Abstract: This investigation describes the one step preparation of potassium carbonate by electrolysis of potassium chloride solution in the electrolyzers with various kinds of Nafion membranes. Potassium bicarbonate solution was fed to the cathode compartment, where it was converted into carbonate by reacting with the hydroxide formed at the cathode. Because of the low OH-concentra-tion in the cathode compartment, the back migration of OH-through the membrane was almost negligible, resulting in a higher current efficiency, say 90% or more. In the study, the electroconductivity, the mass transfer through the membrane, current efficiency and the cell voltage were measured, the feasibility was examined, and the optimal electrolytic condition selected.

摘要： 采用添加KHCO_3的阴极液循环法,由KCl水溶液的离子膜电解,一次得到K_2CO_3.试验中对Nafion膜的导电度进行了测定,探讨了碱金属阳离子在离子膜中的行为.对各种离子在Nafion膜中的移动速度进行了测定,表明影响电流效率的主要因素是OH~-离子的反向渗透.由于CO_3~(2-)在离子膜中的移动速度很小,所以在制取高浓度K_2CO_3时仍可获得90%以上的电流效率.通过控制添加的KHCO_3的量,可以得到KHCO_3及Cl~-含量极低的高纯度K_2CO_3.