Study of Industrial Copper Matte Convert

The converting of copper matte after the smelting process is one of the main steps in the copper-making industry. This work utilized microstructural analyses of samples collected at different stages of converting and thermochemical calculations to study a real converting batch in a Peirce-Smith converter at Atlantic Copper. The study focused on the transformation of matte and slag produced during the converting process. Thermochemical calculations were employed to simulate non-standard process conditions, providing significant insights into converting. Notable non-standard conditions examined included a single slag blow, the influence of the Fe/SiO2 slag ratio, and over-oxidation at the conclusion of the copper blow. Micrographic investigations revealed two predominant phases within the matte matrix that varied in proportion throughout the slag blow, while the slag exhibited two fayalite olivine phases with differing Fe/SiO2 ratios, with the higher ratio phase being more abundant. Additionally, magnetite crystals were observed surrounding fayalite olivine in slags. Analytical data indicated that the copper measured in the slag exceeded the theoretical values from thermochemical calculations, suggesting that physical entrapment of matte/copper droplets in slag hindered complete separation, influenced by factors such as residence time, agitation from blowing, and viscosity. Ultimately, the produced slag contained high copper content distributed post-slow cooling into cuprous (Cu2O) and defectosilic [Cu,Fe]O2 phases.