恒沸精馏法分离回收阿维菌素生产残液中的甲苯和乙醇

在阿维菌素精制工艺中 ,乙醇和甲苯被共用作溶剂及浸泡剂。乙醇与甲苯的混合液在常压下、温度为 76 .7℃时即共沸 (乙醇的沸点为 78.4℃ ,甲苯的沸点为 110 .8℃ ) ,这种残液如不处理则会带来严重的环保问题。此残液无法用普通精馏法分离 ,我们采用恒沸精馏法将其进行分离回收 ,取得了较好的效果。1　残液组成　　以某生物农药厂阿维菌素精制工艺的废溶剂为试验原料 ,其中甲苯的质量分数为 12 %～ 16 %、乙醇的质量分数为 75 %～ 80 % ,其余为水和少量杂质。2　分离原理　　通过在二元共沸物中引入第 3组分 (夹带剂 ) ,使其与乙醇、甲苯形成…     

酚焦油资源化技术研究(Ⅱ)--裂解产物的分离

开发出一种精馏与钠盐法相结合的分离酚焦油裂解产物的新工艺，裂解产物经精馏，蒸出异丙苯等轻组分、苯酚馏分和共沸物。共沸物中加入氢氧化钠，分离出酚钠盐和苯乙酮。轻组分和酚钠盐均返回苯酚、丙酮生产装置。裂解产物中有用物质的收率为92．91％，苯乙酮的收率为82．38％，其纯度大于98％。     

环氧丙烷生产废液中1,2 -二氯丙烷的回收

介绍了从环氧丙烷生产废液中回收1,2-二氯丙烷的新方法。采用常压精馏、减压精馏、共沸精馏工艺分离环氧丙烷生产废液中的1,2-二氯丙烷。实验结果显示,共沸精馏工艺的效果最好;在含有一定量的共沸剂、釜温100℃、顶温86℃、回流比为1的条件下,塔顶馏分中1,2-二氯丙烷的质量分数可达到98％以上,1,2-二氯丙烷的回收率可达到97％以上。     

废溶剂油中二甲苯与醋酸丁酯的回收

以水作为共沸剂，采用间歇萃取精馏法从工业废溶剂油中回收二甲苯和醋酸丁酯，对预处理后的原料进行了萃取精馏。考察了油水比、分离温度、时间等操作参数对分离过程的影响。实验结果表明，在最佳的工艺条件下（回流比为5，V（油）：V（水）=1．5：1），二甲苯和醋酸丁酯在馏出液中的质量分数均达到99％以上，二甲苯的回收率为84．14％以上，醋酸丁酯的回收率为99．43％。     

国内简讯

国内简讯Ｎ┐乙基邻甲苯胺合成过渡液的分离Ｎ－乙基邻甲苯胺是一种重要的有机合成原料。目前，国内生产厂家主要采用邻甲苯胺与乙醇进行高压反应来合成。高压反应合成的反应液成分复杂，含有大量沸点相近的物质，蒸馏时，由于多组分共沸造成分离困难，反应液经反复精馏后...     

催化裂解法处理有机硅高沸物

采用催化裂解法处理有机硅高沸物,解决高沸物储存过程中的安全、环保问题。研究了催化剂种类、HCl加入量和精馏高沸物加入量对高沸物转化率的影响。实验结果表明:在以N,N-二丁基-1-丁胺为催化剂、合成高沸物为原料、HCl加入量为13%(w)的条件下,高沸物转化率为83.10%,二甲基二氯硅烷收率为23.78%;合成高沸物中精馏高沸物加入量为9.0%(w)时,高沸物转化率最高,为85.58%。     

硫酸,磷肥生产废水的综合治理

硫酸、磷肥生产废水的综合治理硫酸生产废水的处理主要是除砷。目前，除砷的主要方法有硫化法、铁盐法、交换吸附法、溶剂萃取法等。这些方法除砷效果很好，去除率可达９９％以上，但处理成本高。磷肥生产排放的含氟废水，含氟浓度高，酸度大，直接用石灰中和并除氟，需消...     

从靛兰废水中回收碱的研究

本文介绍了采用溶剂萃取法、蒸发浓缩法、吸附法和离子交换膜隔膜电解法对靛兰废水进行处理并回收碱的试验研究。试验结果表明,离子交换膜隔膜电解法具有工艺简单、操作和管理方便、碱回收率高、处理费用较低的特点,适于生产性应用。     

抗蚜威农药废水处理

在抗蚜威农药的生产过程中，排出α－甲基乙酰乙酸乙酯合成废水和抗蚜威合成废水。前者采用萃取法回收α－甲基乙酰乙酸乙酯和乙酰乙酸乙酯，简单蒸馏－精馏法回收甲醇；后者采用萃取法回收甲基嘧啶醇中间体。两股废水经预处理后，ＣＯＤ去除率分别达到９７％和７５％，ＢＯＤ５／ＣＯＤ从０．１－０．２提高到０．４，预处理后的废水混合后进行生物接触氧化处理，ＣＯＤ和ＢＯＤ５去除率分别达到８５％和９８％。     

溶济萃取法处理含硫酸及硫酸盐的废水

采用溶剂萃取法处理含硫酸及硫酸盐的工业废水，主产优质农用硫酸钾，副产氯化铵和氮钾复合肥，整个工艺过程基本无三废排放，实现了对该废水的综合有效治理。     

溶剂萃取法提取废旧碱性电池中的有价成分

为回收利用废旧电池，进行了溶剂萃取法提取碱性废弃电池中锌、锰金属的试验研究。选择南孚（AA）碱性废电池为处理样品，通过粉碎、水浸、酸浸等步骤，获得含锌、锰离子的稀溶液，并利用模拟体系得到的萃取结果进行浸出液的萃取性能试验研究。结果表明，每个废电池填充物中含锌和锰分别为0.25g和0.36g，具有可观的回收价值；采用完全皂化的二（2－乙基己基）磷酸（D2EHPA）／煤油为萃取剂提取含锌锰的酸浸出液，一级萃取就可获得60％以上的提取率。     

Thermo-chemical extraction of fuel oil from waste lubricating grease

This study investigated the recovery of oil from waste grease through the process of thermal degradation in an aqueous solution of potassium hydroxide (KOH) followed by solvent extraction. Waste high temperature metal bearing grease was dissolved in a 15 w/w% KOH solution at 80 °C while being agitated at 2000 rpm using a shear action agitator for a period of 15 min. Two distinct layers were observed after 8 min of settling time. The top layer being of dark brown oil and the bottom layer was a heterogeneous mixture. The two layers were separated by decantation. The bottom layer was cooled down to 45 °C followed by slow addition of toluene (C₇H₈) while agitating at 1200 rpm for 15 min to prevent solids settling and minimise rapid volatilisation of the organic compounds in the mixture. Two distinct layers were also formed, the top homogeneous mixture of light brown oil–toluene mixture and the bottom sludge layer. The solvent was recovered from the oil for re-use by fractional distillation of the homogenous mixture. It was observed that 15 w/w% potassium hydroxide solution can chemically degrade the soap matrix in the grease and extract up to 49 w/w% of the fuel oil when subjected to high shear stress at a temperature of 80 °C. The 26 w/w% extraction of oil in the remaining sludge was obtained by solvent extraction process with mass ratios of sludge to solvent of 2:1. Solvent recovery of 88% by mass was obtained via fractional distillation method. The combined extraction processes brought an overall oil yield of 75 w/w% from the waste grease. The fuel oil obtained from this process has similar properties to paraffin oil and can be blended with other oils as an alternative energy source.     

Designing a purification process for chromium-, copper- and arsenic-contaminated wood

The disposal of chromated copper arsenate (CCA)-treated wood is becoming a serious problem in many countries due to increasing levels of contamination by the hazardous elements, chromium, copper and arsenic. The present experiment was conducted as a preliminary step toward one-step solvent extraction of CCA-treated wood. Because chromium, copper and arsenic have different chemical characteristics, it is best to consider them separately prior to designing a one-step extraction process. As a basis, various two-step extraction processes were first designed and tested experimentally to determine feasibility. Among these combinations, the treatment combining oxalic acid as the 1st step and a sodium oxalate solution under acidic conditions (pH 3.2) as the 2nd step was found to be an effective way of extracting CCA elements from treated wood. Extraction efficiency reached 100% for arsenic and chromium and 95.8% for copper after a 3-h sodium oxalate treatment, following a 1-h pre-extraction process with oxalic acid. On the other hand, the same combination under alkaline conditions (pH 11.2) during the 2nd step was ineffective for copper removal, indicating that pH plays an important role in complexation with sodium oxalate solution. The present results suggest that the extraction of CCA elements using a combination of oxalic acid and acidic sodium oxalate solution is a promising basis for application to a one-step extraction method.     

从废FCC催化剂和废汽车尾气净化催化剂中回收稀土的研究进展

以稀土元素(简称稀土)用量较大的废FCC催化剂和废汽车尾气净化催化剂为研究对象,分析总结了两类废催化剂中稀土的成分和回收方法。从废催化剂中回收稀土普遍采用先浸出、后分离提纯的方法。浸出普遍采用无机酸(多为盐酸),分离方法包括溶剂萃取法、化学沉淀法等,最后经焙烧得到稀土氧化物。为从废催化剂中高效回收稀土,可着重考察新浸出机制的引入、分离方式的选择、分离试剂的应用,以及浸出和分离条件的优化,从而为实现工业化回收提供技术支持。     

Solvent extraction and soil washing treatment of contaminated soils from wood preserving sites: Bench‐scale studies

Bench‐scale solvent extraction and soil washing studies were performed on soil samples obtained from three abandoned wood preserving sites included in the National Priority List. The soil samples from these sites were contaminated with high levels of polyaromatic hydrocarbons (PAHs), pentachlorophenol (PCP), dioxins, and heavy metals. The effectiveness of the solvent extraction process was assessed using liquefied propane or dimethyl ether as solvents over a range of operating conditions. These studies have demonstrated that a two‐stage solvent extraction process using dimethyl ether as a solvent at a ratio of 1.61 per kg of soil could decrease dioxin levels in the soil by 93.0 to 98.9 percent, and PCP levels by 95.1 percent. Reduction percentages for benzo(a)pyrene (BaP) potency estimate and total detected PAHs were 82.4 and 98.6 percent, respectively. Metals concentrations were not reduced by the solvent extraction treatment. These removal levels could be significantly improved using a multistage extraction system. Commercial scale solvent extraction using liquefied gases costs about $220 per ton of contaminated soil. However, field application of this technology at the United Creosote site, Conroe, Texas, failed to perform to the level observed at bench scale due to the excessive foaming and air emission problem. Soil washing using surfactant solution and wet screening treatability studies were also performed on the soil samples in order to assess remediation strategies for sites. Although aqueous phase solubility of contaminants seemed to be the most important factor affecting removal of contaminants from soil, surfactant solutions (3 percent by weight) having nonionic surfactants with hydrophile‐lipophile balance (HLB) of about 14 (Makon‐12 and Igepal CA 720) reduced the PAH levels by an average of 71 percent, compared to no measurable change when pure deionized water was used. Large fractioza of clay and silt (<0.06mm), high le!ezielsof orgaizic contami‐ nants and hzimic acid can makesoil washing less applicable.     

Hydrometallurgical recycling of cobalt from zinc plants residue

A large amount of hot filter cake (HFC) is annually generated in Iranian zinc plants. It contains 1% zinc, 16–30% manganese, 5–25% calcium and 1–4.5% cobalt. Usually, zinc is selectively leached by an alkaline medium and its residue is known as alkaline leached HFC (ALHFC). In the present study, the possibility of cobalt extraction from ALHFC was investigated using a creative hydrometallurgical process. At the first stage, zinc and cadmium were selectively removed with sulfuric acid. At the second stage, it was deeply focused on the possibility of selective reductive leaching of cobalt by H₂O₂ as a reductant in the presence of manganese. As results, several differences were found between the mechanism of cobalt and manganese leaching. Accordingly, cobalt leaching was more affected by acid concentration and manganese leaching was more affected by reductant concentration. Consequently, with manipulating these important parameters, it was made possible to selectively separate cobalt from manganese. Based on the obtained results, 90.9% of cobalt and only 10.04% of manganese were leached with 1% of H₂O₂. At the third stage, pregnant cobalt solution was successfully purified through a solvent extraction process with D2EHPA. Finally, cobalt hydroxide as our final product with a purity of more than 99% was precipitated from the pure pregnant solution at 70 °C.     

Alamine336对低浓度模拟含硝酸废水的萃取分离

以模拟低浓度含硝酸废水为研究对象,以煤油为稀释剂,考察了工艺条件对硝酸萃取和反萃效果的影响,并对萃取机理进行了探讨。实验结果表明：以10.0%（φ）Alamine336为萃取剂,在有机相与水相的体积比为1∶2、萃取温度为298 K的条件下,对初始硝酸质量浓度为2.00 g/L的含硝酸废水进行两级逆流萃取操作后,理论上水相硝酸质量浓度低于15 mg/L,达到GB 8987—1996中的一级标准;以0.05 mol/L氢氧化钠溶液为反萃剂,在有机相与水相的体积比为1∶2、反萃温度为298 K的条件下,对硝酸负载量为1.50 g/L的有机相进行两级反萃后,理论上有机相硝酸残余量小于0.005 g/L。机理研究表明Alamine336通过与硝酸形成离子对络合物来萃取硝酸。     

Destruction of PAHS from soil by using pressurized hot water extraction coupled with supercritical water oxidation

Chemical processes utilizing water both as extraction solvent and reaction medium are promising "Green Chemistry" alternatives to conventional techniques. Equipment for on-line coupled hot water extraction and supercritical water oxidation was constructed to extract polyaromatic hydrocarbons and toluene from sea sand followed by oxidation using hydrogen peroxide. The effectiveness of the technique is based on the physico-chemical properties of heated and pressurized water. Extraction efficiency increased with temperature and time; the best results were obtained at 300 degrees C with 40 min extraction time. In the oxidation stage, conversion of the PAHs increased with reaction time and oxidant concentration and the best conversion (97.0-99.9%, depending on the compound) was obtained at 425 degrees C with 43 s reaction time. Benzaldehyde and benzoic acid were the most abundant reaction intermediates in the oxidation process. In addition, phenol, p-cresol, and benzyl alcohol were found as intermediates. The intermediates originated mainly from toluene, which was present in much greater concentration than PAHs in the reaction medium.     

气化炉渣的重金属浸出特性及化学形态分析

分别采用硫酸硝酸法、水平振荡法和醋酸缓冲溶液法制取气化炉渣的浸出液，考察了不同提取方式对浸出液中重金属质量浓度的影响。采用改进BCR连续提取法对气化炉渣中的重金属Cr，Zn，Cu，Pb，Ni，As，Cd的化学形态进行了分析。实验结果表明：煤气化工艺中的气化炉渣属第Ⅰ类一般工业固体废物;在3种提取方式中，醋酸缓冲溶液法的重金属浸出种类最多，且浸出量最大;Cd和Cr对环境具有较高的潜在危害性，Cu次之，Zn，Pb，Ni，As主要以残渣态形式存在，对环境的直接危害性较低。     

Recovery of nickel oxide from spent catalyst

This study investigates the possibility of recovering nickel from the spent catalyst (NiO/Al2O3) resulting from the steam reforming process to produce water gas (H2/H2O) in many industries. In the extraction process, nickel is recovered as sulfate using sulfuric acid as a solvent. The considered parameters affecting nickel recovery were acid concentration, temperature and time of digestion solid:liquid ratio, particle size and stirring rate. Nickel was to be directly recovered as a sulfate salt by direct crystallization method. The conversion was 99% at 50% sulfuric acid concentration, solid: liquid ratio (1:12) by weight, particle size less than 500 micron for more than 5 h and 800 rpm at 100 degrees C.