Method for leaching and recovering rare earth element from rare earth slag

Abstract

The invention relates to a method for leaching and recovering earth element from rare earth slag. According to the invention, a sulfuric acid aqueous solution is adopted as a leaching solution, and ore slurry obtained by wet ball milling of rare earth slag is adopted as a powder slurry; the rare earth powder slurry and the leaching solution are added into a reaction kettle; the reaction kettle is sealed; oxygen is delivered into the reaction kettle for discharging air; an air discharge valve is closed; stirring and leaching is carried out in the reaction kettle under a pressure of 0.6-1.0MPa and a temperature of 140-180 DEG C; when leaching is finished, a material is discharged, and solid-liquid separation is carried out; the pH value of the leachate is regulated to 4-5, and rare earth element is recovered with an extraction method; or a proper amount of sodium carbonate is added, and a carbonic acid-rare earth mixture is prepared. The rare earth element recovery method provided by the invention has the advantage of simple method, low raw material cost, and low production cost. With the method, rare earth large-scale digestion and industrial production are convenient. The method has considerable economic benefit, social benefit, environmental benefit, and ecological civilization benefit.

Description

technical field [0001] The invention relates to the field of rare earth hydrometallurgy, in particular to a rare earth resource leaching and recovery method for leaching rare earth slag with high efficiency and recovering rare earth elements therein. Background technique [0002] Rare earth is an important strategic resource of our country, and has been widely used in strategic emerging industries and national defense industries such as pyrophoric alloys, permanent magnet materials, new energy materials, catalytic combustion-supporting materials, polishing materials, superconducting materials and luminescent materials. With the continuous increase in the application of new rare earth materials, and the long-term extensive separation of rare earth mining and smelting by various enterprises in my country, the accumulation of rare earth slag is also increasing. In view of the fact that these rare earth slags still contain a large amount of rare earth elements and other resource...

AI Technical Summary

Problems solved by technology

[0003] For a long time, because no feasible, effective and economical treatment method has been found, these waste residues have not been recycled. Most companies store them in storage, and some even discard them directly, resulting in resource loss and environmental pollution.

In the past, some companies adopted the method of returning to decomposition and remelting, but failed to persist due to high costs

In recent years, there have been some achievements in the research on related treatment processes. The methods include alkali boiling extraction process, electroosmosis process, fragmented colloid breaking process to extract rare earths, etc. Some of these methods have low recovery rate and high recovery cost; There are difficulties in industrial implementation, and the above methods have certain limitations