Sulfur fixation method of roasting low-grade molybdenite concentrate through lime method

The invention discloses a sulfur fixation method of roasting a low-grade molybdenite concentrate through a lime method. The sulfur fixation method comprises the steps that the low-grade molybdenite concentrate is divided into two parts; one part is mixed with quick lime and MnO2 for pelletizing; obtained pellets, the other part of the low-grade molybdenite concentrate, high-activity quick lime and NaOH or Na2CO3 are mixed for secondary pelletizing, and low-grade molybdenite concentrate pellets of core-shell structures are obtained; the obtained low-grade molybdenite concentrate pellets are dried and roasted in sequence, and reactions including molybdenite concentrate oxidation and sulfur fixation occur. By means of the sulfur fixation method, the concentration of SO2 in roasting flue gas can be reduced to below 200 mg/Nm , the requirements for flue gas emission are met, and it is guaranteed that the molybdenum leaching rate through calcining and acid leaching reaches over 98%.