Synthesis of Zirconium Oxychloride and Zirconia Low TENORM by Zircon Sand from Landak West Kalimantan

Abstract

In order to enhance the added value of zircon minerals (ZrSiO₄) derived from tailing gold mining in Mandor, Landak, West Kalimantan; the hydrometallurgical process is needed to obtain zirconium products such as zirconium Oxychloride (ZrOCl₂.8H₂O) and zirconia (ZrO₂). Zirconium products that are sold must meet the requirement of Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) or (ThO₂ + U₃O₈) is below 500 ppm. The purpose of this research was to process zircon sand with TENORM content 1784 ppm to be ZrOCl₂.8H₂O and ZrO₂ low TENORM. Zircon sand processing has been carried out through melting zircon sand with NaOH to bind Zr became Na₂ZrO₃ and Si as the impurities to become Na₂SiO₃, water leaching to separate Na₂ZrO₃ from Na₂SiO₃ and other impurities, acid leaching (HCl) to convert Na₂ZrO₃ to be zirconium oxychloride low Si (ZOC-1) then ZOC-1 to be zirconium sulfate base (ZBS), ZBS then being deposited to be ZrO(OH)₂, ZrO(OH)₂ converted to be zirconium oxychloride low TENORM (ZOC-2), ZOC-2 then being crystallized to be ZrOCl₂.8H₂O and calcinated to be zirconia. The results showed that zircon sand from Mandor, Landak, West Kalimantan could be synthesized into ZrOCl₂.8H₂O with NORM 1.2586 ppm and zirconia with NORM = 3.5511 ppm, both products have met the industrial-grade requirement.