Preparation method of 4N high-purity rhenium powder

Abstract

The application discloses a preparation method of 4N high-purity rhenium powder and belongs to the field of metal processing. The method uses common 3N high-purity ammonium perrhenate as raw material, and after pretreatment, the target product of 4N can be obtained through specific pickling. The method has simple operation steps, low equipment requirement and low dependence on human operation, and can guarantee the stability of product quality in the process of industrialized scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal processing, in particular to a preparation method of 4N high-purity rhenium powder. BACKGROUND

[0002] Metal rhenium is a rare metal with high melting point, high density, high mechanical strength and high chemical stability, which is widely used in aerospace, military, medical, chemical and other fields. However, the existing preparation methods of metal rhenium powder are mainly hydrogen reduction method or wet method, which have high requirements for raw material quality and equipment, so the production difficulty and cost are difficult to reduce. Although some laboratory methods have lower production difficulty and cost, the artificial operation process is complicated, and it is difficult to guarantee the product quality stability. SUMMARY

[0003] Based on the defects of the prior art, the purpose of the present application is to provide a preparation method of 4N high-purity rhenium powder, which uses common 3N high-purity ammonium perrhenate as raw material, and after pretreatment, the target product of 4N can be obtained by a specific pickling method. The method has simple operation steps, low equipment requirements, and low dependence on artificial operation, which can guarantee the product quality stability in the process of industrialized production.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0005] A preparation method of 4N high-purity rhenium powder, comprising the following steps:

[0006] (1) crushing, hydrogen reduction, ball milling and passing through a 325 mesh screen to obtain a crude rhenium powder from high-purity ammonium perrhenate; the purity of the high-purity ammonium perrhenate is greater than or equal to 3N;

[0007] (2) pickling treatment of the crude rhenium powder in an acid solution, followed by washing treatment and drying to obtain the 4N high-purity rhenium powder; the mass ratio of the acid solution to the crude rhenium powder is greater than or equal to 6:1; the solute of the acid solution includes hydrogen chloride and hydrofluoric acid, the mass concentration of hydrogen chloride is greater than or equal to 5%, and the mass concentration of hydrofluoric acid is greater than or equal to 5%; the pickling treatment time is greater than or equal to 6h.

[0008] The existing industrial preparation process of metal rhenium powder needs to use high-quality raw materials and special equipment for implementation, thereby guaranteeing the purity and stability of the product, but such process production line is difficult to build, the production cost is high, and it is difficult to expand the production line; on the other hand, although some laboratory preparation methods of metal rhenium powder have low production equipment requirements and low production difficulty, they are mostly dependent on some artificial operation steps (such as soaking, filtering and washing the materials for many times), so that the product quality difference between different batches is large, and it is difficult to achieve industrial stability. In order to overcome the above technical difficulties, in the technical scheme of the present application, 3N grade ammonium perrhenate which is common and low in price can be used as raw material for implementation, and the raw material is subjected to conventional crushing and hydrogen reduction treatment to convert it into elemental rhenium. At this time, the impurity content of the product is high, compared with the secondary hydrogen reduction or impurity removal treatment under special atmosphere protection conditions in the general industrial process, the product is directly subjected to pickling treatment with an acid solution with a specific solute and concentration, without the aid of special equipment or environment, after a certain period of time, various target metal or non-metal impurities in the product can be effectively dissolved and separated, and a rhenium powder product with a purity of at least 4N is obtained; at the same time, the method does not depend on manual operation, and the batch quality stability of the prepared product is high, and the production cost performance is high.

[0009] Preferably, in the step (1), the hydrogen reduction is carried out in a tube furnace, the temperature during the hydrogen reduction is 850-900 DEG C, the time is 6-10h, and the flow rate of the hydrogen atmosphere is 5-8L / min.

[0010] The conventional quality ammonium perrhenate can be effectively converted into elemental rhenium by hydrogen reduction treatment under the above preferred conditions, and the target metal or non-metal impurities in the product can be effectively removed by subsequent specific pickling treatment steps, and the operation energy consumption and hydrogen consumption are low.

[0011] Preferably, in the step (2), the mass ratio of the acid solution to the crude rhenium powder is (6-8):1.

[0012] After screening by the inventors for many times, it is found that when the acid solution is prepared in the above mass ratio and used for pickling treatment of the crude rhenium powder, the best impurity removal effect can be achieved, and the production cost is also low.

[0013] Preferably, in the acid solution, the mass concentration of hydrogen chloride is 5-10%, and the mass concentration of hydrofluoric acid is 5-10%.

[0014] As the concentration of the solute in the acid solution gradually increases, the impurity removal effect of the crude rhenium powder also gradually improves, but after a certain degree, the solubility improvement effect of the acid solution on the impurities is no longer obvious, and the above acid solution prepared in the preferred range is the best in terms of comprehensive effect and cost.

[0015] Preferably, the mass concentration ratio of hydrogen chloride and hydrofluoric acid is (0.7-1.4):1.

[0016] The treatment efficiency of hydrogen chloride and hydrofluoric acid on different impurity elements in the crude rhenium powder is not the same in the acid solution, and the inventors find that when hydrogen chloride and hydrofluoric acid in the above-mentioned ratio are used for matching, the obtained acid solution can achieve the best impurity removal effect under the conditions described in the application.

[0017] Preferably, in step (2), the pickling treatment time is 8-12h.

[0018] Preferably, in step (2), deionized water is used for washing treatment, and after washing to a conductivity of the obtained supernatant <10 μs / cm, the supernatant is removed by suction filtration.

[0019] Preferably, in step (2), the drying temperature is 80-120℃, and the time is 3-6h.

[0020] The application has the beneficial effect that the application provides a preparation method of 4N high-purity rhenium powder, which uses common 3N high-purity ammonium perrhenate as raw material, and after pretreatment, the target product of 4N can be obtained by a specific pickling method. The method has simple operation steps, low equipment requirements, and low dependence on human operation, and can guarantee the stability of product quality in the process of industrialized scale production. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The application provides a preparation method of 4N high-purity rhenium powder. DETAILED DESCRIPTION

[0022] In order to better illustrate the purpose, technical scheme and advantages of the application, the application will be further described below in combination with specific examples and comparative examples, and the purpose is to understand the content of the application in detail, rather than to limit the application. All other examples obtained by those skilled in the art without creative labor fall within the protection scope of the application. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of the application are common ordinary reagents and instruments.

[0023] Example 1

[0024] The application provides a preparation method of 4N high-purity rhenium powder, and the preparation method is as shown in the accompanying drawings, which comprises the following steps: Figure 1

[0025] ​(1) 100g of 3N ammonium perrhenate is crushed, passed through a 200-mesh sieve, loaded into a quartz boat and placed in a tube furnace, hydrogen is passed in at a flow rate of 6L / min, then reduced at 880℃ for 8h, the obtained powder is ball milled, passed through a 325-mesh sieve, and then a crude rhenium powder is obtained;

[0026] (2) The crude rhenium powder is placed in an acid solution for pickling treatment, then washed with deionized water for multiple times until the conductivity of the obtained supernatant is less than 10 μs / cm, the supernatant is removed by suction filtration, and then transferred to a vacuum drying oven for drying at a vacuum degree of less than -0.1 MPa and 80℃ for 6h, and then the 4N high-purity rhenium powder is obtained; the mass ratio of the acid solution to the crude rhenium powder is 6:1; the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of hydrogen chloride is 10%, and the mass concentration of hydrofluoric acid is 10%; the pickling treatment time is 10h.

[0027] Example 2

[0028] The embodiment of the preparation method of the 4N high-purity rhenium powder provided by the application, the preparation method comprises the following steps:

[0029] (1) 100g of 3N ammonium perrhenate is crushed, passed through a 200-mesh sieve, loaded into a quartz boat and placed in a tube furnace, hydrogen is passed in at a flow rate of 6L / min, then reduced at 880℃ for 8h, the obtained powder is ball milled, passed through a 325-mesh sieve, and then a crude rhenium powder is obtained;

[0030] (2) The crude rhenium powder is placed in an acid solution for pickling treatment, then washed with deionized water for multiple times until the conductivity of the obtained supernatant is less than 10 μs / cm, the supernatant is removed by suction filtration, and then transferred to a vacuum drying oven for drying at a vacuum degree of less than -0.1 MPa and 100℃ for 4h, and then the 4N high-purity rhenium powder is obtained; the mass ratio of the acid solution to the crude rhenium powder is 7:1; the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of hydrogen chloride is 7%, and the mass concentration of hydrofluoric acid is 7%; the pickling treatment time is 12h.

[0031] Example 3

[0032] The embodiment of the preparation method of the 4N high-purity rhenium powder provided by the application, the preparation method comprises the following steps:

[0033] (1) 100g of 3N ammonium perrhenate is crushed, passed through a 200-mesh sieve, loaded into a quartz boat and placed in a tube furnace, hydrogen is passed in at a flow rate of 6L / min, then reduced at 880℃ for 8h, the obtained powder is ball milled, passed through a 325-mesh sieve, and then a crude rhenium powder is obtained;

[0034] (2) the crude rhenium powder is put into an acid solution for acid washing treatment, and then washed with deionized water for multiple times until the conductivity of the supernatant is less than 10 μs / cm, the supernatant is removed by suction filtration, and then transferred to a vacuum drying oven for drying at a vacuum degree of less than -0.1 MPa and at 120 ℃ for 3 h to obtain the 4N high-purity rhenium powder; the mass ratio of the acid solution to the crude rhenium powder is 8:1; the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of the hydrogen chloride is 5%, and the mass concentration of the hydrofluoric acid is 5%; and the acid washing treatment is performed for 12 h.

[0035] Example 4

[0036] The difference between the embodiment of the method for preparing the high-purity rhenium powder and Example 2 is that the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of the hydrogen chloride is 6%, and the mass concentration of the hydrofluoric acid is 8%.

[0037] Example 5

[0038] The difference between the embodiment of the method for preparing the high-purity rhenium powder and Example 2 is that the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of the hydrogen chloride is 5%, and the mass concentration of the hydrofluoric acid is 9%.

[0039] Example 6

[0040] The difference between the embodiment of the method for preparing the high-purity rhenium powder and Example 2 is that the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of the hydrogen chloride is 9%, and the mass concentration of the hydrofluoric acid is 5%.

[0041] Comparative Example 1

[0042] The difference between the method for preparing the high-purity rhenium powder and Example 2 is that the mass ratio of the acid solution to the crude rhenium powder is 5:1.

[0043] Comparative Example 2

[0044] The difference between the method for preparing the high-purity rhenium powder and Example 2 is that the acid washing treatment is performed for 5 h.

[0045] Comparative Example 3

[0046] The difference between the method for preparing the high-purity rhenium powder and Example 2 is that the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of the hydrogen chloride is 3%, and the mass concentration of the hydrofluoric acid is 3%.

[0047] Comparative Example 4

[0048] The difference between the method for preparing the high-purity rhenium powder and Example 2 is that the acid solution is an aqueous solution of hydrogen chloride, and the mass concentration of the hydrogen chloride is 14%.

[0049] Comparative Example 5

[0050] A method for preparing high-purity rhenium powder, which differs from Example 2 only in that the acid solution is an aqueous solution of hydrogen chloride and hydrofluoric acid, the mass concentration of hydrogen chloride is 2%, and the mass concentration of hydrofluoric acid is 12%.

[0051] Comparative Example 6

[0052] A method for preparing high-purity rhenium powder, which differs from Example 2 only in that the acid solution is an aqueous solution of nitric acid and hydrofluoric acid, the mass concentration of nitric acid is 7%, and the mass concentration of hydrofluoric acid is 7%.

[0053] Comparative Example 7

[0054] A method for preparing high-purity rhenium powder, which differs from Example 2 only in that the acid solution is an aqueous solution of hydrogen chloride and sulfuric acid, the mass concentration of hydrogen chloride is 7%, and the mass concentration of sulfuric acid is 7%.

[0055] Example 1

[0056] In order to verify the quality of the product obtained by the method for preparing high-purity rhenium powder according to the application, the content of various impurity elements such as Al and As in the product obtained in each example and comparative example was analyzed and detected by using the GDMS method, and the total content of each impurity element was counted. Since the detection items are the same, only the detection results of all detection elements in Examples 1-3 are listed in Table 1, and other examples and comparative examples are not described in detail, and only the total content results are listed in Table 2; at the same time, the yield of each product (calculated based on the rhenium in ammonium perrhenate) was counted.

[0057] Table 1

[0058]

[0059]

[0060] Table 2

[0061]

[0062]

[0063] As can be seen from the test results, each example uses common 3N ammonium perrhenate as raw material, and only simple reduction and acid washing treatment is needed to obtain 4N rhenium powder product, the content of key impurity elements in the product is less than 80 ppm, and the yield of the product can reach more than 90%, which has high production cost performance.

[0064] In the technical scheme of the present application, the acid washing stage is very crucial, which not only affects the impurity removal efficiency, but also affects the product yield. If the acid solution ratio is too small, or the acid washing time is too short, or the acid solution concentration used for acid washing is too low, as shown in Comparative Examples 1-3, not only the content of the key impurities in the product increases, but also the yield decreases. On the other hand, the selection and ratio of the acid used in the acid treatment are also very important. In the technical scheme of the present application, based on the characteristics of rhenium powder, a specific combination of hydrogen chloride and hydrofluoric acid is required as the solute, otherwise, as shown in Comparative Examples 4, 6 and 7, using a single acid solute or other acid solutes for compounding, it is difficult to achieve the desired impurity removal effect, it cannot meet the standard, and the yield is also difficult to follow. According to Examples 2, 4-6 and Comparative Example 5, it can be seen that even if hydrogen chloride and hydrofluoric acid are selected as the solute, the concentration ratio of the two also needs to be maintained within a certain range, otherwise the expected impurity removal effect cannot be achieved. Among them, when the mass concentration ratio of hydrogen chloride and hydrofluoric acid is preferably (0.7-1.4):1, the impurity content of the product is lower, and the quality is better.

[0065] Finally, it should be noted that the above examples are only used to illustrate the technical scheme of the present application and do not limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical scheme of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical scheme of the present application.

Claims

1. A method for preparing 4N grade high-purity rhenium powder, characterized in that, Includes the following steps: (1) After crushing, reducing with hydrogen, ball milling and passing through a 325-mesh sieve, ammonium perrhenate is obtained as crude rhenium powder; the purity of the ammonium perrhenate is ≥3N; the hydrogen reduction is carried out in a tube furnace, the temperature of the hydrogen reduction is 850~900℃, the time is 6~10h, and the flow rate of the hydrogen atmosphere is 5~8L / min; (2) The crude rhenium powder is placed in an acid solution for acid washing, followed by washing and drying to obtain the 4N grade high-purity rhenium powder; the mass ratio of the acid solution to the crude rhenium powder is ≥6:1; the solute in the acid solution includes hydrogen chloride and hydrofluoric acid, the mass concentration of hydrogen chloride is ≥5%, and the mass concentration of hydrofluoric acid is ≥5%; the acid washing time is ≥6h. The mass concentration ratio of hydrogen chloride to hydrofluoric acid is (0.7~1.4):

1.

2. The method for preparing 4N-grade high-purity rhenium powder as described in claim 1, characterized in that, In step (2), the mass ratio of acid solution to crude rhenium powder is (6~8):

1.

3. The method for preparing 4N-grade high-purity rhenium powder as described in claim 1, characterized in that, The acid solution contains 5-10% hydrogen chloride and 5-10% hydrofluoric acid by mass.

4. The method for preparing 4N-grade high-purity rhenium powder as described in claim 1, characterized in that, In step (2), the pickling time is 8~12h.

5. The method for preparing 4N-grade high-purity rhenium powder as described in claim 1, characterized in that, In step (2), the drying temperature is 80~120℃ and the time is 3~6h.

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