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

Production of potassium sulfate from potassium hydrosulfate solutions using alcohols

Agnieszka Mientka, Barbara Grzmil, and Maria Tomaszewska

Institute of Chemical and Environment Engineering, Szczecin University of Technology, ul. Pulaskiego 10, 70-322 Szczecin, Poland

E-mail: maria.tomaszewska@ps.pl

Received: 30 March 2007  Revised: 17 July 2007  Accepted: 23 July 2007

Abstract: Potassium sulfate is used to produce multicomponent fertilizers, free of chlorides. The desalting out of potassium sulfate from an aqueous solution of potassium hydrosulfate was conducted using 40 mass %, 45 mass %, or 50 mass % aqueous solutions of either methanol or propan-2-ol. Composition of the resultant precipitate was analyzed using chemical methods and XRD analysis. The results of the XRD analysis revealed that the main precipitate phase is K₂SO₄. Small amounts of K₅H₃(SO₄)₄ were detected when the desalting out was carried out from 2.5 M KHSO₄ solution using 40 mass % and 50 mass % methanol solution. When the amount of potassium bisulfate in the solution increased to 3.5 M and 3.8 M, the main phase consisted of K₃H(SO₄)₂. Generally, the desalting out process using propan-2-ol caused the formation of K₃H(SO₄)₂. Potassium sulfate was obtained only by desalting out the 2.5 M KHSO₄ solution using 50 mass % aqueous propan-2-ol.

Keywords: K₂SO₄ production - desalting out using alcohols

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-007-0088-2

Chemical Papers 62 (1) 123–126 (2008)