In order to understand the effect of oxygen injection into the molten metal on the valuable metals
(VM) recovery and interfacial phenomena, several high-temperature experiments were conducted
using a high-frequency induction furnace with a quartz tube as the reaction chamber at 1673 K.
Copper-based waste printed circuit board (PCB) that contains some impurities was selected as the
end-of-life resource. CaO-SiO2 based pre-fused slag and oxygen gas were used in present works.
The composition change and microstructure of the samples were analysed.
As oxygen was injected into the system, impurities were rapidly removed. After the removal of
impurities, continuously injected oxygen lowered interfacial tension between liquid slag and liquid
metal. Lowered interfacial tension induced Cu loss into the slag.