摘要
铀矿碳酸盐原地浸出和CO_2地质封存均涉及CO_2和重碳酸溶液的混合体系,两者配比直接决定混合体系pH值和溶液组成。本文基于电荷和质量衡算方程,提出了CO_2和重碳酸盐溶液混合体系pH计算公式。定量计算结果表明:(1)加入CO_2会降低溶液pH值,同时增加碳酸氢根离子浓度;(2)浓度高于0.1 mmol/L时,溶液pH值和碳酸氢根离子浓度与CO_2加入量相关性强,而与溶液浓度相关性很弱;(3)浓度低于0.1 mmol/L时,溶液pH值和碳酸氢根离子浓度由CO_2加入量和重碳酸盐浓度两者控制。
A generalized pH formula is proposed for the mixed solution of CO_2 and bicarbonate,which are concerned with carbonate leaching of uranium deposit and geological sequestration of CO_2.This method is based on the conservation equations of carbonate species and electric charges(or electric neutrality),and it should describe the effects of the ratio of CO_2 to bicarbonate on pH and composition of solution.The calculating results show that(1) pH of solution decrease with the increase of ratio;(2) Concentration of bicarbonate can be enhanced with addition of carbonate dioxide,(3) pH of solution and concentration of bicarbonate,are related with addition of CO_2(m)and concentration of sodium bicarbonate(c_0) when c_0<0.1 mmol/L,and are related with addition of CO_2(m) only when c_0>0.1 mmol/L.
引文
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