ZrSiO4 was treated under lab. conditions with concd. HNO3 optionally after addn. of H2SO4, HCI or HF at 150 degrees C under 0.3-0.65 MPa for 1-3 h to produce ZrO(NO3)(2) sepd. then from reaction mixt. by evapn., centrifugation, crystn. and filtration. The Zr recovery was up to 90%. Use of pure HNO3 was recommended to avoid formation of other salts.