The Aqueous Chemistry of Zirconium

Abstract

Three extractions with 0.02 M thenoylrecovery of 50% of the hafnium with zirconium trifluoroacetone of a solution containing 5.0% content of 0.4%. zirconium, based on the hafnium content, gave a

Studies on the solvent extraction of metal dithiocarbamates

“…Thus, solvent extraction of the metal dithiocarbamate is an important step in analytical procedures. Solvent extraction has been extensively used in the determination of stability constants of metal complexes (2)(3)(4)(5)(6) and in the study of the equilibria of complex-ions (7)(8)(9)(10)(11)(12). The present investigation was directed at (i) determination of the extraction constants for divalent metal ions with morpholine DTC (dithiocarbamate) as the complexing agent, and the overall stability constants of the complexes, and (ii) to determine the effect of various substituents at the nitrogen atom in disubstituted dithiocarbamic acids on the magnitude of the stability constants.…”

“…[7] or [8] in combination with eq. [9] enabled the determination of the stability constants of complexes of divalent metal ions, Mn, Fe, Co, Zn, Cu, and Hg, formed with morpholine DTC.…”

An experimental study of the solubility of baddeleyite (ZrO2) in fluoride-bearing solutions at elevated temperature

“…Experimental evidence that zirconium forms stable complexes with fluoride ions and can be easily mobilized by fluoride-bearing aqueous solutions first was provided over 60 years ago by Connick and McVey (1949). However, till recently all the available studies were conducted at ambient temperature, and extrapolations of ambient temperature data have subsequently shown that the stability of zirconium fluoride complexes decreases sharply with increasing temperature (e.g., Aja et al, 1995).…”

Extraction chromatography of the Rf homologs, Zr and Hf, using TEVA and UTEVA resins in HCl, HNO3, and H2SO4 media

“…The speciation of group 4 elements in H 2 SO 4 is more complicated because the successive formation reaction constants for sulfate complexes do not vary greatly [24]. Consequently, the cationic, neutral, and anionic species of Zr and Hf more readily coexist in this particular medium [22,24]. In the range of approximately 2.0-6.0 M H 2 SO 4 , no uptake is observed with UTEVA for both Zr and Hf, evidence that Zr and Hf are not present in solution as neutral species.…”