ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
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
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.
Chemical Papers 62 (1) 123–126 (2008)