阅读说明：本技术 一种高La稀土氧化物预分离Ce、Sm、Eu、Gd、Dy的方法 (Method for pre-separating Ce, Sm, Eu, Gd and Dy from high-La rare earth oxides ) 是由 杨幼明 张小林 牛飞 刘东辉 杨诗旻 孟玉宁 蓝桥发 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种高La稀土氧化物预分离Ce、Sm、Eu、Gd、Dy的方法,包括如下步骤：把高La稀土氧化物缓慢加入至Na<Sub>2</Sub>CO<Sub>3</Sub>溶液中,搅拌过程中缓慢通入CO<Sub>2</Sub>气体,快速过滤,得到滤渣和浸出液；滤渣为La<Sub>2</Sub>O<Sub>3</Sub>；在室温下往浸出液中缓慢通入CO<Sub>2</Sub>并慢速搅拌,使pH降到8.0后停止通气与搅拌,快速过滤,得到沉淀物；得到的沉淀物放入热风烘箱内,在65-75℃下烘24h后,冷却至室温,用水溶解后过滤,得到的滤液为Na<Sub>2</Sub>CO<Sub>3</Sub>溶液,得到的不溶固相为Ce、Sm、Eu、Gd、Dy的碳酸稀土复盐。本发明方法根据中稀土氧化物与重稀土氧化物在碳酸钠水溶液中溶解-络合性质的差异,优先使中稀土氧化物溶解在碳酸钠溶液中,从而达到预分离的目的,以减少中重稀土元素萃取分组与萃取分离的级数。(The invention discloses a method for pre-separating Ce, Sm, Eu, Gd and Dy from high-La rare earth oxides, which comprises the following steps of slowly adding the high-La rare earth oxides into Na 2 CO 3 In the solution, CO is slowly introduced in the stirring process 2 Quickly filtering the gas to obtain filter residue and leachate; the filter residue is La 2 O 3 (ii) a Slowly introducing CO into the leaching solution at room temperature 2 Slowly stirring, stopping ventilation and stirring after the pH value is reduced to 8.0, and quickly filtering to obtain a precipitate; placing the obtained precipitate in a hot air oven, drying at 65-75 deg.C for 24 hr, cooling to room temperature, dissolving in water, and filtering to obtain filtrate Na 2 CO 3 The insoluble solid phase obtained from the solution is the rare earth carbonate double salt of Ce, Sm, Eu, Gd and Dy. The method of the invention preferentially dissolves the medium rare earth oxide according to the difference of the dissolution-complexation properties of the medium rare earth oxide and the heavy rare earth oxide in the sodium carbonate aqueous solutionDecomposing in sodium carbonate solution to reach the aim of pre-separation and reduce the number of extraction groups and extraction separation stages of medium and heavy rare earth elements.)

The method for pre-separating Ce, Sm, Eu, Gd and Dy from high-La rare earth oxides is characterized by comprising the following steps:

s1, preparing Na₂CO₃Solution, adding high La rare earth oxide slowly to Na₂CO₃In solution;

s2, keeping the temperature at 75-85 ℃, and slowly introducing CO in the stirring process₂Gas, leading the pH value to be between 10.5 and 11.5, and stirring;

s3, rapidly filtering while the solution is hot to obtain filter residue and leachate; the filter residue is La₂O₃；

S4, slowly introducing CO into the leachate obtained in the step S3 at room temperature₂Slowly stirring, stopping ventilation and stirring after the pH value is reduced to 8.0, and quickly filtering to obtain a precipitate;

s5, putting the precipitate obtained in the step S4 into an oven, drying for 24 hours at 65-75 ℃, cooling to room temperature, dissolving with water, and filtering to obtain a filtrate Na₂CO₃The insoluble solid phase obtained from the solution is a rare earth carbonate double salt containing Ce, Sm, Eu, Gd and Dy.

2. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxides of claim 1 wherein in step S1 high La rare earth oxides are added to Na₂CO₃Before the solution is prepared, the high-La rare earth oxide is quickly ball-milled by a ball mill, and then the high-La rare earth oxide which is ball-milled uniformly is added into Na₂CO₃And (3) solution.

3. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxide according to claim 2, wherein the high La rare earth oxide is ball milled rapidly with a ball mill to an average particle size of 150-200 mesh.

4. The method for pre-separating Ce, Sm, Eu, Gd and Dy from high La rare earth oxide according to claim 1, wherein in step S1, Na is added by material calculation₂CO₃The total amount of heavy rare earth in the solution is not more than 100 g/L.

5. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxide according to claim 1, wherein in step S1, Na₂CO₃The concentration of the solution is 1.7-2.0 mol/L.

6. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxide according to claim 1, wherein in step S2, the stirring speed is controlled to be 70 r/min.

7. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxides according to claim 1, wherein in step S2, the stirring time is 90 minutes.

8. The method for pre-separating Ce, Sm, Eu, Gd, Dy from high La rare earth oxide according to claim 1, wherein in step S4, the rotation speed of stirring is 30 r/min.

Technical Field

The invention relates to the field of rare earth element hydrometallurgy, in particular to a method for pre-separating Ce, Sm, Eu, Gd and Dy from rare earth oxides with high La content.

Background

The light rare earth bastnaesite rare earth ore mainly takes La and Ce elements as main elements and contains a small amount of medium rare earth elements. At present, the mainstream processes of the ionic rare earth ore are sulfating roasting and oxidizing roasting, after leaching with dilute sulfuric acid, double salt precipitation pre-grouping is carried out with sodium sulfate, La³⁺、Ce⁴⁺In the process of precipitating the sulfuric acid double salt, Ce is often required to be added⁴⁺Reduction to Ce³⁺And a large amount of NaOH is consumed to carry out double-salt transformation of sulfuric acid, then the sulfuric acid is burnt into oxide, and then the hydrochloric acid is dissolved preferentially and then extracted and separated. The process is complicated, the raw material consumption is large, and the pressure on environmental management is large. And the separation project occupies large fixed assets, the separation stages are various, and the separation cost is high.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for pre-separating Ce, Sm, Eu, Gd and Dy from high-La rare earth oxides.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for pre-separating Ce, Sm, Eu, Gd and Dy from kinds of high-La rare earth oxides comprises the following steps:

s1, preparing Na₂CO₃Solution, adding high La rare earth oxide slowly to Na₂CO₃In solution;

s2, keeping the temperature at 75-85 ℃, and slowly introducing CO in the stirring process₂Gas, leading the pH value to be between 10.5 and 11.5, and stirring;

s3, rapidly filtering while the solution is hot to obtain filter residue and leachate; the filter residue is La₂O₃；

S4, slowly introducing CO into the leachate obtained in the step S3 at room temperature₂Slowly stirring, stopping ventilation and stirring after the pH value is reduced to 8.0, and quickly filtering to obtain a precipitate;

s5, putting the precipitate obtained in the step S4 into an oven, drying for 24 hours at 65-75 ℃, cooling to room temperature, dissolving with water, and filtering to obtain a filtrate Na₂CO₃The insoluble solid phase obtained from the solution is the rare earth carbonate double salt of Ce, Sm, Eu, Gd and Dy.

step, in S1, add high La rare earth oxide to Na₂CO₃Before the solution is prepared, the high-La rare earth oxide is quickly ball-milled by a ball mill, and then the high-La rare earth oxide which is ball-milled uniformly is added into Na₂CO₃And (3) solution.

, the high La rare earth oxide is ball milled rapidly by a ball mill to have an average particle size of 150 and 200 meshes.

step, in step S1, add Na by material calculation₂CO₃The total amount of heavy rare earth in the solution is not more than 100 g/L.

step, in step S1, Na₂CO₃The concentration of the solution is 1.7-2.0 mol/L.

, in step S2, the stirring speed is controlled to 70 r/min.

Further , in step S2, the stirring time is 90 minutes.

, in step S4, the rotation speed of the stirrer is 30 r/min.

The invention has the beneficial effects that:

according to the method, the medium rare earth oxide is preferentially dissolved in the sodium carbonate solution according to the difference of the dissolution-complexation properties of the medium rare earth oxide and the heavy rare earth oxide in the sodium carbonate aqueous solution, so that the aim of pre-separation is fulfilled, and the number of stages of extraction grouping and extraction separation of medium and heavy rare earth elements is reduced.

In particular, the method adopts a small amount of low-cost and low-alkalinity sodium carbonate as a complexing agent, and realizes the pre-separation of medium and heavy rare earth elements in a simple and efficient chemical process through short-time wet leaching and solid-liquid separation, namely the hydrochloric acid consumption of rare earth oxides in the acid preferential dissolution process is reduced, and the number of stages of extraction separation is reduced, so that the method has important reference significance for reducing the discharge of high-salinity wastewater. The method has the advantages of simple integral operation step, cyclic utilization of raw materials, no metal loss, high efficiency, low energy consumption, short operation period and the like.

Drawings

FIG. 1 is a schematic general flow diagram of the process of the present invention.

Detailed Description

The present invention will be described in further with reference to the drawings, it should be noted that the present embodiment is based on the technical solution, and the detailed implementation and the specific operation process are given, but the protection scope of the present invention is not limited to the present embodiment.

The method for pre-separating Ce, Sm, Eu, Gd and Dy from rare earth oxides with high La content comprises the following steps as shown in figure 1:

(1) rapidly ball-milling the high-La rare earth oxide by using a ball mill to ensure that the average particle size is 150-200 meshes;

(2) preparing 1.7-2.0mol/L Na₂CO₃Solution of ball-milled uniformly high La rare earth oxide obtained in step S1 slowly added to Na₂CO₃Adding Na into the solution according to the material calculation₂CO₃The total amount of heavy rare earth in the solution is not more than 100 g/L;

(3) keeping the temperature at 75-85 ℃, controlling the stirring speed at 70r/min, and slowly introducing CO in the stirring process₂Gas, the pH value is between 10.5 and 11.5, and the mixture is stirred for 90 minutes;

(4) rapidly filtering to obtain filter residue La₂O₃The leachate contains medium rare earth Ce, Sm, Eu, Gd and Dy and a small amount of heavy rare earth elements;

(5) slowly introducing CO into the leaching solution obtained in the step (4) at room temperature₂Stirring slowly (30r/min), stopping aeration and stirring after pH is reduced to 8.0, and rapidly filtering to obtain precipitate mainly comprising rare earth carbonate double salt containing Ce, Sm, Eu, Gd and Dy and NaHCO₃。

(6) Putting the precipitate obtained in the step (5) into a hot air oven, drying at 65-75 ℃ for 24h, cooling to room temperature, dissolving with water, and filtering to obtain a filtrate Na₂CO₃The solution can be recycled, and the obtained insoluble solid phase is rare earth carbonate complex salt containing Ce, Sm, Eu, Gd and Dy.

Step S4 obtaining La₂O₃In step S6, a double carbonate containing Ce, Sm, Eu, Gd, and Dy is obtained, thereby achieving the purpose of pre-separating La from Ce, Sm, Eu, Gd, and Dy.