不锈钢酸洗废液再生利用的工艺研究

不锈钢酸洗废液中含有大量可回收的硝酸、氢氟酸和铁资源,采用硫酸置换法回收其中的硝酸和氢氟酸,并通过减压蒸发、冷凝回收等过程得到再生混酸(HNO₃+HF)。对硫酸置换废酸工艺进行流程模拟,研究了不同硫酸加入量、蒸发能耗对酸洗废液蒸发温度、混酸回收率的影响,结果表明：适宜的硫酸和酸洗废液加入量比为0.625∶1.000,蒸发能耗以3.4 MJ/kg酸洗废液为宜,蒸发温度为102.4℃,氢氟酸回收率为99.95%,硝酸回收率为93.11%,回收的混酸中氢氟酸、硝酸的质量分数分别为3.98%和7.51%,再生混酸可回用于不锈钢酸洗生产线。废酸经蒸发、结晶处理后得到含铁、镍、铬等重金属的盐泥,盐泥可进一步分级利用处理,分步回收其中的铁、镍、铬等金属或委外处理。     

溶剂萃取法回收不锈钢酸洗废液中再生H2SO4的研究

随着我国不锈钢粗钢产量逐年增大,对不锈钢进行酸洗而产生的酸洗废酸也在逐年增多。不锈钢酸洗排放的废硫酸溶液中含大量游离酸,根据本课题组开发的酸再生循环工艺,在有效回收废酸中有价金属离子的同时,使酸洗废酸中游离酸浓度增大得到再生硫酸。针对不锈钢酸洗废液中再生硫酸浓度较高、中和处理试剂消耗高、废渣产生量大的问题,研究了溶剂萃取法回收不锈钢酸洗废液中硫酸的工艺。研究发现,有机体系40%(体积分数)三(2-乙基己基)胺(TEHA)+50%异构十三醇+10% Exxsol D110为最优化组成,硫酸萃取率随TEHA浓度增加而升高,随温度升高萃取率降低,表明萃取反应为放热反应,计算所得萃取反应的ΔH=?7.5708 kJ/mol。根据萃取和反萃分配曲线分别绘制了McCabe-Thiele图,在30℃、相比A/O=1:2条件下,经过3级(理论)萃取,硫酸的萃取率可达79.8%以上;采用水作反萃剂,在30℃、相比A/O=1:1条件下,经过3级(理论)反萃,硫酸的反萃率可达85.5%。萃取、反萃动力学快,分相迅速,可满足工业连续生产要求。     

药厂废液中的山梨醇纳滤分离实验研究

山梨醇是一种重要的化工原料。为了研究纳滤膜技术分离药厂废液中山梨醇的可行性,采用NT103商品纳滤膜对废液中的纳滤膜进行了纳滤分离实验。实验结果表明:山梨醇截留率随操作压力与回收率的增大而增大,随温度的升高而减小;膜通量随操作压力与温度的升高而增大,随回收率的增大而减小;在操作压力0.8MPa,温度23℃,回收率70%的条件下,山梨醇的截留率能达到87.96%,证明了山梨醇通过纳滤回收的可行性,实现了药厂废液的资源化回收。     

不锈钢酸洗废水资源化处理技术进展与展望

综述了不锈钢酸洗废水中酸和金属离子资源回收技术.其中酸回收技术包括:扩散渗析法、双极膜电渗析法、蒸发法、树脂吸附法;金属离子回收技术包括:选择性沉淀法;酸和金属离子联合回收技术包括:热解法、纳滤-结晶法.比较了各种资源化处理技术的优缺点、适用范围以及工业化应用,展望了优势技术的发展方向及应用前景.     

酸洗废液浸出铁铬废泥制备三氯化铁工艺研究

本文研究了盐酸溶液溶解铁铬废泥工艺以及铁铬的分离与回收。考察了固液质量比、溶液游离酸浓度、搅拌速度及温度等因素,对铁浸出率、铬浸出率、余酸浓度以及过滤性能的影响,同时考察了钢铁酸洗废液代替工业盐酸溶解铁铬废泥的工艺可行性,实现了低成本工艺的开发,以及铁、铬资源的有效分离与利用。     

纳滤膜在钛白粉废酸处理中的应用

介绍了1种2级纳滤膜净化废酸的新工艺,用以处理回收硫酸法钛白产生的废硫酸(母液酸,硫酸质量分数约20%,Fe~(2+)的质量浓度约30 g/L)。实际运行结果表明,纳滤膜分离处理使纳滤产水Fe~(2+)的质量浓度≤140 mg/L,2级纳滤膜系统硫酸综合回收率约48%,所产净酸可以作为硫磺制酸的吸收酸。这样既回收了资源,又减少了废酸的排放治理,降低了硫酸法钛白生产成本。     

不锈钢酸洗废水中的重金属和酸的回收

在不锈钢的制造中，为了去除退火后钢材表面的氧化皮，多半是采用由硝酸和氢氟酸配成的混酸进行表面清洗，此被称作酸洗或酸浸，因其清洗效果好，国内外一直在广泛采用。这种清洗用的混酸(酸洗液)可反复使用，酸洗效果下降以后，其酸洗液作为酸洗废水加以处理后排放，主要的处理方法是加氢氧化钙中和沉淀，是沉淀物与水相分离。沉淀物脱水后可回炉重新利用或填埋，水相作为普通排水经稀释后排毒。     

日本开发回收强酸用离子交换膜装置

日本德山曹达开发了用于回收硝酸和氢氟酸等强酸的离子交换膜装置,当废酸处理量为250升/时,硝酸和氢氟酸的回收率分别为80%和70%,回收的酸可返回再利用,中和剂用量少,废渣处理成本低,回收成本可以降低五分之一,同时,设备投资规模和能耗也少。日前,该装置已开始向不锈钢生产     

不锈钢酸洗废液中金属的综合利用

为了综合利用不锈钢酸洗废液中的金属,采用分步沉淀的方法分离不锈钢酸洗废液中的铁、铬、镍。根据它们沉淀所需要的pH值不同,以及氢氧化铁、氢氧化铬、氢氧化镍的酸碱性不同等因素,设计了合理的分离工艺。研究了pH值等因素对金属离子分离效果的影响。结果表明,选择合适的pH值和辅助添加剂可以很好地分离不锈钢酸洗废液中的不同金属离子。     

不锈钢酸洗废酸的在线再生新工艺

介绍了不锈钢酸洗生产线引进的热废酸在线即时回收再生技术。新工艺设备采用离子交换树脂分离方法,选择性回收废酸液中的有效成分氢氟酸和硝酸,并生成再生酸,送回生产线直接利用。对工艺原理、设备的模块化特点和优势进行了说明。设备对热废酸液的即时回收再生率达到90%及以上,具有很好的环境与经济效益。有可观的引进技术自主化前景。     

油酸的精制研究

油酸酰胺是一种很好的塑料添加剂 ,可用作塑料加工成型时的脱膜剂、润滑剂。油酸的原料来源很广 ,牛油、羊油、猪油等动物油油脂以及大豆油、花生油、棕榈油等植物油脂中都含有大量的油酸。由于油酸的来源和生产方法多种多样 ,因此其所含的脂肪酸种类及含量都不尽相同。除油酸外 ,还有亚油酸、亚麻酸等高不饱和脂肪酸。针对油酸中因含有大量的多不饱和组分如亚油酸、亚麻酸而容易产生氧化泛黄的问题 ,采取了尿素络合法对原料油酸进行精制 ,以减少原料中亚油酸、亚麻酸组分的含量。经气相色谱验证 ,产品达到了应用指标 ,提高了产品的抗氧性。     

Quality of Sunflower Oil Obtained in the Main Producing Region of Brazil: Adherence to the Codex Alimentarius

The objective of this work was to evaluate the quality of the oil extracted from sunflower achenes grown in Campo Novo de Parecis, the main producing region of Brazil, to optimize its use by the processing and food industries. In addition, the fatty acid profiles of the oil were checked for their adherence to the CODEX STAN 210–1999. Traditional and high-oleic genotypes were grown between 2014 and 2017 during trials with a randomized complete block experimental design with four replications. The contents of oleic, linoleic, palmitic, and stearic acids were determined using gas chromatography. The fatty acid profiles of traditional genotypes were observed to be outside the ranges established by the CODEX, with an oleic acid content above 39.4% and linoleic, palmitic, and stearic acid values lower than 48.3%, 2.7%, and 5.0%, respectively, as well as high-oleic sunflower oil with a stearic acid content of less than 2.6%. The availability of this information can, on the one hand, positively impact industries and encourage the use of better quality raw materials that are more technologically and nutritionally adequate. On the other hand, the commercialization of sunflower oil with a fatty acid profile outside the ranges established by CODEX can be difficult, because the contents are out of specification due to the climatic conditions in the cropping region.     

聚乳酸合成的研究进展

简要介绍了生物降解高分子材料聚乳酸的基本性能,对近年来以乳酸为原料合成聚乳酸的两类方法进行了总结,并对聚乳酸合成的发展前景进行了展望。     

酸液体系的研究现状分析和现场应用

酸化解堵与压裂改造相比,它具有施工相对简单和成本相对较低等特点,所以酸化解堵是一项各油田广泛使用的油气田增产技术。酸化解堵技术已有将近100历史,现已研制出具有不同特点的酸液体系,如乳化酸、泡沫酸、固体酸、多氢酸等,基本能满足复杂地质条件对酸液的要求。     

猪磺去氧胆酸的合成

猪去氧胆酸(HDCA)与氯甲酸乙酯在三乙胺存在下反应生成羧酸-碳酸乙酯混合酐,而后将其与牛磺酸钠进行氨解反应,合成猪磺去氧胆酸(THDCA)。考察了合成工艺对THDCA收率及纯度的影响。结果表明,形成混酐时,二氧六环用量为11.3 mL/g HDCA,滴加氯甲酸乙酯后先在10℃反应30 min,再在15℃下反应20 min;用1.5 mol/L的NaOH水溶液溶解牛磺酸后再进行氨解;粗产品用丙酮重结晶。依以上条件,可得到收率约49%,质量分数约97%的THDCA。     

Acid catalytic effects in the chlorination of propanoic acid

Selective α‐chlorination of propanoic acid to form 2‐monochloropropanoic (MCA) and 2,2‐dichloropropanoic acid (DCA) was investigated in a laboratory‐scale, semibatch reactor at 90–130 °C at atmospheric total pressure and in the presence of chlorosulfonic acid (ClSO₃H) and 2,2‐dichloroethanoic acid (DCA′) as catalytic agents and oxygen as a radical scavenger. The decomposition of the catalyst was investigated with sulfur analysis and UV‐spectrometry. The studies revealed that the majority of sulfur remains in the reaction mixture, but is converted to an inactive form during the chlorination. The reasons may be the decomposition of ClSO₃H and its reaction with propanoic acid. The kinetic experiments revealed autocatalytic and parallel formation of MCA and DCA, the selectivity being independent of Cl₂ concentration in the liquid phase. The experiments with DCA′ also demonstrated that DCA′ has a catalytic effect on the chlorination The experiments confirmed the validity of a previously proposed reaction scheme for α‐chlorination, which comprises the formation of the reaction intermediate (propanoyl chloride) from propanoic acid and ClSO₃H, the acid‐catalyzed enolization of the acid and a hydroxyl‐chlorine exchange reaction. The acid‐catalyzed enolization is the rate determining step in the reaction sequence. The kinetic data were fitted to rate equations based on the reaction scheme. © 2000 Society of Chemical Industry     

Influence of Temperature on the Fatty Acid Composition of the Oil From Sunflower Genotypes Grown in Tropical Regions

The influence of temperature on the fatty acid composition of the oils from conventional and high oleic sunflower genotypes grown in tropical regions was evaluated under various environmental conditions in Brazil (from 0° S to 23° S). The amounts of the oleic, linoleic, palmitic and stearic fatty acids from the sunflower oil were determined using gas chromatography (GC). The environment exhibited little influence on the amounts of oleic and linoleic fatty acids in high oleic genotypes of sunflower. In conventional genotypes, there was broad variation in the average amounts of these two fatty acids, mainly as a function of the minimum temperature. Depending on the temperature, especially during the maturation of the seeds, the amount of oleic acid in the oil of conventional sunflower genotypes could exceed 70 %. Higher temperatures led to average increases of up to 35 % for this fatty acid. Although the minimum temperature had the strongest effect on the fatty acid composition, locations at the same latitude with different minimum temperatures displayed similar values for both oleic acid and linoleic acid. Furthermore, minimum temperature had little influence on the amounts of palmitic and stearic fatty acids in the oil.     

煤的溶胀处理对药用腐植酸提取的影响研究

以气煤、肥煤、焦煤、瘦煤为样煤,进行了样煤的粉碎、有机溶剂溶胀和硝酸氧化处理,考察了处理后煤样中的药用腐植酸得率。结果表明,吡啶和N,N-二甲基吡咯烷酮是溶胀较好的溶剂;样煤粉碎后,随着粒度的减小,煤的溶胀率增加;粒度粉碎至200目的气、肥煤经吡啶溶胀和硝酸氧化后,煤样的药用腐植酸得率可达到73.0%和71.4%,而经甲醇溶胀和硝酸氧化的200目气煤药用腐植酸得率为56.4%和58.4%。实验结果表明,煤样经过溶胀和硝酸氧化处理,对药用腐植酸的提取有促进作用。     

N-油酰肌氨酸的合成研究

介绍了一种合成N-油酰基肌氨酸的方法:先以油酸、三氯化磷合成油酰氯,再与肌氨酸钠经Schotten-banmann缩合,获得N-油酰肌氨酸钠,经酸化得到N-油酰肌氨酸。讨论了影响反应的各种因素。产品质量:酸值155-165mgKOH,收率以油酸计可达86.76%。     

胆汁酸溶解度的测定与数据关联

在胆汁酸结晶过程中,温度对胆汁酸在不同有机溶剂中溶解度的影响至关重要。采用平衡法结合HPLC法测定303.15~353.15 K胆酸、鹅去氧胆酸、熊去氧胆酸在5种有机溶剂中的溶解度,分别采用多项式经验方程和理想溶液方程对实验数据进行关联。结果表明,胆酸、鹅去氧胆酸、熊去氧胆酸在不同有机溶剂中的溶解度均随温度升高而增加,这两种方程均能较好地关联溶解度实验数据,其中多项式经验方程关联的相关系数均在0.98以上。