Kinetic study on synergistic roasting of carbonaceous gold ore with cyanide tailings

A non-isothermal kinetic study was conducted on the synergistic roasting of a low-grade carbonaceous gold ore from Shaanxi Province and cyanide tailings, aiming to overcome the low gold recovery inherent to conventional cyanidation. Thermogravimetric analysis （TG-DTG） was conducted on mixed samples under an inert N₂ atmosphere at heating rates of 5 K/min、10 K/min、15 K/min, and 20 K/min. Kinetic parameters were determined, and the reaction model was identified by integrating model-free methods （Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose） with the model-fitting Coats-Redfern. The results show that the synergistic roasting process can be divided into three stages. The main weight-loss stage （conversion \alpha = 15 %−70 %） conforms to the random nucleation and growth mechanism. The most probable kinetic model is the Avrami-Erofeev function, with an average apparent activation energy of 253.93 kJ/mol. This study provides a theoretical basis for optimizing key parameters such as temperature and time in the synergistic roasting process.