6 results about "Tellurous acid" patented technology

The invention discloses a method for extracting tellurium from a sodium tellurite solution through electrodeposition, and belongs to the technical field of non-ferrous metal hydrometallurgy. The method comprises the following steps: dissolving crude tellurium dioxide in a sodium hydroxide solution at 60-90 DEG C to prepare a sodium tellurite electrolyte containing 200-240 g / L of tellurium and 90-110 g / L of sodium hydroxide; in the electrodeposition process, a composite additive composed of sodium ascorbate, pentasodium diethylenetriamine pentaacetate, sodium citrate and polyvinylpyrrolidone is synchronously added into the electrolyte. And carrying out electrodeposition for 14-15 days under the conditions that the current density is 40-60A / m, the voltage is 15-30V and the temperature is 15-30 DEG C. Through the synergistic effect of the composite additive, tellurite radicals in the anode region are remarkably inhibited from being oxidized into insoluble sodium tellurate, heavy metal impurity ions in the electrolyte are strongly complexed, and therefore the direct recovery rate of tellurium is increased to 90% or above while the better current efficiency is kept, and the purity of the obtained tellurium ingot reaches 99.95% or above.

The invention discloses a method for recovering Se and TeO2 from tellurium-containing crude selenium refining slag, which comprises the following steps of: crushing the tellurium-containing crude selenium refining slag, performing temperature-controlled roasting, decomposing nitrate, and oxidizing tellurium into a high valence state; the roasting slag and a reducing agent are mixed and heated under the vacuum condition, so that the selenium compound is reduced into elemental Se and volatilized, and meanwhile high-valence tellurium is reduced into tetravalent tellurium salt residues; crushing the reduced product, performing water-soluble leaching, and filtering to obtain a solution containing selenite and tellurite and TeO2 precipitate; adding acid into the leaching filtrate to hydrolyze the tellurite salt into TeO2 precipitate, and filtering and separating to obtain TeO2 and selenium-containing filtrate; finally, acid and a reducing agent are added into the selenium-containing filtrate, and selenite is reduced into elemental Se precipitate. The method realizes efficient separation and recovery of selenium and tellurium, is reasonable in process flow and high in recovery rate, and has a good application prospect.

The invention discloses a material treatment method for radiopharmaceutical preparation. The material treatment method comprises the following steps: dissolving an irradiated tellurium dioxide target material in a sodium hydroxide solution to generate a sodium tellurite solution; adding hydrogen peroxide and a composite-phase molybdenum carbide catalyst into the solution, and adjusting the pH to an acidic condition to promote the tellurite radical to be preferentially converted into a high-valence tellurium compound; the method comprises the following steps: cooling I-containing iodine vapor through nitrogen-assisted distillation, and introducing the cooled I-containing iodine vapor into an alkaline NaOH solution for capturing; a composite-phase molybdenum carbide catalyst is adopted, the ratio of alpha-MoC to beta-MoC is regulated and controlled, and TiO deposition modification on the surface of beta-MoC is combined, so that the activity, stability and selectivity of the catalyst are remarkably improved; experiments show that the method enables the yield of iodine-131 to reach 92.76%, the purity to reach 99.65% and the content of by-products to be reduced to 0.12%; the contrast experiment further verifies the influence of the catalyst dosage, the phase composition and the distillation condition on the result, and verifies that efficient and high-purity iodine-131 preparation is realized through the catalytic synergistic effect and the surface functionalization design.

The present application belongs to the technical field of battery materials, and specifically relates to a modified high-nickel ternary positive electrode material, and a preparation method therefor and the use thereof. The preparation method for a modified high-nickel ternary positive electrode material provided by the present application comprises the following steps: 1) mixing a lithium source, a precursor, a tellurium source and a divalent metal compound, and subjecting same to first calcination, so as to obtain a first calcined product; (2) dissolving a tellurate in an organic solvent, mixing and grinding the resulting tellurate organic solvent solution and the first calcined product obtained in step (1), and then subjecting same to second calcination to obtain a second calcined product, wherein the tellurate is selected from at least one of potassium tellurite and sodium tellurite; and (3) washing the second calcined product obtained in step (2) with water, mixing same with boric acid, and subjecting the mixture to third calcination, so as to obtain the modified high-nickel ternary positive electrode material. Through the specific preparation method and the synergistic effect among the steps in the present application, the resulting modified high-nickel ternary positive electrode material has a good specific capacity, initial Coulombic efficiency and cycling performance.

The invention relates to the technical field of inorganic micro-nano material synthesis, and provides a rare earth doped tellurite material and a liquid phase preparation method thereof, the chemical formula of the obtained rare earth doped tellurite material is (R.E.) wTexOyClz, and R.E. Is a rare earth element and comprises one or more of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The method is simple in process, good in universality, low in energy consumption and flexible and adjustable in product component, and the mechanical stability and the chemical stability of the rare earth doped tellurite material are improved.

The invention belongs to a gold plating solution, and particularly relates to a composite additive for a semiconductor gold plating solution and application of the composite additive. The tellurite derivative comprises tellurite and substituted benzaldehyde, wherein the substituted benzaldehyde is shown as a general formula I, wherein R is selected from sulfonyl or a derivative thereof. According to the technical scheme provided by the invention, through synergistic compounding of tellurite and substituted benzaldehyde, the grain refinement degree and grain orientation of the plating layer are remarkably improved, so that the surface of the plating layer is flat and bright, and the gold plating layer with high compactness and high conductivity is obtained. And the gold plating solution can meet the defect-free thickness requirement of 0.05-40 [mu] m. Besides, the hardness of the plating layer before annealing is 60-100 HV, the electroplating liquid can operate in a wide process window (the current density is 0.5-5 A / dm, and the temperature is 50-70 DEG C), and various application requirements of semiconductor gold wiring, gold bumps, RDL gold layers and the like can be met.