Extraction of Nitric, Perchloric, and Hydrochloric Acid by N,N‐dibutyl Diethyl Carbamyl Phosphonate

Abstract

Extraction of nitric, perchloric, and hydrochloric acid by N,N‐dibutyl diethyl carbamyl phosphonate in carbon tetrachloride was investigated. The data obtained are treated in terms of stepwise neutralization of the acid with the formation of species y · HA and y · 2HA in the organic phase, where y stands for the extractant and HA for the acid. The equilibrium constants, K̄1 and K̄2 for nitric acid were found to equal 0.24 ± 0.02 and 0.017 ± 0.005, respectively. In case of HClO4 and HCl K̄1 were found to equal 0.031 ± 0.003 and 0.0039 ± 0.0005, respectively. A third phase was observed when extraction of HClO4 was performed using acid concentration higher than 3.5 molar. The preference for partition of different acids was discussed on the light of the competition of the proton between the acid anion, water and the basic extractant as well as the degree of the ionization of different acids.

Liquid-Liquid Extraction and Selective Sorption of Actinides by Use of Carbamoyl-Phosphonic Ligands

“…The different behaviour of the acids may be connected with the competition among anion of the acid, water and extractant toward protons. The distribution coefficients observed for the system DBDECP-xylene are in good agreement with those reported for DBDECP-CCI4 system [19].…”

“…The results obtained, even if limited to few cases for the DBDECP-xylene system, gave the following values forK' H : 0.27 ±0.14 (HN0 3 1-4M), 0.0030± 0.0013 (HCl), 0.029 ±0.004 (HC10 4 ), to be compared with the following values reported for the system DBDECP-CCI4 [19]: 0.24±0.02, 0.0039±0.0005, 0.031±0.003, respectively.…”

IR and 31P NMR spectroscopic study of complexation of carbamoyl methyl phosphinates with UVI and ThIV in nitric acid solutions

“…Thus, the interaction of ligand 2 with solutions of nitric acid results in the successive formation of the mono and diadducts with an increase in the concentration of nitric acid similarly to the interaction of carbamoyl methylphosphine oxides and carbamoyl methyl phospho nates with HNO 3 in organic solvents 8, 11 and during liquid extraction. 12 31 P NMR determination of compositions of the ura nium(VI) and thorium(IV) complexes with methyl phosphinate 2 upon extraction from nitric acid without solvent.…”