Basic research on the microwave absorbing properties and microwave roasting kinetic of cyanide tailings

In this study, a thorough exploration was performed on the mechanism of microwave enhancement in the treatment of cyanide tailings by the microwave chlorination heat treatment process. The improvement rate of the dielectric properties of tailing materials is rapid in the high temperature range (673–1173 K), which indicates that cyanide tailings have favorable microwave- absorbing performance. Under the action of iron oxide, the loss tangent of raw materials increased from 0.0364 to 0.1914. The heating efficiency improved significantly, from 6.73 K/min to 41.667 K/min. The kinetics experiment was performed on tailings in the two different roasting process. Compared with conventional roasting, the activation energy of the chlorination reaction of gold under the microwave roasting decreased by 32.47%. The work provides sound references for promoting the industrial application of microwave chlorination roasting on cyanide tailings. [Display omitted] •Determination of the microwave absorption properties of cyanide tailings for the first time.•The test of the dielectric properties in roasting process demonstrated the positive effects of microwave heating.•The activation energy of the chlorination reaction of gold under microwave roasting decreases by 32.47%.