论文部分内容阅读
采用质量差法研究了不通电时Na3AlF6-K3AlF6-AlF3体系中铝的溶解度。实验首先测定了不同时间内铝溶解的情况,并确定铝饱和溶解的时间为3 h。主要研究了初晶温度、过热度、电解质组成,以及电解质融化之后的熔盐深度对铝溶解度的影响。实验选用刚玉坩埚盛装电解质。测试结果表明,初晶温度为670～900℃的电解质,铝的溶解度为0.05%～0.50%(质量分数)。在初晶温度较低的电解质中,铝的溶解度较低,反之较高。对于某个特定体系来说,提高过热度会增加铝的溶解度。电解质的组成对铝溶解度的影响是:增大KR,可以降低铝的溶解度;AlF3含量增加,铝溶解度降低;对于KR=30,AlF3=26%(质量分数)的电解质,出现了异常的情况。另外,减少电解质的用量,降低熔盐的深度,也会造成铝的挥发损失,并最终导致铝的溶解增加。总之,影响铝溶解度的因素是多方面的,抑制铝的溶解损失,可以从改变电解质的组成、降低初晶温度、减少铝的挥发等方面着手。
The solubility of aluminum in Na3AlF6-K3AlF6-AlF3 system without electricity was studied by the method of poor quality. The experiment first measured the aluminum dissolution in different time, and determined that the time of aluminum saturation dissolution was 3 h. Mainly studied the primary crystal temperature, superheat, electrolyte composition, as well as the depth of the molten salt molten aluminum solubility of the impact. Experimental selection corundum crucible containing electrolyte. The test results show that the solubility of aluminum is 0.05% ~ 0.50% (mass fraction) when the primary crystallization temperature is 670 ~ 900 ℃. In the lower temperature of the primary electrolyte, the solubility of aluminum is low, whereas the higher. For a particular system, increasing the degree of superheat increases the solubility of aluminum. The effect of the electrolyte composition on the aluminum solubility is that increasing KR decreases the solubility of aluminum; the AlF3 content increases and the aluminum solubility decreases; and for the electrolyte with KR = 30 and AlF3 = 26% (mass fraction), an abnormal situation occurs. In addition, reducing the amount of electrolyte and lowering the depth of the molten salt can also result in loss of aluminum volatility and eventually lead to increased aluminum dissolution. In short, the factors that affect the solubility of aluminum are many, to inhibit the loss of aluminum dissolution, from changing the composition of the electrolyte, reducing the temperature of the primary crystal to reduce the volatilization of aluminum and so on.