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1.
本文研究了含硼四元水盐体系MgB4O7-MgO4-MgCl2-H2O及次级体系MgB4O7-MgSO4-H2O和MgB4O7-MgCl2-H2O在298.15K时不同离子强度下的稀释热和热容,并将Debye-Huckel极限公式应用到多元电解质稀溶液中,获得从高离子强度到低离子强度I为19-0.0001范围内的相对表观摩尔焓.  相似文献   

2.
本文采用等温溶解平衡法研究了四元交互体系Li+,Mg2+/CI-,SO-H2O25℃的机关系和平衡液相的物化性质(密度、粘度、电导率、折光率和pH).该体系25℃有七个相区Li2SO4·H2O,MgSO4·7H2O.MgSO4·6H2O.MgSO4·5H2O,MgC12,6H2O,LiCI.MgCl2.7H2O,LiCI·H2O,十一条单变量线,五个共饱点.其中LiCI·H2O+LiCI·MgCl2·7H2O+Li2SO4·H2O为一致零变量点.与文献中的研究结果比较,我们得到两个新相区MgSO4·6H2O和MgSO4·5H2O.用经验和半经验公式计算了平衡液相的密度、折光率.由实验测定的溶解度数据求得了高锂浓度下的Pitzer参数.对该体系25℃溶解度进行了理论计算复证.  相似文献   

3.
MgO,2B2O3-18%MgCl2-H2O过饱和溶液于20℃恒温静置,其结晶过程分为两个阶段,第一阶段结晶析出三方硼镁石(MgO,3B2O3,7.5H2O)。第二阶段析出章氏硼镁(MgO.2B2O3.9H2O),未得到多水硼镁石和库水硼镁石,探讨了两种析出固相的结晶机理并拟事出结晶动力学方程,结果表明,两个种固相结晶机理场为多核表面反应控制生长。  相似文献   

4.
MgO-B2O3-MgCl2-H2O是含硼盐湖日晒浓缩盐卤的典型体系,它与盐酸反应生成硼酸,是从天然浓缩盐卤中制取硼酸的工艺基础,以量热滴定法和PH滴定法研究该反应,结果表明,析出硼酸的反应分两步进行;合成盐卤中硼酸盐可用MgB2nO3N+1(n=1,2,3)综合统计形式来表示;天然浓缩盐卤中硼酸盐可以用四硼酸镁的统计形式进行表示。  相似文献   

5.
SYNTHESIS OF 4-(2,3-DIMETHOXY-4-ISOPROPYLBENZYL)-3-ETHOXYCARBONYLMETHYL-2-CYCLOHEXENONESYNTHESISOF4-(2,3-DIMETHOXY-4-ISOPROPY...  相似文献   

6.
测定了25℃时三元体系MgCl2-CO(NH2)2-H2O的等温溶度及饱和溶液的折光率和密度,且绘制成溶度图和性质,组成图,在三元体系内形成2个三元化合物新相,MgCl2.CO(NH2)2.4H2O(记作A)和MgCl2.4CO(NH2).2H2O(记作B),B为新化合物,三元体系的溶度图由4支单饱和线(对应单饱和因相为MgCl2.6H2O,三元化合物A和B,CO(NH2)2)组成,这4支单饱和线  相似文献   

7.
SYNTHESISOF1H,1'HBIS(BENZ-△~4-IMIDAZOLINE)2,2'-SPIRO-TITANIUMDICHLORIDEWeiRongbao;LiangYa;WuJinguo;XueQifeng(Dept.ofChem.Eng....  相似文献   

8.
MgO·2B2O3-18%MgCl2-H2O过饱和溶液于20℃恒温静置,其结晶过程分为两个阶段.第一阶段结晶析出三方硼镁石(MgO·3B2O3·7.5H2O),第二阶段析出章氏硼镁石(MgO·2B2O3·9H2O).未得到多水硼镁石和库水硼镁石.探讨了两种析出团相的结晶机理并拟合出结晶动力学方程.结果表明,两种固相结晶机理均为多核表面反应控制生长.  相似文献   

9.
Ni-Cu和MgO-SiO_2间的相互作用及其对催化性能的影响   总被引:2,自引:0,他引:2  
本文用TPR,IR,TPD和TPSR等技术研究了以表面改性法制备的MgO-SiO2(MSO)表面复合物担载的Ni-CU合金间的相互作用及其对CO加氢反应催化性能的影响.结果表明,NiO-CuO与MSO间的相互作用导致部分MO与MSO形成表面物种从而使金属组分氧化物还原温度明显升高;还原后的Ni-Cu/MSO表面上存在着两类活性中心,即合金相中的Ni与载体相中的Mg2+(或Mg2+-O);在两类活性中心的协同作用下,CO吸附除有孪生、线式和桥式吸附态物种外,还有一种新的卧式吸附态(Ni...C=O→Mg2+).这种吸附态的活化程度较高,易在表面上发生裂解形成Ni-C和Mg2+-O,其中Ni-C是加氢反应的碳源;H2在催化剂表面上发生解离吸附形成Ni-H和Mg2+-OH,前者比较活泼,是加氢反应的氢原.CO加氢生成烃类的反应在Ni中心上按"表面碳"机理进行,其生成CZH4的选择性高于80%;H2O的生成反应按2(Mg2+-OH)-→Mg2++(Mg2+-O)+H2O方式进行.  相似文献   

10.
LiAgSO4-Al2O3复合电解质的导电性研究   总被引:6,自引:0,他引:6  
研究了分散第二相α-Al2O3对LiAgSO4的离子导电性的影响,发现LiAgSO4-Al2O3的电导率随a-Al2O3含量的增加而升高,在300-500℃间电导率高于纯LiAgSO4,a-Al2O3含量摩尔比约为40时最高。TG-DTA和XRD分析表明,在高温稳定的体立心LiAgSO4降温后以Ag2SO4的正交β相形式存在,但在H2O存在下,生成Li2SO4.H2O和Ag2SO4.FT-IR分析  相似文献   

11.
Solubilities for the system of MgCl2-MgSO4-MgB4O7-H2O at 298.15 K were calculated by using Pitzer and its extended HW model. The values of the parameters were derived from either literature or through fitting with the solubility data of the relative ternary system in literature. A comparison with the experimental values and calculated solubility data shows that the model can be used successfully to predict the solubilities of the mentioned system. Parameters got in this study can be further used for solubility prediction of more complicated system containing MgB4O7, and the results could provide a theoretical basis for exaction of magnesium borate from salt lake brine resources.  相似文献   

12.
张爱芸  姚燕 《化学学报》2006,64(6):501-507
测定了298.15 K下, 无液接电池Li-ISE│Li2B4O7 (mA)(aq.), MgCl2(mB)(aq.)│AgCl/Ag的电动势, 利用测定结果计算了Li2B4O7-MgCl2-H2O体系离子强度在0.05~3 mol•kg-1范围内, 不同MgCl2离子强度分数的溶液中LiCl的平均活度系数, 并给出了其随离子强度I, B4O72-和Mg2+浓度的变化规律. 结合以往关于该体系和Li2B4O7-LiCl-H2O, Li2B4O7-H2O体系的等压研究结果, 用迭代和多元线性回归方法对Li-Mg2+-Cl-B4O72--H2O体系的离子相互作用模型进行了研究. 具体方法为考虑了该体系在不同的总硼浓度范围H3BO3, B(OH)4, B3O3(OH)4和B4O5(OH)42-四种含硼化合物的存在以及各硼化合物间的化学平衡, 以修正了的Pitzer渗透系数方程和活度系数方程为基础, 对该体系的等压法和电动势法研究结果进行最小二乘拟合, 拟合的标准偏差为0.0167, 用该模型计算的该体系的渗透系数、活度系数与实验值基本一致.  相似文献   

13.
The Pitzer ion-interaction model has been used for thermodynamics simulation of the ternary system Cs2SO4-MgSO4-H2O at 298.15 K. The Pitzer ternary mixing parameter $ \psi _{CsMgSO_4 } $ \psi _{CsMgSO_4 } and thermodynamic characteristics for double salt Cs2SO4 · MgSO4 · 6H2O have been calculated and the theoretical solubilities isotherm has been plotted.  相似文献   

14.
(Solid+Liquid) phase equilibria in the quaternary system Na2B4O7‐MgB4O7‐K2B4O7‐H2O at 288 K were studied experimentally using the method of isothermal solution saturation. Solubility of any single salt in the solution of the quaternary system was determined experimentally. Based on the experimental data achieved, the phase diagram and water content diagram of the quaternary system were constructed, respectively. In the phase equilibrium diagram of the quaternary system Na2B4O7‐MgB4O7‐K2B4O7‐H2O at 288 K, there are one invariant point E, three univariant curves E1E, E2E and E3E, and three fields of crystallization corresponding to Na2B4O7·10H2O, K2B4O7·4H2O and MgB4O7·9H2O. The experimental results show that potassium borate (K2B4O7·4H2O) have higher solubilities than the magnesium borate and sodium borate in the quaternary system Na2B4O7‐MgB4O7‐K2B4O7‐H2O at 288 K.  相似文献   

15.
Solubility in the Na2Cr2O7-(NH4)2Cr2O7-K2Cr2O7-H2O four-component water-salt system at 25, 50, and 75°C was studied for the first time. Phase field boundaries for individual salts and potassium and ammonium dichromate solid solutions, monovariant lines, and invariant points were determined. Experimental data were used to optimize the looped isohydric process of potassium dichromate preparation involving additional salts.  相似文献   

16.
利用精密绝热量热仪测定了0.03355mol·kg-1的硼砂水溶液在78~351K温区的热容,从实验热容测定结果得到了该水溶液的凝固点为272.905K。用最小二乘法将实验热容值对温度进行拟合,建立了该溶液的热容随温度变化的多项式方程。根据热力学函数关系式,用此多项式方程进行数值积分,获得了以298.15K为基准的该溶液在80~350K温区每隔5K的热力学函数值,并计算出摩尔熔化焓和熔化熵分别为4.536kJ·mol-1和16.22J·K-1·mol-1。根据溶液凝固点降低值,计算出了该溶液的活度为0.99763。  相似文献   

17.
用Pitzer-Simonson-Clegg热力学模型(PSC模型),分别拟合KCl-H2O、K2SO4-H2O、KNO3-H2O体系以及KNO3-K2SO4-H2O和KNO3-KCl-H2O体系水活度和溶解度实验数据,得到二元参数和三元离子相互作用参数,并以此计算3个二元盐水体系溶解度相图,及2个三元盐水体系在不同温度下的溶解度,结果表明计算值与实验值一致。  相似文献   

18.
This is the first study of solubility in the NaCl-NH4Cl-KCl-H2O four-component water-salt system at 25, 50, and 75°C. Phase fields of individual salts and potassium and ammonium chloride solid solutions were demarcated. Experimental data were used to develop a mathematical model of the K+, Na+, NH4+/Cl, Cr2O72−-H2O five-component reciprocal system, which includes the title four-component system.  相似文献   

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