| 镧石型碳酸钕的形成及晶种对结晶的促进作用 |
| Crystalline Neodymium Carbonate with Lanthanide Structure: Preparation, and Promoting Action of Seeding on Crystallization |
|
| 摘要: |
| 关键词: 碳酸钕 晶种 结晶 pH值原位测定 |
| 基金项目: |
| Abstract: The characteristics of pH value variation during aging process of amorphous neodymium carbonate formed by three different feeding manners have been investigated. The promotion action of seeding on the crystallization of neodymium carbonate is discussed. X-ray diffraction pattern and the elemental analysis results show that neodymium carbonate can transfer from amorphous to crystalline normal neodymium carbonate Nd2(CO3)3·8H2O with lanthanide structure at room temperature. Its crystallization activity zone lies in lower feeding ratio area expressed by nNH4HCO3/nNdCl3 between 2～3. The existing of seeds can shorten crystalline time, from more than 15 h without seed to 2 h with seeds under normal feeding manner. And the spontaneity nucleation time can be shortened further when feeding with multi-steps normal manner. However, whether multi-steps normal or synchronously and continuously feeding manner, the precipitate formed can transfer to crystalline neodymium carbonate directly under seeding. At the same time, it is observed that the variation of pH value reduces with the decrease of feeding amount and the shortening of aging period, indicating that with synchronously and continuously feeding manner can not only realize fast crystallization, but also control pH value within a narrow range, which is beneficial for the producing of neodymium carbonate crystal with narrow-distributed particle size and monitoring of its crystallization process. |
| Keywords: neodymium carbonate seed crystallization pH determination in situ |
| 投稿时间：2004-12-06 修订日期：2005-02-21 |
| 摘要点击次数: 1404 |
| 全文下载次数: 1595 |
| 丁家文,李永绣,黄婷,罗贤满,杨毅,何小彬.镧石型碳酸钕的形成及晶种对结晶的促进作用[J].无机化学学报,2005,21(8):1213-1217. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| Support information: |
|
|
|
|
|
|
