The novel extractants, bis-triamides: Synthesis and selective extraction of thorium(IV) from nitric acid media

Highly Efficient Removal of Thorium in Strong HNO3 Media Using a Novel Polymer Adsorbent Bearing a Phosphonic Acid Ligand: A Combined Experimental and Density Functional Theory Study

“…First, thorium could be a potential nuclear source with larger abundance than uranium in the earth. − Second, a large quantity of inorganic acid including HNO 3 would be utilized during the extraction of thorium from minerals or spent fuel. − Third, exposure to thorium would also do harm to the environment and human health − since it was a radioactive metal with strong toxicity. Generally, liquid–liquid extraction has been widely employed for the extraction of Th­(IV) from a highly acidic solution. ,, However, liquid–liquid extraction has some disadvantages such as large amounts of waste formation and large-scale extraction equipment, which would restrict its wide-ranging application in the nuclear industry. Recently, solid-phase extraction has been widely employed for the effective extraction of thorium from water media due to its high recovery, high enrichment factor, and lower consumption and cost. − To date, many materials including synthetic polymers, silicon materials, and graphene oxide have been employed as adsorbents for the removal of thorium from the high concentration of acid. − Generally, the concentration of organic chelating ligands anchored on the solid-phase extractants has an obvious effect on the adsorption efficiency.…”

“…Generally, liquid−liquid extraction has been widely employed for the extraction of Th(IV) from a highly acidic solution. 6,14,15 However, liquid−liquid extraction has some disadvantages such as large amounts of waste formation and large-scale extraction equipment, which would restrict its wide-ranging application in the nuclear industry. Recently, solid-phase extraction has been widely employed for the effective extraction of thorium from water media due to its high recovery, high enrichment factor, and lower consumption and cost.…”

Selective Extraction and Complexation Studies for Thorium(IV) with Bis-triamide Extractants: Synthesis, Solvent Extraction, EXAFS, and DFT

“…The three bis-triamide extractants were synthesized according to Scheme ; the specific synthesis processes of L1–L3 are included in the Supporting Information. Compounds 1, 2, 3, 4a, 4b, 4c were prepared according to the procedures reported in the previous work . Silica gel (300–400 mesh) was used for column chromatography.…”

“…Compounds 1, 2, 3, 4a, 4b, 4c were prepared according to the procedures reported in the previous work. 20 Silica gel (300−400 mesh) was used for column chromatography.…”

“…14−18 The diamide extractant tetra (2-ethylhexyl) In our previous research, extractants bis-triamide(C4) were synthesized, and their extraction behaviors for Th(IV) were investigated. 19,20 SF Th/U of one bis-triamide(C4) reached 93 and its D Th (135, 0.01 mol/L bis-triamide(C4)) was higher than that of the triamide extractant NTAamide(C8) (55.1, 0.02 mol/L) at 0.1 M HNO 3 . However, the poor solubility in kerosene limited its further application, and the coordination mechanism between extractants and Th(IV) was not clearly elucidated.…”