Method for preparing high-purity potassium rhenate from pure rhenium waste

Abstract

The invention relates to a method for preparing high-purity potassium rhenate from pure rhenium waste. The method specifically comprises the following steps: S1, carrying out acid washing on the pure rhenium waste; s2, the pure rhenium waste washed in the step S1 is placed in a rotational flow electrolytic bath to be subjected to electrochemical decomposition; the rhenium in the rhenium waste is gradually dissolved in the electrolyte until the mass volume concentration of the rhenium in the electrolyte is not less than 25g / L, and the electrolyte is a KCl or KOH aqueous solution; s3, the electrolyte obtained in the step S2 is placed in a refrigerated centrifuge to be refrigerated and centrifuged, and potassium rhenate crystals with the uniform particle size are formed; and washing with deionized water at 0-2 DEG C to finish the preparation of the high-purity potassium rhenate. The method for preparing the high-purity potassium rhenate from the pure rhenium waste is short in process, high in efficiency, high in product purity and stable in quality; the recovery rate is high; and the method has the advantages of low auxiliary material consumption, no wastewater generation, obvious environmental protection advantage and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for preparing high-purity potassium rhenate by utilizing pure rhenium waste. Background Art

[0002] The mass fraction of rhenium in the earth's crust is only 1×10 -9 , belongs to the scattered metal, there is no independently smeltable rhenium mineral. Rhenium has a melting point of up to 3180℃, second only to tungsten and carbon, which makes it have excellent stability in high temperature environment. Rhenium has good oxidation resistance and corrosion resistance, which makes it show excellent performance in high temperature and corrosive environment. The extraction of rhenium metal is difficult, mainly due to its rarity, unique physical and chemical properties and challenging extraction process. These factors work together to make the extraction of rhenium metal a complex and costly process. At the same time, due to its excellent properties such as high melting point, high hardness, creep resistance, corrosion resistance and good plasticity, rhenium occupies a very important position in the cutting-edge scientific fields of chemical industry, metallurgy, aerospace and national defense. In the process of pure Re metal materials being made into plates, bars and wires, because the yield rate is generally less than 70%, a lot of scraps and waste products are often produced, and the rhenium in the residue must be recycled.

[0003] The main processes for recovering rhenium from pure rhenium waste are: pyrometallurgical process, hydrometallurgical process, pyrometallurgical-hydrometallurgical process and electrochemical metallurgical process. The pyrometallurgical process has a long reaction time, incomplete oxidation, and low recovery rate. The single use of this method to recover rhenium is not economical and has serious environmental pollution. At the same time, the energy consumption is high and the collection of rhenium is relatively complicated. The unit production capacity of the hydrometallurgical process is low, and it is easy to produce waste liquid and waste gas, with high energy consumption and low recovery rate. The pyrometallurgical-hydrometallurgical process has a long process, is easy to produce waste liquid and waste gas, and has high energy consumption. The existing electrochemical metallurgical process has poor versatility, many auxiliary materials and by-products, and is easy to produce a large amount of waste liquid. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing high-purity potassium rhenate using pure rhenium waste, which has the advantages of short process, high degree of control in the production process, high product purity and stable quality, high rhenium metal recovery rate, small amount of auxiliary materials, no wastewater generation, obvious environmental advantages and low cost.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing high-purity potassium rhenate using pure rhenium waste, which is specifically carried out according to the following steps:

[0006] S1. Acid washing of pure rhenium waste;

[0007] S2, placing the pure rhenium waste material washed in step S1 in a cyclone electrolytic cell for electrochemical decomposition; as the electrolysis time goes by, the rhenium in the rhenium waste material gradually dissolves in the electrolyte until the mass volume concentration of rhenium in the electrolyte is not less than 25 g / L; wherein the electrolyte is an aqueous solution of KCl or KOH with a mass volume concentration of 30 to 80 g / L;

[0008] S3, placing the electrolyte obtained in step S2 in a refrigerated centrifuge for refrigerated centrifugation to form potassium rhenate crystals with uniform particle size; washing with 10 to 20 L of 0 to 2° C. deionized water to complete the preparation of high-purity potassium rhenate.

[0009] Among them, during the cyclonic electrolysis process, the reaction at the anode is:

[0010] Re+7OH - -7e=ReO 7 - +4H 2 O

[0011] 2Cl - -2e=Cl 2

[0012] The cathode reaction is:

[0013] 2H 2 O+2e=H 2 ↑+2OH -

[0014] Furthermore, in step S1, the acid washing method is specifically as follows: placing the pure rhenium waste in pickling water, and passing compressed air into the pickling water for cleaning for 10 to 30 minutes; taking out the pure rhenium waste, and washing it with two-stage deionized water, and passing compressed air for cleaning for 1 to 3 minutes during the cleaning process.

[0015] Furthermore, in step S1, the pickling water is a hydrochloric acid aqueous solution with a mass concentration of 1 to 3%.

[0016] Furthermore, in step S2, the anode of the cyclone electrolytic cell is a titanium mesh with a surface coating of ruthenium and iridium; and the cathode is 316L stainless steel.

[0017] Furthermore, in step S2, the voltage of the electrolysis reaction in the cyclone electrolytic cell is 5.0-12.0V, and the current is 800A.

[0018] Furthermore, in step S2, the gas generated by the cyclone electrolysis is introduced into a KOH aqueous solution with a mass percentage concentration of 3-5%, and the absorption liquid after absorption is returned to the cyclone electrolysis cell.

[0019] Furthermore, in step S3, the temperature of the refrigerated centrifuge is -10 to -30°C, and the rotation speed is 800 to 1200 r / min.

[0020] Furthermore, the mother liquor after centrifugation in step S3 and the washing water after washing are transferred to the cyclone electrolytic cell in step S2.

[0021] The invention has the following advantages: the invention discloses a method for preparing high-purity potassium rhenate by utilizing pure rhenium waste, wherein rhenium in the pure rhenium waste is oxidized and leached by cyclone electrolysis to obtain a potassium rhenate solution, and rhenium in the solution is extracted by a one-step method of freezing centrifugation to form a potassium rhenate crystalline solid; compared with the prior art, the invention has a simple process and strong versatility, and does not have the problem of collecting rhenium in oxidative roasting, and the recovery rate of rhenium is high, and the quality of the obtained potassium rhenate product is stable; a small number of auxiliary materials are required, and the auxiliary materials are recycled in the process, and no waste water or waste salt is generated, and the environmental protection advantage is obvious; the process flow is short, and there is no need to increase the rhenium concentration in the potassium rhenate solution by concentration, and the energy consumption is low, the efficiency is high, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a process flow chart of a method for preparing high-purity potassium rhenate using pure rhenium waste. DETAILED DESCRIPTION

[0023] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0024] Embodiment 1

[0025] Reference Figure 1 As shown, industrial-grade hydrochloric acid is diluted with deionized water to a mass concentration of 3% and then injected into a pickling tank, a hanging basket of pure rhenium waste (rhenium content>99%) is placed in the pickling tank, compressed air is introduced into the pickling tank for cleaning for 10 minutes, and then the hanging basket is placed in two-stage deionized water tanks for cleaning, and compressed air is introduced for 1 minute respectively. After the two-stage deionized water cleaning is completed, the hanging basket discharge valve is opened to load the waste into the cyclone electrolytic cell, a KCl solution with a concentration of 80g / L is injected into the circulation tank, the circulation pump outlet valve is turned to the electrolytic circulation tank, the circulation pump is started, the electrolytic cell voltage is set to 9.0V, the current is 800A, the power of the electrolytic cell is turned on, until the concentration of rhenium in the electrolyte is 30.1g / L, the refrigerated centrifuge is started, the temperature is set to -20°C, and the speed is 1000r / min, and potassium rhenate crystals with uniform particle size are obtained by refrigerated centrifugation. The potassium rhenate solid is centrifugally washed with 20 L of 0-2° C. deionized water to obtain high-purity potassium rhenate.

[0026] According to GDMS-MS test, the purity of potassium rhenate is greater than 99.99% and the recovery rate of rhenium reaches 99.6%.

[0027] Embodiment 2

[0028] Reference Figure 1 As shown, industrial-grade hydrochloric acid is diluted with deionized water to a mass concentration of 2% and then injected into a pickling tank, a hanging basket of pure rhenium waste (rhenium content>99%) is placed in the pickling tank, compressed air is introduced into the pickling tank for cleaning for 20 minutes, and then the hanging basket is placed in two-stage deionized water tanks for cleaning, and compressed air is introduced for 2 minutes respectively. After the two-stage deionized water cleaning is completed, the hanging basket discharge valve is opened to load the waste into the cyclone electrolytic cell, a KCl solution with a concentration of 40g / L is injected into the circulation tank, the circulation pump outlet valve is turned to the electrolytic circulation tank, the circulation pump is started, the electrolytic cell voltage is set to 9.0V, the current is 800A, the power of the electrolytic cell is turned on, until the concentration of rhenium in the electrolyte is 25.5g / L, the refrigerated centrifuge is started, the temperature is set to -20°C, and the speed is 1200r / min, and potassium rhenate crystals with uniform particle size are obtained by refrigerated centrifugation. The potassium rhenate solid is centrifugally washed with 10 L of 0-2° C. deionized water to obtain high-purity potassium rhenate.

[0029] According to GDMS-MS test, the purity of potassium rhenate is greater than 99.99% and the recovery rate of rhenium reaches 99.4%.

[0030] Embodiment 3

[0031] Reference Figure 1 As shown, industrial-grade hydrochloric acid is diluted with deionized water to a mass concentration of 1% and then injected into a pickling tank, a hanging basket of pure rhenium waste (rhenium content>99%) is placed in the pickling tank, compressed air is introduced into the pickling tank for cleaning for 30 minutes, and then the hanging basket is placed in two-stage deionized water tanks for cleaning, and compressed air is introduced for 3 minutes respectively. After the two-stage deionized water cleaning is completed, the hanging basket discharge valve is opened to load the waste into the cyclone electrolytic cell, a KOH solution with a concentration of 50g / L is injected into the circulation tank, the circulation pump outlet valve is turned to the electrolytic circulation tank, the circulation pump is started, the electrolytic cell voltage is set to 9.0V, the current is 800A, the power of the electrolytic cell is turned on, until the concentration of rhenium in the electrolyte is 27.4g / L, the refrigerated centrifuge is started, the temperature is set to -20°C, and the speed is 800r / min, and potassium rhenate crystals with uniform particle size are obtained by refrigerated centrifugation. The potassium rhenate solid is centrifugally washed with 15 L of 0-2° C. deionized water to obtain high-purity potassium rhenate.

[0032] According to GDMS-MS test, the purity of potassium rhenate is greater than 99.99% and the recovery rate of rhenium reaches 99.5%.

[0033] In the above embodiment, the anode of the cyclone electrolytic cell is a mesh titanium material, the surface coating of the titanium mesh is ruthenium iridium, the cathode is made of 316L material, the electrolyte is injected into the circulation tank, the outlet of the circulation tank is connected to the inlet of the electrolytic cell through a circulation pump, the water outlet of the electrolytic cell is connected to the inlet of the circulation tank, the other outlet of the circulation pump is connected to the refrigerated centrifuge, the centrifuged mother liquor enters the mother liquor tank, and the mother liquor tank outlet pump is connected to the circulation tank. The outlet valve of the circulation pump is turned to the electrolytic circulation tank, and the circulation pump is started. As the electrolysis time passes, the rhenium in the rhenium waste gradually dissolves in the electrolyte.

[0034] The method for preparing high-purity potassium rhenate from pure rhenium waste in the above embodiment comprises the following steps: oxidizing and leaching rhenium in pure rhenium waste by cyclone electrolysis to obtain a potassium rhenate solution, and extracting rhenium in the solution by a one-step method of frozen centrifugation to form a potassium rhenate crystalline solid; compared with the prior art, the process is simple and has strong versatility, there is no problem of rhenium collection during oxidative roasting, the recovery rate of rhenium is high, and the quality of the obtained potassium rhenate product is stable; the required auxiliary materials are few in variety, the auxiliary materials are recycled in the process, no wastewater or waste salt is generated, and the environmental protection advantage is obvious; the process flow is short, there is no need to increase the rhenium concentration in the potassium rhenate solution by concentration, the energy consumption is low, the efficiency is high, and the cost is low.

[0035] The above embodiments should not limit the present invention in any way, and any technical solutions obtained by equivalent replacement or equivalent conversion shall fall within the protection scope of the present invention.

Claims

1. A method for preparing high-purity potassium rhenate using pure rhenium waste, characterized in that: The specific steps are as follows: S1. Acid washing of pure rhenium waste; S2, placing the pure rhenium waste washed in step S1 in a cyclone electrolytic cell for electrochemical decomposition; As the electrolysis time goes by, the rhenium in the rhenium waste gradually dissolves in the electrolyte until the mass volume concentration of rhenium in the electrolyte is not less than 25 g / L; wherein the electrolyte is an aqueous solution of KCl or KOH with a mass volume concentration of 30 to 80 g / L; S3, placing the electrolyte obtained in step S2 in a refrigerated centrifuge for refrigerated centrifugation to form potassium rhenate crystals with uniform particle size; washing with 10 to 20 L of 0 to 2° C. deionized water to complete the preparation of high-purity potassium rhenate.

2. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 1, characterized in that: In step S1, the acid washing method is specifically as follows: placing the pure rhenium waste in pickling water, and passing compressed air into the pickling water for cleaning for 10 to 30 minutes; taking out the pure rhenium waste, and washing it with two-stage deionized water, and passing compressed air for cleaning for 1 to 3 minutes during the cleaning process.

3. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 2, characterized in that: In step S1, the pickling water is a hydrochloric acid aqueous solution with a mass concentration of 1 to 3%.

4. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 1, characterized in that: In step S2, the anode of the cyclone electrolytic cell is a titanium mesh with a surface coating of ruthenium and iridium; the cathode is 316L stainless steel.

5. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 1, characterized in that: In step S2, the voltage of the electrolysis reaction in the cyclone electrolytic cell is 5.0-12.0V, and the current is 800A.

6. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 1, characterized in that: In step S2, the gas generated by the cyclone electrolysis is introduced into a KOH aqueous solution with a mass percentage concentration of 3-5%, and the absorbed solution is returned to the cyclone electrolysis cell.

7. The method for preparing high-purity potassium rhenate using pure rhenium waste according to claim 1, characterized in that: In step S3, the temperature of the refrigerated centrifuge is -10 to -30°C, and the rotation speed is 800 to 1200 r / min.

8. A method for preparing high-purity potassium rhenate using pure rhenium waste according to any one of claims 1 to 7, characterized in that: The mother liquor after centrifugation in step S3 and the washing water after washing are transferred to the cyclone electrolytic cell in step S2.

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