酸化-萃取联合工艺从盐湖卤水中提硼的工艺研究

以西台吉乃尔盐湖卤水为原料,进行了酸化-萃取联合工艺从盐湖卤水中提硼的工艺研究。研究表明,酸化提硼阶段溶液最佳的pH值为2～3,萃取阶段异辛醇与航空煤油最佳的配比为体积比1∶1,相比(O/A)为0.5,萃取级数为7级。采用该工艺萃余液中的B2O3含量仅为27 mg·L-1,原料中的硼酸回收率达到99%以上。

Preparation and in Vitro Evaluation of Polylactic Acid (PLA) or Polylactic-co-Glycolic Acid (PLGA) Microcapsules Loaded with Estradiol

Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.

Effects of Surfactant on Zinc Recovery by Solvent Extraction during Leaching in HCl-FeCl_3 Solution

The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.

Kinetic study on reactive extraction of phenylalanine enantiomers with BINAP-copper complexes

Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in largescale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the kinetic study of reactive extraction of phenylalanine(Phe) enantiomers with BINAP–copper complex(BINAP–Cu) as a chiral selector. The theory of extraction accompanied by a chemical reaction was applied.The effects of agitation speed, interfacial area, p H value of aqueous phase, initial concentration of Phe enantiomers and initial concentration of BINAP–Cu on the specific rate of extraction were investigated. The forward rate constants of the reactions in the reactive extraction process are 7.93 × 10-5m5/2·mol-1/2·s-1for D-Phe and 1.29 × 10-4m5/2·mol-1/2·s-1for L-Phe.

Kinetics of Reactive Extraction of Nd from Nd2O3 with TBP-HNO3 Complex in Supercritical Carbon Dioxide

The process based on supercritical fluid extraction for reprocessing of the spent nuclear fuel has some remarkable advantages over the plutonium-uranium extraction(PUREX) process.Especially,it can minimize the generation of secondary waste.Dynamic reactive extraction of neodymium oxide(Nd2O3) in supercritical carbon dioxide(SC-CO2) containing tri-n-butyl phosphate-nitric acid(TBP-HNO3) complex was investigated.Temperature showed a positive effect on the extraction efficiency,while pressure showed a negative effect when the unsaturated TBP-HNO3 complex was employed for the dynamic reactive extraction of Nd2O3 in SC-CO2.Both temperature and pressure effects indicated that the kinetic process of the reactive extraction was controlled by the chemical reaction.A kinetic model was proposed to describe the extraction process.

Solvent extraction of lanthanum and cerium ions from hydrochloric acidic aqueous solutions using partly saponified 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester

In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000 mol·L^(-1); EHEHPA in a range of 0.2877–0.8631 mol·L^(-1) with saponification rate of 0.3(mole fraction), and the initial aqueous p H in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with.The calculation results are in good agreement well with the experimental data.

丁辛醇装置正丁醛缩合系统废水处理现状

介绍了丁辛醇生产废水污染物来源及特性,叙述了国内外辛醇生产中有机含碱废水处理方法,分析了各种方法的优缺点,认为水蒸汽汽提法、酸化-萃取法都是目前适合于工业化处理辛醇生产废水的较好方法。

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition： concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.

Preparation of PLA or PLGA Microspheres with Estradiol the Effects of THF—adding on the Properties of MS

Aim Polylactic acid (PLA) or polylactide-co-glycolide (PLGA) was used asbiodegradable and biocom-patible carriers to achieve sustained release ofestradial-PLGA/PLA-Microspheres (E_2-PLGA/PLA-MS). THF was added in the organic phase to study itseffects on the properties of MS. Methods MS were formed by an emulsification-solvent extractionmethod with mixture of ethyl acetate (EtoAc) and tetrahydrofuran (THF) as the organic solvents, andthen the properties and in vitro drug release behavior were examined. Results The results indicatedthat the drug loading efficiency decreased when THF added, but when the ratio of EtoAc was more than50% , there was no obvious effect of THF ratio, but the particle size increased accordingly. Thecarriers' properties and the drug contents were the main factors influencing the in vitro drugrelease. Conclusions By controlling the technology and formulation, we can get sustained-release E_2biodegradable microsperes with proper particle size, drug content and low burst-release, althoughTHF with readily solubility in water was used in the organic phase.

Selective extraction of In(Ⅲ),Ga(Ⅲ) and Zn(Ⅱ) using a novel extractant with phenylphosphinic acid

A new extractant, [N,N-di（2-ethylhexyl）aminolmethylphenylphosphinic acid （DEAPP）, was synthesized to de- velop the mutual separation techniques of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ）. The extraction selectivity for In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP was higher than that of the commercial phosphorus acid extractants such as D2EHPA and PC-88A. The extraction selectivity for metal ions in 1 mob L 1 aqueous ammonium nitrate solution with DEAPP was in the following order： In（Ⅲ） 〉 Ga（Ⅲ） 〉 Zn（Ⅱ）. These selective extraction behaviors indicate that the amino moiety of DEAPP plays an important role in the mutual separation of ln（Ⅲ）, Ga（Ⅲ） and Zn（ll）. The extraction equilibria of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP （ = HR） were expressed by the following reactions： In3＋ ＋ 2（HR）2 InR3（HR） ＋ 3H＋, Ga3＋ ＋ 1.5（HR）2 ＋ N- = GaR2（HR）（NO3） ＋ 2H＋, and Zn2＋ 4- 2（HR）2 ZnR2 （HR） 2 determined 4- 2H＋. The extraction equilibrium constants of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP were to be Kex, M = 1.7 × 104 [dm3.mol 1], 4.17 [（dm3.mol-1）s], and 1.55 × 10 2 [-], respectively.

Extraction mechanism of rare earths from chloride acidic solution with ammonium-bifunctionalized ionic liquid extractants

A series of ammonium-bifunctionalized ionic liquid extractants （ammonium-Bif-ILEs） combined with a number of anions, in- cluding carboxylic acids and 1,3-diketonates, have been prepared and studied in this report. Their extraction behavior and properties toward rare earth ions （REs（III）） are systematically investigated in chloride media as a function of important param- eters such as aqueous phase pH, salting-out agent concentrations, and extraction temperature. The separation performance of ammonium-Bif-ILEs toward REs（III） are systematically discussed. The results demonstrate that ammonium-Bif-ILEs have a synergistic effect between the cation and anions in separation of REs（III）. The influences of different anions on separation fac- tor （β） values are further studied. By comparison, ammonium-Bif-ILEs containing 1,3-diketonates have more potential appli- cations in La（III）/RE（III） separation than those containing carboxylic acids.