W. Lada

Solvent extraction of Cu, Mo, V, and U from leach solutions of copper ore and flotation tailings

Flotation tailings from copper production are deposits of copper and other valuable metals, such as Mo, V and U. New hydrometallurgical technologies are more economical and open up new possibilities for metal recovery. This work presents results of the study on the extraction of copper by mixed extractant consisting p-toluidine dissolved in toluene. The possibility of simultaneous liquid–liquid extraction of molybdenum and vanadium was examined. D2EHPA solutions was used as extractant, and recovery of individual elements compared for the representative samples of ore and copper flotation tailings. Radiometric methods were applied for process optimization.

Synthesis of microspheres of triuranium octaoxide by simultaneous water and nitrate extraction from ascorbate-uranyl sols.

A new method for synthesis of uranium oxide microspheres (diameter <100xa0μm) has been developed. It is a variant of our patented Complex Sol–Gel Process, which has been used to synthesize high-quality powders of a wide variety of complex oxides. Starting uranyl-nitrate-ascorbate sols were prepared by addition of ascorbic acid to uranyl nitrate hexahydrate solution and alkalizing by aqueous ammonium hydroxide and then emulsified in 2-ethylhexanol-1 containing 1v/o SPAN-80. Drops of emulsion were firstly gelled by extraction of water by the solvent. Destruction of the microspheres during thermal treatment, owing to highly reactive components in the gels, requires modification of the gelation step by Double Extraction Process—simultaneously extraction of water and nitrates using Primene JMT, which completely eliminates these problem. Final step was calcination in air of obtained microspheres of gels to triuranium octaoxide.

Vitrification of Nuclear Wastes by Complex Sol-Gel Process

For synthesis of silica glasses designed to contain high-level nuclear wastes，a patented complex sol-gel process has been used. Surrogates of the nuclear waste elements Cs, Sr, Co, and Nd (generically denoted Me) were used. Gels in the forms of powders and sintered compacts were prepared by hydrolysis and polycondensation of tetraethoxide/Me nitrate solutions, which contained ascorbic acid as a catalyst. Transformation to final products was studied by thermogravimetric analysis, infrared spectroscopy, and X-ray diffraction. Preliminary testing of Me leaching was also completed in water. Most of the final products were porous; only a single dense form was resistant to leaching.

Preparation of Titanium Oxide and Metal Titanates as Powders, Thin Films, and Microspheres by Novel Inorganic Sol-Gel Process

Titanium oxide and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl 4 and HNO 3 . The main preparation steps for the sols consisted of elimination of chloride anions by distillation with nitric acid and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to (1) prepare irregularly shaped powders by evaporation; (2) produce by a dipping technique thin films on glass, Ag, or Ti substrates; and (3) produce spherical powders (diameters

Preparation of titanium hexacyanoferrate microspheres (diameter < 70 {micro}m) by water extraction variant of sol-gel process and its application to sorption of {sup 137}Cs from nuclear reactor cooling water

Titanium hexacyanoferrate microspheres (diameter < 70{micro}m) were obtained in the following steps: (1) extraction of chlorides from an aqueous solution of TiCl{sub 4} with long chain amine -- Primene JMT -- in paraffin diluent (the resulting sol has the concentration 320 g TiO{sub 2}/dm{sup 3} and the mole ratio Cl{sup {minus}}:Ti{sup 4+} = 1.83); (2) blending of titania sol with an aqueous solution of K{sub 4}Fe(CN){sub 6}{center_dot}3H{sub 2}O (280 g/dm{sup 3}) in order to obtain final sols with Fe(CN){sub 6}{sup 4{minus}}:Ti{sup 4+} mole ratio of 0.05--0.1; (3) formation of multicomponent sol emulsion in 2-ethylhexanol-1 containing 1 vol. % of Ethomen S/15 (EH), (4) gelation of emulsion drops by extraction of water with partially dehydrated EH; (5) filtration and washing with acetone; (6) drying at 140 C using a special procedure elaborated on the basis of TG and DTA studies. The final product is insoluble in water and exhibits high sorption efficiency of {sup 137}Cs.