition not only decreases the flux cost but also reduces the volume of the reduced slag by approximately 30% compared to the previous studies [14,31] where 20% CaO was added.…”

“…However, the cost is high to use high-purity copper, and the distribution of copper in the steel is not uniform, which limits the applications of the Cu-containing steels. Hao et al studied the possibility of producing antibacterial stainless steel from copper cleaning slag via smelting reduction [31]. The optimum condition was found at 1450 • C with 20% CaO and 13% carbon additions.…”