| Abstract Scope |
Novel in situ temperature imaging techniques characterize copper flash-smelting processes involving ignition and combustion on a laboratory scale. After capturing high-speed images using a high-speed camera, a two-color temperature analysis system converted them into temperature images of molten particles during ignition and combustion. The spatial resolution was 15 ìm/pixel. The temporal resolution was 125 ìs/image. The detection temperature ranged from 1300 to 2500 °C, calculated from the intensity ratio at 535 and 599 nm. In this study, the ignition and combustion of primary copper mineral (CuFeS2)/silica stone powder mixture was evaluated to reveal that the sample particles changed into four types momentarily (<100 ms) during dropping: type A; CuFeS2 partial oxidation (≥ 2000 °C), type B; phase separation of slag (FeOx–SiO2, 1600°C) and matte (Cu–Fe–S, 1900 °C), afterward, type C; uniform temperature (~1500 °C) and type D; temperature decreasing to the detective limitation (≤1300 °C). |