Abstract:The pre-reaction process of molybdenite and effects of roasting temperature and time on desulfurization rate of molybdenite in simulated suspension roasting device in laboratory were studied by “two-stages roasting process”, i.e., most of the sulfur was removed in device by suspension roasting and the residual sulfur was removed in rotary kiln. The results show that with the desulfurization rate of ≤80%, the majority generation is MoO2. In suspension pre-reaction test device, the apparent desulfurization rate of molybdenite is above 50% in conditions of suspension roasting temperature of 700~780 ℃, and remaining time of 1~3 s. The desulfurization efficiency is greatly improved compared to accumulation roasting process.