永磁法赤泥选铁的试验研究

Experiment Research of Extracting Iron from Bayer Red Mud by Magnetic Separation Equipment

赤泥是氧化铝生产过程中铝土矿经强碱浸出后所产生的废渣。随着氧化铝工业的高速发展,其排放量增长很快。目前国内外氧化铝厂大都将赤泥筑坝湿法堆存,耗费较多的堆场建设和维护费用,而且其强碱性、高盐度造成土壤严重碱化,污染地表及地下水源,对生态环境造成直接或间接的危害,其综合利用已成为世界性的难题。为了减少赤泥的外排量,综合回收赤泥中的铁矿物,本研究对拜耳法赤泥进行了永磁法选铁的工艺试验研究。针对赤泥矿物成分的特点,选用了高梯度永磁体磁选设备进行赤泥选铁,研究得出了永磁体磁选设备较优运行参数为采用串联运行方式。在较优条件下进行连续小规模工业化试验,结果表明选出的高磁料Fe2O3含量达到69.28%,赤泥回收率达到24.96%,氧化铁回收率达到58.12%。

Red mud is the residue in alumina production process. With the rapid development of alumina industry, its emissions are growing rapidly. At present, both at home and abroad, red mud is wet stored in most alumina plant. More yard construction and maintenance fees are cost and its strong alkalis make the soil more alkaline. As the surface and underground water are polluted and the ecological environment is harmed directly or indirectly, the comprehensive utilization of iron from red mud has become a woddwide problem. In order to reduce the waste of red mud and thoroughly recycle the iron minerals in it, the extraction of iron from red mud by magnetic separation equipment was tested through experiments. According to the characteristics of the minerals in red mud, high-gradient magnetic separation equipment with a permanent magnet was chosen for extracting iron from red mud. The operation mode of the equipment, the working frequency of the magnetic roller, the opening scale of the magnetic equipment, the flushing area, and other influencing factors were studied. Continuous small-scale industdal test under optimal conditions was done. And the results of the test show that： the iron separation efficiency of high magnetic material Fe203 is 69.28%, and the recovery rates of red mud and Fe2O3 are 24.96% and 58.12%, respectively.