Solvent extraction and separation of copper from base metals using bifunctional ionic liquid from sulfate medium

A novel solvent extraction process for extraction and separation of copper from other base metal ions using a bifunctional ionic liquid (IL) (trioctylmethylammonium/2,4,4-trimethylpentyl phosphinate, [A336/Cy272]) in kerosene was reported. This IL was found to extract copper more efficiently than the individual extractants Aliquat 336 or Cyanex 272. Formation of an octahedral copper-IL complex was characterized by UV-Visible spectra and metal ligand interaction was confirmed by FTIR spectra. The loading capacity of 0.1 mol/L [A336/Cy272] was found to be 1.71 g/L. Stripping studies reported that 0.298 g/L copper ions were efficiently stripped using 0.1 mol/L sulfuric acid from 0.05 mol/L loaded IL. The selectivity of copper against nickel, cadmium and iron was investigated from their equimolar binary mixtures using 0.05 mol/L [A336/Cy272] in kerosene. The highest separation factorβCu/Cd=8.41 was obtained at pH 3.56. Copper can be effectively separated from nickel over the pH range studied. The IL extracts preferentially iron over copper and the highest separation factorβFe/Cuwas 3246 at pH 2.4. The extraction rate of metal ions from a synthetic solution containing copper with other metal impurities was in the order of Fe>Zn>Cu>Cd>Co>Ni.

Development of hydrometallurgical process for indium recovery from waste liquid crystal display using Cyphos IL 101

The main goal of this study was to recover indium from the waste liquid crystal display(LCD)panel.In this context,an ionic liquid Cyphos IL 101 was explored.The extraction parameters such as equilibration period,acid concentration,chloride ion concentration,hydrogen ion concentration were examined on the extraction efficiency of Cyphos IL 101 towards In(III).Quantitative extraction of indium was found at 2.0 mol/L HCl using 0.005 mol/L Cyphos IL 101 and quantitative stripping with 1.0 mol/L H2SO4.Job’s method was used to determine the extracted species and R3R'PInCl4(R=C6H13;R′=C14H29)was proposed.Based on the observations on multi-metal studies,Cyphos IL 101 was further employed for the removal of indium,tin and copper from the leach liquors of waste LCDs.Optimized conditions were generated for the recovery of indium from waste LCDs.McCabe−Thiele diagram analysis,counter-current extraction and selective stripping were carried out to separate the metal ions,i.e.,indium,tin and copper.Two stages at O/A ratio of 1:3 were required for complete removal of tin from the feed and selective stripping of In and Sn was achieved using 0.1 mol/L H2SO4.A scheme for separating indium from the waste LCDs was proposed.

Separation of copper and iron from chloride media using Cyanex 921 in kerosene

The extraction and separation of Cu(Ⅱ)and Fe(Ⅲ)from HCl media using Cyanex 921 in kerosene were investigated.The effect of shaking time,aqueous phase acid concentration,Fe(Ⅲ)/Cu(Ⅱ)concentration,Cyanex 921 concentration,temperature and aqueous to organic phase ratio on the separation of Cu(Ⅱ)and Fe(Ⅲ)was studied using 0.1 mol/L Cyanex 921 in kerosene.Maximum separation was achieved from 2 mol/L HCl containing 0.001 mol/L Cu(Ⅱ)and 0.005 mol/L Fe(Ⅲ)with 0.1 mol/L Cyanex 921 in kerosene.Feasible separation of copper and iron was also possible from 5 mol/L HCl using 0.02 mol/L Cyanex 921.

Application of bifunctional ionic liquids for extraction and separation of Eu^(3+) from chloride medium

The extraction of Eu^(3+)from chloride medium using bifunctional ionic liquid extractants(Bif-ILEs)tri-n-octylmethyl ammonium bis(2-ethyl hexyl)phosphate([A336][D2EHP])and trihexyltetradecyl phosphonium bis(2-ethylhexyl)phosphate([P_(66614)][D2EHP])in kerosene was studied to develop environmentally friendly extraction process.The extraction behavior of Eu^(3+)was examined by varying key process parameters.The extraction behavior indicates that ammonium-based ionic liquid[A336][D2EHP]shows better extraction efficiency of Eu^(3+)than that of phosphonium-based ionic liquid[P_(66614)][D2EHP].Quantitative extraction of Eu^(3+)is obtained with 0.05 mol/L[A336][D2EHP],whereas,0.1 mol/L of[P_(66614)][D2EHP]is required to achieve the same extraction rate of Eu^(3+).The extraction process is endothermic with respect to[A336][D2EHP].Stripping experiments indicate that 100%of Eu^(3+)can be back extracted from both the loaded ionic liquids using 20 vol.%HNO_(3).The highest separation factor(βY/Eu)of 653.59 is reported at pH of 3.2,and the separation factor of Eu^(3+)over La^(3+)is 30.6 at the same pH.From the leach liquors of waste tube light powder,99.98%of Eu and 99.99%Y are recovered using 0.2 mol/L[A336][D2EHP]in 2-stage cross current extraction with aqueous to organcic ratio(O/A)of 1:1 and 1:2.

Solvent extraction of neodymium(Ⅲ) from acidic nitrate medium using Cyanex 921 in kerosene

The extraction of neodymium（III） from acidic nitrate medium was investigated using Cyanex 921 as extractant in kerosene. The metal concentration in the aqueous phase before and after extraction was determined spectrophotometrically by Arsenazo III method. The complete equilibration was achieved in 15 rain. The effects of shaking time, nitric acid concentration, nitrate concentration, extractant concen- tration, and temperature on the extraction were studied. The extraction of Nd（III） was found to increase very slowly with increase in concen- tration of HNO3 in the range of 0.001-3.008 mol/L and then decreased when 0.01 mol/L HNO3 was used. The percentage of extraction was increased with increase in nitrate concentration from 0.01M）.45 mol/L and then decreased when nitrate concentration increased to 0.5 mol/L. Quantitative extraction of Nd（III） （98%） was obtained from the aqueous phase containing 0.001 mol/L HNO3 and 0.1 mol/L KNO3 using 0.5 mol/L Cyanex 921. On the basis of slope analysis, the extracted complex in the organic phase was proposed to be Nd（NO3）3.2Cyanex 921. The extraction of Nd（III） was found to increase with increase in concentration of metal ion in the range of 0.0014）.05 mol/L from 0.001 mol/L HNO3 and 0.1 mol/L KNO3 with 0.1 mol/L Cyanex 921. The percentage of extraction of neodymium was found to decrease with in- crease in temperature. From temperature variation studies, the negative value of AH indicated the extraction reaction to be exothermic and the negative value of AS indicated the formation of a stable complex, Almost 100% Nd（III） was recovered from the fully loaded organic phase using 0.002 mol/L H2SO4 and 0.01 mol/L HCl.