scholarly journals Separation of Ag(I) by Ion Exchange and Cementation from a Raffinate Containing Ag(I), Ni(II) and Zn(II) and Traces of Cu(II) and Sn(II)

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 112 ◽  
Author(s):  
Wei Xing ◽  
Man Lee ◽  
Seung Choi

Ion exchange and cementation experiments were done to separate silver(I) from a raffinate containing silver(I), nickel(II), and zinc(II) and small amounts of copper(II) and tin(II). The raffinate resulted from the recovery of gold(III), tin(II) and copper(II) by solvent extraction from a leaching solution of anode slime. Ion exchange with anionic resins was not effective in separating silver(I) because tin(II) and zinc(II) were selectively adsorbed into the anionic resins. It was possible to separate silver(I) by cementation with copper sheet. Treatment of the cemented silver with nitric acid solution increased the purity of silver(I) in the solution from 50.9% to 99.99%. Adjusting the pH of the AgNO3 solution to higher than 6, followed by adding ascorbic acid as a reducing agent, led to the synthesis of silver particles with micron size.

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 858 ◽  
Author(s):  
Hyeong Hun Ahn ◽  
Man Seung Lee

The addition of ruthenium to tungsten carbide-cobalt hard metals improves their mechanical properties. Since ruthenium is a platinum group metal, the recovery of ruthenium together with cobalt from the scrap of hard metals is of great importance. In order to develop a recovery process of ruthenium and cobalt, separation experiments were performed from the synthetic HCl leaching solution of the scrap of hard metals. In this work, solvent extraction and ion exchange were employed to investigate the separation behavior of the two metal ions as a function of HCl concentration. Ru(III) was selectively extracted over Co(II) by Aliquat 336 (trioctyl methylammonium chloride) and Alamine 300 (tri-n-octyl amine) when HCl concentration was lower than 5 M. The highest separation factor between Ru(III) and Co(II) was obtained at 3 M HCl. The loaded Ru(III) was stripped from Aliquat 336 by dilute HCl solution. Only Ru(III) was loaded into the anion exchange resins employed in this work in the HCl concentration range from 1 to 9 M. The highest loading percentage of Ru(III) was obtained from 3 M HCl solution. The loading of Ru(III) into anion exchange resins followed Freundlich isotherm and the loading capacity of the resins were determined. The loaded Ru(III) was eluted by the mixture of HCl and thiourea. Compared to solvent extraction, ion exchange was found to be more efficient to separate Ru(III) and Co(II) from the HCl solution in terms of separation factor and the ease of operation.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1300
Author(s):  
Pan-Pan Sun ◽  
Tae-Young Kim ◽  
Hyeon Seo ◽  
Sung-Yong Cho

A nitrate leachate containing Cu(II), Ag(I), Ni(II), Mg(II), and Al(III) was obtained during the leaching of industrial dust, which arises during the pyrometallurgy of spent camera modules. To separate and recover Cu(II) and Ag(I) from the leaching solution, solvent extraction experiments using 5,8-diethyl-7-hydroxydodecan-6-oxime (LIX63) were conducted. LIX63 was found to selectively extract Cu(II) and Ag(I) over other metal ions (Ni(II), Mg(II), and Al(III)) at low nitric acid concentrations. The extraction efficiency of Cu(II) was more affected than that of Ag(I) by the acidity of the feed solution and the LIX63 concentration in the organic phase. Cu(II) and Ag(I) were simultaneously extracted using 2 mol/L LIX63. Cu(II) was separated from the loaded LIX63 via stripping with 4 mol/L HNO3, whereas Ag(I) was recovered via stripping with 0.1 mol/L thiourea after the removal of Cu(II). McCabe–Thiele diagrams for the extraction and stripping of Cu(II) and Ag(I) were constructed. The complete extraction of Cu(II) and Ag(I) was confirmed via counter-current extraction. Moreover, stripping simulation tests confirmed that higher than 99.99% of Cu(II) and 99.2% of Ag(I) were stripped. The purities of Cu(II) and Ag(I) in the recovered solution were 95.2% and 99.993%, respectively. A process flow chart for the recovery of Cu(II) and Ag(I) from the nitrate leachate of the target industrial dust was also provided.


2019 ◽  
Vol 61 (6) ◽  
pp. 724-727
Author(s):  
M. Yarmohammadi ◽  
M. Mirzaei ◽  
A. Samadi-Maybodi

2020 ◽  
Vol 108 (9) ◽  
pp. 707-716
Author(s):  
Jarrod M. Gogolski ◽  
Peter R. Zalupski ◽  
Travis S. Grimes ◽  
Mark P. Jensen

AbstractSeparation of neptunium by solvent extraction has been based on tributylphosphate (TBP) for decades, but TBP is not fully incinerable, which adds to the burden of long-lived radioactive waste. Alternatives to TBP for uranium and plutonium extraction, such as the N,N-diakylamides, previously have been explored in the hopes of transitioning to an extractant that is incinerable. Four N,N-diakylamides, N,N-dihexylhexanamide (DHHA), N,N-dihexyloctanamide (DHOA), N,N-di(2-ethylhexyl)butanamide (DEHBA), and N,N-di(2-ethylhexyl)-iso-butanamide (DEHiBA) were considered in this work for their potential to extract millimolar concentrations of Np(IV), Np(V), and Np(VI) from nitric acid solutions into organic solutions containing 1 M extractant in Exxsol D60. Under these conditions the branching of the alkyl substituents affects the extractability of Np(VI) and Np(IV), causing three of the dialkylamides, DHHA, DHOA and DEHBA, to extract neptunium in the expected order Np(VI) > Np(IV) > > Np(V). In contrast, branched DEHiBA is so poor an extractant for Np(IV) that the extraction order becomes Np(VI) > > Np(V) > Np(IV) between 0.1 and 5.6 M HNO3 due to partial oxidation of the Np(V) in nitric acid.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 515
Author(s):  
Wei-Sheng Chen ◽  
Shota Mesaki ◽  
Cheng-Han Lee

Tin anode slime is a by-product of the tin electrolytic refining process. This study investigated a route to separate Sn, Sb, Bi, and Cu from tin anode slime after leaching with hydrochloric acid. In the solvent extraction process with tributyl phosphate, Sb and Sn were extracted into the organic phase. Bi and Cu were unextracted and remained in the liquid phase. In the stripping experiment, Sb and Sn were stripped and separated with HCl and HNO3. Bi and Cu in the aqueous phase were also separated with chemical precipitation procedure by controlling pH value. The purities of Sn, Sb, Cu solution and the Bi-containing solid were 96.25%, 83.65%, 97.51%, and 92.1%. The recovery rates of Sn, Sb, Cu, and Bi were 76.2%, 67.1%, and 96.2% and 92.4%.


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