Method for preparing ultra-thin highly-pure lanthanum oxide by beneficiated lanthanum

Abstract

The invention discloses a making method of lanthanum oxide, which comprises the following steps: (1) blending raw material to form enriched lanthanum slurry; (2) fractionating and extracting through ultrasound; obtaining La (NO3) 3 solution and promethium-neodymium enriched liquid; (3) adsorbing impurity; (4) separating solid from liquid; obtaining fined liquid of purified La(NO3)3; (5) crystallizing; sedimenting La2(CO3)3; (6) proceeding solid-liquid separation; (7) drying; sintering; obtaining La2O3 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 lanthanum oxide, in particular to a method for preparing ultrafine high-purity lanthanum oxide by using lanthanum enrichment as a raw material, which belongs to the field of hydrometallurgy. Background technique [0002] Ultra-fine high-purity lanthanum oxide (La 2 o 3 ) products refer to lanthanum oxide products with lanthanum oxide content ≥ 99.99% and particle size ≤ 10.0 μm. At present, ultrafine high-purity lanthanum oxide (La 2 o 3 ) The method used in the preparation of the product is generally based on lanthanum enrichment as raw material, using HNO 3 Dissolve to make lanthanum nitrate solution, and then use P350 etc. as extraction agent for extraction and separation to obtain refined lanthanum nitrate solution. Lanthanum nitrate solution uses oxalic acid as precipitant to form lanthanum oxalate crystals and precipitate out. After drying and burning, lanthanum oxalate can be obtained Ultra-fi...

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Problems solved by technology

The main problem that these preparation methods exist at present is: (1), extraction separation rate and efficiency are low: the equipment that extraction separation method uses at present is mixed settling tank, centrifugal extractor etc., carry out multistage extraction, if improve the purity of product, just The number of stages must be increased, and the existing extraction stages are many, and generally the entire extraction process can only be completed through 70-100 stages; and the rare earth extraction rate and separation efficiency are low, and the extraction time is long, which leads to an increase in production costs and difficult production capacity. Improve; (2), lanthanum oxalate crystal precipitation effect is not good: adding oxalic acid in the refined lanthanum nitrate solution is the precipitating agent to generate lanthanum oxalate crystal precipitation and is the crystallization precipitation method of the rare earth element generally adopted at present

The disadvantage of using oxalic acid as a precipitant is that the production cost is high, and oxalic acid is highly toxic and pollutes the environment

It is difficult for the rare earth element lanthanum to form crystalline carbonate. Usually, the prepared lanthanum carbonate 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. , production is difficult to carry out; (3), poor product quality: the lanthanum oxalate product that adopts the traditional crystallization precipitation method generally adopted at present, the quality of the lanthanum oxide product prepared through solid-liquid separation, drying, burning is unstable, Generally difficult to obtain La 2 o 3 The content is as high as 99.99% purity, especially the particle size of the product is large, and the particle size distribution is uneven, it is difficult to meet the requirements of the product used in the high-tech field

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