REKRISTALISASI GARAM RAKYAT DARI DAERAH DEMAK UNTUK MENCAPAI SNI GARAM INDUSTRI

Abstract

Salt as we known can be defined as chemicals compound which the main part is Sodium Chloride (NaCl) with impurity substances consist of CaSO₄, MgSO₄, MgCl₂, and others. But to get good quality salt from the raw salt can’t be obtained only by washing raw salt. This is caused by the fact that impurities not just only on the surface of crystals salt but also in the crystal lattice salt, so that needs to be purified by recrystallization. This research will use local raw salt 2nd quality from Demak. In this research will be limited in efforts to increase the quality of salt to fullest the Indonesian National Standard (SNI 06-0303-1989) by recrystallization method. Weight of raw salt used as fixed variable. Non-preparation and preparation (addition of Na₂CO₃, NaOH, and PAC) and crystallization time (1, 1.5, 2 and 2.5 hours) used as change variables. Impurity content and NaCl concentration was calculated before and after crystallization treatment. Concentration of Ca, Mg and Na ions was determined using AAS. Best recrystallization results of NaCl salt concentration is obtained at crystallization with preparation in 1.5 hours, concentration 393,044.234 ppm (99.969%), which complied to SNI 06-0303-1989 (98.5% db).