Experiment Research Of Extracting Iron From β-Red Mud

Red mud is the residue in alumina production process,which is generated afetr bauxite leaching by alkali and rich in iron 20%～50%. With the rapid development of alumina industry, its emissions is growing rapidly.At present,both at home and abroad, red mud are wet storaged in most alumina plant. More yard construction and maintenance fees are costed and its strong alkali make the soil alkaline seriously. The surface and underground water are polluted and the ecological environment is harmed directly or indirectly, its comprehensive utilization has become a worldwide problem.In order to reduce the waste of red mud and comprehensively recycle the iron minerals in red mud, the selection of iron in red mud’s test was studied in this paper. According to the characteristics of minerals in red mud, high-gradient permanent magnet for magnetic separation equipment was selected for extracting iron from red mud. The operation mode of the equipment, the working frequency of magnetic roller, the opening scale of the magnetic materials equipment and flushing and other influence factors were studied. Then process conditions were concluded:the optimal operation parameters of the equipment is series operation mode; the frequency of magnetic roller 1 and 2 are 35Hz and 45Hz respectively,the feeding opening is 45%, the opening of the upper roller flush and the under are 75% and 45% respectively. Continuous small-scale industrial test under optimal conditions was done.And the results of the test show that: the content of high magnetic material Fe2O3 is 69.28%,which is selected, the recovery of red mud and Fe2O3 are 24.96% and 58.12% respectively.The optimize experiment of high magnetic materials Fe2O3 and the reducing emissions rate of red mud were done,and it was concluded that:the content of Fe2O3 is about 50%,the red mud reduction rate is increased to 48.39% and the iron oxide recovery rate is increased to 74.59%.Based on experimental results and the existing equipment capability, iron selecting process is designed which can treat 360 thousand tons of red mud a year and can make use of 20% of the total high magnetic material, is equal to 72 thousand tons.The project can generate benefits 5.1886 million yuan per year and has good application value.