scholarly journals Investigation of Withania Somnifera Extract as Corrosion Inhibitor for Copper in Nitric Acid Solutions

2019 ◽  
pp. 5355-5372 ◽  
Author(s):  
H M. Elabbasy ◽  
Keyword(s):  
Nitric Acid ◽  
Corrosion Inhibitor ◽  
Withania Somnifera ◽  
Acid Solutions ◽  
Nitric Acid Solutions

scholarly journals THE EFFECT OF TANNIN ON CARBON STEEL CORROSION IN NITRIC ACID SOLUTIONS

2015 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Anna Sonya Asoka ◽  
Listiani Artha ◽  
Isdiriayani Nurdin ◽  
Hary Devianto
Keyword(s):  
Nitric Acid ◽  
Carbon Steel ◽  
Acid Solution ◽  
Corrosion Inhibitor ◽  
Nitric Acid Solution ◽  
Construction Material ◽  
Steel Corrosion ◽  
Corrosion Mechanism ◽  
Acid Solutions ◽  
Nitric Acid Solutions

Carbon steel is commonly used as construction material of processing equipment due to its strength, ease of fabrication, and low cost. Nevertheless, carbon steel is susceptible to corrosion by process fluid, like nitric acid. However, corrosion effect can be reduced by inhibitor addition. Tannin is one of carbon steel corrosion inhibitors in acidic solution. Tannin is an organic compound which has hidroxyl and carboxyl functional groups, decomposed easily, and non-toxic. The aim of this research is to determine the effectiveness of tannin as a corrosion inhibitor for carbon steel in nitric acid solutions. The corrosion rate is determined using the Tafel method, whereas the corrosion mechanism is predicted by cyclic voltammetry. The results showed that tannin is ineffective to inhibit carbon steel corrosion in nitric acid solution. The carbon steel corrosion reaction in nitric acid solution, with or without tannin addition, is reversible, involving single step oxidation-reduction reaction, resulting stable corrosion product, and not forming any passivation.Keywords: carbon steel, corrosion, inhibitor, nitric acid, tannin

scholarly journals Neptunium extraction by N,N-dialkylamides

2020 ◽  
Vol 108 (9) ◽  
pp. 707-716
Author(s):  
Jarrod M. Gogolski ◽  
Peter R. Zalupski ◽  
Travis S. Grimes ◽  
Mark P. Jensen
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Radioactive Waste ◽  
Partial Oxidation ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Organic Solutions

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.

Extraction of tetra- and hexavalent actinide ions from nitric acid solutions using some diglycolamide functionalized calix[4]arenes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajesh B. Gujar ◽  
Parveen K. Verma ◽  
Prasanta K. Mohapatra ◽  
Mudassir Iqbal ◽  
Jurriaan Huskens ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Extraction Efficiency ◽  
Minor Actinide ◽  
Acid Solutions ◽  
Extraction Mechanism ◽  
Nitrate Ion ◽  
Nitric Acid Solutions ◽  
Actinide Ions ◽  
Acid Extractant

Abstract Neptunium is one of the most important minor actinide elements with some of its isotopes having very long half-lives, therefore necessitating its separation from acidic radioactive wastes. Solvent extraction of Np4+ and NpO2 2+ was studied using three multiple diglycolamide (DGA) extractants with n-propyl, n-octyl and 3-pentyl substituents termed as L I , L II and L III , respectively, in a mixed diluent of 5% isodecanol and 95% n-dodecane. For comparison purpose, the extraction of Pu4+ and UO2 2+ was carried out under identical conditions. The extraction efficiency of the ligands for the tetravalent ions followed the trend: L II  > L I  > L III , which changed to L III  > L II  > L I for the hexavalent ions. While the extraction of the tetravalent ions was reasonably good (ca. 90–98%) with an extremely low (5.0 × 10−5 M) ligand concentration, poor extraction (ca. 5–16%) of the hexavalent ions was seen even with a 20 times higher concentration of the ligand. In general, Pu4+ was better extracted than Np4+, while NpO2 2+ was marginally better extracted then UO2 2+. A ‘solvation’ type extraction mechanism was proposed based on the extraction profiles obtained as a function of the concentrations of the feed nitric acid, extractant as well as nitrate ion. The extracted species were found out to be M(NO3)4·mL and MO2(NO3)2·nL (M = Np or Pu, 1 < m < 2, n ≃ 1).

Separation of Americium and Curium in Nitric Acid Solutions via Oxidation of Am(III) by Bismuthate and Perxenate Ions

2020 ◽  
Vol 62 (5) ◽  
pp. 581-586
Author(s):  
Yu. M. Kulyako ◽  
D. A. Malikov ◽  
T. I. Trofimov ◽  
S. A. Perevalov ◽  
K. S. Pilyushenko ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Acid Solutions ◽  
Nitric Acid Solutions
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