Study On Pretreatment Process Of Carrier Diatomite For Photocatalytic

The diatomite earth is a kind of important nonmetallic mineral materials with natural nano-aperture, It becomes advantaged carrier materials for its unique shell structure, strong adsorption, high surface area, high temperature resistance and other excellent characteristics. In modern industry, diatomite earth is widely used in chemical and environmental protection sector as catalyst carrier. But now, the diatomite earth is high impurity, pore size maldistribution, low surface activity, these problems will affect the catalytic performance of diatomite lacded catalysts. This study aimed to pure diatomite and enlarged its pore volume by physical and chemical methods, the molding technology of diatomite was explored and the photocatalytic effect of TiO2/KL was studied, in order to prepare composite photocatalyst material with high catalytic activity and conveint for return.Treat diatomite with physical, acid, alkali, calcination separately and find the optimum conditions for each method, Then use calcination-alkali-acid-physical-drying comprehensive pretreated process, the results showed that the obtained diatomite recovery rate was59.54%, SiO2content was98.57%, surface area was61.03m2/g, pore volume was0.97cm3/g, the diatomite disk was clear with uniform pore structure and big pore size.The diatomite loaded TiO2photocatalytic materials was prepared with "low-temperature combustion synthesis" method, the degradation rate of the composite photo catalyst materials was74.8%under the conditions that adding1g/L Ce-TiO2powders into the10mg/L Rhodamine B solution and illuminated by mercury lamp for3hours.Pelletization was used to prepare diatomite pellet with its diameter between4and7mm, the best calcination system was calcining temperature at800℃for2hours, the falling strength of the pellet at1meter high was51times.Sol-gel method was adopted to prepare TiO2loading diatomite pellet photocatalytic materials, the adoped amount of TiO2was28.6%, the photocatalytic materials’s degradation rate of Rh B at first time was94.6%and the rate was83.4%used repeatedly six times.