Synthesis Hazenite from Bittern as a Source of Magnesium and Sodium

Struvite is a magnesium ammonium phosphate hexahydrate (MAP) crystal with significant potential in agriculture as a slow-release fertilizer. Struvite and its derivatives, such as Hazenite, Struvite-K, and Struvite-Na, can form through specific chemical reactions. Hazenite, a newly discovered mineral in the struvite group, contains two monovalent cations (Na<sup>+</sup> and K<sup>+</sup>) and can be applied in agriculture and orthopedics. Hazenite has an orthorhombic structure with a dipyramidal crystal system and a formula weight of 276.331 g/mol. It was first discovered in Mono Lake, California, and named in honor of Robert M. Hazen. Hazenite forms biologically by microbes that precipitate this crystal when phosphorus levels in the environment increase. The precipitation of struvite and its derivatives requires magnesium, which can be sourced from alternatives like bittern, a byproduct of salt production. This study successfully synthesized Hazenite from bittern as a source of magnesium and sodium. XRD characterization revealed that Hazenite is the dominant phase in the sample, with a tubular elongated shape detected through FESEM-EDX. Using Response Surface Methodology (RSM) with a Box-Behnken Design (BBD), optimal conditions for Hazenite production were identified: pH 11.0 - 11.5, reaction time 45 - 50 minutes, and Mg:Na:PO<sub>4</sub> molar ratios of 1:1:1 - 1.2:1.2:1 or 1.8:1.8:1 - 2:2:1. These conditions yielded the highest Hazenite percentage (>95%).