- Possibility of integrated processing of the baddeleyite concentrate
-
Main procedures used in integrated processing of baddeleyite, including sintering with calcium carbonate or oxide, decomposition of the cake with hydrochloric acid, and recovery of zirconium in the form of zirconium oxochloride, were studied.
- Lebedev,Lokshin,Mel'nik,Shchur,Popova
-
-
Read Online
- Zirconium complexes of amino(polyphenolic) ligands and their hydrolytic stability
-
Three amino(polyphenolic) ligands, N,N′-bis(5-tert-butyl-2-hydroxybenzyl)-1,2-diaminoethane 1, tris(5-tert-butyl-2-hydroxy-3-methylbenzyl)amine 3, its 3-chloro analogue 4 and their ZrIV complexes have been synthesised. The crystal structure of the ZrIV complex of tris(5-tert-butyl-3-chloro-2-hydroxybenzyl)amine, shows this to be [Zr(4-2H)2] in which both ligands exists in a zwitterionic form with one alkylammonium and three phenolate groups. The complexes are stable in a two phase, chloroform/water, system at high pH, but the zirconium is stripped at pH IV from the complex [Zr(1-4H)] of the tetraphenolic ligand is ～2.0 whilst the complexes [Zr(3-2H)2] and [Zr(4-2H)2] of the triphenolic ligands are slightly more stable with pH1/2 values of ～1.4. We were unable to use the ligands to extract zirconium from low pH aqueous zirconium oxychloride solutions into an organic phase under a variety of conditions.
- Chartres, Jy D.,Dahir, Ahmed,Tasker, Peter A.,White, Fraser J.
-
-
Read Online
- Relaxation of electronic defects in pure and doped La2O3 observed by perturbed angular correlations
-
Slow recovery processes of the electronic environment following the electron-capture decay of 111In can reduce the amplitude of the perturbed γγ-angular correlation of a nuclear decay. This effect was used to quantitatively extract recovery rates of an electrically stable environment at the probe ion 111Cd in La2O3. The recovery rates depend on the availability of electrons at the probe site, which in turn is governed by the concentration of electron sources and the transport mechanisms. Both properties are experimentally analyzed by variations of the temperature and oxygen partial pressure and by doping with two (Ba, Mg) and four-valent ions (Ce, Zr). Tunneling processes between defect levels in the band gap are proposed to account for the temperature dependence of the recovery rates. Unexpectedly, an enhanced electron availability is observed at temperatures below 200 K. The electric field gradients of substitutional 111Cd and those generated by intrinsic defects and dopants are analyzed. A comparison to the probe ion 111mCd, not affected by electron capture, is presented.
- Lupascu, Doru,Habenicht, Soenke,Lieb, Klaus-Peter,Neubauer, Matthias,Uhrmacher, Michael,Wenzel, Thorsten
-
-
Read Online
- The preparation of nano-oxides of zinc and barium of [Ba (o-phen)4] [Zn (EDTA)], [Zn(o-phen)4]2 [ Ba(SCN)6], and synthesis of ZrO2 nanoparticles by chemical methods
-
For the preparation of Nano-oxides of Zinc and Barium, first, the two-component complexes [Ba(o-phen)4] [Zn (EDTA)], [Zn(o-phen)4]2 [Ba(SCN)6] were produced, then they were heated for one hour in 700 and 800 °C
- Hakimi, Mohammad,Saravani, Hamideh,Arbabi, Abdoulhamid
-
-
Read Online
- Synthesis, characterization and biological study on Cr3+, ZrO2+, HfO2+ and UO22+ complexes of oxalohydrazide and bis(3-hydroxyimino)butan-2-ylidene)-oxalohydrazide
-
Cr3+, ZrO2+, HfO2+ and UO22+ complexes of oxalohydrazide (H2L1) and oxalyl bis(diacetylmonoxime hydrazone) [its IUPAC name is oxalyl bis(3-hydroxyimino)butan-2-ylidene)oxalohydrazide] (H4L2) have been synthesized and characterized by partial elemental analysis, spectral (IR; electronic), thermal and magnetic measurements. [Cr(L1)(H2O)3(Cl)]·H2O, [ZrO(HL1)2]·C2H5OH, [UO2(L1)(H2O)2] [ZrO(H3L2)(Cl)]2·2H2O, [HfO(H3L2)(Cl)]2·2H2O and [UO2(H2L2)]·2H2O have been suggested. H2L1 behaves as a monobasic or dibasic bidentate ligand while H4L2 acts as a tetrabasic octadentate with the two metal centers. The molecular modeling of the two ligands have been drawn and their molecular parameters were calculated. Examination of the DNA degradation of H2L1 and H4L2 as well as their complexes revealed that direct contact of [ZrO(H3L2)(Cl)]2·2H2O or [HfO(H3L2)(Cl)]2·2H2O degrading the DNA of Eukaryotic subject. The ligands and their metal complexes were tested against Gram's positive Bacillus thuringiensis (BT) and Gram's negative (Escherichia coli) bacteria. All compounds have small inhibitory effects.
- El-Asmy,El-Gammal,Radwan
-
p. 496 - 501
(2010/08/07)
-
- Synthesis and characterization of Mn(II), Au(III) and Zr(IV) hippurates complexes
-
Mn(II), Au(III) and Zr(III) complexes with N-benzoylglycine (hippuric acid) (abbreviation hipH) were synthesized and characterized by elemental analysis, molar conductivity, magnetic measurements, spectral methods (mid-infrared, 1H NMR, mass, X
- Refat, Moamen S.,El-Korashy, Sabry A.,Ahmed, Ahmed S.
-
p. 840 - 849
(2009/02/01)
-
- Catalysts containing zirconium oxide
-
Catalyst compositions based on amorphous partially dehydrated zirconium hydroxide which are doped with from 0.01 to 20 atom percent of copper and/or from 0.01 to 20 atom percent of nickel, in each case based on zirconium, and have a specific surface area by the BET method of at least 50 m2/g. The catalyst compositions are suitable, in particular, as the catalyst in hydrogen transfer reactions, such as, the Meerwein-Ponndorf-Verley reduction or the Oppenauer oxidation. The preparation of 3-hydroxyquinuclidine of the formula: involves reaction of quinuclidin-3-one with a secondary alcohol in the presence of the amorphous partially dehydrated zirconium hydroxide.
- -
-
-
