25℃下Na2CO3/Na2SO4/NaCl混合盐的溶解动力学研究

摘要

研究了25℃时,搅拌速度、加样量及NaCl的量等不同实验条件下Na2CO3/Na2SO4/NaCl混合盐的溶解过程.对不同时刻液相的化学组成进行分析并鉴定其平衡时的固相,结果表明,混合盐溶解前期搅拌速度占主导因素;当溶液中三种盐达到一定浓度后,同离子效应占主导因素;随着加样量的增加,Na2CO3和Na2SO4浓度达到一定程度之后反应生成碳钠矾.结合动力学模型计算得到体系中NaCl的溶解动力学方程,得出在25℃条件下溶解符合Stumm模型,溶解过程属于扩散过程控制,同时还伴随着界面反应和化学反应.%Dissolving process of salt mixture (Na2CO3 + Na2SO4 + NaCl) under different stirring speed,sample amounts and the amount of NaCl at 25℃ was studied.Liquid phase and the equilibrium solid phase were characterized by chemical analysis and solid phase identification,respectively.The results indicated that at the early stage of the dissolution process,the stirring speed act as the dominant factor,but common ion effect will become the dominant factor after reaching a certain concentration of three salts solution.With the increase of sample amounts,Na2CO3 will react with Na2SO4 to form burkeite after reaching a certain concentration.Dissolution kinetics equations for NaCl were obtained with dynamic model simulation,and it conformed to Stumm model under this experimental condition.It is concluded that dissolving process was controlled by diffusion process,but also accompanied by interface reaction and chemical reaction.