降温速率对硫酸钠溶液晶体析出影响的试验研究  

Experimental study on the influence of cooling rate on salt crystallizing in sodium sulfate solution

作　　者：万旭升[1,2] 赖远明[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [2]西南石油大学土木工程与建筑学院,四川成都610513

出　　处：《冰川冻土》2016年第2期431-437,共7页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41230630);中国科学院西部行动计划项目(KZCX2-XB3-19);西南石油大学青年教师"过学术关"项目(201599010104)资助

摘　　要：为探讨硫酸钠盐渍土盐胀机理,研究了十水硫酸钠晶体在硫酸钠溶液中的析出规律.针对不同浓度的硫酸钠溶液,在1℃·min^(-1)、0.1℃·min^(-1)和0.02℃·min^(-1)3种降温速率下,通过降温试验对晶体初始析出温度进行观测.试验表明:十水硫酸钠晶体的析出受降温速率的影响,随着降温速率的减小,晶体初始析出温度升高;降温速率的大小对晶体析出后溶液浓度变化几乎没有影响,但其会影响晶体形态,降温速率越小,晶体形态更为稳定;晶体析出受到相变驱动力作用,相变驱动力与降温速率大小呈正比,降温速率越大,晶体初始析出结晶力越大.Based on the pull down test of sodium sulfate solution,the crystallization law of sodium sulfate deca-hydrate was studied to explore the mechanism of sodium sulfate saline soil. In our experiment,the initial crystal-lization temperatures of different concentration of sodium sulfate solutions were observed under three kinds of cooling rate,which are 1℃· min-1,0. 1℃· min-1 and 0. 02 · min-1 respectively. The results show that the crys-tallization of sodium sulfate decahydrate is affected by the cooling rate,the initial crystallization temperature in-creases as the cooling rate decreases. The effect of value of cooling rate on concentration changing is very little, but it would affect crystal morphology,the lower the cooling rate,the more stable the crystal morphology. More-over,salts begin to crystallize under the effect of the phase transformation driving force,it is proportional to the value of cooling rate,the higher the cooing rate,the larger initial crystallization force.

关 键 词：硫酸钠溶液 盐胀 晶体析出 降温速率 相变驱动力 

分 类 号：TU448[建筑科学—岩土工程]