Evaluation of Heterogenous Oxidation Reaction of Copper Concentrate/Pyrite/Silica Sand Mixture by Preheated Oxygen Gas Blowing

Abstract

A hand-made apparatus to react copper concentrate (Cc)/pyrite (Py)/silica sand (Ss) mixture was developed for an imitated concentrate burner at laboratory scale. An instantaneous (< 1 s) ignition reaction was macroscopically observed by preheated oxygen gas blowing to Cc/Py/Ss mixture with a Fe/SiO2 mass ratio of 1.1. SEM-EDS analysis was used to observe microstructure and phase distribution in reacted and water-quenched particles. As for the Cc/Ss samples collected at the point close to the gas blowing spot, 70–80 mass% Cu matte phase and heterogeneous slag phase including large amounts of magnetite (Mag) particles were formed. At the lower part from the gas blowing spot with a distance of 275 mm, 60–65 mass% Cu matte phase was confirmed. The area fraction of Mag particles in the slag phase decreased with increasing Py adding concentration in the mixture sample. Our results suggested the concentration and microscopic distribution of Py in the mixture including Cc contributed to control both Cu concentration in matter phase and Mag particle concentration in slag phase.

Keywords

• copper concentrate
• ignition
• microstructure
• mineral composition