CN100391847C - Preparation method and device of rare earth salt - Google Patents

Abstract

The invention belongs to nonferrous metallurgy technology, and a preparation method and device of rare earth salts. The process is as follows: the concentration of the rare earth salt solution is prepared: 0.04-1.2mol/l, the concentration of the precipitating agent: 0.1-3.5mol/l; the mass flow ratio of the above prepared solution is: REO:precipitating agent=1:1.1-1.7 , when the temperature is 15-60°C and the rotation speed is 150-890 rpm, after mixing for 3-30 minutes, it enters the clarifier through the outlet of the mixer and settles; then it is injected into the plate and frame filter press through the mud pump to obtain Rare earth precipitated salts. Its device: the raw material feed hole and the precipitant feed hole are set at the bottom of the cylinder, the bottom of the stirring paddle is a vortex stirring blade, the upper blade is a mixing chamber at the bottom of the cone in the center of the cylinder, and the upper part of the cylinder is Equipped with porous fog plate. The invention adopts rapid sedimentation for solid-liquid separation, realizes the continuous production of sedimentation, improves the production capacity and production efficiency of the equipment, and improves the product quality. The pressure filtration treatment of wastewater not only avoids the loss of yield caused by control errors, but also ensures the simplification of the wastewater treatment process.

Description

Preparation method and device of rare earth salt

1. Technical field

The invention belongs to nonferrous metallurgical technology, and relates to a preparation method and implementation device of rare earth salt.

2. Background technology

The current production methods of rare earth salts (single element or mixed elements) mainly include the following two methods: (1) After the rare earth solution is prepared, a solid precipitation (transformation) agent is directly added to form a rare earth salt; (2) The rare earth solution After preparation, it is directly added to the precipitation (transformation) agent solution to form rare earth salts.

In the existing precipitation process, with the addition of the precipitant, the precipitation conditions at different stages are changing, causing changes in the formation of rare earth salts, and as the concentration of the rare earth solution decreases, the addition rate of the precipitant increases or the overall addition is excessive, and finally This causes fluctuations in the crystallization process of rare earth salts and inconsistent product quality. As far as multiple batches are concerned, due to the inability to achieve consistent operations, differences also occur between batches, which increases the fluctuation of product quality.

The production of rare earth salts by the existing technology usually adopts direct mixing and batch operation, and the formation process takes a long time. Rare earth salts are easy to form peritectic, adsorption and other subsidiary processes, resulting in difficult product quality control, large quality fluctuations, and poor consistency. In addition, the adoption of intermittent operation process will inevitably lead to increased storage and transshipment volume before and after the process, huge storage and reaction equipment, and a large overall investment. In the precipitation (transformation) process, the corresponding non-rare earth salt solution is formed in a large amount, and the concentration is low and it is not easy to recycle.

3. Contents of the invention

The technical problem solved by the present invention is: to precisely control the feed amount, to separate the rare earth salts from the non-rare earth salt solution, to achieve continuous production process and to ensure the consistency of product quality; at the same time, the process steps and the times of solid-liquid separation are reduced, The yield of rare earth is improved, and the recycling of non-rare earth salt solution is improved.

The process steps of the continuous precipitation method for producing rare earth salts in the present invention:

The following process steps are used:

(1) preparing the rare earth salt solution to a concentration of 0.04-1.2mol/l, and preparing the precipitant to a concentration of 0.1-3.5mol/l;

(2) The above-mentioned prepared rare earth salt solution enters the latent chamber of the mixer through the raw material feed port and the precipitant through the reagent feed port according to the mass flow ratio: REO: precipitant=1: 1.1-1.7, and the temperature is 15-75 ℃, the rotation speed is 150-890 rpm, and the above-mentioned raw materials and reagents are sucked into the cylinder by the vortex stirring paddle, and the mixing process is completed by the inclined stirring paddle and the baffle plate, and the mixing is 3-30 minutes;

(3) The mixed material enters the clarifier through the discharge port of the mixer to settle, and the aerosol generated in the reaction process is evenly eliminated through the mist outlet plate;

(4) inject the settled material into the plate and frame filter press through the mud pump to obtain the precipitated rare earth salt.

REO is a rare earth oxide and its salts.

The rare earth salt solution is rare earth sulfate, rare earth hydrochloride or rare earth nitrate.

Precipitating agent is ammonium bicarbonate, oxalic acid, ammonia water, sodium hydroxide, sodium bicarbonate or sodium carbonate.

The device for producing rare earth salts consists of a cylinder, a baffle, a raw material inlet, a precipitant inlet, and a discharge outlet. The raw material inlet and the precipitant inlet are located at the bottom of the cylinder and located in the center of the cylinder. The lower bottom of the stirring paddle is a vortex stirring paddle, and the upper paddle is an inclined stirring paddle. There is a mixer latent chamber at the bottom of the cone in the center of the cylinder, and a porous fog plate is provided on the upper part of the cylinder.

The basic point of the present invention is to choose an easy-to-control solution precipitation method. Through the allocation of raw material concentration and temperature, and the allocation of precipitant concentration and temperature, the initial conditions for forming precipitated salts are consistent, and the metering pump is used to continuously control the two materials. Flow rate, through high-speed mixing to complete the formation process of salts in a short time, overcome the adsorption of harmful elements and peritectic, and use centrifugal sedimentation and centrifugal filtration to complete the separation of salts and mother liquor simultaneously, ensuring the consistency of their physical and chemical properties Consistency to ensure product quality.

The improvement of the equipment of the present invention combines the advantages of conventional settling and mixing equipment, so that the technological process can be completed efficiently. The process reduces the steps of the original process and the times of solid-liquid separation, and improves the yield of rare earth. In addition, the use of ammonium bicarbonate solution for precipitation eliminates the dissolution reaction time of ammonium bicarbonate in the original process, accelerates the carbon precipitation process, reduces the tolerance and adsorption of non-rare earth impurities in the precipitation process, and improves product quality. Thereby canceling the next step of washing process, controlling the generation of washing wastewater, relatively increasing the concentration of ammonium salt in wastewater, reducing the total amount of wastewater, and creating conditions for wastewater treatment.

Output products: ungrouped rare earth carbonate 46.3 tons REO≥45%

Carbonated 3 23.6 tons of REO ≥ 45 %

Carbonic acid 4 14 tons REO ≥ 45 %

Oxytic acid 9.3 tons REO ≥ 35 %

  Lanthanum oxalate 7.5 tons REO≥35%

    Lanthanum Hydroxide                                                                                

The invention adopts rapid sedimentation for solid-liquid separation, fundamentally realizes the continuity of the process, changes the intermittent operation into a continuous operation, improves the production capacity of the equipment, and doubles the production efficiency. The pressure filtration treatment of wastewater is not only to avoid the loss of yield caused by control errors, but also to ensure the simplification of the wastewater treatment process.

4. Description of drawings

Accompanying drawing 1 is process flow chart of the present invention;

Accompanying drawing 2 is the structural representation of the device of the present invention.

5. Specific implementation

Embodiment 1: use rare earth sulfate solution to produce mixed rare earth carbonate continuous precipitation method process steps:

(1) The rare earth sulfate mixed solution is prepared as a concentration of 0.04-0.3mol/l, and the precipitant ammonium bicarbonate is prepared as a concentration of 1-1.5mol/l;

(2) The rare earth sulfuric acid mixed solution prepared above is passed through the raw material feed port 9, and the ammonium bicarbonate solution is passed through the reagent feed port 8 according to the mass flow ratio: REO: NH ₄ HCO ₃ =1: 1.3-1.7 into the latent mixer In chamber 7, the temperature is 15-45°C, and the rotating speed is 350-750 rpm. The above-mentioned raw materials and reagents are sucked into the cylinder 4 by using the vortex stirring paddle 6, and the mixing process is completed by the inclined stirring paddle 3 and the baffle plate 5. Mixing 3 -12 minutes;

(3) the mixed rare earth carbonate that the reaction generates enters in the clarifier through the discharge port 1 of the mixer and settles, and the aerosol produced by the reaction process is evenly removed by the mist plate 2;

(4) injecting the settled mixed rare earth carbonate into a plate and frame filter press through a mud pump to obtain a mixed rare earth carbonate precipitated salt.

Embodiment 2: produce cerium carbonate continuous precipitation method process step with cerium nitrate solution:

(1) The cerium nitrate solution is prepared as a concentration of 0.1-1mol/l, and the precipitant ammonium bicarbonate is prepared as a concentration of 1-3.5mol/l;

(2) The cerium nitrate solution prepared above passes through the raw material feed port 9, and the ammonium bicarbonate solution enters the latent chamber of the mixer through the reagent feed port 8 according to the mass flow ratio: REO: NH ₄ HCO ₃ =1: 1.3-1.7 7. The temperature is 25-50°C, the speed is 255-600 rpm, and the above-mentioned raw materials and reagents are sucked into the cylinder 4 by using the vortex stirring paddle 6, and the mixing process is completed by the inclined stirring paddle 3 and the baffle plate 5, and the mixing process is 5- 12 minutes;

(3) the mixed rare earth carbonate that the reaction generates enters in the clarifier through the discharge port 1 of the mixer and settles, and the aerosol produced by the reaction process is evenly removed by the mist plate 2;

(4) Inject the settled cerium carbonate into a plate and frame filter press through a mud pump to obtain cerium carbonate precipitated salt.

Embodiment 3: Production of rare earth oxalate continuous precipitation method process steps with cerium chloride solution:

(1) preparing the rare earth cerium chloride solution to a concentration of 0.04-0.6mol/l, and simultaneously preparing the precipitant oxalic acid to a concentration of 0.7-1.1mol/l;

(2) The cerium chloride solution prepared above is passed through the raw material feed port 9, and the oxalic acid solution is passed through the reagent feed port 8 according to the mass flow ratio: REO: H ₂ C ₂ O ₄ =1: 1.1-1.6 into the latent mixer In chamber 7, the temperature is 15-75°C, the rotating speed is 180-325 rpm, and the above-mentioned raw materials and reagents are sucked into the cylinder 4 by using the vortex stirring paddle 6, and the mixing process is completed by the inclined stirring paddle 3 and the baffle plate 5, and the mixing process is 10 -15 minutes;

(3) the cerium oxalate generated by the reaction enters the clarifier through the outlet 1 of the mixer and settles, and the aerosol produced by the reaction process is evenly removed by the mist plate 2;

(4) Inject the settled cerium oxalate into a plate and frame filter press through a mud pump to obtain cerium oxalate precipitated salt.

Claims (4)

1. the preparation method of rare-earth salts is characterized in that: adopt following processing step:

(1) rare earths salt being formulated as concentration is 0.04-1.2mol/l, simultaneously precipitation agent is formulated as concentration 0.1-3.5mol/l;

(2) with the above-mentioned rare earths salt for preparing by material inlet (9), precipitation agent by reagent opening for feed (8) in mass rate ratio: REO: precipitation agent=1: 1.1-1.7 enters the mixing tank chamber (7) of diving, temperature is 15-75 ℃, rotating speed is 150-890 rev/min, utilize eddy current stirring rake (6) with finishing mixing process by inclination stirring rake (3) and traverse baffle (5) in above-mentioned raw materials and the reagent suction cylindrical shell (4), mixed 3-30 minute;

(3) discharge port (1) of mixture by mixing tank entered carry out sedimentation in the settler, the aerosol that reaction process produced is evenly got rid of by going out mist plate (2);

(4) sedimentation is good material obtains precipitating rare earth salt by slush pump injection plate-and-frame filter press.

2. the preparation method of rare-earth salts according to claim 1, it is characterized in that: rare earths salt is sulfuric acid rare earth, salt acid rare earth or rare earth nitrate.

3. the preparation method of rare-earth salts according to claim 1, it is characterized in that: precipitation agent is bicarbonate of ammonia, oxalic acid, ammoniacal liquor, sodium hydroxide, sodium bicarbonate or yellow soda ash.

4. implement the device of method according to claim 1 for one kind, form by cylindrical shell (4), traverse baffle (5), material inlet (9), precipitation agent opening for feed (8), discharge port (1), it is characterized in that: material inlet (9) and precipitation agent opening for feed (8) are located at cylindrical shell (4) bottom, be positioned at that the bottom is eddy current stirring rake (6) under the stirring rake at cylindrical shell (4) center, the upper strata blade is inclination stirring rake (3), be provided with the latent chamber (7) of mixing tank at the bottom of cylindrical shell (4) center cone, cylindrical shell (4) top is provided with porous and goes out mist plate (2).

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