Adsorbent combinations for enhanced removal of sodium oxalate from bayer process spent liquor

Sodium oxalate is precipitated from spent Bayer process liquor by mixture with a low total alkalinity (TA) sodium oxalate seed solution that has been treated with two or more adsorbents to remove organic poisons from the sodium oxalate. The adsorbents are preferably two different adsorbents selected from activated carbon, ESP dust, calcium oxide and magnesium oxide. Surprisingly, combination treatments with activated carbon and ESP dust are most effective even though ESP dust alone has little effect on oxalate removal.