Method for removing organic matters in ammonium perrhenate

Abstract

The invention provides a method for removing organic matters in ammonium perrhenate, and particularly relates to the technical field of hydrometallurgy, the method comprises the following steps: adding oxyacid into an ammonium perrhenate solution, and adjusting the pH to acidity to obtain an acidic ammonium perrhenate solution; adding an adsorbate into the acidic ammonium perrhenate solution, stirring and filtering to obtain adsorption slag containing organic matters and a clean ammonium perrhenate solution; adjusting the pH value of the clean ammonium perrhenate solution to be greater than or equal to 5, then carrying out evaporation concentration, cooling crystallization and filtration to obtain ammonium perrhenate crystals, and drying the ammonium perrhenate crystals to obtain an ammonium perrhenate product. According to the method, the oxyacid is added to adjust the pH value to be acidic, under the strong acidic condition, the solubility of organic matter impurities in the solution is remarkably reduced, the impurities are easy to separate out, then the organic matter impurities are adsorbed and removed through the adsorbate, meanwhile, the added oxyacid can also oxidize part of organic matter into gas to be removed, and therefore the content of the organic matter in the solution is reduced. And the removal effect of organic impurities is excellent.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for removing organic matter in ammonium perrhenate. Background Art

[0002] Ammonium perrhenate is also known as ammonium perrhenate, commonly known as ammonium rhenate. The main methods for purifying ammonium perrhenate are recrystallization, ion exchange-crystallization and extraction, and the most widely used in industry is extraction. During the extraction process, due to phase separation, water-in-oil and dissolution loss, a small amount of organic matter contained in the extracted organic phase will be transferred to the crude ammonium rhenate product. When purifying crude ammonium rhenate, these small amounts of organic impurities are difficult to be removed completely, resulting in excessive carbon content or unstable quality of the product. At present, there are two methods for removing organic impurities. One is to add liquid oxidants such as hydrogen peroxide to oxidize organic impurities, thereby removing organic matter, but liquids such as hydrogen peroxide will bring other metal impurities such as sodium, potassium and magnesium due to the impurity of the oxidant itself, which pollutes the purity of the product; the other is to pass strong oxidants such as ozone, chlorine or fluorine into the ammonium rhenate solution to oxidize and decompose organic matter, but there are production safety risks and it is not suitable for large-scale industrial production. Summary of the invention

[0003] The object of the present invention is to provide a method for removing organic matter from ammonium perrhenate to improve the above-mentioned problem. In order to achieve the above-mentioned object, the technical solution adopted by the present invention is as follows:

[0004] The present application provides a method for removing organic matter from ammonium perrhenate, comprising:

[0005] adding an oxygen-containing acid to an ammonium perrhenate solution to adjust the pH of the ammonium perrhenate solution to acidic to obtain an acidic ammonium perrhenate solution;

[0006] Adding an adsorbate to the acidic ammonium perrhenate solution, stirring, and filtering to obtain a clean ammonium perrhenate solution;

[0007] The pH of the clean ammonium perrhenate solution is adjusted to be greater than or equal to 5, and then evaporated and concentrated, cooled and crystallized, filtered to obtain ammonium perrhenate crystals, and the ammonium perrhenate crystals are dried to obtain ammonium perrhenate with organic matter removed.

[0008] Optionally, the oxygen-containing acid includes at least one of hypochlorous acid, chloric acid, perchloric acid, nitric acid and sulfuric acid.

[0009] Optionally, adjusting the pH of the ammonium perrhenate solution to acidic includes: adjusting the pH of the ammonium perrhenate solution to 1-4.

[0010] Optionally, the adsorbent includes at least one of activated carbon and styrene skeleton aromatic macroporous adsorption resin.

[0011] Optionally, the adsorbate is pretreated before adding the adsorbate to the acidic ammonium perrhenate solution;

[0012] The pretreatment comprises: soaking the activated carbon in a 1wt%-5wt% nitric acid solution for 1-3 hours, or / and boiling the styrene skeleton aromatic macroporous adsorption resin for 3-5 hours.

[0013] Optionally, the volume ratio of the acidic ammonium perrhenate solution to the adsorbate is (1-6):1.

[0014] Optionally, adjusting the pH of the clean ammonium perrhenate solution to be greater than or equal to 5 includes: adjusting the pH of the clean ammonium perrhenate solution to 5-10.

[0015] Optionally, after adding the adsorbate to the acidic ammonium perrhenate solution, the stirring temperature is 10-90° C. and the stirring time is 20-60 min.

[0016] Optionally, the cooling crystallization temperature is 0-5°C and the cooling time is 1-2h.

[0017] Optionally, the temperature for drying the ammonium perrhenate crystals is 100-120° C., and the drying time is 2-4 hours.

[0018] The beneficial effects of the present invention are:

[0019] The present application adjusts the pH of the solution to acidic by adding oxygen-containing acid. Under strong acidic conditions, the solubility of organic impurities in the solution is significantly reduced, and the impurities are easily precipitated. The organic impurities are then adsorbed and removed by the adsorbent. At the same time, the added oxygen-containing acid can also oxidize part of the organic matter into gas for removal. The carbon content in the finally obtained ammonium perrhenate is below 0.0008%, which proves that the removal effect of organic impurities is excellent. In addition, the process of the present application does not require the introduction of toxic gases, and is easy to implement and operate in large-scale industrial production.

[0020] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing embodiments of the present invention. DETAILED DESCRIPTION

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0022] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0023] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0024] The extraction method is one of the unit operations for preparing crude ammonium rhenate products. The extractants used are mainly p204 (CAS No.: 298-07-7) and sulfonated kerosene. During the extraction process, due to phase separation, water-in-oil, dissolution loss and other reasons, a small amount of organic matter (extractant) contained in the extracted organic phase will be transferred to the crude ammonium rhenate product. These small amounts of organic impurities are difficult to be removed during purification, resulting in excessive carbon content or unstable quality of the product. Chinese patent CN101643246A proposes adding liquid oxidants such as hydrogen peroxide to oxidize organic impurities, thereby removing organic matter, but liquids such as hydrogen peroxide will introduce other metal impurities such as sodium, potassium and magnesium due to the impurity of the oxidant itself, which is easy to reduce the purity of the product. "Research on the Removal of Carbon Impurities in Typical Processes for the Preparation of Ammonium Rhenate and Rhenium Powder" - Nonferrous Metals Engineering (Volume 11, Issue 9, September 2021) and Chinese Patent CN110002503A proposed introducing strong oxidants such as ozone, chlorine, and fluorine into the ammonium rhenate solution to oxidize and decompose organic matter. However, these gases are highly toxic and easy to leak during use. Therefore, they have high requirements for equipment and process operations, and are inconvenient to transport and store, highly dangerous, and not suitable for large-scale industrial production.

[0025] In addition, in some special fields, there are very strict requirements on the materials of equipment and devices. For example, aircraft engine blades are cast with high-temperature alloy materials. When rhenium metal is used as an additive to prepare high-temperature alloys, the carbon content of high-purity rhenium metal is required to be less than 0.001%; ​​ammonium perrhenate is the raw material for preparing high-purity rhenium metal, so the raw material high-purity ammonium perrhenate must ensure that the carbon content is less than 0.001%; ​​and the existing methods for removing impurities from ammonium perrhenate are difficult to meet this requirement.

[0026] In order to solve the problems of the prior art, the present application provides a method for removing organic matter from ammonium perrhenate, comprising the steps of:

[0027] S1, adding an oxygen-containing acid to the ammonium perrhenate solution, adjusting the pH to acidic, and obtaining an acidic ammonium perrhenate solution;

[0028] S2, adding an adsorbate to an acidic ammonium perrhenate solution, stirring and filtering to obtain an adsorption residue containing organic matter and a clean ammonium perrhenate solution;

[0029] S3, adjusting the pH of the clean ammonium perrhenate solution to be greater than or equal to 5, then performing evaporation concentration, cooling and crystallization, filtering to obtain ammonium perrhenate crystals, and drying the ammonium perrhenate crystals to obtain an ammonium perrhenate product.

[0030] As an optional embodiment, the ammonium perrhenate solution in step S1 is an ammonium perrhenate solution after extraction treatment or a solution prepared by dissolving high-purity ammonium perrhenate solid, and the rhenium (Re) content in the solution is 10-600 g / L.

[0031] As an optional embodiment, the oxygen-containing acid in step S1 includes at least one of hypochlorous acid, chloric acid, perchloric acid, nitric acid and sulfuric acid. There is no specific requirement for the concentration of the oxygen-containing acid used, and the ammonium perrhenate solution can be adjusted to the required pH. The concentration of the oxygen-containing acid does not affect the removal effect of organic impurities.

[0032] As an optional embodiment, in step S1, adjusting the pH of the ammonium perrhenate solution to acidic includes: adjusting the pH of the ammonium perrhenate solution to 1-4.

[0033] As an optional embodiment, in step S2, the adsorbent includes at least one of activated carbon and styrene skeleton aromatic macroporous adsorption resin, which is the preferred adsorption material in the present application; while other adsorption materials, such as molecular sieves, zeolites, etc., are prone to introduce metal ion impurities and are difficult to handle, so they are not selected.

[0034] As an optional embodiment, in step S2, before adding the adsorbate to the acidic ammonium perrhenate solution, the adsorbate is pretreated;

[0035] As an optional embodiment, the pretreatment includes: soaking the activated carbon in a 1wt%-5wt% nitric acid solution for 1-3 hours, or / and boiling the styrene skeleton aromatic macroporous adsorption resin (in boiling water) for 3-5 hours. The pretreatment can remove trace metal impurities in the adsorbate, thereby ensuring the purity of the ammonium perrhenate after impurity removal.

[0036] As an optional embodiment, in step S2, the volume ratio of the acidic ammonium perrhenate solution to the adsorbate is (1-6):1.

[0037] As an optional embodiment, in step S2, after adding the adsorbate to the acidic ammonium perrhenate solution, the stirring temperature is 10-90° C. and the stirring time is 20-60 min.

[0038] As an optional implementation, in step S3, adjusting the pH of the clean ammonium perrhenate solution to be greater than or equal to 5 includes: adjusting the pH of the clean ammonium perrhenate solution to 5-10.

[0039] As an optional implementation, in step S3, the evaporation concentration multiple is 1-15 times; the cooling crystallization temperature is 0-5°C, the cooling time is 1-2h; the drying temperature is 100-120°C, and the drying time is 2-4h.

[0040] The research in this application found that by adding oxygen-containing acid to adjust the pH of the solution to acidic, under strong acidic conditions, the solubility of organic impurities in the solution is significantly reduced, the impurities are easily precipitated, and then the organic impurities are adsorbed and removed by the adsorbent. This method is significantly better than the existing technology in removing organic impurities.

[0041] The following describes the embodiments of the present invention through specific examples.

[0042] Example 1

[0043] A method for removing organic matter from ammonium perrhenate comprises the steps of:

[0044] S1, adding concentrated nitric acid to an ammonium perrhenate solution containing 20 g / L of Re, wherein the concentration of the concentrated nitric acid is 8 mol / L, adjusting the pH of the solution to 3.0, and stirring uniformly to obtain an acidic ammonium perrhenate solution;

[0045] S2. Add activated carbon to the acidic ammonium perrhenate solution at a volume ratio of solution to solid of 3:1, stir at a constant temperature of 40°C for 1 hour, and filter to obtain activated carbon adsorption residue containing organic matter and clean ammonium perrhenate solution;

[0046] The activated carbon was soaked in a 2 wt % nitric acid solution for 2 h before use;

[0047] S3. Place the clean ammonium perrhenate solution in a high and low temperature integrated machine container, adjust the solution pH to 8 with sodium hydroxide, evaporate and concentrate 10 times, cool and crystallize at 0°C for 2 hours, filter again, take out the ammonium perrhenate crystals, and dry the ammonium perrhenate crystals at 100°C for 2 hours to obtain the ammonium perrhenate product.

[0048] Example 2

[0049] A method for removing organic matter from ammonium perrhenate comprises the steps of:

[0050] S1, adding perchloric acid to an ammonium perrhenate solution containing 400 g / L of Re, wherein the concentration of the perchloric acid is 3 mol / L, adjusting the pH value of the solution to 2.0, and stirring uniformly to obtain an acidic ammonium perrhenate solution;

[0051] S2. Add styrene skeleton aromatic macroporous adsorption resin to the acidic ammonium perrhenate solution at a volume ratio of solution to solid of 2:1, stir at a constant temperature of 90° C. for 1 hour, filter, and obtain activated carbon adsorption residue containing organic matter and clean ammonium perrhenate solution;

[0052] The styrene skeleton aromatic macroporous adsorption resin is boiled in boiling water for 2 hours before use;

[0053] S3. Place the clean ammonium perrhenate solution in a high and low temperature integrated machine container, adjust the solution pH to 5 with sodium hydroxide, evaporate and concentrate by 2 times, cool and crystallize at 5°C for 2 hours, filter again, take out the ammonium perrhenate crystals, and dry the ammonium perrhenate crystals at 110°C for 3 hours to obtain the ammonium perrhenate product.

[0054] Example 3

[0055] A method for removing organic matter from ammonium perrhenate comprises the steps of:

[0056] S1, adding sulfuric acid to an ammonium perrhenate solution containing 40 g / L of Re, wherein the concentration of the sulfuric acid is 10 mol / L, adjusting the pH value of the solution to 1.0, and stirring uniformly to obtain an acidic ammonium perrhenate solution;

[0057] S2. Add styrene skeleton aromatic macroporous adsorption resin to the acidic ammonium perrhenate solution at a volume ratio of solution to solid of 6:1, stir at a constant temperature of 30°C for 2 hours, filter, and obtain activated carbon adsorption residue containing organic matter and clean ammonium perrhenate solution;

[0058] The styrene skeleton aromatic macroporous adsorption resin is boiled in boiling water for 1 hour before use;

[0059] S3. Place the clean ammonium perrhenate solution in a high and low temperature integrated machine container, adjust the solution pH to 6 with sodium hydroxide, evaporate and concentrate 15 times, cool and crystallize at 2°C for 2h, filter again, take out the ammonium perrhenate crystals, and dry the ammonium perrhenate crystals at 120°C for 2h to obtain the ammonium perrhenate product.

[0060] Example 4

[0061] A method for removing organic matter from ammonium perrhenate comprises the steps of:

[0062] S1. Add chloric acid to an ammonium perrhenate solution containing 600 g / L of Re, wherein the concentration of the chloric acid is 1 mol / L, and adjust the pH value of the solution to 4.0 while stirring uniformly to obtain an acidic ammonium perrhenate solution;

[0063] S2. Add activated carbon to the acidic ammonium perrhenate solution at a volume ratio of solution to solid of 4:1, stir at a constant temperature of 20°C for 2 hours, and filter to obtain activated carbon adsorption residue containing organic matter and clean ammonium perrhenate solution;

[0064] The activated carbon was soaked in a 5wt% nitric acid solution for 3h before use;

[0065] S3. Place the clean ammonium perrhenate solution in a high and low temperature integrated machine container, adjust the solution pH to 10 with sodium hydroxide, evaporate and concentrate 10 times, cool and crystallize at 0°C for 1 hour, filter again, take out the ammonium perrhenate crystals, and dry the ammonium perrhenate crystals at 105°C for 4 hours to obtain the ammonium perrhenate product.

[0066] Example 5

[0067] A method for removing organic matter from ammonium perrhenate comprises the steps of:

[0068] S1, adding hypochlorous acid to an ammonium perrhenate solution containing 150 g / L of Re, wherein the concentration of the hypochlorous acid is 5 mol / L, adjusting the pH of the solution to 2.0, and stirring uniformly to obtain an acidic ammonium perrhenate solution;

[0069] S2. Add activated carbon to the acidic ammonium perrhenate solution at a volume ratio of 1:1 between the solution and the solid, stir at a constant temperature of 20° C. for 1 hour, and filter to obtain activated carbon adsorption residue containing organic matter and a clean ammonium perrhenate solution;

[0070] The activated carbon was soaked in a 1 wt % nitric acid solution for 3 h before use;

[0071] S3. Place the clean ammonium perrhenate solution in a high and low temperature integrated machine container, adjust the solution pH to 7 with sodium hydroxide, evaporate and concentrate 5 times, cool and crystallize at 4°C for 2 hours, filter again, take out the ammonium perrhenate crystals, and dry the ammonium perrhenate crystals at 100°C for 3 hours to obtain the ammonium perrhenate product.

[0072] Comparative Example 1

[0073] Method for removing organic matter from ammonium perrhenate using hydrogen peroxide:

[0074] Hydrogen peroxide is added to an ammonium perrhenate solution containing 150 g / L of Re, and 300 ml of a hydrogen peroxide solution with a mass percentage concentration of 60% is added to each kilogram of crude ammonium perrhenate product. The mixture is stirred evenly, and organic matter is removed by forming foam through the oxidation of hydrogen peroxide.

[0075] After removing the foam on the surface of the solution, the solution was filtered at 80°C with a filter cloth of 800 mesh. The filtered filtrate was placed in a cooling device and cooled at -1°C for 120 minutes. The solution was filtered again with a filter cloth of 800 mesh. The crystallized material was taken out and dehydrated by a centrifuge. The crystallized material was placed in an oven and dried evenly at 80°C for 60 minutes to obtain an ammonium perrhenate product.

[0076] In the above Examples 1-5 and Comparative Example 1, the ammonium perrhenate samples used were from the same source, and before impurities were removed, the carbon content in the ammonium perrhenate samples was 0.012%.

[0077] The purity of the ammonium perrhenate products obtained after impurity removal in Examples 1-5 and Comparative Example 1 was determined. The impurity content therein was determined according to YS / T902-2013, and the purity of the ammonium perrhenate was calculated by subtraction. The results showed that the purity of the products in Examples 1-5 and Comparative Example 1 could reach 99.99%.

[0078] The carbon content of the ammonium perrhenate products obtained after impurity removal in Examples 1-5 and Comparative Example 1 was measured by high-frequency combustion infrared absorption method. The results are shown in Table 1:

[0079] Table 1 Carbon content of ammonium perrhenate products of Examples 1-5 and Comparative Example 1

[0080]

[0081]

[0082] As can be seen from Table 1, after the ammonium perrhenate is impurity-removed with oxygen-containing acid in the present application, the carbon content of the product is significantly lower than that of the product of Comparative Example 1 which is impurity-removed with hydrogen peroxide, which proves that the method of the present application has excellent effect on removing organic matter in ammonium perrhenate.

[0083] In addition, the document "Research on the Removal of Carbon Impurities in Typical Processes for the Preparation of Ammonium Rhenate and Rhenium Powder" - Nonferrous Metals Engineering (Volume 11, Issue 9, September 2021) on page 13 records the test results of the carbon content in ammonium rhenate before and after ozone / hydrogen peroxide impurity removal. Among them, the carbon content of ammonium rhenate after ozone impurity removal is 0.0017%, and the carbon content of ammonium rhenate after hydrogen peroxide impurity removal is 0.0023% (the carbon content before impurity removal is 0.0043%). The effect of carbon removal by ozone is better, reducing it by about 60%;

[0084] The method of the present application can reduce the carbon content of ammonium perrhenate with an original carbon content of 0.012% to less than 0.0008% after impurities are removed, and the carbon content is reduced by 93%. The impurity removal effect on organic matter is significantly improved compared with the prior art. In addition, the process of the present application does not require the introduction of toxic gases, is easy to implement and operate in large-scale industrial production, and can produce high-quality ammonium perrhenate products in large quantities.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0086] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for removing organic matter from ammonium perrhenate, characterized in that: include: adding an oxygen-containing acid to an ammonium perrhenate solution to adjust the pH of the ammonium perrhenate solution to acidic to obtain an acidic ammonium perrhenate solution; Adding an adsorbate to the acidic ammonium perrhenate solution, stirring, and filtering to obtain a clean ammonium perrhenate solution; The pH of the clean ammonium perrhenate solution is adjusted to be greater than or equal to 5, and then evaporated and concentrated, cooled and crystallized, filtered to obtain ammonium perrhenate crystals, and the ammonium perrhenate crystals are dried to obtain ammonium perrhenate with organic matter removed.

2. A method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The oxygen-containing acid includes at least one of hypochlorous acid, chloric acid, perchloric acid, nitric acid and sulfuric acid.

3. A method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The step of adjusting the pH of the ammonium perrhenate solution to acidic includes: adjusting the pH of the ammonium perrhenate solution to 1-4.

4. A method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The adsorbent includes at least one of activated carbon and styrene skeleton aromatic macroporous adsorption resin.

5. A method for removing organic matter from ammonium perrhenate according to claim 4, characterized in that: Before adding the adsorbate to the acidic ammonium perrhenate solution, pretreating the adsorbate; The pretreatment comprises: soaking the activated carbon in a 1wt%-5wt% nitric acid solution for 1-3 hours, or / and boiling the styrene skeleton aromatic macroporous adsorption resin for 3-5 hours.

6. A method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The volume ratio of the acidic ammonium perrhenate solution to the adsorbate is (1-6):

1.

7. A method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The step of adjusting the pH value of the clean ammonium perrhenate solution to be greater than or equal to 5 comprises: adjusting the pH value of the clean ammonium perrhenate solution to 5-10.

8. The method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: After the adsorbate is added to the acidic ammonium perrhenate solution, the stirring temperature is 10-90° C. and the stirring time is 20-60 min.

9. The method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The cooling crystallization temperature is 0-5°C, and the cooling time is 1-2h.

10. The method for removing organic matter from ammonium perrhenate according to claim 1, characterized in that: The temperature for drying the ammonium perrhenate crystals is 100-120° C., and the drying time is 2-4 hours.

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