结晶膜蒸馏回收废水中氯化铵的研究

采用自制中空纤维膜蒸馏组件对含氯化铵工业废水进行结晶膜蒸馏实验研究,考察了影响水通量的因素,如料液温度、浓度、流速,以及吸收液的流速、浓度等。找到了最佳的工作条件。在料液温度45℃,吸收液温度20℃,两侧流速为11.5ml/min的条件下,膜通量约为1.53×10-3kg/m2·h。经6小时的膜蒸馏NH4Cl开始结晶析出,氯化铵的截留率在95%以上。     

钽铌湿法冶金技术概况及发展趋势探讨

介绍了钽铌湿法冶金技术的发展概况和现状。根据分解介质的不同,钽铌湿法治金技术可分为碱熔融法、酸法和氯化法,碱熔融法可分为钠碱熔融法和钾碱熔融法,酸法主要有氢氟酸法和硫酸法。分别介绍了以上各方法的工艺路线,并对其优缺点进行了分析。针对现行氢氟酸工艺存在严重氟污染和对低品位钽铌矿分解率低的问题,依据清洁冶金原理,提出了钽铌亚熔盐清洁冶金新工艺,从生产源头消除了氟污染,可实现钽铌资源的高效清洁利用,具有良好的应用前景。     

焦油蒸馏塔的腐蚀与防腐

分析了焦油车间蒸馏塔腐蚀的情况，腐蚀的主要原因是固定铵盐、Cl^-、游离碳及过量的水分。采取了在焦油加工前加入Na2CO3溶液等多种防腐措施后，取得了良好的效果。     

液化气脱硫装置闪蒸效率的探讨

对液化气脱硫装置闪蒸罐闪蒸效率进行了分析,提出了调整洗涤剂量、闪蒸罐液位、闪蒸压力及闪蒸温度,从而提高闪蒸效率的问题,并对效益作了分析。     

丁二烯装置第二精馏塔技术改造

对丁二烯装置第二精馏塔进行了技术改造,采用导向浮阀塔板代替原有的F1型浮阀塔板。实践证明,使用高效导向浮阀能使装置的处理能力提高10%,同时稳定了操作,提高了效益。     

湿法磷酸快速萃取技术在小磷酸装置上的应用

介绍湿法磷酸快速萃取技术在小磷酸(<3.0万t/aP2O5)装置上的应用,分别介绍2种技改工艺的工艺流程、需增设备,技改前后主要工艺控制指标与技经指标;该技术可使磷酸生产能力由1.5万tP2O5/a增加至4.5万tP2O5/a,真空冷却工艺比增大排风量工艺年节省电费约33万元(0.45元/kW·h);增大排风量工艺年可副产800t氟硅酸钠,获利约32万元(按每吨利润400元计)。工厂应根据自身情况,选择1种技改工艺。     

反应与催化精馏耦合提纯乳酸新工艺的研究

The purification of lactic acid based on the esterification of raw lactic acid from fermentation broth and then the catalytic distillation hydrolysis of methyl lactate simultaneously to achieve pure lactic acid is reported. The esterification kinetics of lactic acid with methanol catalyzed by strong-acid cation-exchange resins (Amberlyst-15,D001, D002, NKC, 002) was studied under the condition that simulates the real catalytic environment. Experimental results were correlated by a Langmuir-Hinselwood model and the nonideality of the solution was taken into account by using activities calculated by the universal quasichemical functional group activity coefficient (UNIFAC) method.A good agreement between the model and the experimental data was achieved. Continuous purification experiments were conducted to find the optimum column configuration and operation condition for the system. The effects of various parameters, e.g. the length of different section of the column, feed rate and ratio of reactants, packing material and catalyst type, were studied. This novel system shows good separation results in lab scale, and is potential for industrial application.     

水性氯化物介质中对甲基苯烷基硫醚萃取钯的研究

p-Methylphenylalkylsulfide of various alkyl chain length as extractant were synthesized and the extraction of palladium was examined in terms of equilibrium and kinetics. Distribution ratio of Pd was independent of alkyl chain length. For aqueous chloride media, there was a significant difference in distribution ratios for the solution of NaC1 and HC1. The results of loading test and the slope analysis suggest that the extractant and Pd (Ⅱ) form 2:1 complex. Furthermore, the extraction rate based on the volume of aqueous phase was obtained in a stirred vessel, and the rate equation was presented. Unfortunately, it was difficult to construct surfactant liquid membrane system by use of the present extractant.     

超临界流体萃取脱除人参中痕量有机氯农药

The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1×10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.     

浓度极稀物中回收微量重组分的精馏操作策略-准间歇精馏

A new operation policy-quasi-batch distillation for recovering infinitesimal amounts species existing in a mixture is presented. In quasi-batch distillation operation, feed is introduced with a constant flow rate onto the feed stage of the column, and the flow rate of the distillate is the same as that of the feed, whereas the bottom product is withdrawn periodically. The behavior of quasi-batch distillation is simulated and analyzed through an example on heavy water separation. Comparing with continuous or batch distillation, the new operation policy is more reliable and efficient to achieve higher recovery of dilute component. This is especially suitable for separating small amount of precious species from large amount of raw material.