摘要
采用等温溶解平衡的方法,在不同的溶剂组成及平衡温度下,对三元体系Na^( +)、K ^(+)∥NO_(3)^(-)-H _(2)O+CH _(3)CH _(2)OH的固—液相平衡进行研究,并对体系相应的物理性质包括密度(ρ)和电导率(σ)进行测定。在323.15 K条件下,考察了95%H _(2)O+5%C_( 2)H _(5)OH、90%H_( 2)O+10%C _(2)H_( 5)OH、85%H _(2)O+15%C_( 2)H _(5)OH三种不同混合溶剂对盐的溶解度和平衡固相的影响。在Na^(+)、K^(+)∥NO_(3)^(-)—H _(2)O(95%)+C _(2)H _(5)OH(5%)体系中,研究不同温度(278.15 K、298.15 K、323.15 K、348.15 K)对盐溶解度和平衡固相的影响。研究结果表明,在该三元体系中存在一个共饱点、两条单变曲线和三个结晶区域,且KNO 3结晶区域比NaNO 3大。在所研究温度下,KNO 3和NaNO 3在混合溶剂中的结晶区域均比在纯水中的结晶区域大,并且在323.15 K下随着乙醇加入量的增加,结晶相区域变大。提高温度有利于硝酸钾从添加乙醇的钠钾混和溶液中析出。所得数据和结果对从Na^(+)、K^(+)∥NO_(3)^(-)—H _(2)O体系中提取KNO_( 3)的结晶工艺具有重要意义。
The solid-liquid phase equilibrium of the ternary system Na^(+)、K^(+)∥NO_(3)^(-)-H_(2)O+C_( 2)H_(5)OH and the corresponding physical properties,including density(ρ)and conductivity(σ),under different solvent composition and temperature were investigated by the isothermal solution saturation method.More specifically,the effects of composition of mixed solvent,such as 95%H_(2)O+5%C_( 2)H_(5)OH,90%H_(2)O+10%C_( 2)H_(5)OH and 85%H_(2)O+15%C_( 2)H_(5)OH on the solubility of salts and the equilibrium solid phases were inspected at 323.15 K,and the effects of temperature,including 278.15 K,298.15 K,323.15 K and 348.15 K on the solubility of salts and the equilibrium solid phases were studied in the Na^(+)、K^(+)//NO-395%H_(2)O+5%C_( 2)H_(5)OH system.There is one invariant point,two univariant curves,and three crystallization regions in this ternary system,and KNO 3 occupies the larger crystallization region than NaNO 3.The crystallization region of KNO 3 and NaNO 3 become larger in the mixed solvent than that in pure water at whatever temperature,and the crystalline phase area becomes larger as more ethanol is added at 323.15 K.All the data and results obtained in this article are of great significance to the crystallization technology of KNO 3 from Na^(+)、K^(+)∥NO_(3)^(-)—H_(2)O system.
作者
刘建路
袁敬明
张丽娜
岳茂文
LIU Jian-lu;YUAN Jing-ming;ZHANG Li-na;YUE Mao-wen(School of Environment Science and Engineering of Tianjin University.,Tianjin 300072,China;CNOOC and Shandong Haihua Co.,Ltd.,Weifang 262737,China)
出处
《盐科学与化工》
CAS
2021年第3期20-26,共7页
Journal of Salt Science and Chemical Industry
基金
国家循环化园区改造中央财政专项资金扶持项目(国家发改委、财政部[2015]1468号)。
关键词
硝酸钠
硝酸钾
相平衡
水和乙醇混合溶剂
Sodium nitrate
Potassium nitrate
Phase equilibrium
Mixed solvent of water and ethanol
