KVO_3-NaVO_3-CO(NH_2)_2-H_2O体系298K相关系实验研究  

An experimental study on the phase equilibrium of the quaternary system KVO_3-NaVO_3-CO(NH_2)_2-H_2O at 298K

作　　者：曾英[1] 彭芸[1] 倪师军[2] 张成江[2] 

机构地区：[1]成都理工大学化工系,成都610059 [2]成都理工大学地球化学系,成都610059

出　　处：《成都理工大学学报（自然科学版）》2007年第4期460-463,共4页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：四川省教育厅应用基础研究项目(2003B027);四川省科技厅应用基础研究项目(04JY029-008-1);中国地质调查局资助项目(200314200015)

摘　　要：钒在土壤溶液中的溶解性能要受共存离子种类及含量的影响。作者采用等温溶解平衡法研究了KVO3-NaVO3-CO(NH2)2-H2O四元体系298 K时的溶解度相关系,考察了钾、钠、脲素等共存离子或盐类同偏钒酸根离子的相互作用。该四元体系298 K时的溶解度等温图含有3个相区、3条单变量线和1个无变量点。无变量点的平衡固相盐为KVO3+NaVO3+CO(NH2)2;体系中没有复盐或固溶体形成,3个结晶相区分别为盐KVO3,NaVO3和CO(NH2)2的结晶区,其中KVO3的结晶区最大,表明钾离子的存在不利于土壤中钒的溶解。体系共存盐间存在盐析作用。The solubility of vanadium in soil solution is effected by the kinds of co-exist ion in soil. The equilibrium solubilities and phase diagram of the quaternary system KVO3-NaVO3-CO（NH2）2-H2O at 298 K are studied by isothermal dissolution equilibrium method. The reciprocal reaction between potassium, sodium, urea and metavanadate ion is investigated. The solubility diagram of the quaternary system consists of three crystallization fields, three univariant curves and one invariant point. At the invariant point, the saturated solid salts are KVO3 ＋NaVO3 ＋CO（NH2）2. No double salt or solid solution is formed. Three crystallization fields correspond to salt KVO3, NaVO3, and CO（NH2）2, respectively. The crystallization area of KVO3 is the largest. This shows that the presence of potassium in soil may reduce the solubility of vanadium. The salting-out effect lies in the salt of the system.

关 键 词：四元体系 相关系 偏钒酸盐 脲 

分 类 号：O642.42[理学—物理化学]