V. N. Lebedev

Sorption of Cesium on Titanium and Zirconium Phosphates

Titanium and zirconium phosphates were prepared from the mineral raw materials of the Kola Peninsula. Their capability to recover cesium cations from the model solutions and liquid radioactive waste (LRW) was studied. Titanium phosphate prepared from solutions formed by titanite breakdown exhibits greater distribution coefficients of cesium as compared to zirconium phosphate. Titanium phosphate, as being cheaper and possessing greater sorption capacity, was recommended for treatment of LRW to remove cesium.

Sulfuric Acid Technology for Processing of Eudialyte Concentrate

Sulfuric acid decomposition of eudialyte was studied, and a technological process including two-stage treatment with sulfuric acid, separation and washing of an insoluble residue, successive hydrolytic precipitation of zirconium and iron-manganese concentrates from solution, and recovery of rare-earth elements from the insoluble residue by leaching, was considered. It was found that zirconium(IV) is recovered from a complex carbonate precipitate in the form of a basic sulfate.

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.

On production of cerium dioxide

The possibility of obtaining cerium dioxide by recovery of Ce(IV) phosphate from acid nitrate solutions with subsequent conversion of Ce(IV) phosphate to Ce(III) oxalate was studied.

Interaction of baddeleyite with sodium nitrate and nitrite

Features of baddeleiyte concentrate decomposition by interaction with sodium nitrate and nitrite were researched as well as those of hydrolytic and acid decomposition of resulting cakes.

Sulfate-containing zirconium dioxide powders made of products of baddeleyite processing

Manufacture of sulfate-containing zirconium dioxide powders from basic zirconium sulfate, zirconium disulfate, and ammonium sulfatozirconate, which are sulfate-containing products of processing of baddeleyite concentrate, was studied.

Processing of cakes based on sodium metazirconate

Certain methods of processing cakes based on sodium metazirconate and obtained by the reaction of a baddeleyite concentrate with sodium nitrate or nitrite were studied. Conditions were found for the synthesis of strontium metazirconate and also of nanosized powders of basic zirconium sulfate, which is promising as a component of polishing mixtures.

Specific features of disposal of sulfuric acid solutions resulted from magnesium silicate decomposition

The photocatalytic activity of crystalline titania nanopowders synthesized in a stream of ultrahigh-frequency discharge oxygen-containing low-temperature plasma was assessed. To this end, oxidation of an organic dye was carried out in UV-irradiated aqueous suspensions of TiO2 at different concentrations and varied irradiation times.

Purification of baddeleyite concentrate by alloying with sulfuric acid and its salts

The conditions for the sulfation of rough baddeleyite concentrate to remove impurity minerals were studied.

Extraction of oxalic acid from solutions of electrolyte mixture

Extraction of oxalic acid with tributyl phosphate and triisoamyl phosphate from solutions of its mixtures with nitric, phosphoric, sulfuric, and hydrochloric acid and with ammonium nitrate and chloride was studied. In the extractability series, oxalic acid occupies the position between nitric and phosphoric acids, with sulfuric and hydrochloric acids acting as strong salting-out agents. Nitric acid salts drastically decrease the distribution ratios of oxalic acid.