Thorium extraction and separation method

Abstract

The invention provides a thorium extraction and separation method. The thorium extraction and separation method comprises the steps of mixing rare earth waste residues with hydrochloric acid, carryingout solid-liquid separation to obtain hydrochloric acid leachate, and then adjusting the pH value; adding an electrolyte capable of ionizing sulfate radicals into the hydrochloric acid leachate of the rare earth waste residues; mixing primary amine with diluent to obtain an extractant; mixing the leachate with the extractant according to a preset volume ratio for extraction; and carrying out backextraction on the thorium-loaded organic phase obtained through extraction and separation by using a back extractant to obtain a thorium ion-containing solution and a recovered extractant. Accordingto the method, hydrochloric acid is adopted to leach radioactive waste residues of ionic rare earth ores; through comprehensive adjustment to the concentration of N1923, the concentration of sulfate radicals and the acidity of the solution, the extraction rate of the thorium reaches 95% or more, and the rare earth is hardly extracted; the separation order of the thorium and the rare earth is 105 or more; moreover, the thorium in the organic phase is completely back extracted, the extraction capacity of the extractant is not obviously reduced after multiple cycles, and the extractant can be recycled.

Description

technical field [0001] The invention belongs to the field of thorium extraction and separation methods, in particular to a method for extracting and separating thorium from a hydrochloric acid leaching solution of ionic radioactive waste residue. Background technique [0002] With the development of my country's rare earth industry and people's increasing awareness of environmental protection, the problem of radioactivity in ionic rare earth ores has become increasingly prominent. During the mining process of ion-type rare earth ore, radioactive elements are taken out of the mine by the leaching solution and enriched in the liquid collection tank. In acid slag. In the process of slag treatment, in order to avoid the pollution of the radioactive thorium element to the rare earth extraction and separation line, the efficient separation of thorium element from the leaching solution of waste slag is the first step in the safe treatment of waste slag recovery. Liquid-liquid ext...

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Problems solved by technology

Combined with the current single rare earth separation practice in the factory, all of them are carried out in the chloride salt solution, which often converts the sulfuric acid rare earth solution into a hydrochloric acid rare earth solution. In addition, the leaching rate of rare earth radioactive slag leached by sulfuric acid is lower than that of hydrochloric acid. It is not suitable to use sulfuric acid to leaching the southern Ionic radioactive waste

Therefore, it is impossible to directly use primary amine N1923 to treat radioactive waste residues of ionic rare earth mines.

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