Liquid liquid extraction and separation of samarium iii and cobalt ii using some commercial extractants from aqueous nitrate media

Abstract

The ever-growing demand of metals in modern technologies and green energy newlinesources mostly drives the mining and metallurgical production and hence, reduces the newlinestockpiles of primary resources at a faster rate. Such depletion calls for recycling of newlinesecondary resources or post-consumer products to re-circulate valuable metals back into newlinesociety and to develop circular economies. With the contents of valuable techno-metals newlinelike Sm and Co, SmCo permanent magnets used for various technological purposes are newlinegaining special interest for recycling purpose. In the current work, novel extraction newlinemodels have been formulated for recycling of SmCo magnets. The conventional ionic newlineliquid; Aliquat 336 was tested for extractive separation of Sm (III) and Co (II) from newlinenitrate liquor. In the second part, the separation of Sm (III) and Co (II) was performed newlinewith TOPO dissolved in kerosene. TAPO diluted in kerosene was employed as an newlineextracting agent to carry out extractive separation of Sm (III) and Co (II) from nitrate newlinemedium. For all the case studies, NaNO3 was added as salting out agent to the aqueous newlinephase to enhance the extraction efficiency. Various operating parameters like aqueous newlinephase pH, concentration of Sm (III) and Co (II), extractant and salting out agent, newlinetemperature, O:A phase volume ratio and diluent were varied to find out the optimum newlinecondition for extraction and separation. The enthalpy change and spontaneity of the newlineextraction equilibrium was calculated from temperature variation experiment by using newlineVan t Hoff equation. The correlation between observed data and predicted data was newlineanalyzed by linear regression and multiple linear regression. The confirmation of newlineproposed extracted species was done by recording FTIR spectra of metal loaded organic newlinesolvent and pure organic solvent. HCl was used as strippant to recover metals from newlineloaded solvents. The synthesis of nano-oxides of samarium and cobalt with 99.9% purity newlinefrom their nitrate solution by using TOPO and TAPO was carried out from optimum newlineextraction condition.