阅读说明：本技术 一种从离子型稀土矿浸出液中回收稀土的方法 (Method for recovering rare earth from ionic rare earth ore leaching solution ) 是由 张新光 胡振光 韦世强 谭海翔 郭怀兵 甘培原 姚骥 朱和玲 梁超杰 计策 杨鹏 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种从离子型稀土矿浸出液中回收稀土的方法,其包括如下步骤:(1)将浓缩的小球藻微生物冷冻干燥,再研磨经过筛网筛选得到吸附剂；(2)将稀土浸出液过滤去除不溶物,接着在稀土浸出液中加入吸附剂,再在常温下振荡吸附；然后将稀土浸出液离心分离,收集得到沉淀物A；(3)将沉淀物A用去离子水洗涤,再将解吸剂和沉淀物A进行混合,先在温度为20～30℃且pH值为4～5的条件下进行振荡解吸,接着在温度为40～50℃且pH值为5.5的条件下进行振荡解吸,然后离心分离沉淀后得到解吸液,将解吸液干燥煅烧得到稀土氧化物粉体。本发明不仅能够提高回收稀土的效率和质量,又能降低氨氮污染,有利于环境保护。(The invention discloses a method for recovering rare earth from ionic rare earth ore leachate, which comprises the following steps of (1) freeze-drying concentrated chlorella microorganisms, grinding and screening by a screen to obtain an adsorbent; (2) filtering the rare earth leachate to remove insoluble substances, adding an adsorbent into the rare earth leachate, and oscillating and adsorbing at normal temperature; then, centrifugally separating the rare earth leaching solution, and collecting to obtain a precipitate A; (3) washing the precipitate A with deionized water, mixing a desorbent with the precipitate A, firstly carrying out oscillation desorption at the temperature of 20-30 ℃ and the pH value of 4-5, then carrying out oscillation desorption at the temperature of 40-50 ℃ and the pH value of 5.5, then carrying out centrifugal separation precipitation to obtain a desorption solution, and drying and calcining the desorption solution to obtain the rare earth oxide powder. The invention can not only improve the efficiency and the quality of the rare earth recovery, but also reduce the ammonia nitrogen pollution, and is beneficial to environmental protection.)

1. A method for recovering rare earth from ionic rare earth ore leachate is characterized by comprising the following steps: the method comprises the following steps:

(1) culturing chlorella in culture medium, centrifuging, collecting precipitate to obtain concentrated chlorella microorganism; freeze-drying the concentrated chlorella microorganisms for 30-60 min at the temperature of-10 to-20 ℃ and the vacuum degree of 1-10 Pa, grinding, and screening by a screen of 100-200 meshes to obtain an adsorbent;

(2) filtering the rare earth leachate to be treated to remove insoluble substances, adding the adsorbent obtained in the step (1) into the rare earth leachate, wherein the liquid-solid ratio of the rare earth leachate to the adsorbent is 1L (10-20) g, and oscillating and adsorbing for 3-5 h at normal temperature and under the condition that the pH value is 5.5; then, centrifugally separating the rare earth leaching solution, and collecting to obtain a precipitate A;

(3) washing the precipitate A obtained in the step (2) with deionized water for 2-3 times, mixing a desorbent and the precipitate A according to the liquid-solid ratio of the desorbent to the precipitate A being 1L (5-10) g, firstly carrying out oscillation desorption for 2-3 h at the temperature of 20-30 ℃ and the pH value of 4-5, then carrying out oscillation desorption for 0.5-1 h at the temperature of 40-50 ℃ and the pH value of 5.5, then carrying out centrifugal separation at the rotating speed of 500-800 r/min, separating and precipitating to obtain a desorption solution, drying the desorption solution to obtain powder, and then calcining the powder in a muffle furnace at the temperature of 1000-1200 ℃ for 2-5 h to obtain rare earth oxide powder; the desorbent is one or a mixture of citric acid and malic acid.

2. The method for recovering rare earth from ionic rare earth ore leachate according to claim 1, wherein: the desorbent in the step (3) is a mixture obtained by mixing citric acid and malic acid according to the volume ratio of (1-3) to 1; the concentration of the citric acid is 0.1mol/L, and the concentration of the malic acid is 0.1 mol/L.

3. The method for recovering rare earth from ionic rare earth ore leachate according to claim 1, wherein: the centrifugal separation in the step (1) is carried out at the rotating speed of 1000-2000 r/min.

4. The method for recovering rare earth from ionic rare earth ore leachate according to claim 1, wherein: the centrifugal separation in the step (2) is carried out at the rotating speed of 500-800 r/min.

5. The method for recovering rare earth from ionic rare earth ore leachate according to any one of claims 1 or 5, wherein: and (3) in the step (2), the concentration of the rare earth ions in the rare earth leaching solution is 0.10-0.15 g/L.

Technical Field

The invention belongs to the technical field of mineral processing engineering, and particularly relates to a method for recovering rare earth from ionic rare earth ore leachate.

Background

Rare Earth (Rare Earth) is a general name of seventeen metal elements including lanthanide elements, scandium and yttrium in a chemical periodic table, and 250 Rare Earth ores exist in nature. The rare earth element is widely used in agriculture, aerospace, electronic manufacturing industry, transportation industry, medical industry and the like, has important significance for high and new technology and economy, and is called industrial gold. China is the first rare earth resource country in the world and is called rare earth kingdom. The proven rare earth resource reserves in China are 4300 ten thousand tons, which account for 43 percent of the total reserves in the world, and the annual output of the rare earth elements in China already accounts for more than 95 percent of the total output in the world.

According to the difference of physicochemical properties of rare earth elements, the rare earth elements can be divided into light, medium and heavy rare earth elements. The europium, terbium, dysprosium and other medium-heavy rare earth have small reserves, large gaps, high value and small replaceability, are widely applied to the high and new technology fields of national defense, military industry, aerospace and the like, and are key materials for preparing high-performance magnetic materials, luminescent materials, laser crystals, high-technology ceramics and the like. At present, medium-heavy rare earth is mainly derived from ion adsorption rare earth ore in China, and the proportion of medium-heavy rare earth elements such as terbium, dysprosium, europium, yttrium and the like is ten times or even dozens of times higher than that of light rare earth ore. The ion adsorption type rare earth ore is usually leached by ammonium sulfate, the obtained rare earth leachate is subjected to impurity removal by ammonium bicarbonate, and the rare earth is recovered by ammonium bicarbonate or oxalic acid precipitation, but the existing rare earth precipitation and recovery process has the problems of low rare earth recovery rate, high consumption of chemical reagents, high production cost, discharge of ammonia nitrogen wastewater and oxalic acid wastewater and the like, and a method for recovering the rare earth by the ion type rare earth ore leachate, which can reduce the production cost and the ammonia nitrogen pollution and ensure the purity of the rare earth in the product, is still lacked.

Disclosure of Invention

Aiming at the defects, the invention provides a method for recovering rare earth from ionic rare earth ore leaching solution, which not only can improve the efficiency and quality of recovering rare earth, but also can reduce ammonia nitrogen pollution and is beneficial to environmental protection.

The invention is realized by adopting the following technical scheme:

a method for recovering rare earth from ionic rare earth ore leaching solution comprises the following steps:

(1) culturing chlorella in culture medium, centrifuging, collecting precipitate to obtain concentrated chlorella microorganism; freeze-drying the concentrated chlorella microorganisms for 30-60 min at the temperature of-10 to-20 ℃ and the vacuum degree of 1-10 Pa, grinding, and screening by a screen of 100-200 meshes to obtain an adsorbent;

(2) filtering the rare earth leachate to be treated to remove insoluble substances, adding the adsorbent obtained in the step (1) into the rare earth leachate, wherein the liquid-solid ratio of the rare earth leachate to the adsorbent is 1L (10-20) g, and oscillating and adsorbing for 3-5 h at normal temperature and under the condition that the pH value is 5.5; then, centrifugally separating the rare earth leaching solution, and collecting to obtain a precipitate A;

(3) washing the precipitate A obtained in the step (2) with deionized water for 2-3 times, mixing a desorbent and the precipitate A according to the liquid-solid ratio of the desorbent to the precipitate A being 1L (5-10) g, firstly carrying out oscillation desorption for 2-3 h at the temperature of 20-30 ℃ and the pH value of 4-5, then carrying out oscillation desorption for 0.5-1 h at the temperature of 40-50 ℃ and the pH value of 5.5, then carrying out centrifugal separation at the rotating speed of 500-800 r/min, separating and precipitating to obtain a desorption solution, drying the desorption solution to obtain powder, and then calcining the powder in a muffle furnace at the temperature of 1000-1200 ℃ for 2-5 h to obtain rare earth oxide powder; the desorbent is one or a mixture of citric acid and malic acid.

The desorption is carried out in two stages in the desorption process of the chlorella adsorbent, the desorption is carried out at normal temperature, and then the desorption temperature is relatively increased in the later stage of the desorption process, so that the desorption reaction rate is accelerated, and the desorption time is favorably shortened.

Further, the centrifugal separation in the step (1) is carried out at the rotating speed of 1000-2000 r/min.

Further, the centrifugal separation in the step (2) is carried out at the rotating speed of 500-800 r/min.

Further, the desorbent in the step (3) is a mixture obtained by mixing citric acid and malic acid according to a volume ratio of (1-3) to 1; the concentration of the citric acid is 0.1mol/L, and the concentration of the malic acid is 0.1 mol/L.

Further, the concentration of rare earth ions in the rare earth leaching solution in the step (2) is 0.10-0.15 g/L.

Compared with the prior art, the technical scheme has the following beneficial effects:

1. according to the invention, chlorella is used as an adsorbent, active groups such as carboxyl, carbonyl, hydroxyl, sulfydryl and the like contained in cell walls of the chlorella are utilized to interact with rare earth ions, the rare earth ions in the leachate are adsorbed and enriched, the adsorption effect is good, the chlorella adsorbent can be repeatedly used after desorption, the production cost is reduced, and the problems of low rare earth recovery rate, high consumption of chemical reagents, high production cost, discharge of ammonia nitrogen wastewater and oxalic acid wastewater and the like in the existing process for precipitating and recovering rare earth are solved.

2. In the process of preparing the chlorella adsorbent, concentrated chlorella is subjected to vacuum freeze drying, then grinding and screening by a 100-200-mesh screen are carried out, so that the chlorella has a large adsorption area, and the adsorption efficiency is improved; meanwhile, according to the adsorption characteristics of the chlorella to the rare earth ions, the adsorption process conditions such as the dosage of the adsorbent, the adsorption time, the adsorption acidity and the like are optimized, and the adsorption rate and the adsorption quantity of the chlorella to adsorb the rare earth ions are improved.

3. According to the invention, citric acid and malic acid are mixed with rare earth ions to prepare the desorbent suitable for desorbing the rare earth ions in the chlorella adsorbent by utilizing the principle of chelating reaction between the citric acid and the malic acid and the rare earth ions, and the process conditions such as temperature, time, desorbent dosage, desorption acidity and the like in the desorption engineering are optimized, so that the desorption efficiency of the rare earth ions is improved, the rare earth ions are favorably desorbed from the chlorella, and the chlorella adsorbent is favorably reused.

4. The method has the advantages of simple operation, low energy consumption and low production cost, avoids using a large amount of medicament harmful to the environment, can improve the efficiency and the quality of the rare earth recovery, and is beneficial to environmental protection.

Detailed Description

The invention is further illustrated by the following examples, which are not to be construed as limiting the invention thereto. The specific experimental conditions and methods not indicated in the following examples are generally conventional means well known to those skilled in the art.