Method for preparing ultra-thin highly-pure terbium oxide by beneficiated terbium-dysprosium

Abstract

The invention discloses a making method of terbium oxide, which comprises the following steps: (1) blending raw material; (2) distilling and extracting through ultrasound; obtaining enriched liquid of TbCl3; (3) fractionating and extracting through ultrasound; obtaining fined liquid of TbCl3; (4) adsorbing impurity; (5) separating solid from liquid; (6) crystallizing; sedimenting Tb2 (CO3) 3; (7) proceeding solid-liquid separation; (8) drying; sintering; obtaining Tb4O7 with content not less than 99.99% and grain size at 0.01-10.0um.

Description

technical field [0001] The invention relates to a method for preparing terbium oxide, in particular to a method for preparing ultrafine high-purity terbium oxide by using terbium-dysprosium Tb-Dy enrichment as a raw material, belonging to the field of hydrometallurgy. Background technique [0002] Ultrafine high-purity terbium oxide (Tb 4 o 7 ) products refer to terbium oxide products with terbium oxide content ≥ 99.99% and particle size ≤ 10.0 μm. Terbium belongs to the heavy rare earth, and its abundance in the earth's crust is very low, only 1.1ppm. In the Baiyan Obo rare earth mine in my country, terbium oxide accounts for less than 0.01% of the total rare earth. Even in the high yttrium ion heavy rare earth ore with the highest terbium content, the content of terbium only accounts for 1.1-1.2% of the total rare earth. It has the same chemical activity as other rare earth metals, and can chemically react with many non-metals. It can be positive trivalent and positive t...

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Problems solved by technology

The mixing is sufficient, the extraction balance is high, and the distribution ability of the extractant is fully exerted. At this time, the particles of the dispersed phase are small, and it is difficult to aggregate and separate phases, which ultimately affects the separation effect.

In order to improve the stage efficiency of the tank, it is necessary to lengthen the residence time of the phase in the mixing chamber and increase the clarification time, resulting in an increase in the total volume of the tank and an increase in the number of separation stages.

The stability of the tank is often achieved through the accumulation of rare earths in the tank, which will inevitably lead to an increase in investment in the tank

In addition, the current literature has no introduction on the further separation and purification of the feed liquid for the production of pure terbium oxide by fractional distillation and extraction, and the subsequent process of producing terbium oxide with a purity greater than 99.90%.

The main problems existing in these separation and preparation methods at present are: (1), extraction and separation rate and efficiency are low: the equipment used in the extraction and separation method at present is mixing and settling tank, centrifugal extractor equipment etc., rare earth extraction rate and separation efficiency are low, extraction time Long, this has caused the increase of production cost, and production capacity is difficult to improve; Existing extraction stage is many, generally will pass through 70-100 stage and just can complete whole extraction process; (2), terbium oxalate crystal precipitation effect is not good: with oxalic acid Used as a precipitant, the production cost is high, and oxalic acid is highly toxic and pollutes the environment

It is difficult for the rare earth element terbium to form crystalline carbonates. The terbium carbonate usually produced is an amorphous flocculent precipitate with a large volume, which contains a large amount of water and impurities. It is difficult to wash and filter, and the product quality is poor and the loss of rare earth is large. , difficult to produce

(3) Poor product quality: the terbium oxalate product obtained by the traditional crystallization precipitation method commonly used at present, the quality of the terbium oxide product prepared by solid-liquid separation, drying, and burning is unstable, and it is generally difficult to obtain terbium oxide (Tb 4 o 7 ) content up to 99.99% purity, large particle size, it is difficult to achieve high-grade terbium oxide ≤ 10.0μm, and the particle size distribution is uneven, it is difficult to meet the requirements of the product used in high-tech fields

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