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在脱硝废催化剂中钛含量远远高于常用的钛精矿,本文以废催化剂经过钠化焙烧后的低
浓度钛液为水解原料,采用常压自生晶种热水稀释水解工艺获得纳米 TiO2前驱体偏钛酸,重点考察了水解温度、钛液质量浓度、钛液 F值和水解时间对钛液水解率的影响。通过对这 4个关键因素采用四因素四水平正交设计,比较各水平的极差,确定了各因素影响水解率的主次关系:水解温度 >钛液 F值 >钛液质量浓度 >水解时间。然后采用单因素控制法,研究了水解温度、钛液 F值、钛液质量浓度和水解时间对钛水解率的最优条件,研究表明:升高水解温度、降低钛液 F值和钛液质量浓度、延长水解时间均可起到提高水解率的作用。最优水解条件为:水解温度 95 ℃,钛液质量浓度 190 g/L,钛液 F值为 1. 8,水解时间为 2h,在此工艺下钛的水解率可达 97%。 相似文献
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以攀枝花某钛白粉厂的工业硫酸氧钛浓钛液为原料,采用外加晶种水解工艺制备水解偏钛酸,通过检测钛液水解过程中浆料透过率的变化间接检测水解过程反应速率的变化,通过分析水解过程不同时间段的偏钛酸粒度分布,确定了影响偏钛酸粒度分布的主要因素。在此基础上考察了钛液浓度、F值、铁钛比、水解晶种加量、熟化搅拌时间对偏钛酸粒度分布的影响。结果表明钛液沸腾后快速水解,再随钛液浓度降低水解速率逐渐降低,浆料粒度逐渐长大,二次沸腾20 min后,浆料的粒度分布逐渐稳定,后期保温过程对粒度分布影响不大;钛液浓度、铁钛比、F值、晶种加量和熟化期间搅拌时间均对偏钛酸粒度分布有影响,D50随着钛液浓度的增加而减小,随F值和铁钛比的增大而增加,随着晶种加量的增加而减小,随熟化期搅拌时间的延长而降低。 相似文献
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提出的钛液反应水解法,改变了传统的外加晶种存在下具有工业意义的水解过程。该法无须外加晶种,选择了以酒石酸,聚丙烯酰胺为沉淀剂,絮凝剂,在常压下使钛液直接长温水解,液相共沉淀制备金红石型TiO2。还研究了反应条件,分析了产品的特性。 相似文献
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文章主要介绍了钛液水解的基本原理和过程,以及影响钛白水解的关键因素,包括钛液本身的性质、组成和水解的操作条件等. 相似文献
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报道了2,6-二氯苯甲醛合成新技术。2,6-二氯甲苯在光照条件下与氯气进行光氯代侧链反应,生成2,6-二氯-α,α-二氯甲苯的氯化液,氯化液在复合催化剂下进行水解反应生成2,6-二氯苯甲醛,经精制后得含量≥98%的产品,收率为94%。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses. 相似文献