制浆干燥法制备高性能活性白土的工艺研究

提出制备高性能活性白土的制浆干燥工艺,以解决膨润土在酸活化过程中性能不高及污染严重的问题.以盐酸为改性剂,通过单因素实验得到的制浆干燥工艺条件为:盐酸溶液质量分数5%,膨润土与盐酸溶液的质量体积比1:2,反应温度50℃,时间10 h,得到活性白土的活性度可达320,菜油脱色率为86%.采用制浆干燥法改性的膨润土,反应条件温和,活性度高,结构破坏轻,废酸少,具有较广阔的应用前景.     

利用酸性含铝废液制备工业硫酸铝

采用活性白土工艺废酸液补加硫酸和铝矾土的方法制备工业硫酸铝,既消除活性白土工艺废酸液排放造成的污染问题,又回收了废酸液中的硫酸和硫酸铝。通过实验得到最佳工艺条件：pH=3.0、铝矾土量为每100 mL废酸液加入15 g、浓硫酸用量为10%（质量分数）。研究了结晶法与硫化钡法除铁,可分别得到硫酸铝产品,一等品中Al2O3和Fe3+的质量分数分别为16.5%（±0.06%）和0.095%（±0.18%）,合格品中Al2O3和Fe3+的质量分数分别为16%和0.308%,符合标准HG/T 2225-2010中工业硫酸铝Ⅱ类产品质量指标要求。     

电石法PVC含汞废酸处理系统

阐述了氯乙烯合成过程中过量的氯化氢气体回收处理的工艺流程:首先采用组合塔吸收净化氯乙烯气体,同时吸收氯化氢气体制取质量分数为31%的浓盐酸;然后采用浓盐酸解吸系统、稀盐酸深度解吸/负压浓缩系统对浓盐酸进一步处理,得到高纯度氯化氢气体。整个系统闭路循环,没有多余废气、废酸排放。     

钛白废酸循环利用工艺的研究

钛白废酸循环利用工艺是采用反渗透法将质量分数为20%的钛白废酸浓缩到45%,一部分作为酸解用酸的稀释水,一部分用作硫酸锰的酸解用酸,剩余的45%的浓废酸与质量分数为98%的浓硫酸调配增浓、冷冻、除杂,作为补充水送到硫酸生产装置的吸收系统再制酸。以德天化工为例,实施该工艺每年可减排废酸14.29万t,节约中和废水的石灰2.86万t,减排废水11.43万t,原材料硫酸消耗节省2.86万t,表明该工艺具有技术先进性和推广性。     

钛白废酸回收利用项目全线贯通

<正>日前,益诺欧环保集团首个硫酸法钛白粉废酸资源回收项目在四川攀枝花大互通钛业有限公司全线贯通,并完成调试顺利达产。该项目将质量分数22%废酸净化后浓缩,获得达到工业一级品标准的质量分数65%的硫酸产品,酸回收率高达95%。大互通循环利用项目是国内首个硫酸法钛白粉生产废酸及废水回收项目,采用益诺欧的钛白粉酸性废水处理资源全回收技术,以大互通现     

盐酸法生产钛白废液制取高纯Fe2O3实验研究

对盐酸法生产钛白的含氯化亚铁废酸液制取高纯氧化铁产品和无害化排放应用进行了实验研究.实验结果表明,用质量分数为7.5%的氨水作中和沉淀剂,控制溶液pH值为4,反应温度50℃,除去钛硅等杂质;再用质量分数为0.21%的稀硝酸处理氧化铁,除去钙镁杂质,所得产品Fe2O3纯度可大于99.3%,符合原电子部工业标准SJ/T 10383-93要求.废液中硝酸的质量浓度低于0.4g/L,沉淀氧化铁后的滤液经蒸发结晶回收氯化铵,可实现废液无害化排放.     

萃取法分离钛白废酸中的铁

首先通过臭氧氧化作用把钛白废酸中的二价铁转化成三价铁,然后采用萃取法去除其中的三价铁。考察了络合剂（盐酸）浓度、萃取剂、萃取相比等对三价铁萃取率的影响,并初步探索了反萃法回收萃取剂及萃取剂的循环利用。结果表明：当盐酸浓度为3.4 mol/L时,几乎可完全络合溶液中的三价铁;在萃取剂磷酸三丁酯中加入苯作为稀释剂,可有效降低磷酸三丁酯的粘度,消除萃取过程中的乳化现象;磷酸三丁酯萃取三价铁的传质过程很快,2-3 min即达平衡;当萃取相比O/W（萃取剂与钛白废酸体积之比）=0.6∶1时,三价铁萃取率可达97%以上。当反萃相比W/O=4∶1时,三价铁反萃率接近100%。磷酸三丁酯经过5次萃取-反萃循环后,三价铁的萃取率没有明显下降。去除三价铁后的钛白废酸,经蒸馏浓缩到质量分数70%左右,再与浓硫酸混合后可用于钛白粉的生产,蒸馏过程中回收的盐酸循环使用。反萃出来的三价铁可作为生产铁红的原料。     

组合塔在电石法氯乙烯生产中的应用

在电石法氯乙烯合成过程中,以组合塔代替水洗塔和泡沫塔。改造后经济效益显著,提高了盐酸的浓度,减少了含汞废酸的排放量,使含汞废酸实现最大自循环。     

利用制硫酸废渣和制药废酸制备聚合硫酸铁

以制硫酸废渣和制药废酸为原料,通过酸浸、水解、聚合制备聚合硫酸铁,考察了废酸的含量和用量以及酸浸时间对反应的影响.结果表明,废渣20 g与质量分数为40%的废硫酸60 mL反应3 h,用Ca(OH)2调节pH值至0.8～1.1,再聚合2～3 h后,可得到红棕色、粘稠的液体产品,烘干后可得淡黄色固体粉末状的固体产品.所得固体聚合硫酸铁的全铁质量分数18.9%,盐基度为11.2%,质量符合国家标准.与传统工艺相比,具有无需氧化剂、原料价廉和生产成本低等优点.     

用废酸制备活性白土

分析了废酸的产生和危害, 阐述了利用钛白粉厂的废酸生产活性白土的意义及生产方法     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H₂SO₄) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.     

Conjugated linoleic acid production from linoleic acid by lactic acid bacteria

After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA.     

乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的联合测定

以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气（N2）流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10％PEG-20M（3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0．9994和0．9996,相对标准偏差分别为O．74％和0．56％,平均回收率分别为97．35％-1197．60％,检出限分别为8．62mg·L^-1和1．21mg·L^-1方法简便、快速、准确。     

由氯乙酸副产盐酸精制高纯盐酸

开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准     

炼厂酸性气制取硫酸生产总结

介绍炼厂酸性气制硫酸装置的工艺过程。由于实供气源与设计值有较大出入,二氧化碳浓度偏高, 并且夹带烃类物质较多,使装置无法正常运行。通过对酸性气进行预处理后,一次开车成功,各项工艺指标均达到设计要求,遇酸性气流量突降时可补充适量硫磺,维持正常生产。     

The performic acid oxidation of linoleic acid

The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent.     

Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid

The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO₂, DSA^®O₂, DSA^®Cl₂, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm^-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis.     

液相色谱法测定氯乙酸中乙酸、二氯乙酸的含量

提出了液相色谱法测定氯乙酸中乙酸和二氯乙酸含量的分析方法,计算出氯乙酸的含量,并与现行工业氯乙酸国标分析方法进行了比较,证明液相色谱分析方法简洁、快速,分析结果准确,在氯碱行业具有推广运用的价值。