Abrégé

The invention relates to mining and can be used in the stimulation of downhole uranium recovery by in-situ leaching. The technical result of the invention is that of obtaining a composition for chemically treating the near-filter region of wells for the in-situ leaching of uranium, and of developing a composition for chemically treating the near-filter region of wells for the in-situ leaching of uranium that permits an increase in the productivity and injectivity of production wells. The claimed technical result is achieved in that a composition for chemically treating the near-filter region of wells for the in-situ leaching of uranium is claimed which contains hydrofluoric acid and sulphuric or hydrochloric acid, wherein the components of the composition are present in the following mass fractions: 50.0-98.0% sorption mother liquor or process water or leaching solution; 1.0-40.0% hydrofluoric acid; 1-10% sulphuric or hydrochloric acid.

Classes IPC  ?

• E21B 43/28 - Dissolution de matières minérales autres que des hydrocarbures, p. ex. par un agent de lessivage alcalin ou acide
• C09K 8/72 - Produits chimiques érosifs, p. ex. acides

Abrégé

The invention relates to hydrometallurgy. A method for concentrating uranium in a uranium-containing solution includes separating a uranium-containing solution by nanofiltration, with uranium being concentrated in a concentrate. The uranium-containing solution used is a uranium-rich eluate. Before separation by nanofiltration, the uranium-containing solution is fed to fine filters for the removal of suspended particulates. The solution is separated in three or four stages of nanofiltration using membrane modules. Said membrane modules are modules having selective membranes. A portion of the concentrate obtained after the last nanofiltration module is returned to the start of the nanofiltration process. The result is that of increasing the efficiency with which uranium is concentrated from an initial uranium-containing solution.

Classes IPC  ?

• B01D 61/02 - Osmose inverseHyperfiltration
• C22B 60/02 - Obtention du thorium, de l'uranium ou des autres actinides
• B82Y 99/00 - Matière non prévue dans les autres groupes de la présente sous-classe

Abrégé

The invention relates to chemistry and metallurgy. A method for producing uranium tetrafluoride includes obtaining a solution of tetravalent uranium, precipitating uranium-containing raw material from said solution to produce a sludge, filtering said sludge, washing the residue, and drying and calcining same. The solution of tetravalent uranium is obtained using, as a starting material, a solution of a uranium-rich eluate formed as a result of the sorption concentration of uranium from pregnant solutions during the in-situ leaching of uranium, said solution is pre-acidified with sulphuric acid to a concentration of 200-250 g/dm3, and the acidified solution is passed through a layer of zinc, or uranium is electrochemically reduced using a uranium-rich eluate pre-acidified with sulphuric acid to a concentration of 40-45 g/dm3. The uranium-containing raw material is precipitated in the form of ammonium uranium pentafluoride by the introduction of ammonium bifluoride in three stages every 15 minutes at 90-100°С under vigorous stirring, and washing is carried out using process water at a liquid to solid ratio of 3:1. Drying is carried out at 210-250°С for one hour, and calcining is carried out at 600-650°С for one hour. The invention makes it possible to precipitate crystalline hydrates of ammonium uranium pentafluoride directly from solutions of uranium-rich eluates, thus reducing consumption of chemical reagents and electrical energy.

Classes IPC  ?

• C01G 43/06 - Fluorures