副产氟硅酸制白炭黑新工艺研究

简述了氟硅酸的年副产量以及对其“氟、硅”的循环利用开发状况;重点阐述了利用氟硅酸与水玻璃反应制取绿色轮胎级白炭黑工艺的研究现状,包括工艺原料、反应机理、生产工艺、工艺难点和关键点、主要设备以及对工艺进行了综合评价;对比说明了传统法白炭黑与氟硅酸和水玻璃反应制得的白炭黑产品的质量差异,为中国白炭黑的质量提升和发展奠定了技术支撑。     

脂肪酸酯类抗静电剂的合成及应用研究

以棕榈酸和回收的聚乙二醇为原料,采用酯化法合成了一种脂肪酸酯类抗静电剂,研究了醇酸摩尔比、催化剂用量、反应时间和反应温度对酯化反应的影响。结果表明,在醇酸摩尔比为1.5:1,催化剂用量为0.8 %,反应时间为5 h,反应温度为140 ℃的条件下,所得产物的综合性能最好。将制备的脂肪酸酯应用于聚乙烯中作为抗静电剂,讨论了其含量、试样放置时间、环境温度对聚乙烯抗静电性能的影响,发现随着脂肪酸酯含量的增加、放置时间的延长和环境温度的升高,抗静电效果提高,当脂肪酸酯含量为3份时,抗静电效果最佳。     

A new method for free fatty acid reduction in frying oil using silicate films produced from rice hull ash

Sodium silicate films were produced from rice hull ash silica, and their application in reducing free fatty acid (FFA) in frying oil was investigated. Sodium hydroxide concentration of these films was 32, 28, 24, and 20% with silica concentration of 45, 50, 55, and 60%, respectively. Moisture contents of these films were 20–23%. Adsorption performance of the films was investigated in frying oil at 80°C for 10–40 min. FFA content gradually decreased with treatment time for all films. There were no significant differences in FFA content among films for treatments up to 30 min. Treatment with 45 and 50% silica films for 40 min led to significantly larger reduction in FFA compared to treatment with 60% silica film. Differences between the FFA content of oil treated for 40 min with 55% silica and the FFA content of oils treated with other silica films were insignificant. FFA content of oil decreased from 0.8 to 0.55, 0.55, 0.57, and 0.59% after 40 min treatment with 45, 50, 55, and 60% silica film, respectively. Peroxide values (PV) of treated oils slightly increased from 48 to about 60 meq/kg for films with 45, 50, and 55% silica. Treatment with 60% silica led to a decrease in PV values to 42 meq/kg. Soap content of oil increased from 51 to over 100 ppm as a result of silicate film treatment.     

酸浸工艺脱除微硅粉杂质离子及其对热碱溶解过程的强化

针对热碱溶解微硅粉制备水玻璃的过程中存在Si转化率较低的问题,提出了采用酸浸预处理的方法脱除微硅粉中的金属杂质,强化其热碱溶出过程,以提高Si的转化率。本研究通过采用X射线荧光仪(XRF)、冷场发射扫描电子显微镜与能谱分析仪(SEM-EDS)、X射线衍射仪(XRD)以及滴定分析检测方法,研究了酸种类、酸浓度、反应温度、固液比、反应时间对金属杂质浸出率的影响和酸浸工艺对微硅粉热碱溶出过程的强化作用,得出适宜的酸浸条件:HCl浓度2mol/L、反应温度60℃、固液比1:(6～8)、反应时间40～60min。在碱溶出过程初期,酸浸处理后的微硅粉中SiO₂的溶出率由46.62%增至61.91%,得到了显著提高。结果表明:酸浸预处理对微硅粉的碱溶过程起到很好的强化作用,提高了Si的转化率,这将在增大微硅粉利用率的同时也有利于满足工业水玻璃[Na₂O·(2.5～3)SiO₂]对模数的要求。     

牙膏磨擦剂二氧化硅制备条件的优化

以硅酸钠和硫酸为原料,采用硫酸沉淀法,合成适用于牙膏以及透明牙膏的SiO2。首先考察了釜底液硅酸钠浓度、温度以及陈化时间对SiO2性能的影响。结果表明：当釜底液中硅酸钠浓度为0.13mol/L、合成温度为65℃以及陈化时间为30min的条件下,合成SiO2的透光率可以达到89%。随后,以提高透光率为目标研究了在釜底液中添加Na2SO4、NaCl两种电解质对SiO2性能的影响。结果表明：在合成温度为65℃的条件下,添加浓度为0.04～0.12mol/L的Na2SO4、NaCl对合成SiO2的透光率基本上没有影响;而在合成温度为85℃的条件下,添加浓度为0.08mol/L的Na2SO4合成SiO2的透光率可以达到97%,添加浓度为0.12mol/L的NaCl合成SiO2的透光率可以达到96%。造成这种现象的可能原因是：在相对高的合成温度下,电解质能够更加有效的参与到硅酸的聚合中,使得SiO2的透光率得到一定的改善。按照QB/T 2346—2007对所合成的物质的牙膏磨擦剂特性进行测定,达到了标准要求。     

硅丙乳液改性高模数硅酸钾水性无机富锌涂料的研究

以硅溶胶、氢氧化钾为主要原料,硅丙乳液为改性剂,制备了一种稳定的高模数硅酸钾有机-无机复合基料,与锌粉以1∶2比例配制高模数硅酸钾水性无机富锌涂料.探讨了模数、固含量、反应时间、硅丙乳液用量对高模数硅酸钾溶液贮存稳定性和涂料性能的影响.采用正交实验的方法,确定了涂料的最优工艺条件.制备的水性无机富锌涂料是一种经济实用的绿色涂料.     

硅溶胶系列FCC催化剂制备技术研究

介绍了以硅溶胶为粘结剂的催化裂化催化剂国内外研究现状,以及硅溶胶的性能、特点和影响硅溶胶稳定性的因素。综述了由硅酸钠经离子交换法制备和硅酸钠与无机酸反应制备催化剂的方法。含硅粘结剂的催化剂抗磨损能力和焦炭选择性较好,催化剂的强度可以通过添加表面活性剂和铝盐得到改善。     

Preparation of amorphous silica

Amorphous silica having reinforcing properties for styrene butadiene rubber (SBR) was obtained by contacting silica aquagel seed, containing 1-3% SiO₂ by weight, with a freshly prepared silica sol. Reinforcing by the isolated silica was greatly affected by the pH of the aquagel-sol system and moderately affected by temperature and by the silica content of the aquagel seed. Maximum tensile strengths for the vulcanizates were found using the product obtained from a 2 to 2.5% silica aquagel seed-sodium silicate system acidified with sulphuric acid to pH 3 at 85 to 95°C.     

Ex situ Raman mapping study of mechanism of cordierite formation from stoichiometric oxide precursors

Ex situ Raman spectroscopy and Raman mapping showed that at temperatures below 1300 °C, magnesia reacted with either alumina or silica to form magnesium aluminate (spinel) or magnesium silicate. At 1300 °C or higher, the reaction between magnesium silicate and alumina, or spinel and silica, led to cordierite formation. Moreover, the presence of silica and spinel, and the disappearance of magnesium silicate at 1400 °C, indicated that cordierite formation was more favored by the reaction between alumina and magnesium silicate than by that between silica and spinel.     

Synthesis of the structured lipid 1,3-dioleoyl-2-palmitoylglycerol from palm oil

Human milk fat contains 20–25% palmitic acid (16∶0) and 30–35% oleic acid (18∶1). More than 60% of the plamitic acid occurs at the sn-2 position of the glycerol backbone. Palm oil is a rich source of both palmitic and oleic acids. The structured lipid 1,3-dioleyl-2-palmitoylglycerol (OPO) is an important ingredient in infant formula. OPO was synthesized from palm oil by a three-step method. In the first step, low-temperature fractionation was applied to palm oil FA, yielding a palmitic acid-rich fraction (87.8%) and an oleic acid-rich fraction (96%). The palmitic acid content was further increased to 98.3% by transforming palmitic acid into ethyl palmitate. In the second step, esterification of ethyl palmitate and glycerol catalyzed by lipase Novozym 435 under vacuum (40 mm Hg) was employed for the synthesis of tripalmitin. Finally, OPO was obtained by the reaction of tripalmitin. Finally, OPO was obtained by the reaction of tripalmitin with oleic acid catalyzed by Lipase IM 60. In this final step, the TAG content in the product acylglycerol mixture was 97%, and 66.1% oleic acid was incorporated into TAG. Analysis of the FA composition at the sn-2 position of TAG showed 90.7 mol% of palmitic acid and 9.3 mol% of oleic acid. OPO content in the product TAG was ca. 74 mol%. Thus, an efficient method was developed for the synthesis of OPO from palm oil.     

赤泥制备水玻璃工艺研究

为了提取利用赤泥中的硅元素,实现赤泥的资源化,同时为水玻璃的制备寻找一种新原料。本文以中铝山西新材料有限公司两组分赤泥为研究对象,通过化学分析法、XRD对赤泥进行了化学组成及矿物组成分析。表明该赤泥中二氧化硅含量较高且都为非晶态,反应活性高,为制备水玻璃的理想硅源。对赤泥进行酸浸可得到纯度为92%的硅胶。硅胶湿法制备水玻璃最佳工艺参数为NaOH质量浓度15%,液固质量比3,体系温度95 ℃,反应时间为15 min。经实验验证,最佳参数下的二氧化硅溶出率可达91%,对该赤泥中硅的利用率达84.6%。该研究可为赤泥资源化和水玻璃原料选取提供新的思路和依据。     

Processing and kinetics studies on the alumina enrichment of coal fly ash by fractionating silicon dioxide as nano particles

Coal fly ash produced in the northern China is a potential bauxite substitute for aluminum production because of its high alumina content. However, this industrial application has been limited for its high silicon content. Alumina enrichment by removing silicon becomes a key technology for its utilization. A novel process was developed to fractionate the coal fly ash into high purity nano silicon particles and aluminum enriched residual ash. The procedure has major steps as sodium silicate dissolution with sodium hydroxide, first carbonation to remove impurities, second carbonation to precipitate silicon, and silicon precipitate recovery as a mesospheric nano particles product. Morphological and X-ray diffraction evidences indicated the glassy amorphous silicon content of the ash was dissolved in the sodium hydroxide solution whereas mullite remained in the residue. Kinetics study indicated that the second carbonation was a kinetically second order medium fast multi-phase reaction in which sodium silicate was precipitated as silicic acid. It was found that the reaction was controlled by the mass transferring resistance in the liquid membrane. These nano silicon dioxide particles were in size of 50 nm with a purity of 96%. Alumina content in process residue was slightly increased from 42.00 to 49.20%. Silicon dioxide content was reduced from 48.89 to 30.26%. Ratio of alumina/silica was increased from 0.86 to 1.63.     

粉煤灰预脱硅液动态水热合成硅酸钙晶须的影响因素

以分析纯试剂模拟粉煤灰预脱硅液,采用动态水热法合成硅酸钙晶须,研究了反应体系碱浓度、反应温度、反应时间、溶液中铝硅(Al2O3与SiO2)和钙硅(CaO与SiO2)质量比对产物物相组成及其形貌的影响. 结果表明,控制碱浓度80 g/L以下,反应温度220℃,反应时间6 h,铝硅质量比0.06以下,钙硅质量比0.9,可制备出纯度83%以上的硅酸钙晶须,晶须长度可达20 mm.     

响应面法优化四氯化硅制备超细白炭黑工艺

以四氯化硅和水玻璃为原料,在单因素实验基础上,采用响应面优化工艺并建立数学模型,探讨水玻璃质量分数、添加剂质量分数和反应温度各因素之间相互作用对白炭黑DBP吸收值的影响。确定了最佳工艺条件： w（水玻璃）=8.6%、w（添加剂）=2.7%、水解温度为76 ℃。在此条件下,制得的白炭黑DBP吸收值为2.806 7,与预测值2.801 1仅有0.005 6的误差,证明该模型具有较好的拟合度,能够真实地反映各实验因素对DBP吸收值的影响。     

Preparation and Characterization of Precipitated Silica using Sodium Silicate Prepared from Saudi Arabian Desert Sand

The present study reveals a cost benefit process in an open system for utilizing desert sand for preparing sodium silicate or precipitated silica. A simple alkali fusion method has been developed to prepare sodium silicate directly from sand and finally pure precipitated silica by acid precipitation. The reaction weight ratio of alkali to sand reaction parameters are studied for optimizing the silica yield. About 80% pure precipitated silica has been prepared in an open system at 150 ^°C within 45 min. Wet chemical methods, FTIR, TG-DTA, XRD and SEM techniques are used to characterize the silica prepared from sand available in Saudi Arabian deserts. In the XRD pattern, the peak corresponding to silica was obtained at the diffraction angle of 21.8 ^° and it was found to be amorphous in nature.     

Production and Characterization of DHA and GLA-Enriched Structured Lipid from Palm Olein for Infant Formula Use

Palm olein was modified via lipase-catalyzed acidolysis reaction to obtain fatty acid composition and positional distribution similar to human milk fat. In the reaction, a free fatty acid mix containing 23.23 % docosahexaenoic (DHA), 31.42 % gamma-linolenic (GLA), and 15.12 % palmitic acid was employed. The DHA and GLA were incorporated into the structured lipid (SL) product to improve its nutritional value. Response surface methodology (RSM) was used to investigate the effects of reaction time and substrate mole ratio (palm olein to a free fatty acid mix) on the amount of palmitic acid at the sn-2 position of SL triacyglycerols (TAG), and on the total DHA and GLA incorporation. Gram-scale production of SL was performed using the conditions predicted by RSM to maximize the content of palmitic acid at the sn-2 position. Verification of the predictions from RSM confirmed its practical utility. The resulting SL had 35.11 % palmitic acid at the sn-2 position, with 3.75 % DHA and 5.03 % GLA. Differential scanning calorimetry and HPLC analyses of the TAG revealed changes in their polymorphic profiles and TAG molecular species of SL compared to palm olein. The SL from this study can potentially be used in infant formula formulations.     

白炭黑制备工艺对比表面积和吸油值的影响

利用正交设计安排实验，在超重力旋转床中，采用硫酸沉淀法制备超细白炭黑，研究实验制备工艺条件pH、硅酸钠浓度、温度、电解质和旋转床转数以及不同干燥方式对白炭黑的BET比表面积和DBP吸油值的影响。实验结果表明，反应终止时pH对白炭黑的BET比表面积影响最大，其次是温度、电解质、硅酸钠的浓度和旋转床的转数。干燥方式是影响DBP吸油值的决定性因素，其次是温度、电解质、旋转床的转数、硅酸钠的浓度和反应终止时pH。制得产品的BET比表面积140～351m^2／g，DBP吸油值1．42-4．41mL/g。     

单体酸组成分析及在生物柴油方面的应用

单体酸甲酯化后用气相色谱．质谱联用仪测定单体酸的主要组成,共鉴定出硬脂酸（32．72％）、十八烯酸（25．53％）、肉豆蔻酸（12．16％）、棕榈酸（8．51％）等15种物质。用单体酸为原料制备生物柴油的方法为：单体酸与甲醇在对甲苯磺酸催化作用下,进行酯化反应来获得脂肪酸甲酯。考察了甲醇与单体酸的摩尔比、催化剂浓度、反应时间以及反应温度对酯化率的影响。结果表明,最佳酯化反应条件为：醇酸摩尔比3：1,对甲苯磺酸用量6％,反应时间3h,反应温度60℃。在此条件下,单体酸酯化率达98％,实验所得生物柴油的主要性能指标符合ASTN质量标准,并接近O#柴油性质。     

Reaction of Glasses with Hydrofluoric Acid Solution

The gravimetric method was used to study the reaction between fused silica and silicate glasses with HF acid solution. The reaction was found to be transport-controlled. Additions of Al₂O₃, CaO, or both to fused silica caused a reduction in corrosion resistance of the resulting glasses.     

Structure Control of Calcium Silicate Hydrate Gels for Dye Removal Applications

The structure of calcium silicate hydrate (C‐S‐H) gels was modified by hydrothermal reaction with aqueous acetic acid solvent, and then the C‐S‐H gels were used for dye removal from aqueous solution. With increasing acetic acid concentration, the Ca:Si molar ratio decreased and the length of the silicate anion chain structure of the C‐S‐H gels increased. The silicate anion chain length affects the number of available silanol groups on the surface of the C‐S‐H gel: the longer the silicate anion chain length, the greater the number of negative charges and the higher the surface potential. C‐S‐H gels with a long silicate anion structure exhibited higher adsorption capacity for methylene blue than gels with a short silicate anion structure. The enhanced adsorption capacity of the C‐S‐H gels is related to the higher number of silanol groups in the bridging silica tetrahedra of the intermediate anion chain structure compared with those in the end units of silica tetrahedra.