关于K₃ZrF₇-NaCl伪二元系的研究

来源期刊：中南大学学报(自然科学版)1979年第2期

论文作者：赵秦生

文章页码：66 - 75

关键词：差热分析； 熔体； 相图； 文献； 二元系； 固态； 固溶体； 相分析； 液相线； 交互反应

摘    要：国外对K₃ZrF₇-NaCl盐系的研究,得到的结论各不相同,互相矛盾。为弄清K₃ZrF₇-NaCl系的实际情况,作者对此体系进行了差热分析和X光相分析。X光相分析表明,在K₃ZrF₇-NaCl系熔体的室温X光象片中,除K3ZrF7和NaCl的谱线外,还可能有Na₃ZrF₇、K3Na3Zr2F14和KCl的谱线。根据[K₃ZrF₇-NaCl]的比例不同,可发生下列两个交互反应: K₃ZrF₇+3NaCl——Na₃ZrF₇+3KCl (1) 2K₃ZrF₇+3NaCl——K₃Na₃Zr₂F₁₄+3KCl (2) 作者将K₃ZrF₇和NaCl按一定比例熔合,成功地分离出纯的交互产物K₃ZrF₇和K₃Na₃Zr₂F₁₄,并用X光相分析加以证实。结合差热分析的数据,说明K₃ZrF₇-NaCl系独立的二元系,而是(K⁺、Na⁺/ZrF₇^3-、Cl^-)三元交互系的一个不稳定的对角剖面。其液相线由二支组成,相应于K₃ZrF₇-Na₃ZrF₇固溶体和KCl-NaCl固溶体的析出。液相线最低点的组成为24%(克分子)K₃ZrF₇+76%NaCl,熔点为560℃。视K₃ZrF₇和NaCl的相对含量而定,得到的固态交互产物为K₃Na₃Zr₂F₁₄+KCl,K₃Na₃Zr₂F₁₄+Na₃ZrF₇+KCl或Na₃ZrF₇+KCl。

Abstract: There are different conclusions concerning the study of the potassium zirco nate (K₃ZrF₇) sodium chloride (NaCl) system. In order to clarify the aciual condition this system was investigated by (he author,using both thermal and X-ray methds. The X-ray phase analysis shows that in the spektra of K₃ZrF₇-NaCl melts at room temperature besides the spectral lines of K₃ZrF₇ and NaCl there is a possibilily of the existence of the spectral lines of Na₃ZrF₃, K₃Na₃Zr₂F₁₄ and KCl. According to the proportion of K₃ZrF₇ and NaCl the following two reciprocal reactions are possible: K₃ZrF₇+3NaCl→Na₃ZrF₇+3KCl (1) 2K₃ZrF₇+3NaCl→K₃Na₃Zr₂F₁₄+3KCl (2) From the K₃ZrF₇+NaCl melts prepared with the nearly stoichiometricpro por tion the pure N₃ZrF₇ and K₃Na₃Zr₂F₁₄ were successfully separated as produ cts of the reciprocal reaction and were identified by X-ray phase analysis. The DTA and X-ray data indicate that the K₃ZrF₇ NaCl system is not an independent binary system but an unstable diagonal section of K+, Na⁺//ZrF₇^3-, Cl^- ternary reciprocal system. The liquidus consists of two branches correspon ding to precipitation of K₃ZrF₇-Na₃ZrF₇ solid solution and KCl NaCl solid solution. The composition of lowest point of the liquids is 24% (mol.) K₃ZrF₇ + 76% NaCl with melting point 560℃. The obtained solid products of the reciprocal reaction are K₃Na₃Zr₂F₁₄+KCl,K₃Na₃Zr₂F₁₄+Na₃ZrF₇ + KCl or Na₃ZrF₇ +KCl according to the relative content of K₃ZrF₇ and NaCl.