Extraction of Chloride Ions from Zinc-Bearing Waste Lixivium by Trioctyl Amine (TOA)

This paper presents research on separating Cl^? from zinc-bearing waste lixivium by using trioctylamine as an extractant, 2-octanol as a solvent, and sulfonated kerosene as a diluent. The effects of trioctylamine concentration, organic/aqueous phase ratio, extracting stages, and waste lixivium pH were investigated, and the process of stripping was also discussed. The optimal conditions were achieved. The extraction efficiency, separation factor, and stripping efficiency were calculated with optimal values of 99.47%, 595, and 99.99%, respectively. Besides, the extractant regenerated after stripping was observed without the emulsifying phenomenon. The mechanism of extraction and stripping was also discussed.     

The extraction of lactic acid by emulsion type of liquid membranes using alamine 336 in escaid 100

The extraction of lactic acid from aqueous solutions through an emulsion liquid membrane containing Alamine 336 as carrier was investigated. The influence of mixing speed, diluent type, surfactant concentration, extractant concentration, feed solution pH, stripping concentration, phase ratio, and feed concentration were examined. Liquid membrane consists of a diluent (n‐heptane, toluene, kerosene, Escaid 100, and Escaid 200), a surfactant (Span 80) and an extractant (Alamine 336), and Na₂CO₃ were used as a stripping solution. It is possible to extract 91% of lactic acid from aqueous solutions using Alamine 336 in Escaid 100, as an extractant and a diluent respectively.     

萃取-Fenton氧化法预处理富马酸生产废水

采用萃取-Fenton氧化相结合的工艺来预处理富马酸生产废水,考察了萃取剂种类、油水体积比、萃取剂与稀释剂体积比、萃取反应pH值、温度等因素对萃取效果的影响,同时研究了Fenton氧化法对萃取后废水的进一步处理效果,结果表明：以磷酸三丁酯为络合萃取剂,异辛醇为稀释剂,最佳油水体积比为0.8,最佳稀释体积比为V（萃取剂）∶V（稀释剂）=3∶1,最佳pH值为废水初始pH值,一次萃取废水CODCr去除率为73%;对萃取后废水采用Fenton氧化法进一步处理,H2O2投加量为9/5 Qth（理论投加量）,n（Fe2＋）∶n（H2O2）=1∶4,反应最佳pH值为3,反应时间为1 h,处理后废水CODCr质量浓度降至1 000 mg/L,总的CODCr去除率达到96.5%。     

Solvent extraction with LIX 973N for the selective separation of copper and nickel

LIX 973N diluted with Iberfluid was used to co‐extract copper and nickel from ammoniacal/ammonium carbonate aqueous media. The influence of equilibration time, temperature, equilibrium pH and extractant concentration on the extraction of both metals has been studied. It was observed that neither copper nor nickel extraction is sensitive to temperature and equilibrium pH, however nickel extraction equilibrium is reached at a longer contact time (20 min) than that of copper (5 min), in addition nickel extraction depends greatly on the extractant concentration in the organic phase. For a solution containing 3 g dm⁻³ each of copper and nickel and 60 g dm⁻³ ammonium carbonate, conditions were established for the co‐extraction of both metals, ammonia scrubbing and selective stripping (with H₂SO₄) of nickel and copper. Using the appropriate extractant concentration the yield (extraction stage) for both metals is near 100%, whereas the percentage of nickel and copper stripping is also almost quantitative. © 1999 Society of Chemical Industry     

从没食子酸结晶母液中回收没食子酸的萃取工艺

引言没食子酸又名五倍子酸,是一种应用很广泛的化工原料[1],可用作食品抗氧化剂、着色剂、净化剂、防腐剂等[2],且具有抗肿瘤、抗炎、抗突变等多种生物学作用[3]。没食子酸是单宁酸的水解产物,国内厂家大多数以含水解单宁的植物五倍子、塔拉为原料生产没     

Photocatalytic decomposition of nonbiodegradable substances in wastewater from an acrylic fibre manufacturing process

The testing samples in this experiment were obtained from an acrylic fibre manufacturing companys industrial wastewater. The water was the waste of the acrylic polymerization process. The company is located in Ulsan, Korea. The concentration of acrylonitrile (AN) in the wastewater was about 25–35 mg/L. Concentrations of 3–10 mg/ L of methyl acrylate (M-35) were also found. The samples were treated by the TiO₂/UV system and were analyzed to determine the values of COD_cr, ammonia, nitrite nitrogen, and nitrate nitrogen by using an Auto Analyzer (Bran+ Luebbe, Germany) and a TOC (Tekmar Dohrmann, USA). Various reaction parameters, such as TiO₂ content, light intensity and wavelength, and the number of UV lamps were varied and their effects or decomposition efficiency were analyzed. The adsorption onto TiO₂ surfaces by organic materials in the wastewater was negligible. The reaction-rate constant was also calculated. The reaction rate constant for the G36T6L lamp at both 185 nm and 256 nm was 0.0661 hr^-1 which is 1.3 times higher than that of the TUV36T5 lamp at 256 nm. While the reaction rate was increased by increasing the surface area of the photocatalyst, the excess photocatalyst blocked the light sources, causing a photoenclosure effect. The stability of the treated wastewater was greatly increased because the elimination of the concentration of nitrite was followed by an increase in the concentration of nitrate. Generally, the ratio of BOD₅/COD_cr is used as the criterion for determining biodegradability. A ratio of 0.3 is needed for biological degradation. The ratio of the treated wastewater increased to 0.5 after 12 hours of reaction. The ratio increased to 0.8 after 20 hours.     

Silver Extraction from Hydrochloric Acid Solutions with the Disulfide of Bis(2,4,4-trimethylpentyl)Dithiophosphinic Acid

Silver extraction from hydrochloric acid solutions with the disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (L) in toluene is described in this work. Based on the analysis of the extraction data, it was concluded that silver extraction is due to the formation of the compound AgCl?2L in the organic phase. An increase in the concentration of hydrochloric acid in the aqueous phase leads to a decrease in AgCl extraction because of the formation of non-extractable anionic complexes of silver. Solvent extraction efficiency decreases in the series octanol > decane > chloroform > toluene, which is due to the preferential solvation of the extracted complex by the solvent. A significant increase in the extraction of silver chloride with disulfide in the presence of octanol is caused by the strong interaction of the extracted compound and the alcohol, due to the chloride ion solvation by octanol. The possibility of using the disulfide for silver extraction from hydrochloric acid solutions containing metal impurities (Ni, Cu, Co, Zn, Fe (III), and Na) has been demonstrated. The degree of silver recovery in one stage was 98.62%, while the extractant showed high selectivity toward silver: the separation factors of silver over metal (β_Ag/_Me) ranged from 9000 to 30,000. Almost complete silver stripping from the organic phase was achieved when using a mixture of thiourea and sulfuric acid solutions. The extraction characteristics of the disulfide are much better as compared to that of the well-known commercially available extractant triisobutylphosphine sulfide. The disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid can be used for efficient extraction of silver from industrial hydrochloric acid solutions of different origin.     

Solvent Extraction Studies for Separation of Zn(II) and Mn(II) from Spent Batteries Leach Solutions

This study aims at assessing the possibility of using solvent extraction processes for separating Zn(II) and Mn(II) dissolved in aqueous solutions obtained by acid bioleaching of spent alkaline and Zn-C batteries. In this context, Cyanex 272 and DEHPA were tested as extractant agents, and the former was shown to have better performance. Hence, the effect of four factors (equilibrium pH, extractant concentration, A/O ratio, and temperature) into three response variables (extraction efficiency of Zn, Y_Zn; extraction efficiency of Mn, Y_Mn; separation factor, β) were tested according to a full factorial design (2⁴) with two replicated center points. Our study revealed that Y_Zn depends mainly on the extractant concentration, Y_Mn on the equilibrium pH and β on the equilibrium pH, extractant concentration, and A/O ratio as well as on second and third order interactions. One extraction step is sufficient to reach high extraction of zinc in synthetic solutions, but two stages were required for real leaching liquor. The extraction kinetics is fast (less than 15 min) for both metals, even when real liquor was tested. The organic solvent can be efficiently recovered using a stripping solution of H₂SO₄ 1 M and thus the process can be considered environmentally sustainable.     

Recovery of copper from ammoniacal/ammonium sulfate medium by LIX 54

The extraction‐stripping reaction of Cu(II) by LIX 54 in Iberfluid from aqueous ammonium sulfate medium at pH 8.5 has been investigated. The effects of pH, metal ion, extractant concentration as well as the loading capacity of the reagent were studied. The extraction equilibrium constant for copper was determined numerically to be 7 × 10⁻⁷. Experimental data can be explained assuming the formation of CuR₂ species in the organic phase (R represents the extractant). Copper stripping was studied using typical spent copper electrowinning solutions as stripping medium. The number of stages required for the extraction and stripping of copper was also evaluated. The results were used to asses the conditions for purification of industrial waste solutions (eg spent etchants) containing copper through counter‐current extraction‐stripping. © 1999 Society of Chemical Industry     

Decomposition of acetic acid by advanced oxidation processes

Decomposition of acetic acid, known as a non-degradable organic compound, was conducted for several advanced oxidation processes such as TiO₂-UV-H₂O₂, Fe²⁺-H₂O₂-UV, UV-H₂O₂ and TiO₂-UV system. Acetic acid was efficiency decomposed within 120 minutes of UV radiation under the initial concentration of 500 ppm. The initial chemical oxygen demands (COD _cr ) tended to increase as H₂O₂ was added in most reactions. However, the initial COD _cr was not increased as H₂O₂ was consumed for the oxidation of iron salt in the photo-Fenton oxidation process. COD _cr and concentration of acetic acid rapidly decreased as the mole ratio of hydrogen peroxide increased owing to rapid decomposition of the reactant at the beginning of reaction. All reactions show first order pseudo reaction rate. The COD _cr removal rate and the decomposition efficiency of acetic acid were fastest in the UV-H₂O₂ process.     

Intensification of Nicotinic Acid Separation using Organophosphorous Solvating Extractants by Reactive Extraction

Nicotinic acid (3‐pyridine carboxylic acid) is widely used in food, pharmaceutical, and biochemical industries. Compared to chemical methods, enzymatic conversion of 3‐cyanopyridine is an advantageous alternative for the production of nicotinic acid. This study is aimed to intensify the recovery of nicotinic acid using reactive extraction with organophosphorus solvating extractants such as tri‐n‐octyl phosphine oxide (TOPO) and tri‐n‐butyl phosphate (TBP). The distribution of nicotinic acid between water and phosphorus‐based solvents dissolved in various diluents and the comparison of extraction efficiency with pure diluents are studied at isothermal conditions. Pure diluents are not found to be good extracting agents and the maximum distribution coefficient (K_D) obtained with 1‐octanol is 0.31. Experimental studies are carried out to investigate the effect of diluent, initial acid concentration, extractant type, and extractant composition on the degree of extraction. The maximum recovery of nicotinic acid is obtained by dissolving TOPO in MIBK at an initial nicotinic acid concentration of 0.10 kmol/m³. Solvation numbers and extraction equilibrium are also estimated with both TBP and TOPO.     

溶剂萃取法从提锂后盐湖卤水中提硼的工艺研究

以青海东台吉乃尔盐湖提锂后卤水为原料,用2-乙基-1,3-己二醇分别与异辛醇、异戊醇组合的混合醇从卤水中萃取硼,从萃取剂体积分数、酸度、相比、萃取时间、萃取温度、饱和萃取容量、反萃剂浓度、反萃时间等方面加以实验,获得了混合醇从卤水中萃取提硼的最佳工艺条件:萃取剂体积分数30% ,水相pH为3,相比1:1,萃取时间10 min,最大饱和容量61.4 g/L(B2O3).并与一元醇进行了比较,得出混合醇的萃取效果远好于一元醇.     

Demonstration of a SANEX Process in Centrifugal Contactors using the CyMe4‐BTBP Molecule on a Genuine Fuel Solution

Efficient recovery of minor actinides from a genuine spent fuel solution has been successfully demonstrated by the CyMe₄‐BTBP/DMDOHEMA extractant mixture dissolved in octanol. The continuous countercurrent process, in which actinides(III) were separated from lanthanides(III), was carried out in laboratory centrifugal contactors using an optimized flow‐sheet involving a total of 16 stages. The process was divided into 9 stages for extraction from a 2 M nitric acid feed solution, 3 stages for lanthanide scrubbing, and 4 stages for actinide back‐extraction. Excellent feed decontamination factors for Am (7000) and Cm (1000) were obtained and the recoveries of these elements were higher than 99.9%. More than 99.9% of the lanthanides were directed to the raffinate except Gd for which 0.32% was recovered in the product.     

Continuous Laboratory Gold Solvent Extraction from Cyanide Solutions using LIX 79 Reagent

Continuous laboratory solvent extraction of gold from cyanide solutions has been investigated by using LIX 79 guanidine‐based extractant. Different variables that affected the extraction included aqueous pH, extractant concentration and modifier concentration. Extraction isotherms of the aurocyanide complex with respect to the other cyanoanions were compared, and the following order of selectivity was observed: Au > Ag > Cu > Zn > Fe. According to the pH isotherms, aurocyanide can be extracted in alkaline media, and a better separation with respect to other cyano anions was obtained in the pH range 10.5–11.2. From the McCabe‐Thiele diagrams, better recovery was observed when using LIX 79 and tridecanol at 10 vol.‐%. Stripping gold from the loaded organic was carried out at pH > 12 by using NaOH and NaCN solutions. The pilot plant tests indicate that a two‐stage extraction followed by one strip step are more than adequate to obtain an overall process efficiency of 92 %. However, for those cases where copper is present significantly, a copper wash stage is recommended before gold stripping. In this case, stripping of copper is accomplished at a pH 10.8, whereas the gold stripping was done at a pH of 12.0.     

Solvent extraction of gold(I) from alkaline cyanide solution by dibutylcarbitol (DBC) with n‐octanol

BACKGROUND: Currently, cyanidisation is preferred for the extraction of gold because it has a number of advantages over other methods. Gold(I) can be extracted with various extractants, but there are no reports on the extraction of gold(I) from cyanide solution by dibutylcarbitol (DBC). In this work the extraction of gold(I) from alkaline cyanide solution using DBC with n‐octanol was studied. Several factors affecting the percentage extraction of gold(I), including DBC concentration, diluent concentration, equilibrium time, phase ratio, pH and gold concentration in aqueous phase, were investigated. RESULTS: The results showed that 96.2% of gold(I) could be extracted using an organic phase composed of 40% (v/v) DBC, 50% (v/v) n‐octanol and 10% (v/v) odourless kerosene. The extraction was quite fast and equilibrium could be established within 2 min. Stripping of the gold‐laden organic phase was carried out using sodium sulfite (Na₂SO₃) and sodium thiosulfate (Na₂S₂O₃) solutions, with Na₂S₂O₃ proving better than Na₂SO₃. The percentage stripping of gold(I) was 96.5% when the Na₂S₂O₃ concentration was 4% (w/w), and the stripping capacity of gold(I) exceeded 311.3 mg L^?1 when the phase ratio (A/O) was equal to 0.2. CONCLUSION: Gold(I) can be extracted from aqueous cyanide solution by DBC in the presence of n‐octanol and efficiently stripped by aqueous Na₂S₂O₃ solution. This method has the potential for practical application in the extraction and separation of gold. Copyright © 2008 Society of Chemical Industry     

Extracting Performance of Cesium by 25,27‐Bis(2‐Propyloxy) Calix[4]‐26,28‐Crown‐6 (iPr‐C[4]C‐6) in n‐octanol

Abstract

In this work, the extraction of cesium(Cs⁺) in nitric acid and in a simulated high level liquid waste (HLLW) by iPr‐C[4]C‐6 was investigated in the diluent n‐octanol. The slope of the extractant dependency equals 1, indicating that the complex has 1∶1[Cs⁺ · iPr‐C[4]C‐6]Cs⁺ to ligand. 0.025 mol/L iPr‐C[4]C‐6 in n‐octanol (abbreviated to iPr‐C[4]C‐6‐n‐octanol) has a stronger extracting ability to Cs when acidities are between 1.0 mol/L and 4.0 mol/L. The stripping properties of Cs loading in 0.025 mol/L iPr‐C[4]C‐6‐n‐octanol was studied. Cs loading in iPr‐C[4]C‐6‐n‐octanol can be stripped easily into the aqueous phase because the distribution ratios of Cs are lower than 0.5 when pH is between 2 and 10 in the aqueous phase. On the above basis, the better parameters were selected and the cold cascade test for removing Cs from the simulated HLLW was investigated on miniature centrifugal contactor. The results of the test are attractive. The removing ratio of Cs from the simulated HLLW is 99.5% and the stripping ratio of Cs loading in 0.025 mol/L iPr‐C[4]C‐6‐n‐octanol is 99.2%. The results show that 0.025 mol/L iPr‐C[4]C‐6‐n‐octanol is an effective process for removing Cs from HLLW.     

Separation of cobalt and nickel from acidic sulfate solutions using mixtures of di(2‐ethylhexyl)phosphoric acid (DP‐8R) and hydroxyoxime (ACORGA M5640)

DP‐8R and ACORGA M5640 extractants diluted in Exxsol D100 were used to co‐extract cobalt and nickel from aqueous acidic sulfate media. The influences of equilibration time, temperature, equilibrium pH and reagent concentrations on the extraction of both metals have been studied. It was observed that both cobalt and nickel extraction are slightly sensitive to temperature but are pH dependent. Metal extraction equilibria are reached within about 5 min contact time. In addition, cobalt extraction depends on the extractant concentration in the organic phase. For a solution containing 0.5 g dm^?3 each of cobalt and nickel and an initial pH of 4.1, conditions were established for the co‐extraction of both metals and selective stripping (with H₂SO₄) of cobalt and nickel. Using the appropriate reagent concentrations the yield (extraction stage) for both metals exceeded 90%, and stripping of cobalt and nickel was almost quantitative. Copyright © 2004 Society of Chemical Industry     

Influence of Solvent Polarity on the Mechanism and Efficiency of Formic Acid Reactive Extraction with Tri‐n‐Octylamine from Aqueous Solutions

The reactive extractions of formic acid with tri‐n‐octylamine (TOA) dissolved in three solvents with different dielectric constants (dichloromethane, butyl acetate, n‐heptane) without and with 1‐octanol as phase modifier were comparatively analyzed. The results indicated that the mechanism of the interfacial reaction between acid and extractant (Q) is controlled by the organic phase polarity. In the absence of 1‐octanol, the structures of the extracted complexes are (HA)₂Q₂ for dichloromethane and butyl acetate, and (HA)₂Q₄ for n‐heptane. These structures are modified by adding 1‐octanol and become (HA)₂Q for extraction in dichloromethane or butyl acetate, and (HA)₂Q₂ for extraction in n‐heptane. Although the presence of 1‐octanol improves the extraction efficiency, it leads to a reduction of the extraction constants for all considered solvents, an influence that is more significant for n‐heptane.     

Study of lactic acid extraction with higher molecular weight aliphatic amines

Lactic acid extraction was studied with two extractants, trioctyl amine (TOA) and Aliquat 336, in three diluents (methylisobutyl ketone (MIBK), octanol and paraffin liquid). The effects of organic phase extractant concentration and aqueous phase pH on the extraction process were examined. Among the extractants, TOA was found to be a better extractant than Aliquat 336 in all the diluents. In experiments with 50% (v/v) TOA in methylisobutyl ketone, 79% lactic acid could be extracted (initial lactic acid concentration 86·96 g dm⁻³). MIBK had a profound effect on the extraction behaviour of TOA in comparison with octanol and paraffin liquid while none of the diluents affected the extraction with Aliquat 336. The extraction of lactic acid was favoured at low pH. The toxicities of TOA and the diluents to Lactobacillus rhamnosus NRRL B445 were also studied. While TOA was found to be highly toxic at the molecular and the phase level, the paraffin liquid was totally non-toxic. The extraction of glucose and yeast extract by TOA and the diluents used was found to be low, which thus enables the selective extraction of lactic acid. © 1998 SCI     

Extraction of vanadium(V) from sulfate solutions by ACORGA M5640

ACORGA M5640 (hydroxy‐oxime derivative) has been applied as an extraction reagent for vanadium(V) from sulfate media. The extraction system was studied as a function of contact time, temperature, aqueous pH, diluent of the organic phase, and metal and extractant concentrations. The extraction reaction is endothermic and it is dependent on the organic diluent, aqueous pH and extractant concentration. The data have been analysed numerically to determine the stoichiometry of extracted species and their equilibrium constants. It was found that vanadium was extracted into the organic phase by a complex mechanism which involves the formation of two species (VO₂R and VO₂R. HR, where R represents the extractant). Vanadium stripping by acidic and ammonium hydroxide solutions was also studied. Copyright © 2003 Society of Chemical Industry