CaCO3-Al(OH)(3) mixtures were calcined at 1,273 K by varying the mixing ratio and the removal behavior of PO43- from solution was examined. The calcination products of CaCO3 mixed with a small amount of Al(OH)(3) (Ca/(Ca+Al) = 0.85-0.91), whose major crystalline component was lime (CaO), showed higher PO43- removal than the calcination products of other CaCO3-Al(OH)(3) mixtures and of CaCO3: The maximum amount of PO4 removal and the lowest concentration of the remaining PO43- in solution were 10 mmol.g(-1) and 0.002 mmol.dm(-3), respectively. PO43- ions were removed by the precipitation of hydroxyapatite (Ca-10(PO4)(6)(OH)(2)) and the related compound, Ca-8(HPO4)(6)(OH)(4)center dot H2O.