排序方式: 共有112条查询结果,搜索用时 15 毫秒
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盐卤硼酸盐化学 Ⅹ.MgO·2B2O3-MgCL2-H2O浓盐溶液在20℃时硼酸盐的结晶动力学研究 总被引:12,自引:3,他引:12
配制MgO·2B_2O—MgCl_2—H_2O浓盐溶液在20℃恒温静置过程中,第一阶段析出MgO·3B_2O_3·7H_2O,第二阶段析出2MgO·2B_2O_3·MgCl_2·14H_2O。采用一级和二级混合反应速率模型,用计算机对结晶动力学C_B—t实验曲线进行拟合,给出结晶动力学速率方程-r=-dC/dt-k(C-C_(平衡))~2+k’(C-C(平衡))。基于高硼浓盐溶液中硼氧配阴离子是以多粒子共存的设想,提出了这两种水合硼酸镁盐结晶反应过程的机制,结晶过程中溶液pH变化的测定结果证实了这一解释。 相似文献
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Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃ for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part- icles were characterized by powder X-ray diffraction(XRD),thermal analysis(TGA-DSC), infrared spectroscopy(FT-IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker-like and nanocrystalline materials are in the range of 10~50μm and 10~20nm respectively. The whisker MOS is metastable phase in MgSO4-NaOH-H2O system at 140℃,whereas nanometer MOS is stable phase. 相似文献
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MgSO4-NaOH-H2O四元交互体系160℃水热相作用 总被引:1,自引:0,他引:1
在MgO-MgSO4-H2O体系中存在多种硫氧镁化合物[1-4],其中5Mg(OH)2·MgSO4·2H2O晶须(简称MOS)被开发用作塑料、树脂和橡胶等复合材料添加剂,提高基底材料的抗冲击力、抗弯曲力和耐磨性,也可以用作填料和过滤材料和阻燃剂[5-8]。由于MOS价廉、安全,同时具有多种功能,具有广阔的应用前景。本文对MgSO4-NaOH-H2O四元交互体系160℃水热条件下相作用进行研究,得到同一组成形貌不同的晶须,同时还存在另外两种硫氧镁化合物。1 实验用分析纯MgSO4·7H2O(西安化学试剂厂)分别配制质量百分比浓度为6%、1… 相似文献
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某些有机溶剂加入无机水盐体系能较大地改变无机盐在水溶液中的溶解度 ,反之 ,某些盐类也可显著地影响双液系组分之间的相对挥发度 ,这方面的理论研究和应用研究已有较多报道[1 ,2 ] 。利用一些有机溶剂的强盐析作用 ,以期实现对某些混合盐类的分离和纯化 ,在盐卤工业等领域具有很重要的意义。Nikolskaya等[3] 和潘焕泉等[4] 分别测定了三元系Li2 SO4 C2 H5OH H2 O在不同温度 (- 2 0~ 5 0℃ )下的互溶度 ,没有发现该体系产生分层现象 ,确定了各温度下的平衡固相皆为Li2 SO4·H2 O。Aravamu dan[5] 及… 相似文献
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模拟合成盐卤与盐酸反应的热化学研究 总被引:2,自引:0,他引:2
青藏高原新类型盐湖卤水日晒蒸发过程中硼酸盐在浓缩卤水中富集L‘。,我们在前又问中曾报道天然浓缩盐卤中硼酸盐是以“四硼酸盐”的综合统计形式存在,当盐卤浓缩到氯化镁共饱和时,可视为MgO-BZO3-MgC12-HZO四元体系中的一个特定的膺三元体系MgO·2B2O3-MgC12-H。O.该四元体系20oC热力学非平衡态液固相图问与25oC热力学平衡态相图*存在较大差别.由于聚合翻氧配阴离子的存在,使得对含棚浓缩盐卤的研究变得复杂而困难*.李积才等“~SJ对合成盐卤的稀释热和表观摩尔热径进行过测定,李军间在对多种水合硼酸盐在盐酸中… 相似文献
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三元系RbCl-C2H5OH-H2O液固相平衡及其物化性质研究 总被引:2,自引:0,他引:2
The isothermal solubility and physico-chemical properties (density, refractive index) of ternary system RbCl-EtOH-H2O at 25℃ and 50℃ have been firstly investigated by means of self-made micro-equilibrium and sampling apparatus .The compositions of liquid and solid at equilibrium state were determined, and the problem of analysis of ethanol content in system was properly solved. The phase diagram was drawn by the TPD phase-diagram computer program developed by us. Three empirical formulae were proposed to correlate the solubility, density and refractive index respectively. No demixing phenomena was observed in the range of temperature related in this study. 相似文献
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The FT-IR difference spectroscopy and the Raman spectroscopy were used to identify the polyborate ions in saturated aqueous solutions during dissolution and transformation of 2MgO·2B2O3·MgCl2·14H2O in different HCl solutions at 30℃. The assignments of the recorded IR-Spectroscopic frequencies and Raman shift of the borate aqueous solution are given. The existing forms of polyborate anions in saturated aqueous solution and their inter-action have been discussed. The relationships between the existing forms of polyborate anions and the crystallizing solid phases have been gained. 相似文献
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