Study On Thermal Alteration Products And Properties Of Tourmaline Under Alkaline Conditions

As the important components of the zeolites family,sodalite,cancrinite,analcime were widely used in adsorption,catalysis,drug release and so on.It is significance to study their synthesis and properties.In this paper,the effects of alkali types,hydrothermal temperature and time on product phase and morphology were investigated by hydrothermal method.The structure,morphology of products were Characterized by X ray diffractometer,scanning electron microscope.The results show that:?1?the hydrothermal product is sodalite,when the concentration of sodium hydroxide is 1 mol/L and the hydrothermal temperature is between 200 ? and 350 ?.Then the product is analcime,when the concentration of sodium hydroxide is 0.75 mol/L and the hydrothermal temperature is 350 ?.In addition,the product is cancrinite,when silica is used as an additional silicon source,and the concentration of sodium hydroxide is 1.5 mol/L.?2?The adsorption experimental results showed that analcime exhibited good adsorption performance,and the adsorption capacity of Cu²⁺,Co²⁺,Ni²⁺,Cr³⁺ were 56.4,43.5,40.6,18.3 mg/g respectively.?3?by using potassium hydroxide as mineralizer,Tourmaline hydrothermal products were kalsilite series.When taken lithium hydroxide as mineralizer,the product was Li₃AlSiO₅.In summary,the tourmaline phase change is very varied in alkali hydrothermal process.Sodalite,cancrinite,analcime,kalsilite could be synthesized when using black tourmaline as raw material.