Local salt purification in Aceh Timur regency using alkaline (KOH and NaOH) activated bentonite

Abstract

Various purification methods have been developed to improve local salt quality, with the NaCl content above 94%. Bentonite is one of the materials used as binder impurities in purification. The purpose of the study was to synthesize a modified bentonite using an alkaline solution, which includes sodium hydroxide (NaOH) and potassium hydroxide (KOH) with various concentrations (1 M, 1.5 M, 2 M, and 2.5 M) and determined levels of Na+, Ca2+ and Mg2+ metals using AAS. The bentonite and activating agent 1 M (1:10) were stirred for three hours. Then, the bentonite was dried for two hours in an oven at 110°C. The activated bentonite was dried for four hours at 170°C. The activated bentonite was characterized using XRD, FTIR, and SEM. The basal spacing d001 on the diffractogram bentonite was significantly unaffected by alkaline activation. FTIR analysis represents the stretching vibration of -OH shifts towards a lower wavenumber. Alkaline activation reduced impurities from bentonite and increased the pore surface''s porosity. NaCl levels in people's salt increased after being activated using alkaline. The increase in Na+ levels was followed by a decrease in Ca2+ and Mg2+ contents. KOH-activated bentonite had a higher NaCl level than NaOH-activated bentonite.

Keywords

• bentonite
• activation
• alkaline
• salt purification