Effects of conductive agent type on lithium extraction from salt lake brine with LiFePO_(4) electrodes

Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines give rise to challenges,such as prolonged lithium extraction periods,diminished lithium extraction efficiency,and considerable environmental pollution.In this work,Li FePO4(LFP)served as the electrode material for electrochemical lithium extraction.The conductive network in the LFP electrode was optimized by adjusting the type of conductive agent.This approach resulted in high lithium extraction efficiency and extended cycle life.When the single conductive agent of acetylene black(AB)or multiwalled carbon nanotubes(MWCNTs)was replaced with the mixed conductive agent of AB/MWCNTs,the average diffusion coefficient of Li+in the electrode increased from 2.35×10^(-9)or 1.77×10^(-9)to 4.21×10^(-9)cm^(2)·s^(-1).At the current density of 20 mA·g^(-1),the average lithium extraction capacity per gram of LFP electrode increased from 30.36 mg with the single conductive agent(AB)to 35.62 mg with the mixed conductive agent(AB/MWCNTs).When the mixed conductive agent was used,the capacity retention of the electrode after 30 cycles reached 82.9%,which was considerably higher than the capacity retention of 65.8%obtained when the single AB was utilized.Meanwhile,the electrode with mixed conductive agent of AB/MWCNTs provided good cycling performance.When the conductive agent content decreased or the loading capacity increased,the electrode containing the mixed conductive agent continued to show excellent electrochemical performance.Furthermore,a self-designed,highly efficient,continuous lithium extraction device was constructed.The electrode utilizing the AB/MWCNT mixed conductive agent maintained excellent adsorption capacity and cycling performance in this device.This work provides a new perspective for the electrochemical extraction of lithium using LFP electrodes.

Salting-out Extraction of 2,3-Butanediol from Jerusalem artichoke-based Fermentation Broth

The removal of solid impurities and separation of target products from a fermentation broth is becoming more tedious with the utilization of lignocelluloses as source of substrate.2,3-Butanediol,an important chemical used widely is also a main product of sugar-based fermentation carried out by Klebsiella pneumoniae.In this study,we investigated the use of salting-out extraction(SOE) that employed a K2HPO4/ethanol system consisting of 21% ethanol and 17% K2HPO4(mass fraction) to separate 2,3-butanediol from the viscous Jerusalem artichoke-based fermentation broth.After SOE,about 98% of solid matters was removed,and the viscosity decreased from 72.5 mPa s in the original fermentation broth to 4.4 mPa s in the top phase.The partition coefficient and yield of 2,3-butanediol reached 13.4 and 99%,respectively,and 89% of soluble proteins was removed from the broth.The results showed that SOE is an efficient way for isolating 2,3-BD from a highly viscous fermentation broth by removing much of the solid matters within the broth.

Recovery of Aniline from Wastewater by Nitrobenzene Extraction Enhanced with Salting-Out Effect

Objective Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25 ℃. Method Batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance, including acidity of wastewater, initial aniline concentration, ratios of solvent to wastewater, extraction stages, concentrations and different types of inorganic salts, such as NaCl, KCI, Na2SO4, CaCl2 and K29O4. Results Nitrobenzene with a concentration of 20% and a pH value of 9.1 at the temperature of 25 ℃ together with NaCl of a concentration of 14 wt.% realized nearly 100% aniline recovery at the fifth stage of wastewater treatment. Conclusions High pH values and volume ratios of nitrobenzene/wastewater are more suitable for recovery of aniline. In addition, recovery of aniline is significantly elevated with increase of the concentration of salts, whose promoting effects are in the following order: NaCI〉Na2SO4〉K2SO4〉CaC12〉KCI on the weight basis of wastewater. Furthermore, aniline in wastewater can be almost completely recovered by five-stage sequential nitrobenzene extraction, which is promoted continuously by the salting-out effect.

Liquid-liquid Extraction System Based on Non-ionic Surfactant-salt-H_2O and Mechanism of Drug Extraction

Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydro- chloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, while that of PCN is 77%. This system produces the distribution coefficients (KD) of 12.3 and 2.6 respectively for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet and molecular fluorescence spectra variation of the drugs in the system studied.

The extraction of potassium from K-feldspar ore by low temperature molten salt method

The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO_3, NaOH, H_2O and K-feldspar ore, particle size of K-feldspar ore,reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS,separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%.Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.

Highly efficient extraction of lithium from salt lake brine by LiAl-layered double hydroxides as lithium-ion-selective capturing material

The extraction of lithium from salt lake brine in the Chinese Qaidam Basin is challenging due to its high Mg/Li and Na/Li ratios. Herein, we utilized a reaction-coupled separation technology to separate sodium and lithium ions from a high Na/Li ratio brine(Na/Li = 48.7, w/w) and extracted lithium with Li Al-layered double hydroxides(Li Al-LDHs). The Li Al-LDHs act as lithium-ion-selective capturing materials from multication brines. That is, the lithium ions selectively enter the solid phase to form Li Al-LDHs, and the sodium ions are still retained in the liquid phase. This is because the lithium ions can be incorporated into the structural vacancies of LiAl-LDHs, whereas the sodium ions cannot. The effects of reaction conditions on lithium loss and separation efficiency were investigated at both the nucleation and the crystallization stage, e.g., the nucleation rotating speed, the Li/Al molar ratio, the crystallization temperature and time, and co-existing cations. The lithium loss is as low as 3.93% under optimal separation conditions.The sodium ions remained in the solution. Consequently, an excellent Na/Li separation efficiency was achieved by this reaction-coupled separation technology. These findings confirm that LiAl-LDHs play a critical function in selectively capturing lithium ions from brines with a high Na/Li ratio, which is useful for the extraction of lithium ions from the abundant salt lake brine resources in China.

Study on Salt-Containing Extractive Distillation for the 2-Propanol/Water System

为 2-propanol/water/ethanediol/KAc 系统的咸包含的引得出的蒸馏列和咸包含的代理人恢复列被 NRTL 模型和修改罗斯松驰方法模仿。模拟结果证明在蒸汽液体平衡和 NRTL 参数的关联方法(TDCM ) 的盐效果的预言对说的系统合适。四个不同蒸馏技术过程被调查；结果证明咸包含的引得出的蒸馏过程是最好的。引得出的蒸馏列的模仿的设计在不同全部的阶段数字的条件下面被执行，喂地点，倒流比率，混合代理人的数量和 KAc 的集中。结果证明象 17 个阶段，在第 9 舞台的一个喂的地点， 1.2 的倒流比率，和喂的一个混合代理人的如此的因素 1.141 kmol/h 评价，最好可能被适合操作条件。模仿的设计也为恢复咸包含的代理人为列被做。咸包含的引得出的蒸馏的模拟方法在这个工作简单、有效。

Salting-Out Assisted Liquid-Liquid Extraction Combined with HPLC for Quantitative Extraction of Trace Multiclass Pesticide Residues from Environmental Waters

In this study, salting-out assisted liquid-liquid extraction combined with high performance liquid chromatography diode array detector (SALLE-HPLC-DAD) method was developed and validated for simultaneous analysis of carbaryl, atrazine, propazine, chlorothalonil, dimethametryn and terbutryn in environmental water samples. Parameters affecting the extraction efficiency such as type and volume of extraction solvent, sample volume, salt type and amount, centrifugation speed and time, and sample pH were optimized. Under the optimum extraction conditions the method was linear over the range of 10 - 100 μg/L (carbaryl), 8 - 100 μg/L (atarzine), 7 - 100 μg/L (propazine) and 9 - 100 μg/L (chlorothalonil, terbutryn and dimethametryn) with correlation coefficients (R2) between 0.99 and 0.999. Limits of detection and quantification ranged from 2.0 to 2.8 μg/L and 6.7 to 9.5 μg/L, respectively. The extraction recoveries obtained for ground, lake and river waters were in a range of 75.5% to 106.6%, with the intra-day and inter-day relative standard deviation lower than 3.4% for all the target analytes. All of the target analytes were not detected in these samples. Therefore, the proposed SALLE-HPLC-DAD method is simple, rapid, cheap and environmentally friendly for the determination of the aforementioned herbicides, insecticide and fungicide residues in environmental water samples.

Lithium Ion Extraction from the High Ration Mg/Li Salt Lake Brine with Ionic Liquid in Triisobutyl Phosphate and Kerosene

1 Introduction As the lightest metal with the unique properties of energy production and storage,lithium is regarded as the new century energy metal.Lithium and its compounds were widely used in various industrial fields,especially in

碳酸肼对乏燃料后处理模拟污溶剂中磷酸二丁酯和Zr(Ⅳ)的洗涤行为研究

碳酸肼作为碱性无盐试剂对钚铀氧化还原萃取(PUREX)流程的污溶剂的洗涤有广泛的应用前景。本文使用碳酸肼溶液对30%磷酸三丁酯-正十二烷有机溶液中的磷酸二丁酯和Zr(IV)进行洗涤,利用单一变量原则,考察了振荡时间、温度、水相与有机相体积比、碳酸肼质量分数以及磷酸二丁酯质量浓度等因素对去除有机溶液中磷酸二丁酯和Zr(IV)的影响。结果表明:在25℃下振荡洗涤15 min,5%碳酸肼洗涤3次同体积的有机溶液后对0.1 g/L和0.5 g/L的磷酸二丁酯的去除率分别约为98.7%和88.1%。此外,磷酸二丁酯的存在可以促进有机相对Zr(IV)的萃取和保留,当磷酸二丁酯的质量浓度为0时,碳酸肼对Zr(IV)的去除率为98.5%。

菜籽蛋白的弱酸高盐法提取工艺优化及品质分析

旨在揭示弱酸高盐法提取菜籽蛋白的潜力,以脱脂低温压榨菜籽饼为原料,MgCl2溶液为提取液,采用弱酸高盐法提取菜籽蛋白,采用单因素实验研究提取温度、提取pH、提取时间、提取液浓度及料液比对菜籽蛋白提取率的影响,采用正交实验进行菜籽蛋白的弱酸高盐法提取工艺优化,并比较弱酸高盐法菜籽蛋白与碱提酸沉法菜籽蛋白在抗营养因子(植酸、硫苷和单宁)含量与感官特性(气味、色泽)上的差异。结果表明:弱酸高盐法提取菜籽蛋白的最佳工艺条件为提取温度50℃、提取pH 6.5、提取时间150 min、提取液浓度150 mmol/L、料液比1∶30,在最佳工艺条件下菜籽蛋白提取率为(48.00±1.12)%,纯度为(73.99±2.87)%;弱酸高盐法菜籽蛋白的单宁含量为(0.90±0.06)%,植酸含量为(0.04±0.01)%,未检测出硫苷,色泽为浅黄色,各指标明显优于碱提酸沉法菜籽蛋白。弱酸高盐法作为一种温和的工艺在菜籽蛋白提取方面具有较好的开发潜力和应用前景。

锂资源提取技术研究进展

锂被认为是21世纪最重要的能源金属之一,在全球减碳的共同目标下,新能源产业快速发展,推动过去3a锂消费量的持续增长,引发国内外对提锂技术的研究热潮。根据锂资源的赋存状态,对矿石提锂及卤水提锂技术进行综述,系统性地总结对比了各种方法的优缺点。从矿石中提取锂的方法主要有石灰石烧结法、硫酸法、硫酸盐法、压煮法、氯化焙烧法、直接酸浸法;卤水提锂中受到广泛关注的技术主要有沉淀法、吸附法、溶剂萃取法、膜分离法、电化学法。由于碳酸锂价格高位回落,国际锂盐获取形势愈加严峻,因此不断开发并完善提锂技术,增强中国的锂资源自供自给能力,实现提锂技术的降本增效势在必行。

盐湖卤水萃取法提锂的研究进展

随着全球锂电行业的迅猛发展,作为原材料的锂需求量也日益攀升。盐湖卤水中蕴含着丰富的锂资源,但浓度低、成分复杂。开发高效锂分离技术,从卤水中提取锂资源具有重要的经济价值和战略意义。溶剂萃取法具有处理量大、萃取效率高、优异选择性以及易于规模化操作等优点,具有良好的工业应用前景。本文主要综述了近5年常用的萃取体系,包括β-二酮、有机磷化合物、大环分子、磷酰基吡唑啉酮、离子液体以及低共熔溶剂。系统地分析了各种萃取体系的作用机理、适用的环境以及存在的优缺点,对于萃取体系存在的问题进一步介绍了萃取过程强化技术,如膜萃取强化、电场强化。最后,对未来各种萃取体系的研究重点和改进提出了观点和评述,同时对萃取体系的发展前景进行了展望。

高温熔盐储能提升燃煤机组动态响应的分析

为了提高燃煤机组调峰负荷响应速率,基于Dymola软件的Modelon组件库,建立某600 MW超临界燃煤机组的动态模型,研究采用高温熔盐替换抽汽加热给水对燃煤机组主要参数动态特性的影响。研究结果表明:替换低压加热器(简称低加)比替换高压加热器(简称高加)对机组主、再热蒸汽和给水参数的影响更小,随着机组负荷的降低,机组负荷响应能力降低。高温熔盐替换高加时,负荷响应时间较长、负荷变化量较大、负荷平均变化速率较小,而高温熔盐替换低加时的效果相反,熔盐替换高加时的热电转化效率比替换低加要高。

萃取分光光度法测定氯化钾体系中的十八胺

十八胺是冷结晶-正浮选法生产氯化钾的常用捕收剂,用量显著影响浮选分离效率。由于其会吸附在氯化钾表面,不可避免地在氯化钾中残留,不利于高纯钾盐产品的开发。针对氯化钾生产过程及产品中十八胺含量测定的需求,依据十八胺和溴酚蓝通过范德华力和氢键络合的作用原理,开发了以乙酸丁酯为萃取剂、溴酚蓝钠盐为显色剂的萃取分光光度法测定氯化钾中十八胺的浓度。考察了溶液pH、十二烷基吗啉、共存盐、平衡时间、显色剂用量对十八胺浓度测量的影响。结果表明:当溶液pH从3~9逐渐增大时,十八胺与溴酚蓝的络合作用减弱且络合分子极性增大,导致吸光度降低;在pH<5时,十二烷基吗啉和溴酚蓝能形成有色络合物,当pH为6~9时萃取液吸光度值趋近于零;共存氯化钾、氯化钠、硫酸钾、氯化镁等溶液的离子强度增大,氢键作用减弱但络合分子的盐析效应增强,溶液中微量的Li^(+)、NH_(4)^(+)和B对萃取液吸光度影响不大;显色剂用量过大时,吸光度值太大且不符合朗伯-比尔定律,平衡时间影响较小。选择测定条件为:溶液的pH为6、离子强度为1 mol·L^(-1),2 mmol·L^(-1)显色剂的用量为0.50 mL,采用缓冲溶液定容至25 mL,反应5 min后加入5.00 mL乙酸丁酯萃取,待分层平衡2 min后于458 nm处测定萃取液吸光度,工作曲线为A=0.04949c+0.06624(R^(2)=0.9923,ε=1.33×10^(4) L·mol^(-1)·cm^(-1),0~10 mg·L^(-1))。该方法的相对标准偏差为0.33%~2.63%,平均相对误差为-0.90%,十八胺和十二烷基吗啉混合体系的平均相对误差为-0.25%。采用该方法测得正浮选精钾母液中十八胺含量为8.66 mg·L^(-1),加标回收率为95.5%~106%,可用于测定盐湖钾肥生产过程中十八胺的浓度。

焦炉煤气深度脱硫脱氰技术在攀钢焦化的应用

介绍了一塔式高效脱硫脱氰再生工艺在攀钢的应用情况。通过在脱硫脱氰再生系统中应用低压力降除雾沫设备、再生槽尾气治理设备和塔内气液隔离水封,结合硫膏生产和提盐系统,塔后H2S含量降到了20 mg/m^(3)以下。经计算,应用该系统可降低SO2排放4 636 t/a,节省环保排放税约1 718万元/a,值得参考和借鉴。

盐析辅助液液萃取-超高效液相色谱-串联质谱法快速测定糕点中14种生物碱

目的建立一种应用盐析辅助液液萃取前处理技术结合超高效液相色谱-串联质谱法快速测定糕点中14种常见有毒生物碱的分析方法。方法样品加水超声处理后,在碱性条件下(pH=11),用乙腈提取,加入氯化钠盐析分层。取乙腈相氮吹至干后用40%甲醇水溶液复溶,使用0.1%甲酸-5 mmol/L甲酸铵的水溶液和乙腈为流动相,在C18色谱柱(100 mm×2.1 mm,2.5μm)上通过梯度洗脱实现目标物分离,在串联质谱正离子多反应监测模式下进行检测,溶剂标准曲线外标法定量。结果14种生物碱在0.5~100.0 ng/mL的范围内具有良好的线性关系,相关系数均≥0.999,检出限和定量限范围分别为0.1~2.2μg/kg和0.3~7.1μg/kg。在8.00、50.00和200.00μg/kg的加标浓度下,14种生物碱的平均回收率为76.3%~105.7%,相对标准偏差为1.2%~9.8%(n=6)。结论本方法简单、快速、准确,能满足糕点中14种生物碱的快速筛查和定量分析,可用于疑似生物碱中毒的应急事件处理。

纳滤膜在盐湖提锂领域的研究进展

中国锂(Li)资源消耗量占全球消耗量的40%,然而其产能仅满足工业需求的20%,80%的Li需要进口,研究新一代提Li技术迫在眉睫。纳滤(NF)膜具有选择性离子分离能力,在Mg^(2+)、Li^(+)的选择性分离中表现出突出的潜力。商用NF膜多荷负电,受Donnan效应和静电引力影响,其对正离子的分离能力有限。近年来的研究发现,荷正电NF膜可以有效分离具有相似水合物离子半径的Mg^(2+)和Li^(+)。该文介绍了NF膜中离子传输理论和选择性筛分机理,综述了商用NF膜在盐湖提Li领域的研究现状及不足,分析了荷正电NF膜的制备方式(包括胺单体的选取、纳米材料掺杂、引入中间层及表面接枝等)对提升Mg^(2+)、Li^(+)的选择性分离性能的影响规律。最后,总结了荷正电NF膜在实际工程应用中的挑战和前景。

焦化厂脱硫废液回收工艺的研究

传统脱硫废液的处理方法如分布结晶法、阴离子树脂交换法等均具有回收利用率低的缺点,且不能实现硫氰酸钠及硫代硫酸钠的高纯度回收。基于此,根据脱硫废液副盐中硫氰酸钠易溶于醇而其他主要成分不溶于醇的性质,提出了脱硫废液醇处理方法,分离回收副盐中的硫氰酸钠和硫代硫酸钠,解决焦化企业脱硫废液难处理的问题。

氯乙烯装置焚烧系统积盐及废水提盐情况分析

分析了氯乙烯装置焚烧系统设备积盐结晶、烟气换热设备腐蚀、废液提盐等问题,提出了有效的解决方案。