Preparation method of 3A molecular sieve

Abstract

The invention provides a preparation method of a 3A molecular sieve. The preparation method includes the steps of primary exchange and secondary exchange. Primary exchange includes the following steps that a 4A molecular sieve and potassium-containing washing water recycled through secondary exchange are mixed and stirred in a primary exchange tank for exchange, filter-press washing is carried out after exchange is completed, and a primary filter-press material is obtained. Secondary exchange includes the following steps that the primary filter-press material, water and potassium chloride are mixed and stirred in a secondary exchange tank for exchange, press-filter washing is carried out after exchange is completed, and a secondary press-filter material and potassium-containing washing water are obtained, the potassium-containing washing water is recycled into primary exchange to participate in exchange, and after the secondary press-filter material is subjected to press-filter washing with water, the 3A molecular sieve is prepared through drying.

Description

technical field [0001] The invention relates to a preparation method of 3A molecular sieve. Background technique [0002] Chinese patent document CN102351213A discloses a method for preparing 3A-type zeolite molecular sieves, which includes the following steps: 1) Calcination of kaolin: Calcining soft kaolin in Lincang, Yunnan Province at 550-700° C. for 3-5 hours to obtain metakaolin; 2. ), the preparation of 4A molecular sieve: according to the proportioning of metakaolin and NaOH aqueous solution: 1530g: 100mL, select metakaolin and NaOH aqueous solution, wherein, the concentration of NaOH aqueous solution is 2-5mol / L; Metakaolin and NaOH aqueous solution are mixed uniformly , raise the temperature to 60-80°C, age under strong stirring for 3-5 hours, then raise the temperature to 90-100°C, and stir at a medium speed for 4-6 hours to obtain the mixture; filter the mixture, wash the filter cake with distilled water and filter again , filter the obtained filter cake again a...

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Problems solved by technology

[0002] Chinese patent document CN102351213A discloses a method for preparing 3A-type zeolite molecular sieves, which includes the following steps: 1) Calcination of kaolin: Calcining soft kaolin in Lincang, Yunnan Province at 550-700° C. for 3-5 hours to obtain metakaolin; 2. ), the preparation of 4A molecular sieve: according to the proportioning of metakaolin and NaOH aqueous solution: 1530g: 100mL, select metakaolin and NaOH aqueous solution, wherein, the concentration of NaOH aqueous solution is 2-5mol / L; Metakaolin and NaOH aqueous solution are mixed uniformly , raise the temperature to 60-80°C, age under strong stirring for 3-5 hours, then raise the temperature to 90-100°C, and stir at a medium speed for 4-6 hours to obtain the mixture; filter the mixture, wash the filter cake with distilled water and filter again , filter the obtained filter cake again and dry at 90-100°C for 2-4 hours to obtain 4A molecular sieve; 3), the preparation of 3A type zeolite molecular sieve: according to the ratio of 4A molecular sieve and KCl solution: 5-10g: 100mL, select 4A Molecular sieve and KCl solution, wherein the concentration of KCl solution is 2-5mol / L; 4A molecular sieve and KCl solution are reacted in a reactor at 70-90°C for 3-5 hours, and then cooled, washed and filtered. The filtered cake was dried at 90-100°C for 2-4 hours to obtain 3A zeolite molecular sieves; in the preparation process of the above-mentioned 3A molecular sieves, K ions could not be completely exchanged with Na ions in 4A molecular sieves, and the utilization rate of K ions was low. The exchange rate of ions and Na ions is low, and after filtering and washing, the washing water containing K ions will be drained, polluting the environment

[0003] In addition, the exchange rate of existing 3A molecular sieves is generally between 38-55%, and the relative water adsorption value is between 25-23.5%, and the higher the exchange rate, the lower the water adsorption value, which is a big defect. The technical problem is that it is impossible to increase K ions to replace more Na ions. When more K ions replace Na ions, more adsorption pores will be blocked, resulting in low water adsorption value.

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