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1.
(Na+、K+、Mg2+),(Cl-、SO42-),H2O五元系统介稳平衡的研究 总被引:8,自引:0,他引:8
本文报道(Na+、K+、Mg2+),(Cl-、SO42-),H2O五元系统介稳平衡实验的数据。并作出25℃的(Na+、K+、Mg2+),(Cl-、SO42-),H2O五元介稳平衡相图。包括八个均为氯化钠所饱和的结晶区域即:氯化钾、钾钠芒硝(3K2SO4·MgSO4)、软钾镁矾(MgSO4·K2SO4·6H2O)、硫酸钠、白钠镁矾(MgSO4·Na2SO4·4H2O)、七水硫酸镁、光卤石和水氯镁石(MgCl2·6H2O)。(Na+、K+、Mg2+),(Cl-、SO42-),H2O五元系统介稳平衡相图研究的成功证明在复杂的多组元系统中存在介稳平衡。和Van't Hoff的该五元系统稳定平衡相图比较有较大的差别:钾镁矾(MgSO4·K2SO4·4H2O)、钾盐镁矾(KCl·MgSO4·3H2O)及硫酸镁的低水化合物结晶区域消失了;钾钠芒硝、白钠镁矾结晶区域缩小;氯化钾、七水硫酸镁、光卤石结晶区域增大,特别是软钾镁矾结晶区域约增大20倍,这对于制取硫酸型钾盐具有重要意义。在所制作的五元系统介稳相图中,由于钾镁矾和钾盐镁矾结晶区域消逝,因而硫酸镁与氯化钾结晶区直接连接,在蒸发海水时,有可能直接析出氯化钾。根据所作的五元系统介稳相图,提出了自盐湖析出的芒硝和光卤石、氯化钠直接加工为硫酸型钾盐的原则流程。 相似文献
2.
研究了添加Al对SO42-/ZrO2超强酸样品的晶化、比表面、硫含量、超强酸性和正戊烷反应性能的影响,考察了活化温度、反应温度、Al含量和载Pt对催化剂活性和选择性的影响.SO42-/Al2O3ZrO2催化剂的酸强度与SO42-/ZrO2基本相当,但超强酸位比后者多,未载Pt时正戊烷反应活性和稳定性明显高于后者.负载Pt后,正戊烷异构化选择性和稳定性大大提高,但Pt/SO42-/Al2O3ZrO2催化剂的反应活性与Pt/SO42-/ZrO2相近,Al的促进作用不明显. 相似文献
3.
将一种均相季铵型阴离子交换膜用于修饰水/1,2-二氯乙烷(W/DCE)界面,并利用循环伏安法、差分脉冲伏安法和计时电量法考察了该界面上强亲水性阴离子SO42-的转移反应过程.研究结果表明,该阴离子交换膜所修饰的W/DCE界面比修饰前具有更宽的电化学窗口,而且在界面上可获得完整的SO42-转移的循环伏安曲线和差分脉冲伏安曲线.其中,循环伏安曲线的峰电流与扫速平方根呈线性关系,SO42-在膜内水相中的扩散系数为7.6×10-8 cm2/s;差分脉冲伏安曲线的峰电流与SO42-的浓度在5~25 mmol/L范围内呈线性关系.另外,利用计时电量法测得SO42-在该界面上转移反应的标准速率常数为1.49×10-3 cm/s. 相似文献
4.
湿法脱硫浆液中Hg的还原机制研究 《燃料化学学报》2017,45(6):755-760
针对燃煤电厂湿法脱硫浆液中Hg2+易被还原的特性,研究Hg2+在模拟湿法脱硫系统中的迁移机制,考察了浆液温度、pH值以及SO32-、Cl-、Ca2+、Mg2+浓度等因素对Hg2+还原性能的影响。结果表明,Hg2+还原率随着浆液中SO32-浓度的增大而降低;pH值对Hg2+的还原呈先增加后降低的趋势,在pH值为5.5时还原率最高;温度的升高不利于浆液中稳定的二价汞盐络合物存在,导致Hg2+还原率增加;Ca2+、Mg2+以及Cl-浓度的增加有利于形成稳定化合物,从而抑制Hg2+的还原。 相似文献
5.
电解质水溶液结构研究进展及前景* 总被引:11,自引:0,他引:11
叙述盐湖中主要离子Li+ 、Na+ 、K+ 、Mg2+ 、Ca2+ 、Cl- 、SO2-4 、NO-3 的水溶液和纯水的结构, 简单介绍了主要的研究方法, 分析讨论了溶液结构研究的现状和发展前景。 相似文献
6.
SO42-/MxOy型固体超强酸催化剂研究(Ⅰ) 总被引:14,自引:0,他引:14
合成了一种新的SO42-/MxOy型固体超强酸-SO42-/ZrO2-Fe2O5,研究了它对正戊烷反应的活性与选择性;制备并测定了SO42-/TiO2固体超强酸对正戊烷的异构化活性与裂解活性及其某些物性;重复合成了文献报导的SO42-/ZrO2固体超强酸并测定了它对正戊烷异构化的催化性能,表明所采用的测定方法与所得结果可与文献值相比较。 相似文献
7.
以四甲基乙二胺和1,3-二溴丙烷为原料,合成了聚电解质阳离子功能基--2,3-聚季铵盐功能基。以聚苯乙烯为种子,通过种子溶胀法制备了多孔型聚(苯乙烯-二乙烯基苯)微球(PS-DVB),并对其进行磺化。以附聚的方式在磺化的PS-DVB微球上附聚2,3-聚季铵盐功能基,得到附聚型离子交换固定相,通过匀浆法装入色谱柱,并将其用于SO42-的分离分析。SO42-能与其他常见的6种阴离子在8 min内完成分离,实现SO42-的快速测定。其中,SO42-的线性范围为0.5~50 mg/L,线性相关系数r为0.9992;加标回收率在99.2%~101.8%之间;峰面积和保留时间的相对标准偏差分别为2.4%和3.1%;根据信噪比(S/N=3)计算出检出限为0.04 mg/L。结果表明该自制色谱柱适用于复杂基质中SO42-的快速测定。 相似文献
8.
本文考察了ZnO·WO3悬浮水溶液中污染物SO2的可见光催化氧化并建议通空气处理较高浓度的SO32-扩水溶液。含0.15mol/LSO32-水溶液可见光照2h可将SO32-基本上光催化氧化成SO42-。对这光助SO32-自发氧化反应中可能平行存在的自发、多相催化、光化学和光催化等反应进行实验对比;筛选出克分子比0.5ZnO·WO为最佳掺杂配比;考察了光催化剂热处理、空气流量、pH对光催化活性的影响,得出pH7.5为最佳值;太阳光催化SO32-氧化速率比室内实验更快,展现了利用太阳能于环保的应用前景,对所有实验结果都给以理论解释,并提出一个较详细的反应机理。 相似文献
9.
利用软模板结合电沉积法制备了一种有序化氰桥混配聚合物修饰铂电极(Nd-Fe-MoO42-/Pt),用循环伏安法研究了在该化学修饰铂电极的丙三醇电催化氧化,并重点讨论了支持电解质的H+和SO42-浓度、丙三醇浓度、扫速等因素对丙三醇电催化氧化活性的影响. 结果表明,在弱酸性硫酸钠支持电解质中,适当量SO42-的存在有助于提高Nd-Fe-MoO42-/Pt电极的丙三醇电催化氧化电流;-0.2 ~ 0.3 V电位区间内,其丙三醇氧化峰电流1与循环伏安曲线扫描速率的平方根之间呈现良好的线性关系,体现了扩散控制的反应特性;Nd-Fe-MoO42-/Pt电极的丙三醇电催化氧化电流密度值约为裸铂电极的4倍,而丙三醇电催化氧化反应的表观活化能相对较小,修饰电极的电催化氧化呈现了明显的协同效应,其电催化氧化活性高、电流响应快、催化稳定性好. 相似文献
10.
R.W.Cattrall等曾研制PVC膜CdCl42-离子选择电极,其线性响应范围10-1-10-4M,级差26-28mV。本文报道以三辛基十二烷基碘化铵与镉澳络阴离子形成的缔合物为电活性物的涂碳(PVC膜)CdBr42-离子选择电极的研究结果。 相似文献
11.
In order to utilize the brine resources in China, the solid-liquid equilibria in quaternary system Li+, K+//SO42-, B4O72--H2O at 288 K was studied by the isothermal solution equilibrium method. Solubilities and densities of solutions were determined experimentally. According to the experimental data, the equilibrium phase diagrams, density-composition diagram and corresponding water content diagram of the quaternary system were plotted. Double salt KLiSO4 was found in the reciprocal quaternary system Li+, K+//SO42-, B4O72--H2O at 288 K. The quaternary system has three invariant points, seven univariant curves and five fields of crystallization. The five crystallization regions correspond to Li2B4O7·3H2O, Li2SO4·H2O, K2B4O7·4H2O, K2SO4 and KLiSO4, respectively. The crystallization field of salt Li2B4O7·3H2O is the largest, whereas that of Li2SO4·H2O is the smallest. The experimental results show that Li2SO4·H2O has a strong salting-out effect on other salts. 相似文献
12.
四元体系H3BO3-MgSO4-MgCl2-H2O在273.15K的溶解度等温线 总被引:1,自引:0,他引:1
作者考察了H3BO3-MgSO4-MgCl2-H2O四元体系在273.15±0.05K温度下的溶解度等温线。四元体系共饱和点的液相组成为33.44%(重量)MgCl3,1.77%MgSO4和0.65%H3B03。 相似文献
13.
Chromium oxides supported on TiO2 showed good activity for the selective catalytic reduction of NO by NH3.The catalytic activity of Cr2O3-SO42-/TiO2 catalyst was greatly enhanced by the addition of SO42-into TiO2 support.The catalyst surface properties were characterized with NH3-TPD(temperature programmed desorption) and H2-TPR(temperature programmed reduction).The sulphate on the catalyst surface could enhance the acidity and redox of the catalyst obviously.The reaction mechanism on this catalyst was researched in detail by in situ diffuse reflectance Fourier transform infrared(FTIR) spectroscope.Eley-Rideal and Langmuir-Hinshelwood mechanism existed simultaneously for selective catalytic reduction(SCR) reaction of NO over Cr2O3-SO42-/TiO2 catalyst. 相似文献
14.
研究了MgCl2-MgSO4-H2O、H3BO3-MgCl2-H2O、H3BO3-MgSO4-H2O三个三元体系及由它们所组成的四元体系H3BO3-MgCl2-MgSO4-H2O在288.15K的溶解度等温线。确定了六水硫酸镁的存在,讨论了各相之间的关系及各化合物相互间的盐析作用。 相似文献
15.
This work presents chemical modeling of solubilities of metal sulfates in aqueous solutions of sulfuric acid at high temperatures. Calculations were compared with experimental solubility measurements of hematite (Fe2O3) in aqueous ternary and quaternary systems of H2SO4, MgSO4 and Al2(SO4)3 at high temperatures. A hybrid model of ion-association and electrolyte non-random two liquid (ENRTL) theory was employed to fit solubility data in three ternary systems H2SO4–MgSO4–H2O, H2SO4–Al2(SO4)3–H2O at 235–270 °C and H2SO4–Fe2(SO4)3–H2O at 150–270 °C. Employing the Aspen Plus™ property program, the electrolyte NRTL local composition model was used for calculating activity coefficients of the ions Al3+, Mg2+ Fe3+ and SO42−, HSO4−, OH−, H3O+, respectively, as well as molecular species. The solid phases were hydronium alunite (H3O)Al3(SO4)2(OH)6, hematite Fe2O3 and magnesium sulfate monohydrate (MgSO4)·H2O which were employed as constraint precipitation solids in calculating the metal sulfate solubilities. A correlation for the equilibrium constants of the association reactions of complex species versus temperature was implemented. Based on the maximum-likelihood principle, the binary interaction energy parameters for the ionic species as well as the coefficients for equilibrium constants of the reactions were obtained simultaneously using the solubility data of the ternary systems. Following that, the solubilities of metal sulfates in the quaternary systems H2SO4–Fe2(SO4)3–MgSO4–H2O, H2SO4–Fe2(SO4)3–Al2(SO4)3–H2O at 250 °C and H2SO4–Al2(SO4)3–MgSO4–H2O at 230–270 °C were predicted. The calculated results were in excellent agreement with the experimental data. 相似文献
16.
SO功能化处理对FeO催化剂上氨选择性催化还原NOx性能的促进机理研究 《燃料化学学报》2020,48(5):584-593
采用沉淀法制备了Fe(OH)_3和Fe_2O_3。通过硫酸化处理得到SO_4~(2-)/Fe(OH)_3和SO_4~(2-)/Fe_2O_3两种催化剂,并将其应用于氨选择性催化还原NO_x(NH_3-SCR)反应,研究了SO_4~(2-)功能化处理对Fe_2O_3催化剂上NH_3-SCR脱硝性能的促进机理。结果表明,与纯的Fe_2O_3相比,硫酸化处理得到的催化剂上SCR活性得到显著提升;其中,SO_4~(2-)/Fe(OH)_3表现出更加优异的催化性能,在250-450℃时NO_x转化率高于80%,且具有优异的稳定性和抗H_2O+SO_2性能。XRD、Raman、TG、FT-IR、H_2-TPR、NH_3-TPD和in situ DRIFTS等表征结果显示,硫酸功能化处理能抑制Fe_2O_3的晶粒生长,同时SO_4~(2-)与Fe~(3+)结合形成硫酸盐复合物,提高了催化剂表面酸性位点的数量和酸强度,抑制了Fe_2O_3上的氨氧化反应,从而提高了其脱硝催化性能。 相似文献
17.
According to the compositions of the underground gasfield brines in the west of Sichuan Basin, the solu- bilities and densities of the solid-liquid equilibria in the quaternary system Na+, K+//Br-, B4O72--H2O at 298 K were determined by the method of isothermal solution saturation. From the experimental data, the phase diagram, water content diagram and density-composition diagram were obtained. This quaternary system is of simple eutectic type, without double salt and solid solution. There are two invariant points, five univariant curves, four fields of crystalli- zation in the system. The equilibrium solid phases are Na2BaO7·10H20, K2B4O7·4H2O, NaBr·2H2O and KBr. Na2B4O7·10H2O has a larger crystallization field, and NaBr·2H2O has a smaller crystallization field. It is also found that bromide has the salting-out effect on borate in the quaternary system Na+, K+//Br-, B4O72--H2Oat 298 K. 相似文献