Iodization of Local Salt Based on Purification Technique using Saturated Brine Washing Method

Based on Indonesia National Standards (SNI), Indonesian local-salt is currently unavailable to produce high-quality salt. This study was aimed to investigate the purification process of local salt that has been carried out by local salt farmers in Sumenep, Madura Island, Indonesia and to determine the highest level of NaCl content from local salt using a washing method to make iodized salt. Purification process involves washing technique using a nearly saturated brine. The research was conducted in various particle-size (10-20 mesh and 20-35 mesh), salt/brine ratio (1:20, 1:40, 1:60), duration (10, 30, 60 minutes) and stirring speed (100, 200, 300 rpm). The highest NaCl content of 94.45 % was obtained at the washing process using the salt of 20-35 mesh at 1:60 ratio with washing time of 30 minutes at a speed of 100 rpm. The result of the process shows a decrease of Calcium and Magnesium levels by 95.56 %. In iodization process, the determination of the highest NaCl concentration was carried out using washing brine method and spray mixing injection was also done to develop a stable salt formulation. The optimum stability of KIO₃ in salt was observed as a function of time.