Process for removing silica from alkali metal zirconosilicates (alkali metal zirconium silicates)

摘要

SiO2-containing zirconium ores or technical-grade zirconium compounds, particularly the (alkali metal)2ZrSiO5 obtained by alkaline digestion, are very substantially freed of SiO2 by heating with sulphuric acid, admixing with an approximately equal amount of water, filtering at above 60@C and crystallising Na2SO4.Zr(SO4)2 or Zr(SO4)2.