Kaolin Sorting Of Ion-adsorption Rare Earth Tailings In Southern China

After mining the ion-adoption rare earth tailings in Southern China by thirty years, the tailings piles up to be mountain.The tailings cause a lot of serious environmental problems. So it has great significance to solve the problem that how to use the rare earth tailings effectively. In this paper, we used ion-adoption rare earth tailings in South of GanChou(JiangXi Province) as study object.By investigatd the systematic mineral properties of tailings, the feasibility of sorting kaolin in the tailings and the sorting process were studied.Then we studied the bleaching processing and iron removal treatment with the sub-elected kaolin. The results show that the product which by the sorting method meets the Chinese national standard of TC-3 grade raw materials for ceramic industry applications.Properties of rare earth mineral tailings were studied systematically. The chemical element analysis of tailings was performed with an XRF spectrometer.The mineral composition and the existing state of major minerals was performed with X-ray diffraction and MLA process mineralogy.The particle size characteristics at different granularity were performed by using screening classification.And the thermal analysis and scanning electron microscopy morphology were studied with the part of scrreening product.The results show that the main chemical composition of tailings is:SiO272.13%, Al2O317.69%, Fe2O31.93%, TiO20.33%. The main minerals are quartz, kaolin, feldspar, biotite and muscovite.The main iron minerals are magnetite, limonite, pyrite and ilmenite. The kaolin in the tailings aggregates with scaly microcrystalline.The quartz grain is ranging thickness.The magnetite has larger size changes with particle state. Most limonite was dust-like distribution in kaolin. The ilmenite is granular and particle size is fine.The differential thermal analysis results showed that the main ingredients of the tailings is quartz,while kaolinite content is less. SEM results showed that in the coarse particles (+0.45 mm) is mostly quartz.With the particle class decrease,granular aggregate is presented.In the-10um class,kaolinite mostly exist in 2um flake and small amount of needle shaped is presented.By evaluate the separation feasibility of rare earth tailings and determine its separation process, the gravity and magnetic separation were studied.The shaking table gravity separation test show that kaolin and quartz can separate by gravity separation.The high gradient magnetic separator was used in the magnetic separation, and the result show that the iron mineral can be removed effectively.The iron removal rate was 45.08%.At last the "a rough two fine"sorting process was determined to be sdpoted by the shaking table separation and the high gradient magnetic separation.In the "rough" process we use spiral chute and in the "fine" process we use Φ50 hydrocyclone as the first selected, Φ25 hydrocyclone as the second selected.Finally the product of the gravity separation was treated with high gradient magnetic separator.Through this process? we get the sorting product with its content as:Al2O329.32%, Fe2O30.84%, TiO20.06%.The yield of the sorting kaolin was 20.56% and the recovery rate of Al2O3 was 38.14%.The bleaching and iron removal research by reduction-complexation method used ionic rare earth tailings in Southern China as raw material.The effects of reduction-complexation method on pH value, reaction temperature, dosage of sodium hyposulfite, bleaching time, dosing frequency, oxalic acid dosage were studied.The results show that the appropriate condition is pH 3, reaction temperature 50℃, dosage of bleaching powder 3%.bleaching time 60min, dosing frequency 4, oxalic acid dosage 2.5%.Under the process conditions, the whiteness of bleached tailings increases from 57.7 to 72.3 by the reduction-complexation method, while the Fe2O3 content reduces from 2.11% to 1.43%.