热-水-力-化学耦合作用下Ca_(0.86)Nd_(0.14)Ti_(0.86)Al_(0.14)SiO_5固溶体的化学稳定性

Chemical Stability of Ca_(0.86)Nd_(0.14)Ti_(0.86)Al_(0.14)SiO_5 Solid Solution by Coupling Effect of THMC

以CaCO3、Nd2O3、TiO2、SiO2、Al2O3为原料,用固相法制备掺钕榍石固溶体(Ca0.86Nd0.14Ti0.86Al0.14SiO5)。采用PCT法进行浸泡实验,借助X射线衍射(XRD)、扫描电镜(SEM)、电感耦合等离子体发射光谱(ICP-OES)等分析手段,研究掺钕榍石固溶体在热-水-力-化学(THMC)耦合作用下的化学稳定性。结果表明,在pH值为5～9、温度150～200℃、压强0.476～1.554MPa的耦合作用下,Ca0.86Nd0.14Ti0.86Al0.14SiO5固溶体具有良好的化学稳定性;pH值、温度(压力)对Ca0.86Nd0.14Ti0.86Al0.14SiO5固溶体中Si 4+、Al 3+、Nd3+的归一化浸出率无明显影响;Ca2+在200℃(1.554MPa)时的抗浸出性能较150℃时的好;在浸泡初期(1～21d)Ca2+在pH值为9时的抗浸出性能优于pH值为5和7时的,浸泡后期(28、42d)3种溶液中固溶体的Ca2+抗浸出性能趋于一致;Ti 4+在pH值为9时的抗浸出性能较pH值为5和7时的好。

Sphene solid solution doped neodymium（Ca0.86Nd0.14Ti0.86Al0.14SiO5） was prepared using CaCO3,Nd2O3,TiO2,SiO2 and Al2O3 as raw materials by solid-reaction.The chemical stability of sphene solid solution doped Nd by the coupling effect of thermodynamics-hydrodynamics-mechanics-chemistry（THMC） was investigated by the means of product consistency test（PCT）,X-ray diffraction（XRD）,scanning electron microscope（SEM）,inductively coupled plasma atomic emission spectrometry（ICP-OES） and so on.The results indicate that Ca0.86 Nd0.14Ti0.86Al0.14SiO5 solid solution has good chemical stability by the coupling effect of the pH=5-9,150-200 ℃ and 0.476-1.554 MPa;the pH value and temperature（pressure） have no significant impact on the normalized leach rate of Si4＋,Al3＋ and Nd3＋;the anti-leaching property of Ca2＋ at 200 ℃（1.554 MPa） is better than that at 150 ℃;early in the immersion,the anti-leaching property of Ca2＋ in pH=9 is better than that in pH=5 and 7,late in the immersion,the anti-leaching property of Ca2＋ in solid solution is converge in the three solution;the anti-leaching property of Ti4＋ in pH=9 is better than that in pH=5 and 7.