软锰矿在辉钼矿焙烧过程中的固硫作用

Sulfur-retained in roasting process of molybdenite concentrate by pyrolusite

为克服辉钼矿传统焙烧-氨浸工艺中含硫烟气对环境的严重污染, 提出联产钼酸铵和硫酸锰的软锰矿与辉钼矿共同焙烧新工艺, 并从热力学角度和通过热重分析等手段在理论上论证该新工艺的可行性. 根据焙烧产物的性质, 设计了软锰矿和辉钼矿共同焙烧新工艺的工艺流程, 采用分段升温焙烧, 研究了辉钼矿与软锰矿的物料配比对固硫率的影响. 研究结果表明: 加入软锰矿可以显著降低辉钼矿的焙烧温度, 在450～550 ℃时, MoS2的分解率可达100%, 产物以MnMoO4为主;焙烧过程中的固硫率随着MnO2含量增加而升高, 固硫效果非常明显, 当n(MnO2):n(MoS2)=9时, 固硫率接近98%.

In order to avoid pollutant SO2 in the traditional process of roasting and ammonia-leaching for molybdenite, the new process of molybdenite and pyrolusite co-roasting, in which （NH4）2MoO4 and MnSO4 could be obtained at the same time, was put forward, and its practicability was demonstrated theoretically through thermodynamics analysis and thermogravimetry. According to the properties of products, principle technological flow of the new process of molybdenite and pyrolusite co-roasting was designed. The effects of material ratio between MoS2 and MnO2 on sulfur-retained ratio were investigated under the condition of temperature-gradient method roasting. The results show that the roasting temperature can be decreased observably after the addition of pyrolusite, and dissolution ratio of MoS2 can reach 100% at 450-550 ℃, and that MnMoO4 is the major product. The effect of sulfur-retained is very evident, furthermore, the sulfur-retained ratio increases with the dosage of MnO2. When n（MnO2） ： n（MoS2） is 9, the sulfur-retained ratio reaches about 98%.