Method for preparing nanoscale anionic laminar material continuously

Abstract

The invention discloses a method for preparing a nanoscale anionic laminar material continuously, which mainly comprises the steps of reacting, filtering, washing and drying. Compared with the conventional method for preparing the anionic laminar material in China, the method has the following advantages: (1) a helix channel rotating bed high gravity reactor is adopted to enable nucleus formationto be formed in a uniform micro hybrid environment quickly with a narrowed particle size distribution, the reaction solution in the reactor is kept under a stable high pH value condition by condensing NH3 so as to avoid generating an impurity phase, the reaction time is short and the operation is simple; (2) crystal seeds are added during reaction to greatly reduce the induction period of nucleusformation and accelerate nucleus formation, the crystallinity is high, the particle size distribution is more uniform, the size and distribution of newly generated particles can be controlled according to the particle size of the added crystal seeds, and thus, the particle size is controllable; (3) a crystallization process is not required for product post processing; and (4), the process is quick and allows for continuous production, and the average particle size of the prepared anionic laminar material is 30 to 90 nanometers.

Description

technical field [0001] The invention relates to a method for continuously preparing nanoscale anion layered materials, in particular to a method for continuously preparing nanoscale anion layered materials with uniform particle size distribution under supergravity conditions. Background technique [0002] As a new type of anionic clay material, anionic layered materials have broad application prospects in many fields such as catalysis, adsorption, flame retardancy, medicine, electronics and environmental protection. At present, the relatively mature preparation method in China is the co-precipitation method, but due to the uneven microscopic mixing of the co-precipitation method, it is easy to cause nucleation and crystallization to proceed at the same time, resulting in heterogeneous phases, resulting in uneven grain size of the product. At the same time, follow-up treatment such as crystallization is required, and the crystallization time is long. For example, in CN128807...

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Problems solved by technology

CN101665233 prepares layered double metal hydroxides with particles of 12-80nm, but the reaction requires high-energy autoclave crystallization and the addition of combustible sodium borohydride. The process is complex, the production cost is high, and it is difficult for large-scale industrial production

The nano-hydrotalcite particle size prepared by CN101538019 is between 30-70nm, but toluene extraction is required after the reaction, the follow-up treatment is complicated, and three wastes are generated

The preparation process of ZL01134425.3 magnesium-aluminum double hydroxyl compound metal oxide requires secondary reaction and crystallization, the process operation is complicated, and the reaction conditions are difficult to control

Wang Yongzai et al. [Wang Yongzai et al., Acta Synthetic Crystallography. 2008, 37(5): 1219-1223] prepared Mg-Al hydrotalcite by microwave hydrothermal one-step method, the process is time-consuming and does not require crystallization process, but The reaction temperature is high, impurity phases are easily generated, and the production cost is high, so continuous production is not possible

However, there is no report on the continuous preparation of nano-scale anionic layered materials with uniform particle size distribution by using high gravity technology without crystallization process.

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