Method for separating and extracting uranium and thorium from superior molten slag

Abstract

The invention relates to the field of hydrometallurgy, in particular to a method for separating enriched uranium and thorium from rare earth superior molten slag. In the method for separating the enriched uranium and thorium from the superior molten slag, disclosed by the invention, the technical scheme for performing alkaline leaching on the superior molten slag, performing acid leaching on precipitated uranium and separating precipitated thorium is adopted, so that the precipitate of uranyl and precipitate of thorium are obtained respectively. Due to the adoption of a separation technology of stepwise leaching and precipitating, complete separation of thorium and uranium is realized, the equipment and process flow are simple, the operation is convenient, raw material are readily available, and the environmental pollution is reduced.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for separating and enriching uranium and thorium from rare earth slag. Background technique [0002] Excellent molten slag is the solid waste after the main rare earth elements are extracted from monazite. Since this excellent molten slag contains a large amount of uranium, thorium and other radioactive elements, it is often piled up in the environment in the form of waste, which is harmful to the natural environment and human body. Great health hazard. The main chemical components of the excellent slag are amphoteric metal hydroxides, hydroxides of thorium and uranium, and insoluble minerals. After leaching, extraction and separation of the excellent slag, a mixture of thorium and uranium can be obtained. Currently, acid leaching is usually used Extraction technology is used to separate the mixture of thorium and uranium. The main steps are: 1. Nitric acid leaching and d...

AI Technical Summary

Problems solved by technology

The main disadvantages of the separation method of this leaching extraction are:

[0003] 1. The product is impure, uranium and thorium still exist in the form of a mixture, the product needs to be further purified, and the industrial use value is low

[0004] 2. In the process of acid leaching and extraction, not only nitric acid, but also kerosene and ammonia water are used. The use of these chemical raw materials will pollute the environment and make the equipment often in a state of strong corrosion

[0005] 3. As the extraction proceeds, thorium and uranium are continuously transferred from the aqueous phase to the organic extraction phase, which greatly reduces the content of thorium and uranium in the aqueous phase, thereby slowing down the extraction speed, and the resulting mixture of thorium and uranium in the extraction phase The content of thorium and uranium is relatively low, and it is impossible to reach the saturation concentration. To reach the saturation concentration, the load of subsequent evaporation and concentration will inevitably increase. Not only the comprehensive recovery rate of thorium and uranium is low, but also the amount of feed liquid in the subsequent refining process is also large. If zero The clean production of the discharge will cost a lot of treatment, and if it is not treated, it will aggravate the environmental pollution;

[0006] 4. The separation process is complex, requiring both leaching equipment and extraction equipment, as well as stripping equipment, and the production capacity of the equipment is low;

[0007] 5. The leaching and extraction speed and efficiency in the existing separation process are low, and the economic and social benefits are not high

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