Mechanism of Solidification Neodymium in Assorted Minerals of Zirconolite and Sphene

The assorted minerals of zirconolite and sphene doping simulated actinide neodymiumwere fabricated by solid reaction, using zircon, titanium dioxide, calcium carbonate, Al₂O₃ as raw materials.The phase assemblage, microstructure and elemental distribution were researched by X-ray diffractometer, scanning electron microscopy with energy dispersive spectrometer. The mechanism of solidification neodymium in assorted minerals of zirconolite and sphene was probed into. The better condition synthesizing the assorted minerals of zirconolite and sphene doping neodymium is holding 30 min at 1 230 ℃, and the better formula is n(Ca_1-x/2－y/4Nd_(x+y)/2Zr_1－y/4Al_x/2Ti_2－x/2O₇)∶n(Ca_1－xNd_xAl_xTi_1－xSiO₅)＝4/(4-y)∶1.Nd³⁺ can enter crystal lattices of zirconolite and sphene. Sphene can immobilize Zr⁴⁺,Al³⁺ and Nd³⁺; Zr⁴⁺ and Nd³⁺ replace Ca²⁺，and Al³⁺ replaces Ti⁴⁺. Zirconolite can immobilize Al³⁺ and Nd³⁺; Nd³⁺ replaces Ca²⁺ and Zr⁴⁺, and Al³⁺ and replaces Ti⁴⁺.