Preparation And Application Of Silica Hollow Spheres By Oil Shale Ash

Oil shale has the potential to be an important replacement of petroleum. Usually,there are two important uses of oil shale, one is retorting oil shale to produce shale oiland fuel gas, and the other is burning it to generate electricity. A large amount of oilshale ash （OSA） has always been produced in these two processes. The OSA maycause environmental pollution, and it wastes lots of land. These problems limit thedevelopment of the oil shale. Previous experimental results indicated that about60%of OSA is SiO₂and Al₂O₃, therefore, it is feasible to synthesis silicon-containingmaterial and Al2O3from OSA.In the past few decades, intensive researches have been done in the synthesis ofhollow spheres due to their good properties such as large surface area, highmechanical and chemical stability, low density, etc. So hollow spheres have latentapplications in the fields of drug delivery, electronic devices, catalysts and so on.Silica hollow spheres with a low density, high surface area, good integrity anddispersity, uniform thickness, high mechanical strength could be prepared by usingwater glass extracted from oil shale ash as silica source, and based on this, itsadsorption properties were researched so as to expand the application fields of oilshale ash, increase economic efficiency, and truly achieve efficient utilization of oilshale ash.It is the first time to prepare silica hollow spheres by using microemulsion methodin water/ethanol system, using amphiphilic triblock polymer PE6800as templates,and using water glass extracted from oil shale ash as silicon source. There are manyreactive hydroxyl groups on the surface of the hollow silica spheres, which are themost basic condition as an adsorbent, and the hollow structure greatly increased theratio of surface area of the silica. Therefore, the prepared hollow silica spheres havebeen applied in the adsorption of organic dyes and heavy metal. The samples were characterized by XRD、SEM、FT-IR、UV-Vis and AAS. Experiments show that silicahollow spheres in the applications of adsorption of organic dyes and heavy metalshave very good results.