ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Recycling of NH₄Cl in the synthesizing process of analcime to ammonioleucite by separating NH₄Cl-NaCl mixed solution

Yunfei Li, Yong Tang, Meitang Liu, and Haisheng Hu

Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, Beijing, People’s Republic of China

E-mail: Mtliu@cugb.edu.cn

Received: 31 March 2022  Accepted: 26 May 2022

Abstract:

During the transformation of analcime to ammonioleucite, the mol ratio of \({\text{NH}}_{4}^{ + }\): Na⁺ in the NH₄Cl-NaCl mixed solution will seriously affect the conversion rate of ammonioleucite. How to separate the mixed solution and recover NH₄Cl becomes the critical problem for the industrialization of this process. In this paper, the critical separation point of the mixed solution was testified to 8:2 (mol concentration ratio of \({\text{NH}}_{4}^{ + }\): Na⁺). The isothermal evaporation equilibrium method was used to explore the dissolution equilibrium law of NH₄Cl-NaCl mixed solution at 343 K, 353 K, and 363 K. The separation of the mixed solution under the conditions of 343 K, 353 K, and 363 K were studied by using the three-time evaporating-cooling crystallization process. At 353 K, the recycling rate of NH₄Cl can reach 91.12%. This work provides a foundation for the industrial feasibility of synthetic ammonioleucite from analcime.

Keywords: Phase diagrams; Separate; Ammonium chloride; Recycling; Ammonioleucite

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02300-2

Chemical Papers 76 (9) 5943–5954 (2022)