Preparation method and system of high-purity rare earth carbonate

Abstract

The invention relates to the technical field of a rare earth material and provides a preparation method of high-purity rare earth carbonate. The preparation method comprises the following steps: firstly, filtering rare earth material liquid, introducing the filtered rare earth material liquid into cation exchange resin to adsorb and adsorbing rare earth ions and impurity ions to the resin to obtain loaded resin; then performing drip washing on the loaded resin and eluting the impurity ions to obtain rare earth ion loaded resin; finally, desorbing the rare earth ion loaded resin by a carbonateor hydrocarbonate solution, filtering rare earth carbonate precipitate obtained through desorption and washing to obtain the high-purity rare earth carbonate. Desorption of the rare earth ion loaded resin, resin transformation and rare earth carbonate precipitation are synthesized into one process, so the operation process is simplified, the production cost is reduced, the civil engineering investment is reduced, the investment utilization rate is increased and resources are saved. The invention also provides a preparation system of the high-purity rare earth carbonate. The system is simple instructure and small in occupied area and can be integrally moved along with transfer of a mining point.

Description

technical field [0001] The invention relates to the technical field of rare earth materials, in particular to a method and system for preparing high-purity rare earth carbonate. Background technique [0002] During the mining and extraction of rare earths, a large amount of low-concentration rare earth feed liquid (REO concentration ≤ 2g / L) will be produced. The mine leaching mother liquid, tailings leachate, tailings leaching water, Lime slag leaching solution, etc. are low-concentration rare earth feed liquids, and the feed liquids also contain more impurity ions, such as iron and aluminum. When preparing rare earth products, rare earths need to be enriched and removed. [0003] Taking the process of preparing ionic rare earth ore mother liquor into the tank as an example, in the process of preparing rare earth products, ammonium sulfate leaching-ore leaching mother liquor pH adjustment and impurity removal-mine leaching mother liquor carbonate precipitation-rare earth car...

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Problems solved by technology

[0006] (3) The concentration of rare earths in the early and late stages of the leaching mother liquor is generally low. In order to collect the rare earths in the low-concentration feed liquid, the consumption ratio of the precipitant is greatly increased, resulting in a large unit consumption of the precipitant, especially when the concentration of rare earths is lower than 0.10g / When L, the rare earth is difficult to recover, which affects the rare earth yield;

Especially when Al in mixed rare earth carbonate 2 o 3 When the content is high, the neutralization and impurity removal effect of the rare earth decomposition liquid is poor, and it takes a long aging time to separate the solid and liquid, the amount of slag is large, and the direct recovery rate of rare earth is low

The aluminum hydroxide and ferric hydroxide precipitates contained in the neutralization slag produced during the impurity removal process are colloidal in the pH range, which is not easy to filter, and the slag has a high moisture content and is heavily wrapped with rare earths, which can be as high as 8% to 10% of the total amount of rare earths. , leading to a low direct recovery rate of rare earth

In order to recover the rare earths in the iron-aluminum slag, it is necessary to consume a large amount of hydrochloric acid to remelt the slag and oxalic acid to precipitate and recover the rare earths, resulting in repeated consumption of acid and alkali

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