摘要
针对高硫铝土矿传统焙烧脱硫方式中温度高、时间长、脱硫率低等问题,采用微波焙烧方式对以黄铁矿硫为主的高硫铝土矿进行脱硫实验。研究结果表明:微波焙烧脱硫具有低温、短时高效的特点,在600℃焙烧15 min,可将铝土矿中硫的质量分数从2.01%降低到0.32%,脱硫率达到85%左右;微波场中,黄铁矿脱硫以4FeS2+11O2→2Fe2O3+8SO2的反应为主,同时,在低温和氧气不充足的条件下会伴随2FeS2+5O2→2FeO+4SO2及4FeO→Fe3O4+Fe中间反应发生;黄铁矿的极性分子在偶极子取向极化的作用下,电磁能转化为热能,促使Fe—S键断裂,硫离子被大量分离,并不断向矿物表面扩散,与空气结合生成SO2气体而脱除;由于黄铁矿颗粒内部快速积聚的热量不能迅速散掉,颗粒内部和外部形成明显的局部温差,从而产生热应力,使得颗粒形成不同程度的裂隙,甚至发生热破裂现象,有效促使黄铁矿的单体解离和增加其有效反应面积,为黄铁矿脱硫反应的快速进行提供了有利条件。
Considering that desulfurization from high-sulfur bauxite by traditional roasting process has obvious issues, such as high temperature, long time and low desulfurization rate, the microwave roasting process was carried out to remove sulfur of pyrite from high-sulfur bauxite. The results show that desulfurization by microwave roasting has the characteristics of low temperature, short time and high efficiency. Under the condition of microwave roasting at 600 ℃ for 15 min, the sulfur mass fraction in bauxite decreases from 2.01% to 0.32%,and the desulfurization rate can reach about 85%. In the microwave field, the main reaction of pyrite desulfurization is 4FeS2+11O2→2Fe2O3+8SO2, and the intermediate reactions of 2FeS2+5O2→2FeO+4SO2 and4 FeO→Fe3 O4+Fe may occur under the condition of low temperature and insufficient oxygen. Under the action of dipole oriented polarization, the polar molecules of pyrite convert electromagnetic energy into heat energy, which makes the Fe—S bond break, sulfur ions separated in large quantities, and continue to diffuse to the surface of minerals, combined with air to generate SO2 gas for elimination. At the same time, due to the rapid accumulation of heat inside the pyrite particles can not be dissipated quickly, obvious local temperature difference is formed inside and outside the particles, resulting in thermal stress to make the particles crack in different degrees, and even causes thermal fracture in different degrees. In this way, the monomer dissociation of pyrite is effectively promoted and the effective reaction area is increased, which provides favorable conditions for the rapid desulfurization of pyrite.
作者
金会心
吴复忠
李军旗
陈朝轶
刘虹伶
杨黔
JIN Huixin;WU Fuzhong;LI Junqi;CHEN Chaoyi;LIU Hongling;YANG Qian(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Key Laboratory of Metallurgical Engineering and Process Energy Saving of Guizhou Province,Guiyang 550025,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第10期2707-2718,共12页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(U1960201,51874108)
贵州省科技计划项目(黔科合支撑[2017]2806)。
关键词
高硫铝土矿
微波焙烧
黄铁矿
脱硫机理
high-sulfur bauxite
microwave roasting
pyrite
desulfurization mechanism
