对某低品位软锰矿进行还原焙烧试验并考察低品位软锰矿浆对焙烧反应过程中产生的尾气(二氧化硫)的资源化利用及其动力学模型。实验结果表明:浓硫酸加入量为锰含量的1.5倍,并在400℃下焙烧120 min,软锰矿锰还原率在98%以上。当矿浆固液比为6:1,吸收温度为80℃时,低品位软锰矿浆中一级锰浸出率为98.60%,二级锰浸出率为98.61%;根据低品位软锰矿浆尾气资源化利用的反应动力学模型,反应的表观活化能为16.04k J/mol。本工艺利用回转炉高效还原低品位软锰矿并实现低品位软锰矿浆对尾气的充分资源化利用,对锰资源高效充分利用的同时,实现反应体系硫资源的循环利用,以达到对工艺流程的绿色创新,为低品位软锰矿资源的高效工业化利用提供了参考和依据。
The reductive roasting of low-grade pyrolusite by rotary kiln and kinetics of tail-gas resource utilization were investigated. The results show that the manganese reduction efficiency is higher than 98% at the roasting temperature of400 ℃ for 120 min when the addition of concentrated sulfuric acid is 1.5 times of the stoichiometric amount. As for the tail-gas resource utilization by low-grade pyrolusite pulp, the leaching efficiencies of the first and second stage are98.60% and 98.61%, respectively under the conditions that the ratio of solid to liquid is 6:1 and the adsorption temperature is 80 ℃. According to the kinetic model of the tail-gas resource utilization, the apparent active energy is16.04 k J/mol. The technology can realize both high reduction efficiency of low-grade pyrolusite and fully recycling use of tail-gas by low-grade pyrolusite pulp. The eco-innovation about this technical process is characterized by high manganese reduction efficiency and cyclic utilization of sulfur resource in tail-gas, providing some references and judgments for the high utilization of low-grade pyrolusite in industrial scale.