Novel method for preparing high-purity anhydrous ferric trichloride

Abstract

The invention relates to a novel method for preparing high-purity anhydrous ferric trichloride, which is technically characterized by comprising the following steps of: S1, filling 5000mg of high-purity FeCl2. 4H2O crystal particles into a polytetrafluoroethylene tank protected by argon atmosphere, heating to 220-225 DEG C by using microwaves or / and light waves, arranging a tail gas absorption device above, cooling the absorbed mixed gas to form a liquid state, collecting the liquid state for reutilization, and recycling the liquid state by using the tail gas absorption device; heating is conducted for 20 min to 30 min; s2, small blocky solids of anhydrous FeCl2 are put into a grinding machine groove protected by argon to be ground, and grinding is stopped after the diameter of particles ranges from 0.1 micrometer to 5 micrometers; and S3, loading the powdery anhydrous FeCl2 particles into a stirring and grinding reaction kettle, stirring and grinding at 50-90r / min, meanwhile, adding dried high-purity chlorine gas into the bottom of the reaction kettle, and terminating the reaction when the pressure is 0.10-0.11 MPa, the chlorine gas and the anhydrous FeCl2 powder are subjected to an exothermic reaction (90 DEG C) and Fe < 2 + > is less than or equal to 0.15 wt%, so as to obtain the powdery anhydrous FeCl3. The method has the advantages of short process flow, capability of being operated at normal temperature and normal pressure, low energy consumption required by reaction, high final product purity and the like.

Description

Technical Field

[0001] The present invention relates to using high-purity FeCl2·4H2O (crystalline particles) as raw material and producing anhydrous high-purity FeCl3 (powdered solid) through three steps. Background Art

[0002] In the prior art, the method for preparing high-purity anhydrous ferric chloride generally adopts a method of dissolving iron (III) chloride salt and then drying. However, this method has the following problems: A large amount of water needs to be added when dissolving iron (III) chloride salt, making it difficult to control the purity of anhydrous ferric chloride during the preparation process; The drying process requires high temperature drying, high energy consumption, and is prone to produce harmful gases.

[0003] Therefore, a new method for preparing high-purity anhydrous ferric chloride is needed to solve the problems existing in the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a new method for preparing high-purity anhydrous ferric chloride, which fundamentally solves the above problems and has the advantages of short process flow, operability at normal temperature and pressure, low energy consumption required for reaction, high purity of final product, etc.

[0005] To achieve the above object, the present invention provides the following technical solution: The new method for preparing high-purity anhydrous ferric chloride comprises the following technical points: Step S1, 5000 mg of high-purity FeCl2·4H2O crystal particles are placed in a polytetrafluoroethylene tank protected by an argon atmosphere, and heated to 220°C~225°C by microwave or / and light wave, and a tail gas absorption device is arranged on the top, and the absorbed mixed gas is cooled to form a liquid for collection and reuse, and heated for 20min~30min; when no mixed gas is discharged, the reaction is terminated, and anhydrous FeCl2 (small block solid) is immediately obtained; Step S2, putting the small solid pieces of anhydrous FeCl2 into a grinding machine tank protected by argon gas and grinding them until the particle diameter reaches 0.1 μm to 5 μm; Step S3, the powdered anhydrous FeCl2 particles are placed in a stirred mill reactor and stirred at 50-90 r / min. At the same time, high-purity chlorine gas after drying is added to the bottom of the reactor at 0.10-0.11 MPa. The chlorine gas reacts with the anhydrous FeCl2 powder exothermically (90°C). 2+ The reaction was terminated when the content was ≤0.15wt%; anhydrous FeCl3 and Fe 3+ ≥33wt%, FeCl3≥95.85wt%.

[0006] Beneficial effects of the present invention: No need to add a large amount of water, so that the purity of anhydrous ferric chloride can be effectively controlled during the preparation process; It adopts vacuum drying, does not require high-temperature drying, has low energy consumption, and does not produce harmful gases.

[0007] In summary, the preparation method of the present invention is simple to operate, saves time, labor, money, is safe and reliable, and is environmentally friendly, especially with significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0009] The present invention is further described below in conjunction with specific implementations.

[0010] Example 1 Step S1, 5000 mg of high-purity FeCl2·4H2O crystal particles are placed in a polytetrafluoroethylene tank protected by an argon atmosphere, and heated to 220°C~225°C by microwave or / and light wave, and a tail gas absorption device is arranged on the top, and the absorbed mixed gas is cooled to form a liquid for collection and reuse, and the heating is performed for 20~25 minutes; when no mixed gas is discharged, it is confirmed that the water in the FeCl2 raw material is completely removed, and the heating is terminated; 2480 mg of anhydrous FeCl2 solid block is obtained; Step S2, putting the anhydrous FeCl2 block solid into a grinder protected by argon gas for crushing and grinding, and stopping the grinding after the particle size reaches 0.1 μm to 5 μm; Step S3, the powdered anhydrous FeCl2 particles are placed in a stirred mill reactor and stirred at 50-80 r / min. At the same time, high-purity chlorine gas after drying is added to the bottom of the reactor at 0.10-0.11 MPa. The chlorine gas reacts with the anhydrous FeCl2 powder to produce an exothermic reaction (90°C). 2+ The reaction was terminated when ≤0.15wt%; 3100mg of anhydrous FeCl3 was obtained. 3+ It is 33.2wt%; the anhydrous FeCl3 is 96.43wt%, which is better than the Class I requirement of the national standard GB / T4482-2018.

[0011] Example 2 Step S1, 6000 mg of high-purity FeCl2·4H2O crystal particles are placed in a polytetrafluoroethylene tank protected by an argon atmosphere, and heated to 220°C~225°C by microwave or / and light wave, and a tail gas absorption device is arranged on the top, and the absorbed mixed gas is cooled to form a liquid for collection and reuse, and heated for 20~26 minutes; when no mixed gas is discharged, or FeCl2≥98.5wt%, after confirming that the water in the FeCl2 raw material is completely removed, the heating is terminated to obtain 2970 mg of anhydrous FeCl2 solid block; Step S2, putting the anhydrous FeCl2 block solid into a grinder protected by argon gas for crushing and grinding, and stopping the grinding after the particle size reaches 0.1 μm to 5 μm; Step S3, the powdered anhydrous FeCl2 particles are placed in a stirred mill reactor and stirred at 50-90 r / min. At the same time, high-purity chlorine gas after drying is added to the bottom of the reactor at 0.10-0.11 MPa; the chlorine gas reacts with the anhydrous FeCl2 powder exothermically (90°C), and Fe 2+ The reaction was terminated when ≤0.15wt%; 3727mg of anhydrous FeCl3 was obtained. 3+ It is 33.8wt%, and the FeCl3 in sewage is 98.17wt%, which is better than the Class I requirement of the national standard GB / T4482-2018.

[0012] Example 3 Step S1, 7000 mg of high-purity FeCl2·4H2O crystal particles are placed in a polytetrafluoroethylene tank protected by an argon atmosphere, and heated to 220°C~225°C by microwave or / and light wave, and a tail gas absorption device is arranged on the top, and the absorbed mixed gas is cooled to form a liquid for collection and reuse, and heated for 20~27 minutes; when no mixed gas is discharged, or FeCl2≥98.5wt%, after confirming that the water in the C raw material is completely removed by high temperature, the heating is terminated to obtain 3460 mg of anhydrous FeCl2 solid block; Step S2, putting the anhydrous FeCl2 block solid into a grinder protected by argon gas for crushing and grinding, and stopping the grinding after the particle size reaches 0.1 μm to 5 μm; Step S3, the powdered anhydrous FeCl2 particles are placed in a stirred mill reactor and stirred at 60-90 r / min. At the same time, high-purity chlorine gas after drying is added to the bottom of the reactor at 0.10-0.11 MPa. The chlorine gas reacts with the anhydrous FeCl2 powder exothermically (90°C). 2+ The reaction was terminated when ≤0.15wt%; 4342mg of anhydrous FeCl3 was obtained; Fe 3+ It is 33.7wt%, and the FeCl3 in sewage is 97.88wt%, which is better than the Class I requirement of the international GB / T4482-2018.

Claims

1. A new method for preparing high-purity anhydrous ferric chloride, characterized in that: The following steps are involved: Step S1, 5000 mg of high-purity FeCl2·4H2O crystal particles are placed in a polytetrafluoroethylene tank protected by an argon atmosphere, and heated to 220°C~225°C by microwave or / and light wave, and a tail gas absorption device is arranged on the top, and the absorbed mixed gas is cooled to form a liquid for collection and reuse, and heated for 20min~30min; when no mixed gas is discharged, the reaction is terminated, and anhydrous FeCl2 (small block solid) is immediately obtained; Step S2, putting the small solid pieces of anhydrous FeCl2 into a grinding machine tank protected by argon gas and grinding them until the particle diameter reaches 0.1 μm to 5 μm; Step S3, the powdered anhydrous FeCl2 particles are placed in a stirred mill reactor and stirred at 50-90 r / min. At the same time, high-purity chlorine gas after drying is added to the bottom of the reactor at 0.10-0.11 MPa. The chlorine gas reacts with the anhydrous FeCl2 powder exothermically (90°C). 2+ The reaction is terminated when the concentration is ≤0.15wt% to obtain powdered anhydrous FeCl3.

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