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焙烧水滑石对Cr(Ⅵ)的去除性能研究 总被引:1,自引:0,他引:1
采用共沉淀法制备了Mg/Al-CO3水滑石,经焙烧得CLDH,用傅里叶红外光谱仪对物相进行表征;利用水滑石焙烧后在一定条件下可重新吸收水和阴离子,从而部分恢复层状结构的结构记忆效应,考察了不同温度焙烧的水滑石去除铬离子[Cr(Ⅵ)]的性能。实验结果表明,400℃下焙烧的水滑石对Cr(Ⅵ)的去除率最高。 相似文献
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碳酸根型水滑石焙烧产物对阴离子染料具有特异的吸附性能。该研究考察了两种具有不同镁铝摩尔比的镁铝复合氧化物对靛蓝胭脂红的吸附性能,并探讨了焙烧温度、投加量、初始染料浓度、溶液初始pH以及共存阴离子这几个因素的影响。结果表明经过500℃焙烧处理后的水滑石对染料的去除效果最好,去除率高达95%,平衡吸附量高达811.5 mg/g(1.74 mmol/g);且吸附过程不受初始溶液pH和共存阴离子的影响。水滑石焙烧产物直接用于印染废水处理,脱色率达68%~84%。 相似文献
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采用共沉淀法一步合成系列类水滑石负载磁性粒子的颗粒,经煅烧得到磁性焙烧产物.利用焙烧产物吸附水中腐殖酸,得到磁性焙烧态锌铝类水滑石去除腐殖酸效果较好.考察了磁性焙烧态锌铝类水滑石制备条件对腐殖酸去除效果的影响,通过正交试验优化了制备条件.静态吸附实验表明:吸附剂投加量0.2 g/L, 30 min内20 mg/L腐殖酸去除率为97.96%.X射线衍射(XRD)、红外光谱(FT-IR)、热重-差热(TG-DSC)和比表面积(SSA)表征结果表明:一定量的磁性基质掺入并没有破坏锌铝类水滑石典型的层状结构;焙烧态产物为氧化物,磁性保持良好;比表面积达80.00 m2/g.磁性焙烧态锌铝类水滑石在水中因"记忆效应"而结构重建通过表面吸附和腐殖酸结构中小尺寸的官能团插层快速去除腐殖酸. 相似文献
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以乙酸镁、偏硅酸钠为原料、低品位滑石矿为晶种,采用晶种诱导法水热合成滑石。研究了低品位滑石矿焙烧产物在不同焙烧温度和时间条件下的活性,得出适宜的低品位滑石矿焙烧温度并获得高活性滑石矿晶种;以低品位滑石焙烧矿为晶种,考察原料配比、醋酸用量、水热温度、水热时间、晶种用量、p H等对合成滑石的纯度、结晶度的影响。结果表明:在焙烧温度为700℃、焙烧时间为1.5 h条件下获得的低品位滑石焙烧矿晶种的活性最佳;在乙酸镁与偏硅酸钠的物质的量比为3∶4、pH为7、水热温度为180℃、水热反应时间为48 h、加入一定量的低品位滑石焙烧矿晶种的条件下,可以制备出结晶度良好的滑石。 相似文献
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Cone calorimetry tests performed at 50 kW/m2 heat flux have been exploited for assessing the fire resistant properties of nano-structured intumescent coatings containing modified layered double hydroxides (hydrotalcites, LDHs) and deposited on steel plates. The effects of different types of modified hydrotalcites (i.e. magnesium–aluminum lactate hydrotalcite, magnesium–aluminum gluconate hydrotalcite, magnesium–aluminum hydrotalcite modified with a fatty acid, magnesium–aluminum hydrotalcite modified with rosin) on the thermal shielding performances of the intumescent coatings and their intumescent degree have been thoroughly discussed and compared with the pristine unfilled counterparts.More specifically, the coatings containing organo-modified LDHs showed better thermal shielding performances with respect to the reference intumescent coating; on the contrary, the use of unmodified hydrotalcite in the intumescent formulations was found detrimental. The thermal shielding performances of the coatings filled with modified LDHs were found to be strictly related to the intumescent degree developed during the cone calorimetry tests. In addition, it was possible to compare the thermal shielding performances of the nanofilled coatings by evaluating the temperatures achieved after 2000 s exposure to the 50 kW/m2 heat flux of the cone: the thermal shielding performance sequence was LDH-GL > LDH-RS > LDH-LA > LDH-FA > LDH).Finally, the intumescent degree of the modified coatings was found to decrease with increasing the hydrotalcite content, hence lowering their thermal shielding performances. 相似文献
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催化热分解脱酸是一种方便且成本低廉的脱酸方法,但脱酸率较低,限制了工业化。通过采用氧化镁、氧化锌、镁铝水滑石和H-ZSM-5作为催化剂活性组分进行脱酸实验,发现镁铝水滑石对催化热分解脱酸具有较高的活性,可作为催化剂的活性组分,从机理方面证明具有催化石油酸分解的作用。对不同制备工艺制备的催化剂进行评价,得出最佳的催化剂制备工艺为:采用机械混合制球法,镁铝水滑石用量为催化剂质量的30%,活性氧化铝为载体,焙烧温度500 ℃。将中海油减二线馏分油与脱酸后油品进行红外分析,表明脱酸后油品中的环烷酸消失,证明镁铝水滑石催化剂具有良好的脱酸效果。 相似文献
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以硝酸镁晶体和硝酸铝晶体为原料,在弱碱性条件下,通过共沉淀法合成出具有水滑石类结构的含Mg-Al基复合物酸/碱双活性位催化剂。该催化剂经过花生酸改性后,用XRD、NH_3-TPD和CO_2-TPD测试表征发现,改性后的催化剂相比未改性的在性能方面有明显提高。通过固定床反应器对醋酸丁酯的乙氧基化催化工艺进行了研究,结果表明自制Mg-Al基复合物酸/碱双活性位催化剂经过花生酸改性后反应活性明显提高,产物乙二醇丁醚醋酸酯1-EBAC和2-EBAC含量显著增大,产品分布变窄。 相似文献
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以氢氧化镁和水合铝盐作为沉淀剂,采用实验室配制的模拟工业废水,对废水中硫酸根的去除进行研究。考察溶液中氢氧化镁投加量、铝离子的投加量、反应时间、硫酸根的初始浓度、反应温度等因素对硫酸根去除率的影响,并且设置三因素三水平正交试验,在SO_4~(2-)初始质量浓度为2 000 mg/L,溶液体积为50 m L的情况下,得出最佳工艺条件为Mg(OH)_2投加量1.4 g,Al3+投加量0.284 g,反应时间40 min,去除率95.84%;工艺最高去除率可达97.68%。经XRD分析测得沉淀物为镁铝水滑石。 相似文献
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The inhibition effect of hydrotalcite addition to hybrid sol–gel coatings applied on AA2024-T3 alloy was evaluated. Hydrotalcite belongs to the anionic clay family with wide applications, most of them based on its anion exchange capacity due to its double layered structure. In this work hydrotalcite (HT) powder was prepared by the classical co-precipitation method using magnesium and aluminum nitrates as precursors. Different weight percentages (1, 5 and 10%, w/w) of hydrotalcite with Mg/Al ratio of 2.5 were added to hybrid sols prepared by copolymerization of 3-Glycydoxypropyltrimethoxysilane (GPTMS) and tetra-n-propoxyzirconium (TPOZ). The sol–gel coatings were deposited by dip-coating method on AA2024-T3 substrate. Scanning electron microscopy (SEM) and mechanical profilometry measurements revealed the heterogeneous particle sizes and the distribution of the agglomerates. Hydrotalcite additions significantly increased the bond strength between metal and coating, according to pull-off test results.The corrosion performance was evaluated by the salt spray fog chamber test and by Electrochemical Impedance Spectroscopy (EIS). The results showed a marked improvement of the corrosion resistance on the aluminum alloy when HT was added to the hybrid sol–gel coating. This positive effect was more evident at higher weight percentages of hydrotalcite. 相似文献
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改性活性炭脱硫剂脱硫性能的研究 总被引:2,自引:0,他引:2
对煤质活性炭改性,包括加压水热活化、浸渍铜氨络合液,通过正交实验对改性活性炭脱硫剂的脱硫性能进行研究。结果表明,改性活性炭脱硫剂的最佳制备工艺条件为:加压水热活化压力为4.052 MPa,CuO/C为2.5%,煅烧温度为500℃,脱硫温度为25℃。各因素对改性活性炭脱硫活性的影响顺序为加压水热活化>煅烧温度>CuO/C>脱硫温度。 相似文献
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活性炭改性对用于甲酸分解的Pd/活性炭催化剂的影响 总被引:1,自引:0,他引:1
采用磁力搅拌法和水浴振荡法制备应用于甲酸分解的Pd/活性炭(AC)催化剂,研究了活性炭载体改性和制备方法对催化剂分解甲酸性能的影响。采用恒温水浴振荡装置,在80℃水浴中进行甲酸催化分解反应,以甲酸的催化分解率评价催化剂催化活性。结果表明,以经过不同的酸、碱、盐溶液改性后的活性炭为载体采用不同方法制备的Pd/AC催化剂对甲酸的催化分解效果不同,以Na2CO3改性的活性炭为载体采用磁力搅拌法制备的催化剂活性最好,甲酸水溶液的分解率达85%以上,含甲酸的工业废水的分解率达70%。 相似文献
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To Thi Xuan Hang Nguyen Tuan Anh Trinh Anh Truc Bui Van Truoc Thai Hoang Dinh Thi Mai Thanh Siriporn Daopiset 《Journal of Coatings Technology and Research》2016,13(5):805-813
Zinc aluminum hydrotalcite intercalated with molybdate (HTM) and modified by 3-glycidoxypropyltrimethoxysilane (HTM-GS) was prepared and incorporated into a waterborne epoxy coating. The synthesized HTM-GS was characterized by FTIR, XRD, SEM, and TEM. The inhibitive action of HTM-GS on carbon steel was evaluated using electrochemical measurement and SEM/EDX analysis. The corrosion protection of the waterborne epoxy coating containing HTM-GS was evaluated and compared to that of the pure waterborne epoxy coating and the waterborne epoxy coating containing HTM by salt spray test and adhesion measurement. It was shown that the molybdate was intercalated in the hydrotalcite structure and the molybdate contents in HTM and HTM-GS were 16.0 and 13.2 wt%, respectively. The polarization curves obtained on the carbon steel electrode showed that HTM and HTM-GS are anodic corrosion inhibitors, and their inhibition efficiencies at concentration of 3 g/l were 92.0 and 94.7%, respectively. Additionally, HTM and HTM-GS at concentration of 0.5 wt% improved corrosion resistance and adhesion of waterborne epoxy coatings. Surface modification by 3-glycidoxypropyltrimethoxysilane ameliorated the dispersion of HTM in epoxy matrix and the effect of HTM on protection properties of waterborne epoxy coating. 相似文献
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Faissal‐Ali El‐Toufaili Fatemeh Ahmadniana Arne Dinse Gunter Feix Karl‐Heinz Reichert 《大分子材料与工程》2006,291(9):1136-1143
Summary: The hydrotalcite‐catalyzed synthesis of PET was studied to clarify the effect of hydrotalcite properties on its catalytic activity. Hydrotalcite was modified by various treatments to tune its activity as a polycondensation catalyst. Hydrotalcite activity was found to decrease upon calcination. However, rehydration of the calcinated hydrotalcite resumed the catalytic activity. The hydrotalcite activity depends on the ratio of magnesium to aluminum cations in its composition, and highest activity occurs at a molar ratio of 2:1. Replacement of the carbonate anions of hydrotalcite by more nucleophilic ones like hydroxide and alkoxide groups resulted in improved catalytic activity. Hydrotalcite has two assembly orders: primary lamination of sheets into plates and secondary agglomeration of plates into particles. Hydrotalcite with larger sheet size showed lower activity. On the other hand, milling of hydrotalcite particles did not affect its activity as it probably enters the reaction on a plate level, which is not affected by milling. Polycondensation resulted in expansion of the hydrotalcite sheets under the effect of formed polymer. Reuse of hydrotalcite after polycondensation followed by depolycondensation resulted in a large activity enhancement.