Aluminum dross fluxing agent and method for recovering aluminum from aluminum dross

Abstract

The application discloses an aluminum ash roasting agent and a method for recycling aluminum from aluminum ash, and provides the aluminum ash roasting agent, which comprises the following components in percentage by mass: sodium nitrate 25-35%, charcoal powder 25-35%, camphor powder 15-25% and zinc chloride 15-25%. The application has simple formula components, is convenient to prepare, does not contain sulfur element, greatly reduces the emission amount of the sulfur element, avoids the problem of sulfur element emission exceeding the standard, and simultaneously, by adding the camphor powder into the aluminum ash roasting agent, the camphor powder is filled in the aluminum ash and provides a large amount of oxygen by thermal decomposition, so that the aluminum ash becomes an oxygen environment, changes the phenomenon that only the uppermost aluminum element can contact with oxygen in the traditional stirring kettle, the camphor powder is uniformly mixed with the internal aluminum ash, fully contacts with the internal aluminum ash, releases a large amount of oxygen to promote the oxidation reaction of aluminum, so that the aluminum ash is fully heated, and the heating speed is greatly increased.

Description

Technical Field

[0001] This application relates to the field of aluminum ash treatment technology, and in particular to an aluminum ash frying agent and a method for recovering aluminum using the aluminum ash frying agent. Background Technology

[0002] Aluminum ash frying agent can quickly heat low-temperature aluminum ash to the separation temperature, thereby accelerating the separation of molten aluminum and aluminum ash.

[0003] For example, the Chinese invention patent with application number 202110135644.1 and titled "An Aluminum Ash Frying Agent and Its Application" involves adding substances including charcoal powder, sulfur, iron and aluminum powder, sodium nitrate, sodium fluorosilicate, and sodium sulfate. At 250°C, the sulfur spontaneously combusts and releases heat, raising the temperature to around 380°C. Sodium nitrate decomposes and releases heat, continuing to raise the temperature to 450°C. Under the influence of temperature and the decomposition products of sodium nitrate, the charcoal powder burns and continues to release heat, raising the temperature to the aluminothermic reaction temperature. When the temperature is reached, a large amount of heat is released, increasing the temperature of the entire environment. The use of stable components makes the temperature rise process easy to control, and the reaction process is safe and reliable.

[0004] However, the existing aluminum ash slagging agents have complex material compositions and contain a large amount of sulfur. The emitted products contain a large amount of sulfur dioxide, which poses a certain danger. Furthermore, because the slagging agent is buried in the aluminum ash due to the stirring effect, it does not have sufficient contact with external oxygen, resulting in an insignificant effect of the slagging agent on the aluminum ash. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides an aluminum ash frying agent and a method for recovering aluminum from aluminum ash.

[0006] On the one hand, this application provides an aluminum ash ash-making agent, comprising, by weight percentage: 25-35% sodium nitrate, 25-35% charcoal powder, 15-25% camphor powder, and 15-25% zinc chloride.

[0007] Through the above technical solution, after the aluminum ash calcining agent is added to the aluminum ash, when the aluminum ash reaches 180℃, the camphor powder decomposes upon heating, releasing a large amount of oxygen. The oxygen fills the aluminum ash, allowing the aluminum at the bottom to fully contact with the oxygen, improving the oxidation efficiency of the aluminum and increasing the heating efficiency of the aluminum ash. When the aluminum ash reaches 380℃, the sodium nitrate decomposes upon heating, producing oxygen and sodium nitrite and releasing heat, further increasing the temperature of the aluminum ash. When the temperature of the aluminum ash reaches 500℃, the charcoal powder is ignited, further releasing heat. At the same time, the decomposition products of sodium nitrite and camphor powder have a combustion-supporting effect on the charcoal powder, allowing the charcoal powder to burn completely and accelerating the heating efficiency of the aluminum ash, shortening the time required for the aluminum ash to heat up to 800℃ to within 120 minutes.

[0008] As a further technical solution of the present invention, the mass ratio of sodium nitrate to camphor powder is (28-32):(18-22).

[0009] As a further technical solution of the present invention, the particle size of the charcoal powder is 0.2-0.5 mm.

[0010] As a further technical solution of the present invention, the particle size of the sodium nitrate is 2-3 mm.

[0011] As a further technical solution of the present invention, the particle size of the camphor powder is 15-30 mm.

[0012] As a further technical solution of the present invention, the particle size of the zinc chloride is 50-100 μm.

[0013] On the other hand, this application provides a method for applying aluminum ash ash-making agent to aluminum ash recovery, the specific steps of which are as follows:

[0014] Mix hot aluminum ash with cold aluminum ash, then add aluminum ash frying agent and stir-fry.

[0015] As a further technical solution of the present invention, the mass ratio of aluminum ash to aluminum ash frying agent is 100:(2-3).

[0016] As a further technical solution of the present invention, the temperature of the hot aluminum ash and cold aluminum ash after mixing is 200℃~300℃.

[0017] In summary, the present invention has at least one of the following beneficial technical effects:

[0018] 1. The formula of this application has simple components, is easy to prepare, and does not contain sulfur, which greatly reduces the amount of sulfur emissions and avoids the problem of excessive sulfur emissions. At the same time, by adding camphor powder to the aluminum ash frying agent, the camphor powder decomposes when heated in the aluminum ash, providing a large amount of oxygen and making the aluminum ash an aerobic environment. This changes the phenomenon that only the top layer of aluminum in the traditional stirred tank can contact oxygen. After the camphor powder is evenly mixed with the aluminum ash inside, it comes into full contact with the aluminum ash inside, releasing a large amount of oxygen to promote the oxidation reaction of aluminum, so that the aluminum ash is heated all over and the heating rate is greatly increased.

[0019] 2. Stirring allows the aluminum ash ash-making agent to be evenly distributed within the aluminum ash and to fully contact it. By utilizing the characteristic of the aluminum ash ash-making agent to release oxygen upon heating, the oxidation rate of aluminum is increased, thereby increasing the heating speed of the aluminum ash. Detailed Implementation

[0020] The following embodiments provide a further detailed description of this application.

[0021] This application designs an aluminum ash frying agent, comprising sodium nitrate, charcoal powder, camphor powder and zinc chloride, wherein the mass percentage of sodium nitrate, charcoal powder, camphor powder and zinc chloride is (25-35):(25-35):(15-25):(15-25).

[0022] The mass ratio of sodium nitrate to camphor powder is (28-32):(18-22).

[0023] in:

[0024] The particle size of the charcoal powder is 0.2–0.5 mm;

[0025] Sodium nitrate has a particle size of 2–3 mm;

[0026] The particle size of camphor powder is 15-30 mm;

[0027] The particle size of zinc chloride is 50–100 μm.

[0028] Prior to this application, aluminum ash frying agents had complex material compositions. After adding the aluminum ash frying agent, the time required for the aluminum ash to heat up to 800℃ was generally more than 120 minutes. Moreover, the aluminum ash was often heated by the decomposition of sulfur. However, the sulfur dioxide emitted after decomposition contains a large amount of sulfur dioxide, which leads to environmental degradation and poses certain dangers. Furthermore, it did not take into account that the frying agent, due to the influence of stirring, was buried in the aluminum ash and had insufficient contact with external oxygen, resulting in an insignificant effect of the frying agent on the aluminum ash and affecting the heating rate of the aluminum ash.

[0029] To address the aforementioned technical problems, the inventors of this application have formulated an aluminum ash frying agent using sodium nitrate, charcoal powder, camphor powder, and zinc chloride. Unlike complex formulations, the formulation of this application has simple components, is easy to prepare, and does not contain sulfur, thus significantly reducing sulfur emissions and avoiding the problem of excessive sulfur emissions.

[0030] Simultaneously, by adding camphor powder to the aluminum ash ash-making agent, the camphor powder, when buried in the aluminum ash, decomposes upon heating, providing a large amount of oxygen and creating an aerobic environment within the aluminum ash. This changes the traditional phenomenon where only the top layer of aluminum elements in the stirred tank can contact oxygen. After the camphor powder is evenly mixed with the aluminum ash inside, it fully contacts the aluminum ash, releasing a large amount of oxygen to promote the oxidation reaction of aluminum, causing the aluminum ash to heat up comprehensively and significantly increasing the heating rate. On the other hand, it also provides a combustion environment for the subsequent charcoal powder, allowing the charcoal powder to fully contact oxygen and burn completely, accelerating the heating of the aluminum ash.

[0031] Unless otherwise specified, all key components involved in this application are purchased from commercially available products, including:

[0032] Sodium nitrate was purchased from Weifang Xinmaoyuan Chemical Co., Ltd.

[0033] Charcoal powder, purchased from Hebei Yanxing Chemical Co., Ltd.

[0034] Camphor powder was purchased from Shanxi Jinyang Pharmaceutical Excipients Co., Ltd.

[0035] Zinc chloride was purchased from Weifang Hengfeng Zinc Industry Co., Ltd.

[0036] The ash roasting machine used is model Mingtou 5139, purchased from Shandong Mingtou Machinery Co., Ltd.

[0037] It should be noted that the components of the prepared aluminum ash frying agent do not come into contact with each other; that is, sodium nitrate, charcoal powder, camphor powder, and zinc chloride are all sealed separately when not in use.

[0038] Example 1

[0039] In this embodiment, the components and their mass percentage ratios of the aluminum ash frying agent are as follows: sodium nitrate 35%, charcoal powder 25%, camphor powder 25%, and zinc chloride 15%.

[0040] 50 kg of freshly excavated hot aluminum ash and 50 kg of cold aluminum ash were put into a ash-frying machine and stirred. The temperature was measured to be 200℃. After adding 2 kg of aluminum ash frying agent, stirring was continued until the aluminum ash temperature rose to 800℃.

[0041] Example 2

[0042] In this embodiment, the components and their mass percentage ratios of the aluminum ash frying agent are as follows: sodium nitrate 30%, charcoal powder 30%, camphor powder 20%, and zinc chloride 20%.

[0043] 50 kg of freshly excavated hot aluminum ash and 50 kg of cold aluminum ash were put into a ash-frying machine and stirred. The temperature was measured to be 200℃. After adding 3 kg of aluminum ash frying agent, stirring was continued until the aluminum ash temperature rose to 800℃.

[0044] Example 3

[0045] In this embodiment, the components and their mass percentage ratios of the aluminum ash frying agent are as follows: sodium nitrate 25%, charcoal powder 35%, camphor powder 15%, and zinc chloride 25%.

[0046] 50 kg of freshly excavated hot aluminum ash and 50 kg of cold aluminum ash were put into a ash-frying machine and stirred. The temperature was measured to be 200℃. After adding 2.5 kg of aluminum ash frying agent, stirring was continued until the aluminum ash temperature rose to 800℃.

[0047] Comparative Example 1

[0048] In this embodiment, the components and their mass percentage ratios of the aluminum ash frying agent are as follows: sodium nitrate 24%, charcoal powder 36%, camphor powder 14%, and zinc chloride 26%.

[0049] 50 kg of freshly excavated hot aluminum ash and 50 kg of cold aluminum ash were put into a ash-frying machine and stirred. The temperature was measured to be 200℃. After adding 1.5 kg of aluminum ash frying agent, stirring was continued until the aluminum ash temperature rose to 800℃.

[0050] Comparative Example 2

[0051] In this embodiment, the components and their mass percentage ratios of the aluminum ash frying agent are as follows: sodium nitrate 36%, charcoal powder 24%, camphor powder 26%, and zinc chloride 14%.

[0052] 50 kg of freshly excavated hot aluminum ash and 50 kg of cold aluminum ash were put into a ash-frying machine and stirred. The temperature was measured to be 200℃. After adding 3.5 kg of aluminum ash frying agent, stirring was continued until the aluminum ash temperature rose to 800℃.

[0053] Detection

[0054] The temperature of the aluminum ash in Examples 1 to 3, Comparative Example 1 and Comparative Example 2 was monitored, and the time required for the aluminum ash to heat up to 800°C was detected, as shown in Table 1 below.

[0055] Table 1

[0056] Example Time required to heat to 800℃ (min) Example 1 113 Example 2 108 Example 3 114 Comparative Example 1 135 Comparative Example 2 132

[0057] As shown in Table 1, the heating time required to reach 800℃ in Examples 1 to 3 is shorter and the heating rate is faster. The time required to heat aluminum ash to 800℃ can be shortened to within 115 minutes, thus improving the heating efficiency. That is, when the components and their mass percentage ratios in the aluminum ash frying agent are: sodium nitrate 25-35%, charcoal powder 25-35%, camphor powder 15-25%, and zinc chloride 15-25%, the aluminum ash frying agent has a good heating effect on aluminum ash, a fast heating rate, and high heating efficiency.

[0058] In this application, the ratio of sodium nitrate and camphor powder has a synergistic effect. Based on this, this application designs Examples 4 to 7 based on Example 2. In Examples 4 to 7, except for the ratio of charcoal powder and camphor powder, everything else remains the same, and the preparation method also remains the same. See Table 2 for details.

[0059] Table 2

[0060] Example 4 Example 5 Example 2 Example 6 Example 7 Sodium nitrate 26％ 28％ 30％ 32％ 34％ Camphor powder 24％ 22％ 20％ 18％ 16％

[0061] The temperature of the aluminum ash in Examples 4 to 7 was monitored, and the time required for the aluminum ash to heat up to 800°C was determined, as shown in Table 3.

[0062] Table 3

[0063] Example Time required to heat to 800℃ (min) Example 4 114 Example 5 107 Example 2 106 Example 6 105 Example 7 117

[0064] As shown in Table 3, the time required for the aluminum ash to reach 800°C using the aluminum ash frying agent in Examples 5, 6, and 2 can be shortened to within 109 minutes. Combined with Table 2, it can be seen that in Examples 4 to 6, as the sodium nitrate content gradually increases and the camphor powder content gradually decreases, the time required for the aluminum ash to reach 800°C gradually shortens. However, in Example 7, when the mass ratio of sodium nitrate to camphor powder is 34:16, and the sodium nitrate content is more than twice the camphor powder content, the time required for the aluminum ash to reach 800°C increases sharply. Based on the above research, a mass ratio of sodium nitrate to camphor powder of (28–32):(18–22) is more suitable.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An aluminum ash slaking agent, characterized in that, It includes, by weight percentage: 25-35% sodium nitrate, 25-35% charcoal powder, 15-25% camphor powder, and 15-25% zinc chloride.

2. The aluminum ash slaking agent according to claim 1, characterized in that: The mass ratio of sodium nitrate to camphor powder is (28-32):(18-22).

3. The aluminum ash slaking agent according to claim 1, characterized in that: The particle size of the charcoal powder is 0.2 to 0.5 mm.

4. The aluminum ash slaking agent according to claim 1, characterized in that: The sodium nitrate has a particle size of 2-3 mm.

5. The aluminum ash slaking agent according to claim 1, characterized in that: The camphor powder has a particle size of 15–30 mm.

6. The aluminum ash slaking agent according to claim 1, characterized in that: The zinc chloride has a particle size of 50–100 μm.

7. The method for applying the aluminum ash frying agent according to any one of claims 1 to 6 to aluminum recovery from aluminum ash, characterized in that, The specific steps are as follows: Mix hot aluminum ash with cold aluminum ash, then add aluminum ash frying agent and stir-fry.

8. The method for preparing aluminum ash slaking agent according to claim 7, characterized in that: The mass ratio of aluminum ash to aluminum ash frying agent is 100:(2-3).

9. The method for preparing aluminum ash slaking agent according to claim 7, characterized in that: The temperature of the mixture of hot and cold aluminum ash is 200℃~300℃.