Study On The Bayer Red Mud Property Based On The Iron Recovery

Zhongzhou and Shandong Bayer red mud had been used for the experimental material, and they were studied on the iron recycle. Analyzing the properties of red mud, exploring high temperature reduction roasting on modification effect and its mechanism of red mud magnetic, optimizing high temperature reduction roasting process conditions, thus it can better provide a theoretical basis on Bayer red mud magnetic separation iron.Firstly, with the method of XRD analysis, X-ray fluorescence spectrum analysis, chemical analysis, SEM and EDS analysis, magnetic analysis,comprehensive thermal analysis(TG and DSC)and laser particle size analysis, these two kinds of red mud was analyzed based on the basic physical properties of iron recycling. The results show that the main mineral compositions of Zhongzhou red mud are hematite, calcite, hydrogrossular and quartz. And the main mineral compositions of Shandong red mud are hematite, sodalite and quartz. The main iron mineral of Zhongzhou and Shandong red mud exist in the form of weak magnetic hematite, its contents are 21.11% and 35.32% respectively. Hematite and other minerals inclusions distributed in red mud. Under the condition of high temperature, two kinds of red mud total weightlessness is around 12%.If you don't add other material, red mud itself will not occur reduction reaction. The particle size of Zhongzhou red mud and Shandong red mud is small, and they are fine materials.They are weak magnetic minerals for weak magnetic.Secondly, based on the recovery of iron minerals in red mud, experimental study was carried out to restore the modified magnetic roasting. Using single factor experiment and orthogonal experiment, the experimental results are as follows:(1)When the Zhongzhou red mud is roasted on the condition that the roasting temperature being 980?, the roasting time lasting 100 min, and the dosages of red mud, reducing agent(activated carbon)and additives(Na2CO3) being 100:10:4, the effect of reduction roasting magnetization modification of red mud is best. After magnetic separation was carried out on the modified red mud, the iron content of red mud get concentrated, with the grade being 56.91%, the pure iron mineral rate being 23.50%,the recovery rate being 82.25%.(2) When the Shandong red mud is roasted on the condition that the roasting temperature being 1080?, the roasting time lasting 70 min, and the dosages of red mud, reducing agent(anthracite coal) and additives(Na2CO3) being 100:9:7, the effect of reduction roasting magnetization modification of red mud is best. After magnetic separation was carried out on the modified red mud, the iron content of red mud get concentrated, with the grade being 67.36%, the pure iron mineral rate being 34.01%,the recovery rate being 85.54%,the enrichment ratio being 2.52.Finally, physical and chemical characteristics on the iron recovery of two kinds of modified red mud and magnetic concentrate were analyzed. Through high temperature reduction roasting modification, iron minerals in the red mud from the original weak magnetic hematite iron into strong magnetic minerals, and iron minerals magnetic have been significantly enhanced. High temperature reduction roasting makes iron concretions lager in red mud, which is advantageous to the iron magnetic extraction thanks to rich and gangue mineral dissociation effectively after grinding.