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Effect of inorganic salt impurities on seeded precipitation of silica hydrate from sodium silicate solution
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作者 Xiao-bin LI Xiao-bing GAO +5 位作者 Qiu-sheng ZHOU Yi-lin WANG Tian-gui QI Lei-ting SHEN Gui-hua LIU Zhi-hong PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期3016-3028,共13页
To clarify the precipitation of silica hydrate from the real desilication solutions of aluminosilicate solid wastes by adding seeds and improve integrated waste utilization,the seeded precipitation was studied using s... To clarify the precipitation of silica hydrate from the real desilication solutions of aluminosilicate solid wastes by adding seeds and improve integrated waste utilization,the seeded precipitation was studied using synthesized sodium silicate solution containing different inorganic salt impurities.The results show that sodium chloride,sodium sulfate,sodium carbonate,or calcium chloride can change the siloxy group structure.The number of high-polymeric siloxy groups decreases with increasing sodium chloride or sodium sulfate concentration,which is detrimental to seeded precipitation.Calcium chloride favors the polymerization of silicate ions,and even the chain groups precipitate with the precipitation of high-polymeric sheet and cage-like siloxy groups.The introduced sodium cations in sodium carbonate render a more open network structure of high-polymeric siloxy groups,although the carbonate ions favor the polymerization of siloxy groups.No matter how the four impurities affect the siloxy group structure,the precipitates are always amorphous opal-A silica hydrate. 展开更多
关键词 ALUMINOSILICATE sodium silicate solution siloxy group IMPURITY silica hydrate
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Effect of Compounding of Sodium Tripolyphosphate and Super Plasticizers on the Hydration of α-calcium Sulfate Hemihydrate 被引量:3
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作者 潘伟 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第4期737-744,共8页
The inhibition and its mechanism of sodium tripolyphosphate (STP) composited with super plasticizers (SPs) on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-r... The inhibition and its mechanism of sodium tripolyphosphate (STP) composited with super plasticizers (SPs) on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electronic probe micro analysis (EPMA), scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) measurements. The experimental results show that compared with STP addition, compositing STP with polycarboxylate (PC) plasticizer, the final setting time is prolonged from 0.5h to 2hs. While formulating STP with naphthalene-based plasticizer (NAP) or sulfonate melamine formaldehyde plasticizer (SMF), the final setting time is reduced to quarter of an hour. Similar changes can also be found in the rate of exothermic hydration and hydration degree. Formulating STP with suitable addition of PC can enhance the strength, while compositing STP and NAP or SMF weakens the strength. Besides, adding STP or STP and SMF, obvious movement (more than 1ev) of binding energy of Ca2p1/2 and Ca2p3/2 is detected. Compared with STP addition, content of the characteristic element (P) of STP is cut down form 1.1% to 0.49% by compositing STP with SMF. Furthermore, as hydration age increases, hydration inhibition in the presence of admixtures weakens and even disappears within 56 h. 展开更多
关键词 α-calcium sulfate hemihydrate hydratION sodium tripolyphosphate PLASTICIZER ADSORPTION
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SiO2/Al2O3 RATIO OF HYDRATED SODIUM ALUMINOSILICATE IN ALUMINA PRODUCTION
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作者 Deng, Hongmei Zeng, Wenming Chen, Nianyi 《中国有色金属学会会刊:英文版》 EI CSCD 1997年第2期44-47,共4页
SiO2/Al2O3RATIOOFHYDRATEDSODIUMALUMINOSILICATEINALUMINAPRODUCTION①DengHongmei,ZengWenming,ChenNianyiShanghai... SiO2/Al2O3RATIOOFHYDRATEDSODIUMALUMINOSILICATEINALUMINAPRODUCTION①DengHongmei,ZengWenming,ChenNianyiShanghaiInstituteofMetalu... 展开更多
关键词 hydrated sodium ALUMINOSILICATE HYDROXY SODALITE Si atom VACANCY
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Adsorption of sodium ions and hydrated sodium ions on a hydrophobic graphite surface via cation-π interactions
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作者 石国升 王志刚 +2 位作者 赵纪军 胡钧 方海平 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第6期474-479,共6页
Using density functional theory computation, we show that sodium ions and hydrated sodium ions can be strongly adsorbed onto a hydrophobic graphite surface via cation-π interactions. The key to this eation-π interac... Using density functional theory computation, we show that sodium ions and hydrated sodium ions can be strongly adsorbed onto a hydrophobic graphite surface via cation-π interactions. The key to this eation-π interaction is the coupling of the delocalized π states of graphite and the empty orbitals of sodium ions. This finding implies that the property of the graphite surface is extremely dependent on the existence of the ions on the surface, suggesting that the hydrophobic property of the graphite surface may be affected by the existence of the sodium ions. 展开更多
关键词 GRAPHITE sodium ion and hydrated sodium ion cation-π interaction density functional theory
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COMPOSITION AND SPECTROSCOPIC STUDIES OF HYDRATED SODIUM ALUMINATE COMPOUNDS
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作者 QIU Guofang, DENG Hongmei, ZENG Wenming and CHEN Hianyi(Shanghai Institute of Metallurgy, Chinese Academy of Sciences, Shanghai 200050, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1996年第3期177-180,共4页
XRD, IR, NMR and a 'tracer method' are used to investigate two hydrated sodium aluminates. It has been found that the compositions of these two compounds are 4Na2O-Al2O-3-12H2O and Na2O-Al2O3-2.5H2O, respecttv... XRD, IR, NMR and a 'tracer method' are used to investigate two hydrated sodium aluminates. It has been found that the compositions of these two compounds are 4Na2O-Al2O-3-12H2O and Na2O-Al2O3-2.5H2O, respecttvely. The aluminate anion in the former consists of condensed AlO4 tetrahedra. 展开更多
关键词 sodium aluminate hydrate COMPOSITION spectroscopic study
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A DFT Study on the Reaction Mechanism Involved in the Synthesis of Sodium Azide via Hydrazine Hydrate Method
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作者 孙华云 李明晶 刘永军 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第7期1045-1051,共7页
Sodium azide is a widely used inorganic compound. Besides the commonly used method of "Wislicenus process" which uses ammonia, nitrous and sodium as materials, the hydrazine hydrate route is also employed for the pr... Sodium azide is a widely used inorganic compound. Besides the commonly used method of "Wislicenus process" which uses ammonia, nitrous and sodium as materials, the hydrazine hydrate route is also employed for the preparation of sodium azide particularly in laboratory. However, because many species are involved in the reaction system, the reaction details for the hydrazine hydrate route are still unclear. A comprehensive understanding of the reaction mechanism may provide meaningful help for optimizing the production process. In this work, the reaction mechanism for the synthesis of sodium azide by hydrazine hydrate route has been studied using density function theory(DFT) method. On the basis of our calculations, the reaction details, including the energetics of ten elementary steps, the structures of intermediates and transition states as well as the influence of inorganic acids and alcohols, were illuminated at the atomistic level. Both the two steps, the generation of key intermediate(NH2-NH-NO) and the trans-cistransformation of NH2-NH-NO, are suggested to be the possible rate-limiting step, corresponding to the energy barriers of 20.3 and 22.7 kcal/mol, respectively. In the early reaction steps to generate NH2-NH-NO, the main role of sulphuric acid is to donate proton, which can be replaced by nitric acid or hydrochloric acid. From the energy point of view, isopropanol has similar reactivity as methanol and ethanol. 展开更多
关键词 sodium azide HYDRAZINE hydrate DFT method ISOPROPANOL sulphuric acid
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Measurements of Hydrate Equilibrium Conditions for CH4, CO2, and CH4+C2H6+C3H8 in Various Systems by Step-heating Method 被引量:8
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作者 陈立涛 孙长宇 +3 位作者 陈光进 聂运强 孙占松 刘延涛 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第4期635-641,共7页
Phase equilibrium conditions of gas hydrate in several systems were measured by the step-heating method using the cylindrical transparent sapphire cell device.The experimental data for pure CH4 or CO2+deionized water ... Phase equilibrium conditions of gas hydrate in several systems were measured by the step-heating method using the cylindrical transparent sapphire cell device.The experimental data for pure CH4 or CO2+deionized water systems showed good agreement with those in the literatures.This kind of method was then applied to CH4/CO2+sodium dodecyl sulfate(SDS)aqueous solution,CH4/CO2+SDS aqueous solution+silica sand,and(CH4+C2H6+C3H8)gas mixture+SDS aqueous solution systems,where SDS was added to increase the hydrate formation rate without evident influence on the equilibrium conditions.The feasibility and reliability of the step-heating method,especially for porous media systems and gas mixtures systems were determined.The experimental data for CO2+silica sand data shows that the equilibrium pressure will change significantly when the particle size of silica sand is less than 96μm.The formation equilibrium pressure was also measured by the reformation of hydrate. 展开更多
关键词 equilibrium condition hydrate step-heating sodium dodecyl sullate silica sand
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Predicting hydrate forming pressure of pure alkanes in the presence of inhibitors 被引量:4
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作者 Alireza Bahadori Hari B.Vuthaluru +1 位作者 Saeid Mokhatab Moses O.Tade 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2008年第3期249-255,共7页
An inherent problem with natural gas production or transmission is the formation of gas hydrates, which can lead to safety hazards for production/transportation systems, and substantial economic risks. Hydrate inhibit... An inherent problem with natural gas production or transmission is the formation of gas hydrates, which can lead to safety hazards for production/transportation systems, and substantial economic risks. Hydrate inhibition with different inhibitors such as, methanol, ethylene glycol (EG), triethylene glycol (TEG), and sodium chloride solution continues to play a critical role in many operations. An understanding of when the hydrates form in the presence of these hydrate inhibitors, is therefore necessary to overcome hydrate problems. Several thermodynamic models have been proposed for predicting the hydrate formation conditions in aqueous solutions containing methanol/glycols and electrolytes. However, available models have limitations that include the types of liquid, compositions of fluids, and inhibitors used. The aim of this study is to develop a simple-to-use correlation for accurate prediction of hydrate-forming pressures of pure alkanes in the presence of different hydrate inhibitors, where the obtained results illustrate good agreement with the reported experimental data. 展开更多
关键词 gas hydrates pure alkanes methanol: ethylene glycol triethylene glycol sodium chloride
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Hydration Characteristics of Sodium Sulfate Slag Cement System 被引量:2
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作者 陈友治 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2001年第4期45-47,61,共4页
The hydration characteristics by thermal analysis (DTA) were determined, and an isothermal calorimeter (IC) was used to study the pastes. The experimental results indicate: (1) The main hydration products of SSC are C... The hydration characteristics by thermal analysis (DTA) were determined, and an isothermal calorimeter (IC) was used to study the pastes. The experimental results indicate: (1) The main hydration products of SSC are C-S-H (I) gel with a low Ca/Si ratio, crystalline Thomsonite-type and AFt-type phases containing certain alkali cations; (2) No phases of the AFm-type and high alkaline Ca (OH)(2) in SSC system could benefit the hydrated cements to improve its strength and durability; (3) Crystalline Thomsonite-type and AFt-type phases containing Na+ will greatly reduce free alkali and alleviate the harmness of alkali aggregate reaction (AAR) in SSC system; (4) Similar to ordinary Portland cement (OPC), the hydration process of SSC could be classified into five stage: initial, induction, acceleration, deceleration and decay; (5) Regardless of the activator used, the apparent activation energy is higher with the increased slag in cement system, and the rising temperature could promote the hydration of SSC. 展开更多
关键词 sodium sulfate slag cement (SSC) hydratION alkali cation crysta pline phase heat evolution apparent activation energy
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三轴应力下CO_(2)置换开采天然气水合物实验研究
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作者 王婷婷 赵建忠 +1 位作者 高强 张驰 《太阳能学报》 EI CAS CSCD 北大核心 2024年第4期584-591,共8页
为模拟海域真实环境,在三轴应力、氯化钠体系以及水合物储层富水状态的条件下,开展针对氯化钠体系、储层初始饱和度以及置换压应力对液态CO_(2)置换开采海域天然气水合物的实验。研究表明:在三轴应力以及孔隙度约46.70%的条件下,氯化钠... 为模拟海域真实环境,在三轴应力、氯化钠体系以及水合物储层富水状态的条件下,开展针对氯化钠体系、储层初始饱和度以及置换压应力对液态CO_(2)置换开采海域天然气水合物的实验。研究表明:在三轴应力以及孔隙度约46.70%的条件下,氯化钠体系对CH4置换效率影响较小,但对CO_(2)水合物合成表现出抑制作用;储层初始饱和度与CH4置换效率之间是负相关关系且高的储层含水率更有利于CO_(2)封存;CH4置换效率随着置换压应力的增长有一定幅度的提高,置换压应力的增大为CO_(2)水合物合成提供了高的驱动力,进而提高了CO_(2)封存效率。 展开更多
关键词 天然气水合物 二氧化碳 甲烷 氯化钠 置换 三轴应力 储层初始饱和度
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高掺量煅烧煤矸石粉胶结料的力学和水化特性研究
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作者 杨永恒 迟骋 刘东升 《中国建材科技》 CAS 2024年第2期53-58,共6页
研究了煅烧煤矸石-水泥熟料-石膏胶材体系的力学和水化特性。结果表明,煅烧煤矸石适当取代部分熟料制备的胶凝材料具有较好的力学性能,最佳取代量为35%,7d和28d强度可达23.8MPa和29MPa。无水硫酸钠的掺入可明显提升胶材体系的早期和后... 研究了煅烧煤矸石-水泥熟料-石膏胶材体系的力学和水化特性。结果表明,煅烧煤矸石适当取代部分熟料制备的胶凝材料具有较好的力学性能,最佳取代量为35%,7d和28d强度可达23.8MPa和29MPa。无水硫酸钠的掺入可明显提升胶材体系的早期和后期强度,最佳掺量为5%,3d、7d和28d强度分别提升100%、32.4%和40%。利用XRD和SEM对胶凝材料改性前后的物相组成分析发现,无水硫酸钠的掺入使体系早期生成了大量的Ca(OH)_(2)贯穿于C-S-H凝胶中,且Ca(OH)_(2)的存在加速石膏溶解,加快AFt生成,填充孔隙,使体系结构致密,提高了早期强度。 展开更多
关键词 煤矸石 无水硫酸钠 早期强度 水化机理
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葡萄糖酸钠对大掺量石灰石粉水泥浆体水化行为的影响 被引量:1
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作者 朱鹏飞 余熠 +4 位作者 石研然 蒋林华 储洪强 徐菲 徐宁 《长江科学院院报》 CSCD 北大核心 2024年第1期183-189,共7页
为了研究葡萄糖酸钠对大掺量石灰石粉水泥浆体水化行为的影响,采用等温量热测试、X射线衍射测试、热重测试研究了胶凝材料体系的水化进程、水化产物种类与含量的变化;并采用相边界成核与生长模型探究了葡萄糖酸钠作用下大掺量石灰石粉... 为了研究葡萄糖酸钠对大掺量石灰石粉水泥浆体水化行为的影响,采用等温量热测试、X射线衍射测试、热重测试研究了胶凝材料体系的水化进程、水化产物种类与含量的变化;并采用相边界成核与生长模型探究了葡萄糖酸钠作用下大掺量石灰石粉水泥水化产物成核与生长机制。结果表明:葡萄糖酸钠能够延缓大掺量石灰石粉水泥的水化,减少水化产物的生成,从而降低其水化程度;另外,葡萄糖酸钠能够降低水化产物早期成核与生长的速率,减小水化产物早期在相边界成核与生长的面积。 展开更多
关键词 葡萄糖酸钠 大掺量石灰石粉 水化进程 水化产物 水化动力学
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无机阴离子对低温拜耳法中脱硅产物析出的影响
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作者 刘吉龙 潘晓林 +2 位作者 吴鸿飞 侯宪林 于海燕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第4期1300-1310,共11页
利用XRD、FT-IR、SEM和PSD等手段系统研究无机阴离子对低温拜耳法过程中脱硅产物(DSPs)的组成、结构以及微观形貌的影响。当溶液中存在氯化物、硫酸盐和碳酸盐时,形成氯化物型方钠石、碳酸盐型方钠石和黝方石,部分铝酸盐离子被阴离子杂... 利用XRD、FT-IR、SEM和PSD等手段系统研究无机阴离子对低温拜耳法过程中脱硅产物(DSPs)的组成、结构以及微观形貌的影响。当溶液中存在氯化物、硫酸盐和碳酸盐时,形成氯化物型方钠石、碳酸盐型方钠石和黝方石,部分铝酸盐离子被阴离子杂质取代。硫酸盐与DSPs的结合能力强于铝酸盐、氯化物和碳酸盐。随着阴离子浓度的增加,DSPs的粒径增大,且DSPs的团聚程度和圆形片层结构的厚度均有所增加。此外,阴离子杂质会促进沸石骨架的溶解和方钠石中四元环的形成,从而促进沸石向方钠石转化。 展开更多
关键词 拜耳法 水合铝硅酸钠 无机阴离子 脱硅 晶体结构
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基于分子动力学的钠离子与纳米二氧化硅表面的相互作用过程模拟
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作者 张凤娟 张磊 +5 位作者 吕振虎 麦尔耶姆古丽·安外尔 余维初 王牧群 董景锋 庄为杰 《油田化学》 CAS CSCD 北大核心 2024年第3期491-497,共7页
认识盐水中的Na^(+)对纳米SiO_(2)的作用过程,可为优化纳米SiO_(2)在石油开采领域的应用参数提供依据。以无定形纳米SiO_(2)粒子为研究对象,构建了一种既有饱和稳定的硅醇基团,又有脱质子化的硅醇基团的纳米SiO_(2)粒子模型。通过分子... 认识盐水中的Na^(+)对纳米SiO_(2)的作用过程,可为优化纳米SiO_(2)在石油开采领域的应用参数提供依据。以无定形纳米SiO_(2)粒子为研究对象,构建了一种既有饱和稳定的硅醇基团,又有脱质子化的硅醇基团的纳米SiO_(2)粒子模型。通过分子模拟方法,刻画了Na^(+)在纳米SiO_(2)表面的运移特征、扩散行为、对氢键的影响以及体系中的相互作用能。结果表明,在纳米SiO_(2)-NaCl溶液体系中,当Na^(+)运移至距纳米SiO_(2)粒子表面6.540A时,短程力开始起作用;当Na^(+)运移至距纳米SiO_(2)粒子表面2~3A时,二者发生电荷交换,Na^(+)产生振荡运动。在NaCl质量浓度为3 g/L时,Na^(+)与水分子主要进行水合作用,形成稳定的溶剂化层,Na^(+)与纳米SiO_(2)粒子之间的作用力弱,Na^(+)更易在溶液中扩散。随着NaCl质量浓度增至7 g/L,Na^(+)突破溶剂化层,和水分子一起被吸附到纳米SiO_(2)粒子的表面,发生电荷置换,Na^(+)的运移能力减弱,扩散系数由1.39×10^(-4)A^(2)/ps下降至3.75×10^(-5)A^(2)/ps,斯特恩层的厚度由0.88A下降至0.72A,亥姆霍兹层的厚度由0.64A下降至0.20A,纳米SiO_(2)与Na^(+)之间的相互作用能由-14 000 kcal/mol变为-22 000 kcal/mol,纳米SiO_(2)的稳定性逐渐被破坏。Na^(+)与纳米SiO_(2)粒子的静电相互作用是影响纳米SiO_(2)粒子表面性质的主要作用力,氢键和范德华力则是次要作用力。研究结果可为纳米SiO_(2)材料在油气开采领域及其他相关行业的应用提供基础理论认识。 展开更多
关键词 分子模拟 纳米SiO_(2) 钠离子 水合离子 表面作用
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葡萄糖酸钠对水泥浆体流动度的影响及作用机理 被引量:2
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作者 栗翔 毛永琳 +2 位作者 张建纲 周栋梁 杨勇 《混凝土与水泥制品》 2024年第2期24-27,共4页
研究了葡萄糖酸钠对掺减水剂水泥浆体流动度的影响,并通过测试减水剂在水泥颗粒表面的吸附率、水化产物含量、固体颗粒的比表面积,分析了葡萄糖酸钠对流动度的影响机理。结果表明:葡萄糖酸钠的掺入提高了水泥浆体的流动度,降低了减水剂... 研究了葡萄糖酸钠对掺减水剂水泥浆体流动度的影响,并通过测试减水剂在水泥颗粒表面的吸附率、水化产物含量、固体颗粒的比表面积,分析了葡萄糖酸钠对流动度的影响机理。结果表明:葡萄糖酸钠的掺入提高了水泥浆体的流动度,降低了减水剂的吸附率,抑制了水泥浆体中早期钙矾石生成,但加速了中期钙矾石的生成速率,使钙矾石总量提高;葡萄糖酸钠降低了水泥浆体早期的比表面积,但后期比表面积明显增加。 展开更多
关键词 葡萄糖酸钠 流动度 吸附 水化产物
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驱动压力影响下不同体系煤层气水合分离实验
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作者 王世海 吴强 +2 位作者 李忠辉 陈勇 赵子琪 《低碳化学与化工》 CAS 北大核心 2024年第10期136-142,共7页
煤层气(CBM)分离提纯对保障矿井安全生产、实现双碳目标等具有重要意义。基于水合物法分离技术,在十二烷基硫酸钠(SDS)、油水乳液和纯水体系中施加4种驱动压力(1 MPa、2 MPa、3 MPa和4 MPa),开展了高浓度煤层气(甲烷体积分数60%)水合分... 煤层气(CBM)分离提纯对保障矿井安全生产、实现双碳目标等具有重要意义。基于水合物法分离技术,在十二烷基硫酸钠(SDS)、油水乳液和纯水体系中施加4种驱动压力(1 MPa、2 MPa、3 MPa和4 MPa),开展了高浓度煤层气(甲烷体积分数60%)水合分离实验。结果表明,3种体系中煤层气水合物的生长速率均随驱动压力的增大而持续增大,添加SDS和油水乳液能进一步增大水合物生长速率。不同驱动压力下,煤层气经纯水体系、SDS体系和油水体系分离后,甲烷回收率分别为10.02%~11.75%、31.00%~43.36%和21.68%~24.36%,其中SDS体系较纯水体系甲烷回收率增大了3~4倍,油水体系则增大了约2倍。3种体系中甲烷回收率均随驱动压力增大而增大,但驱动压力为3~4 MPa时,SDS和油水乳液体系的分离因子呈下降趋势,分离难度变大,可见3 MPa为最佳驱动压力,此时煤层气经SDS和油水乳液体系提纯后,甲烷体积分数分别达到81.13%和82.32%。 展开更多
关键词 煤层气水合物 水合分离 驱动压力 十二烷基硫酸钠 油水乳液
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铝酸钠对磷石膏矿渣干硬水泥性能的影响机理
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作者 唐佩 文嘉祺 陈伟 《硅酸盐通报》 CAS 北大核心 2024年第8期2924-2932,共9页
磷石膏矿渣水泥是一种低碳水泥,该体系中反应物矿粉的溶出速度较慢,导致凝结时间长,早期强度低。降低水灰比并使用干压成型方式制备干硬水泥,通过颗粒的紧密堆积提供初始强度,但极低的水灰比使反应进行缓慢,因此提出通过外掺铝酸钠促进... 磷石膏矿渣水泥是一种低碳水泥,该体系中反应物矿粉的溶出速度较慢,导致凝结时间长,早期强度低。降低水灰比并使用干压成型方式制备干硬水泥,通过颗粒的紧密堆积提供初始强度,但极低的水灰比使反应进行缓慢,因此提出通过外掺铝酸钠促进早期产物产生及后期矿渣水化。通过抗压强度、水化放热、物相分析以及微观形貌观测研究外掺铝酸钠对干硬水泥性能的影响。结果表明,铝酸钠的掺入能够促进磷石膏矿渣干硬水泥水化的进行,且在早期生成更多的水化产物以提升强度的发展,后期能促进矿粉的持续水化,掺加铝酸钠试块在各个养护龄期的强度均高于对照组,掺量为混合粉体质量的0.5%时效果最佳。 展开更多
关键词 磷石膏 干硬水泥 铝酸钠 水化产物 钙矾石 物相分析
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水玻璃固化冰碛物的强度及固结机理分析
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作者 杨朝义 韩江峰 +3 位作者 朱乾坤 丁林娜 卞立波 刘娟红 《硅酸盐通报》 CAS 北大核心 2024年第6期2217-2224,共8页
为解决普朗铜矿在开采过程中地表松散冰碛物堆积造成地面塌陷和泥石流的问题,本文采用水玻璃复合酯类固化剂制备固结材料固结冰碛物,对冰碛物固结体的抗压强度进行了研究,并通过XRD、FTIR、DSC-TG和SEM对水玻璃复合酯类固化剂固结材料... 为解决普朗铜矿在开采过程中地表松散冰碛物堆积造成地面塌陷和泥石流的问题,本文采用水玻璃复合酯类固化剂制备固结材料固结冰碛物,对冰碛物固结体的抗压强度进行了研究,并通过XRD、FTIR、DSC-TG和SEM对水玻璃复合酯类固化剂固结材料固结冰碛物的固结机理进行了探究。结果表明,冰碛物固结体28 d抗压强度最高可达2.05 MPa,具有较好的固结性能。酯类固化剂作用下,水玻璃水解产物与酯类固化剂的水解产物反应生成乙酸钠和硅凝胶,硅凝胶起到了填充冰碛物颗粒之间的空隙、胶结冰碛物颗粒的作用。 展开更多
关键词 酯类固化剂 水玻璃 冰碛物 凝胶 水合乙酸钠 固结
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纳米氧化锌和SDS促进二氧化碳水合物生成特性实验研究
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作者 崔茂 辛公明 李德祥 《低碳化学与化工》 CAS 北大核心 2024年第6期129-140,共12页
水合物法捕集和封存二氧化碳(CO_(2))具有储气量高和成本低等优点,但生成CO_(2)水合物(简称“水合物”)的诱导时间长、生成速率缓慢限制了该方法的应用。为促进水合物的生成,采用恒容法研究了纳米氧化锌(ZnO)和十二烷基硫酸钠(SDS)对水... 水合物法捕集和封存二氧化碳(CO_(2))具有储气量高和成本低等优点,但生成CO_(2)水合物(简称“水合物”)的诱导时间长、生成速率缓慢限制了该方法的应用。为促进水合物的生成,采用恒容法研究了纳米氧化锌(ZnO)和十二烷基硫酸钠(SDS)对水合物生成的影响。结果表明,在一定条件下增大初始压力和引入机械搅拌可以促进水合物生成,并且单独添加纳米ZnO或SDS均能显著缩短诱导时间。其中,在ZnO质量分数为0.06%和275.65 K的条件下,确定了初始压力和搅拌速率的最优值分别为4.5 MPa和500 r/min。在3.5 MPa、275.65 K和300 r/min的条件下,加入质量分数为0.10%、粒径为50 nm的纳米ZnO(ZnO-50)体系的诱导时间为41.6 min,较纯水体系的诱导时间(487.4 min)缩短了91.5%。体系中ZnO-50的质量分数为0.06%时,气体消耗总量为0.903 mol,较纯水体系的气体消耗总量(0.444 mol)提高了103.4%。提高SDS的质量分数对气体消耗总量的促进效果逐渐增强,当体系中SDS的质量分数为0.10%时,气体消耗总量达到最大(1.027 mol),比纯水体系的气体消耗总量提高了131.3%。以质量分数为0.10%的SDS与质量分数为0.02%的ZnO-50构建协同体系,其气体消耗总量(1.045 mol)受相平衡压力的影响变化不大,但可以显著加快水合物生成速率,实验半程(反应5 h)的气体消耗量可达0.924 mol,占实验全程(反应10 h)气体消耗总量的88.4%,明显高于单独使用质量分数为0.02%的ZnO-50和质量分数为0.10%的SDS体系的相应数据(分别为63.7%和48.5%)。相关研究结果可为应用水合物技术进行CO_(2)捕集和封存提供一定的理论指导。 展开更多
关键词 水合物 纳米氧化锌 十二烷基硫酸钠 诱导时间 气体消耗量
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三种温和还原法制备Pt/SDB
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作者 付昆 高月 +4 位作者 汤义萍 朱磊 刘才林 杨海君 任先艳 《化学研究与应用》 CAS 北大核心 2024年第5期1092-1100,共9页
Pt/SDB是液相催化交换(LPCE)反应处理核电产生含氚废水的一种很有前途的催化剂。采用悬浮聚合法制备得到介孔聚苯乙烯-二乙烯基苯(SDB),以硼氢化钠(SBH)、水合肼(HH)或乙二醇(EG)为还原剂,温和还原法制备SDB载体负载铂活性颗粒,产物分... Pt/SDB是液相催化交换(LPCE)反应处理核电产生含氚废水的一种很有前途的催化剂。采用悬浮聚合法制备得到介孔聚苯乙烯-二乙烯基苯(SDB),以硼氢化钠(SBH)、水合肼(HH)或乙二醇(EG)为还原剂,温和还原法制备SDB载体负载铂活性颗粒,产物分别记为Pt/SDB-SBH、Pt/SDB-HH或Pt/SDB-EG。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、氮气吸附脱附和氢-水催化交换实验等对其结构形貌及催化活性表征。结果表明:Pt/SDB-SBH疏水催化剂具有突出的性能和优异的催化活性,Pt纳米颗粒平均粒径约为3.3 nm,Pt^(0)组分比例为72.0%,催化交换柱效率达65.0%,并在120 min保持稳定。为低温还原制备Pt/SDB疏水催化剂提供了一种新的策略。 展开更多
关键词 液相催化交换(LPCE) 铂/苯乙烯-二乙烯基苯共聚物(Pt/SDB) 硼氢化钠还原法 水合肼还原法 乙二醇还原法
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