Separation of Pt(IV) and Rh(III) from Chloride Solution by Solvent Extraction with Amine and Neutral Extractants

Abstract

Solvent extraction experiments were performed to separate platinum and rhodium from mixed chloride solution by using amine and neutral extractants. Effects of extraction conditions on the separation of the two metals were investigated as a function of extractant concentration in the HCl concentration range from 1 to 9 mol/dm 3 . Alamine304-1, Alamine308, Alamine336, Aliquat336, TBP, TOPO and DOS were tested in our study. The concentration of Pt(IV) and Rh(III) in the mixed solution was fixed at 0.001 mol/dm 3 and 0.0001 mol/dm 3 , respectively. In the extraction with amine, Pt was completely extracted irrespective of HCl concentration, while the extraction percentage of Rh depended on extraction condition. In the extraction with neutral extractants, the extraction percentage of Rh was nearly zero whereas 1 mol/dm 3 TOPO completely extracted most of Pt in our experimental range. Separation of Pt from Rh by amines except Alamine336 was possible only from 9 mol/dm 3 HCl solution, while complete separation of the two metals by TOPO was possible in the HCl concentration range from 1 to 9 mol/dm 3 . From the consideration of the economics of the separation process, our results indicate that TBP is better than TOPO in separating Pt and Rh from chloride solution.

Selective and Mutual Separation of Palladium (II), Platinum (IV), and Rhodium (III) Using Aliphatic Primary Amines

“…Typically, solvent extraction is regarded as a practical method to recover and separate PGM ions from metal-containing aqueous solutions. For example, tertiary amines [6,7], organophosphates [8][9][10][11], and organosulfides [12,13] have been reported to act as Pd(II) or Pt(IV) extractants. However, solvent extraction processes require organic solvents, which are used as diluents of extractants or extractants themselves, and the use of organic solvents is problematic because of their toxicity and environmental concern.…”

Calix[4]arene‐Based n‐Dialkylamino Extractants for Selective Platinum Group Metal Separation from Automotive Catalysts

“…Recycling of valuable PGMs from secondary resources is highly desirable; recycling can also reduce the environmental burden related to primary mining and dumping of PGMs. However, no effective extractants have yet been developed for the complete recovery of PGMs from secondary resources . PGM extractants with higher selectivity and extraction rates and superior durability are required .…”

New type of highly selective microcapsules for the removal of mercury from surface polluted waters

“…The above equations imply that the extraction of mercury by the microcapsules is unfavoured at high chloride concentrations owing to the mass action effect of chloride ions [12,24].…”