KNO_3-Ca(NO_3)_2二元体系相图及热稳定性研究  

Phase diagram and thermal stability of KNO_3-Ca(NO_3)_2 binary system

作　　者：陈静[1,2] 曾德文[1,3] 李东东[1,2] 王军涛[3] 韩海军[1] 郭立江[1] 

机构地区：[1]中国科学院青海盐湖研究所,青海西宁810008 [2]中国科学院大学 [3]中南大学化学化工学院

出　　处：《无机盐工业》2015年第11期38-41,共4页Inorganic Chemicals Industry

摘　　要：针对KNO3-Ca(NO3)2二元体系的相图和热稳定性做了研究。借助DSC对不同组成比的KNO3和Ca(NO3)2混合盐样品做了相转变温度测定,利用XRD表征分析了体系中存在的固相。根据实验结果获得了KNO3-Ca(NO3)2二元体系的相图。研究发现,在KNO3-Ca(NO3)2二元体系中存在2种复盐,即4KNO3·Ca(NO3)2和KNO3·Ca(NO3)2,且该二元体系的最低共熔点为4KNO3·Ca(NO3)2与KNO3·Ca(NO3)2形成的共晶点,共晶温度为154℃,Ca(NO3)2的物质的量分数为31%。通过热稳定性研究发现,任意比例的样品都能在500℃下稳定存在。The phase diagram and thermal stability of KNO3-Ca （NO3）2 binary system were studied.DSC was used to test the phase transition temperatures of the samples mixed with different ratios of KNO3 and Ca （NO3）2.The solid phase existed in the system was characterized by the XRD.Based on the test results the phase diagram of KNO3-Ca （NO3）2 binary system was obtained.Research indicated that two double salts,gKNO3-Ca（NO3）2 and KNO3-Ca（NO3）2,could be found in the binarysystem. And the eutectic point temperature of 4KNO3-Ca（NO3）2 and KNO3-Ca（NO3）2 was 154 ℃ which was the lowest melting temperature of binary system,with 31% in amount-of-substance fraction of Ca（NO3）2. The study of the thermal stability indicated that the molten salts samples with any mixed proportion could be stable under 500 %.

关 键 词：硝酸熔盐 DSC 相图 热稳定性 

分 类 号：TQ131.13[化学工程—无机化工]