Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

Minerals

Zdeněk Tišler¹  Jan Šafář¹  Kateřina Hrachovcová¹  Lenka Pelíšková¹  Eliška Svobodová¹ 

[1] Unipetrol Centre for Research and Education, a.s, Areál Chempark 2838, Záluží 1, 436 70 Litvínov, Czech Republic;

关键词: natural zeolite;    clinoptilolite;    alkali activation;    inorganic foam;    acid leaching;   

DOI  :  10.3390/min9120719

来源: DOAJ

【 摘 要 】

The foamed alkali-activated zeolite materials have been studied primarily in terms of mechanical and structural properties as potential substitutes for concrete and other building materials. However, they also have interesting textural and acid properties that make them much more useful, especially in the chemical industry. The aim of the study is to map in detail the influence of post-synthesis modifications of alkali-activated natural zeolite foams on their chemical, mechanical, and textural properties for possible use in catalytic and adsorption applications. Alkali-activated natural zeolite foam pellets were prepared by activation with mixed potassium hydroxide and sodium silicate activator and foamed using H₂O₂ solution. The foam pellets were post-synthetic modified by leaching with mineral and organic acids and calcination. The properties of the modified materials were characterised on the basis of XRF, XRD, N₂ physisorption, DRIFT, SEM, NH₃-TPD analyses, and the strength measurements. Our data showed that the basic clinoptilolite structure remains unchanged in the material which is stable up to 600 °C after acid leaching. In two-step leaching, the specific surface area increases to 350 m²/g and the leaching process allows the acid properties of the materials to be varied.

【 授权许可】

Unknown