STUDY OF SOLUBILITY PRODUCT ON PRECIPITATE OF MOLYBDENUM AND ZIRCONIUM IN NITRIC ACID

The composition and character of precipitates of Mo and Zr are studied by XFA, TGA, XRD and IR methods. The results show that the precipitate can be present in the form of a mixture of ZrMo 2O 7(OH) 2·2H 2O and Zr(MoO 4)·2H 2O in 1.0 mol/L HNO 3, and the formula Zr(MoO 4) 2·2H 2O in ≥2 0 mol/L HNO 3. Some data about apparent solubility product ( K ′ sp ) of Mo and Zr precipitates have been determined in 1.0, 2.0, and 3.0 mol/L HNO 3 solutions. The effects of different concentration of nitric acid and initial concentration of Mo and Zr on the apparent solubility product are also investigated. It is found that K ′ sp increases with increasing nitric acid concentration. The initial concentration of Mo and Zr dose not influence K ′ sp .