Acid pickling process for removing oxide layer on surface of high-purity nickel particle

Abstract

The invention relates to the field of removal of oxide layers on the surfaces of metal materials, in particular to an acid pickling process for removing oxide layers on the surfaces of high-purity nickel particles. High-purity nickel particles with oxide layers on the surfaces are placed in a beaker to be decontaminated, the nickel particles are washed three times with pure water and washed once with alcohol, and then the nickel particles are blow-dried through a blow gun; an acid solution is prepared according to the proportion of nitric acid to concentrated sulfuric acid to water being 1: 1: 4; soaking the nickel sheet and the nickel particles in the mixed acid solution, and finally, flatly laying the nickel sheet and the nickel particles on purification cloth, simply wiping and drying; according to the method, oxide skin on the surfaces of high-purity nickel particles is directly removed through soaking; the pickling method is simple, the high-purity nickel particles with good surface brightness are obtained by controlling parameters such as the pickling solution ratio, the pickling temperature and the pickling time of the pickling process, the problems of poor surface smoothness and size precision caused by mechanical pretreatment can be effectively solved, and metal loss caused by mechanical treatment can be reduced.

Description

Technical Field

[0001] This invention relates to the field of oxide layer removal from the surface of metal materials, and more particularly to an acid pickling process for removing the oxide layer from the surface of high-purity nickel particles. Background Technology

[0002] The oxide adhesion on the surface of high-purity nickel granules or sheets is stronger than that of stainless steel. Therefore, the oxide layer on the surface of the material is not easy to remove after hot working or heat treatment. At home and abroad, fine sand belts, fine grinding wheels, steel brushes or sandblasting are generally used to remove the oxide layer. Then, acid washing is carried out in a mixed solution of hydrofluoric acid and nitric acid. However, the effect is not ideal. It also has solubility in metallic nickel itself. Especially when the concentration is high, the temperature is high or the time is long, it is easy to cause the surface of nickel granules to become rough, excessive weight loss, or even pitting corrosion.

[0003] This mechanical treatment method, which removes the oxide layer by grinding or shot peening, usually makes it impossible to guarantee the surface quality and dimensional accuracy of nickel alloy processed materials. It may introduce abrasive contamination, change the shape and size distribution of particles, and is ineffective for complex shapes or fine particles. The surface may also be cold-worked.

[0004] Therefore, the applicant proposes an acid pickling process to remove the oxide layer on the surface of high-purity nickel particles to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing an acid pickling process for removing the oxide layer from the surface of high-purity nickel particles. This process directly removes the oxide layer from the surface of the high-purity nickel particles using an acid pickling solution, eliminating the need for prior mechanical treatment of the nickel or nickel alloy surface and avoiding damage to the surface. The technical solution is as follows:

[0006] A pickling process for removing the oxide layer from the surface of high-purity nickel particles includes the following steps.

[0007] Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes;

[0008] Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower.

[0009] Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing.

[0010] Step S4: Spread the high-purity nickel granules evenly in the water tank, and slowly pour the acid mixture into the water tank so that the nickel sheets and nickel granules are submerged in the acid mixture.

[0011] Step S5: Let stand at room temperature and observe the immersion for 14 minutes. Use tweezers to turn the nickel sheets and nickel granules over and gently shake the water tank to ensure that all sides of the nickel sheets and nickel granules are evenly in contact with the acid mixture.

[0012] Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them;

[0013] Step S7: Weigh the product using an analytical balance or platform scale, vacuum seal the product, and affix the product label.

[0014] Optionally, the acid mixture contains 15%–17% nitric acid, 15%–17% concentrated sulfuric acid, and the remainder is water.

[0015] Optionally, the mass percentage concentration of nitric acid is 65%-68%.

[0016] Optionally, the concentrated sulfuric acid has a mass percentage concentration of 98%.

[0017] Optionally, step S5 may also employ room temperature agitation pickling or room temperature ultrasonic pickling.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the oxide layer on the surface of nickel particles is removed by an acid mixture, which is more effective and faster than the existing method of using hydrofluoric acid and nitric acid to remove nickel particles. At the same time, it eliminates the need for mechanical treatment of the nickel surface, thus avoiding damage to the surface of nickel or nickel alloy.

[0019] The pickling formula of this invention is simple, low-cost, and highly efficient. This method directly removes the oxide scale from the surface of high-purity nickel particles through immersion. The pickling method is simple; by controlling parameters such as the pickling solution ratio, pickling temperature, and pickling time, high-purity nickel particles with excellent surface brightness can be obtained. This effectively solves the problems of poor surface finish and dimensional accuracy caused by mechanical pretreatment and also reduces metal loss during mechanical processing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be discussed below. Obviously, the technical solutions described in conjunction with the accompanying drawings are only some embodiments of the present invention. For those skilled in the art, other embodiments and their accompanying drawings can be obtained based on the embodiments shown in these drawings without creative effort.

[0021] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0022] The technical solutions of various embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The embodiments of the present invention provide an acid pickling process for removing the oxide layer on the surface of high-purity nickel particles.

[0026] Example 1:

[0027] Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes;

[0028] Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower.

[0029] Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing.

[0030] Step S4: Spread the high-purity nickel granules evenly in the water tank, avoiding any accumulation or contact. Slowly pour the acid mixture into the water tank, immersing the nickel sheets and granules in the acid mixture.

[0031] Step S5: Let the nickel sheets and nickel granules stand at room temperature for pickling. During the 14-minute immersion period, use tweezers to turn them over and gently shake the water tank to ensure that all sides of the nickel sheets and nickel granules are evenly in contact with the acid mixture.

[0032] Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them;

[0033] Weigh the pickled nickel granules or sheets and record the data in Table 1.

[0034] Example 2:

[0035] Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes;

[0036] Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower.

[0037] Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing.

[0038] Step S4: Spread the high-purity nickel granules evenly in the water tank, avoiding any accumulation or contact. Slowly pour the acid mixture into the water tank, immersing the nickel sheets and granules in the acid mixture.

[0039] Step S5: Stir and pickle at room temperature. During the 15-minute immersion period, use tweezers to turn the nickel sheets and granules over and gently shake the water tank to ensure that all sides of the nickel sheets and granules are evenly in contact with the acid mixture.

[0040] Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them;

[0041] Weigh the pickled nickel granules or sheets and record the data in Table 1.

[0042] Example 3:

[0043] Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes;

[0044] Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower.

[0045] Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing.

[0046] Step S4: Spread the high-purity nickel granules evenly in the water tank, avoiding any accumulation or contact. Slowly pour the acid mixture into the water tank, immersing the nickel sheets and granules in the acid mixture.

[0047] Step S5: Stir and pickle at room temperature. During the 12-minute immersion period, use tweezers to turn the nickel sheets and granules over and gently shake the water tank to ensure that all sides of the nickel sheets and granules are evenly in contact with the acid mixture.

[0048] Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them;

[0049] Weigh the pickled nickel granules or sheets and record the data in Table 1.

[0050] Example 4:

[0051] Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes;

[0052] Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower.

[0053] Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing.

[0054] Step S4: Spread the high-purity nickel granules evenly in the water tank, avoiding any accumulation or contact. Slowly pour the acid mixture into the water tank, immersing the nickel sheets and granules in the acid mixture.

[0055] Step S5: Room temperature ultrasonic pickling. During the 8-minute immersion period, use tweezers to turn the nickel sheets and granules over and gently shake the water tank to ensure that all sides of the nickel sheets and granules are evenly in contact with the acid mixture.

[0056] Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them;

[0057] Weigh the pickled nickel granules or sheets and record the data in Table 1.

[0058] Table 1. Experimental Records of Examples and Comparative Examples

[0059]

[0060] In summary, the best pickling effect is achieved by using a mixed acid solution of nitric acid, concentrated sulfuric acid, and water in a volume ratio of 1:1:4, and pickling at room temperature for 14 minutes with stirring and agitation during the process.

[0061] Meanwhile, a metallographic microscope is used to observe the surface layer thickness of nickel granules and nickel sheets; it is also possible to remove oil stains from the surface of nickel sheets by adding cleaning powder to a magnetron polisher and washing for 2 minutes.

[0062] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects. The scope of the invention is defined by the appended claims, not by the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A pickling process for removing the oxide layer from the surface of high-purity nickel particles, characterized in that: Includes the following steps, Step S1: Place the high-purity nickel granules with an oxide layer on the surface in a beaker, add detergent and cleaning powder, soak in 75-degree hot water, and ultrasonically vibrate for 10 minutes; Step S2: Wash the nickel granules three times with pure water, wash them once with alcohol, and then dry them with a blower. Step S3: Preparation of acid solution, according to the ratio of nitric acid: concentrated sulfuric acid: water 1:1:4; first, measure pure water with a graduated cylinder and add it to a beaker; in a fume hood, measure nitric acid and add it, while stirring with a glass rod, being careful to avoid inhaling volatile gases; finally, measure the target volume of concentrated sulfuric acid, slowly add it to the beaker while stirring continuously, being careful to prevent splashing. Step S4: Spread the high-purity nickel granules evenly in the water tank, and slowly pour the acid mixture into the water tank so that the nickel sheets and nickel granules are submerged in the acid mixture. Step S5: Let stand at room temperature and observe the immersion for 14 minutes. Use tweezers to turn the nickel sheets and nickel granules over and gently shake the water tank to ensure that all sides of the nickel sheets and nickel granules are evenly in contact with the acid mixture. Step S6: Lay the nickel sheets and nickel granules flat on the cleaning cloth, wipe them simply, and dry them; Step S7: Weigh the product using an analytical balance or platform scale, vacuum seal the product, and affix the product label.

2. The pickling process for removing the oxide layer from the surface of high-purity nickel particles according to claim 1, characterized in that: The acid mixture contains 15%–17% nitric acid, 15%–17% concentrated sulfuric acid, and the remainder is water.

3. The pickling process for removing the oxide layer from the surface of high-purity nickel particles according to claim 2, characterized in that: The mass percentage concentration of nitric acid is 65%-68%.

4. The pickling process for removing the oxide layer from the surface of high-purity nickel particles according to claim 2, characterized in that: The concentration of concentrated sulfuric acid is 98% by mass.

5. The pickling process for removing the oxide layer from the surface of high-purity nickel particles according to claim 1, characterized in that: Step S5 also employs room temperature agitation pickling or room temperature ultrasonic pickling.

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