Continuous microwave fluidized roasting process
This invention disclosed a continuous microwave fluidized roasting process, in which prepared materials to be roasted is fed to the continuous microwave fluidized roaster by an enclosed spiral feeder, and microwave from its source radiates into the resonant cavity. Because the materials contain sulphide, oxidized, and carbonaceous minerals of higher dielectric constants, temperature of the roasted materials will quickly rise after absorbing microwave. When the temperature is higher than set value, the electrical circuit will be shut down automatically, the microwave generator stops emitting, and the temperature of materials starts to cool down. When the temperature of materials is lower than the set value, the circuit will be switched on automatically, the microwave generator restarts to work to emit microwave, and the temperature of materials increases. After entering the air box, air is fed into material layers in the fluidized roasting chamber, while the materials, after being kept for set time at set temperature, is discharged via a discharging opening, which is called calcine. This process deals with the problems in traditional fluidized roasting that fuels such as coal have to be added and it is difficult to conduct roast at lower temperature when treating gold ore with lower content of sulphides, and avoids uneven roasting by current continuous hot microwave roasting process.