Chemical Modeling of Nesquehonite Solubility in Li+Na+K+NH_4+Mg+Cl+H_2O System with a Speciation-based Approach  

三水碳酸镁在Li+Na+K十NH_4+Mg+Cl+H_2O体系中溶解度的全组分化学模拟(英文)

作　　者：王道广 李志宝 

机构地区：[1]Key Laboratory of Green Process and Engineering,National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,Chinese Academy of Sciences

出　　处：《Chinese Journal of Chemical Engineering》2012年第2期267-276,共10页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (21076212,21076213,21146006);the National Basic Research Program of China (2009CB219904);Key Program in Science and Technology of Qinghai Province (2010-G-A4)

摘　　要：A chemical model,based on Pitzer activity coefficient model,is developed with a speciation approach to describe the solubility and chemistry of nesquehonite in concentrated chloride solutions.The chemical equilibrium constants for nesquehonite and aqueous species,i.e.0 3 MgCO,3 MgHCO,and MgOH +,are precisely calculated as a function of temperature according to the Van't Hoff equation by use of standard Gibbs free energy,standard formation enthalpy and heat capacity.The most recent solubility data are regressed to obtain new Pitzer parameters with good agreement.The predictive ability of the new model is improved significantly in comparison with previous models.The behavior of speciation chemistry for nesquehonite in various chloride media is explained through this modeling work on the basis of the 2 3 Mg /CO bearing species distribution,activity coefficient and pH changes.A chemical model,based on Pitzer activity coefficient model,is developed with a speciation approach to describe the solubility and chemistry of nesquehonite in concentrated chloride solutions.The chemical equilibrium constants for nesquehonite and aqueous species,i.e.0 3 MgCO,3 MgHCO,and MgOH ＋,are precisely calculated as a function of temperature according to the Van＇t Hoff equation by use of standard Gibbs free energy,standard formation enthalpy and heat capacity.The most recent solubility data are regressed to obtain new Pitzer parameters with good agreement.The predictive ability of the new model is improved significantly in comparison with previous models.The behavior of speciation chemistry for nesquehonite in various chloride media is explained through this modeling work on the basis of the 2 3 Mg /CO bearing species distribution,activity coefficient and pH changes.

关 键 词：chemical modeling SPECIATION EQUILIBRIUM nesquehonite solubility 

分 类 号：O614.22[理学—无机化学]