关键词: 分子筛, 天然硅铝矿物, 介尺度, 机械活化, 热活化, 碱熔活化, 亚熔盐活化, 拟固相活化

Abstract:

The traditional hydrothermal synthesis of molecular sieve is not environmentally friendly in terms of the synthetic raw materials, because the silicon and aluminum reagents used in it are prepared from natural aluminosilicate minerals through a complex reaction and separation process. Using natural aluminosilicate minerals as silicon and aluminum sources to directly synthesize molecular sieve without chemical reagent intermediates is regarded as one of the promising research directions for green synthesis of molecular sieves. The key is the mesoscale activation of natural aluminosilicate minerals, which refers to the destruction of high-polymerization degree structure of natural aluminosilicate minerals and the depolymerization of them into molecular sieve synthetic raw materials with different mesoscale structures by means of physical, chemical or combination of physical and chemical action. From the perspective of energy consumption, activation mechanism and effect and the mesoscale structure of the activated products, the research advances of mesoscale activation methods for natural minerals are summarized and the widely used mesoscale activation method such as the mechanical activation, thermal activation, alkali fusion activation, sub-molten salt activation and quasi-solid-phase activation are introduced in detail. Based on the development process of mesoscale activation methods, the present situations of synthesizing high-performance molecular sieves from different mesoscale activation products are summarized, which provides important guiding strategy for the selection of mesoscale activation methods aimed to the synthesis of high-performance molecular sieve.

Key words: molecular sieves, natural aluminosilicate mineral, mesoscale, mechanical activation, thermal activation, alkali fusion activation, sub-molten salt activation, quasi-solid-phase activation