Method for rapid detoxification and resource utilization of secondary aluminum ash

Abstract

The invention discloses a method for rapid detoxification and resource utilization of secondary aluminum ash, which comprises the following steps: S1, ball-milling the secondary aluminum ash, then carrying out magnetic separation treatment to obtain an iron-rich material and an excess material, screening the excess material to obtain coarse secondary aluminum ash and fine secondary aluminum ash, and mixing and stirring the fine secondary aluminum ash and water to obtain a mixed liquid material; s2, the coarse secondary aluminum ash and sodium carbonate are mixed to form a ball milling system, the ball milling system is heated and roasted, generated ammonia gas and combustible gas are collected, then cooling is conducted, the mixed liquid material is added into the ball milling system, NaOH is added for ball milling and water washing, and a water washing liquid material is obtained; s3, the collected ammonia gas and the collected combustible gas are subjected to recovery treatment; and S4, the water washing liquid material is subjected to filter pressing treatment to obtain wet ash and waste liquid, the waste liquid is recycled, and the wet ash is dried to prepare the high-aluminum material. According to the method, gas, liquid and solid components in the secondary aluminum ash treatment process are fully utilized in a gradient mode, and clean value-added product and zero waste emission are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment, and in particular to a method for rapid detoxification and resource utilization of secondary aluminum ash. Background Art

[0002] Aluminum ash is the ash floating on the surface of aluminum liquid in the casting furnace during the electrolytic aluminum or recycled aluminum process. The ash regularly scraped off during the casting process is called primary aluminum ash. The mass fraction of metallic aluminum in primary aluminum ash is 70%~80%. Due to the high content of metallic aluminum in primary aluminum ash, the metallic aluminum is usually recovered by frying or pressing. After the ash is cooled, the aluminum particles are finely ground and screened. The residue after the above treatment is called secondary aluminum ash. In addition, the dust collected by the dust removal device during the recovery of metallic aluminum from primary aluminum ash, that is, the dust removal ash, is also called secondary aluminum ash. According to the production process, secondary aluminum ash can be divided into electrolytic aluminum ash and recycled aluminum ash. The former comes from the electrolytic aluminum process, and the latter comes from the recycled aluminum process.

[0003] The main phases in secondary aluminum ash are aluminum compounds (Al2MgO4, Al2O3, AlN, etc.), metallic aluminum, other oxides (SiO2, Fe2O3, MgO, etc.), fluorides (NaF, Na3AlF6, CaF2, etc.), and chlorides (NaCl, KCl, etc.). These complex chemical compositions give secondary aluminum ash the dual characteristics of hazardous waste and valuable resources. Its pollution comes from AlN, fluorides, chlorides, and heavy metal cations, while the valuable resources are mainly aluminum resources. Therefore, it is a common goal of many researchers to develop harmless treatment technologies for secondary aluminum ash and explore economical and effective methods to utilize and treat secondary aluminum ash, thereby realizing the reuse of secondary aluminum ash resources. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for rapid detoxification and resource utilization of secondary aluminum ash.

[0005] The technical solution of the present invention is: a method for rapid detoxification and resource utilization of secondary aluminum ash, comprising the following steps: S1, ball-milling the secondary aluminum ash and performing magnetic separation to obtain iron-rich material and residual material, then sieving the residual material to obtain coarse secondary aluminum ash and fine secondary aluminum ash, and then mixing the fine secondary aluminum ash with water to obtain a mixed liquid material; S2. Mix the crude secondary aluminum ash and sodium carbonate to form a ball milling system, wherein the amount of sodium carbonate added is 8-12wt% of the mass of the crude secondary aluminum ash; and heat the ball milling system to 500-600°C and roast for 10 min, during which the ball milling speed is controlled at 300-500r / min, and the generated ammonia and combustible gas are collected; then cool down to 120-150°C, add the mixed liquid to the ball milling system, and add NaOH to wash the ball milling to obtain a washed liquid, wherein the amount of NaOH added is 1-3wt% of the mass of the crude secondary aluminum ash; S3, the collected ammonia is absorbed by an ammonia absorption system to prepare a 20wt% ammonia water product, and the collected combustible gas is collected by a gas collection system and used as a secondary fuel; S4. The water washing liquid obtained in S2 is subjected to filter pressing treatment to obtain wet ash and waste liquid with a water content of 10-15wt%, and the waste liquid is subjected to purification and evaporation and crystallization treatment to obtain a salt-containing product and water; the wet ash is dried to prepare a high-aluminum material.

[0006] Furthermore, the mass ratio of the fine secondary aluminum ash to water is 1:2-5.

[0007] Description: The hydrolysis of aluminum nitride in secondary aluminum ash requires alkaline solution catalysis. The introduction of sodium carbonate can improve the purity of the product obtained after ball milling and washing of secondary aluminum ash, and the obtained product has a single phase, which is particularly suitable for the recovery and treatment of aluminum ash with low aluminum content. At the same time, the use of sodium carbonate solution to hydrolyze aluminum nitride in aluminum ash can also realize the recycling of sodium carbonate solution; On the basis of the alkali leaching process of the present invention, sodium carbonate and coarse secondary aluminum ash are introduced and ball-milled at 120-150° C. for pretreatment. Compared with the traditional method, the roasting time is short, the energy consumption is low, and the Al recovery rate is high.

[0008] Furthermore, the method of adding the mixed liquid material to the ball milling system is: The mixed liquid material is equally divided into n mixed liquid separations, wherein a single mixed liquid separation must satisfy the requirement that the temperature of the ball milling system can be reduced to 80-90° C. within 90 seconds after being added to the ball milling system. When the temperature of the ball milling system reaches 120-150°C, add a single portion of the mixed liquid to reduce the temperature of the ball milling system to 80-90°C, then warm the ball milling system to 120-150°C, and repeat this operation until the addition of the mixed liquid is completed.

[0009] Description: By adopting the method of adding mixed liquid for multiple times, on the one hand, the temperature of the ball milling system is controlled by the mixed liquid, so that the two systems produce temperature difference contact when mixed, so as to improve the ball milling water washing effect; on the other hand, the water content of the ball milling system can be controlled, thereby improving the ball milling treatment effect, and then improving the recovery rate of Al.

[0010] Furthermore, the NaOH is added into the ball milling system together with the first single mixture separation.

[0011] Note: By adding the full amount of NaOH, the mixed system of the ball mill system and the mixed material separation will be at a high NaOH concentration in the initial stage, and the subsequent addition of the mixed material separation will cause the alkali concentration in the entire mixed system to decrease in a direction. However, the full amount addition method will make the overall operation more convenient, simplify the operating steps, and be easier to operate.

[0012] Furthermore, the NaOH is divided into n equal parts, and each part of NaOH is added into the ball milling system together with each liquid separation of a single mixed material.

[0013] Note: The gradual addition of NaOH will make the mixed system of the ball mill system and the mixed material separation at a relatively low NaOH concentration in the early stage, but the subsequent addition of the mixed material separation and NaOH will make the alkali concentration in the whole mixed system relatively stable, which can make the treatment effect of the ball mill water washing more stable. However, compared with the full amount addition, NaOH needs to be added gradually, and the operation steps are relatively complicated. Therefore, corresponding selection can be made according to actual usage needs.

[0014] Furthermore, the sodium carbonate is doped with calcium oxide accounting for 2-5% of its mass.

[0015] Note: Experiments have shown that adding a certain amount of calcium oxide to sodium carbonate can significantly affect the leaching performance of secondary aluminum ash. The introduction of calcium oxide can reduce the temperature and alkali content required by the process system, thereby improving the recovery rate of Al.

[0016] Furthermore, the residual material is separated into coarse secondary aluminum ash and fine secondary aluminum ash by vibrating screening, the particle size of the coarse secondary aluminum ash is ≥0.3mm, and the particle size of the fine secondary aluminum ash is <0.3mm.

[0017] Note: By dividing the secondary aluminum ash into coarse and fine secondary aluminum ash according to the above-mentioned particle size, the requirements of the process of the present invention for coarse and fine secondary aluminum ash can be well met, so that when used in conjunction with the ball milling and water washing process, it has a better aluminum ash resource processing effect.

[0018] Furthermore, the purification and evaporation crystallization treatment method in S4 is: filtering the waste liquid using liquid filter paper and then introducing it into an MVR evaporator for evaporation to obtain a salt-containing product and water.

[0019] Note: Through the above treatment, the waste liquid in the secondary aluminum ash treatment process can be fully utilized to achieve clean product value-added and zero waste discharge, thereby achieving the advantages of no secondary pollution, safety, reliability, and green environmental protection of the method of the present invention.

[0020] Furthermore, the high-aluminum material is processed to obtain a refractory material, and the processing method is: kaolin with an Al content of 20-30% and a high-aluminum material are mixed in a mass ratio of 4:6 and pressed into a billet, and then fired in a tunnel kiln at 1550-1560° C. for 24-32 hours to obtain a refractory material.

[0021] Description: The high-aluminum material obtained after treatment has high alumina content and low impurity content, meeting the use requirements of high-grade bauxite. It can be used as an intermediate product for the preparation of refractory materials, water purifiers, steelmaking refining agents, metallurgical-grade alumina, etc., realizing the full quantitative resource utilization of aluminum ash.

[0022] The beneficial effects of the present invention are: (1) The present invention adds a regulator and a catalyst to carry out a hydrolysis leaching reaction under ball milling and water washing, and achieves catalytic enhanced decomposition of active components such as aluminum nitride and rapid leaching of soluble salts (Na, K, Cl, F, etc.) by precisely controlling process conditions such as reaction temperature and reaction time, thereby achieving the purpose of efficient separation of active components and soluble salt components.

[0023] (2) The high-aluminum material prepared by the present invention has a leaching toxicity content lower than the limit value in the "Hazardous Waste Identification Standard - Leaching Toxicity Identification" (GB5085.3-2007), and an alumina content of >70%. It can be used as a substitute product for high-quality bauxite to prepare refractory materials, calcium aluminate for water treatment agents, steelmaking refining agents, metallurgical-grade alumina and other products, thereby realizing the value-added utilization of aluminum ash.

[0024] (3) The process of the present invention is simple, safe and reliable, without secondary pollution, and the gas, liquid and solid components of the secondary aluminum ash treatment process are fully utilized in a cascade manner to achieve clean product value-added and zero waste emissions. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific implementation methods to better reflect the advantages of the present invention.

[0026] Embodiment 1: A method for rapid detoxification and resource utilization of secondary aluminum ash, comprising the following steps: S1, ball-milling the secondary aluminum ash and performing magnetic separation to obtain iron-rich material and residual material, then sieving the residual material to obtain coarse secondary aluminum ash and fine secondary aluminum ash, and then mixing the fine secondary aluminum ash with water to obtain a mixed liquid material; wherein the mass ratio of the fine secondary aluminum ash to water is 1:4; S2, the crude secondary aluminum ash is mixed with sodium carbonate to form a ball milling system, the amount of sodium carbonate added is 9wt% of the crude secondary aluminum ash, and the ball milling system is heated to 560°C and roasted for 10min, during which the ball milling speed is controlled at 420r / min, and the generated ammonia and combustible gas are collected; then the temperature is lowered to 135°C, the mixed liquid is added to the ball milling system, and NaOH is added to perform ball milling washing, and a water washing liquid is obtained after ball milling washing for 120min, and the amount of NaOH added is 2.5wt% of the crude secondary aluminum ash; S3, the collected ammonia is absorbed by an ammonia absorption system to prepare a 20wt% ammonia water product, and the collected combustible gas is collected by a gas collection system and used as a secondary fuel; S4, the water washing liquid obtained in S2 is subjected to filter pressing treatment to obtain wet ash and waste liquid with a water content of 12wt%, and the waste liquid is subjected to purification and evaporation and crystallization treatment to obtain a salt-containing product and water. Specifically, the purification and evaporation and crystallization treatment method in S4 is: the waste liquid is filtered using liquid filter paper and then introduced into an MVR evaporator for evaporation at 70°C to obtain a salt-containing product and water; the wet ash is dried at 80°C to prepare a high-aluminum material; at the same time, the high-aluminum material can be processed to obtain a refractory material, and the processing method is: kaolin with an Al content of 25% and a high-aluminum material are mixed in a mass ratio of 4:6 and pressed into a billet, and then fired in a tunnel kiln at 1555°C for 28h to obtain a refractory material. The obtained high-aluminum material is not limited to the preparation of refractory materials, but can also be used for the production and preparation of products such as water purifiers, steelmaking refining agents, and metallurgical-grade alumina; It can be understood that the moisture content of wet ash is affected by the filter press equipment and the required moisture content of wet ash. The moisture content range is not limited and can be selected accordingly according to actual production conditions.

[0027] It should be noted that the residual material is separated into coarse secondary aluminum ash and fine secondary aluminum ash by vibrating screening, the particle size of the coarse secondary aluminum ash is ≥0.3mm, and the particle size of the fine secondary aluminum ash is <0.3mm; It should be noted that the ammonia absorption system and gas collection system used in this embodiment are both existing technologies and are not specifically limited here.

[0028] Example 2: This example is different from Example 1 in that the mass ratio of the fine secondary aluminum ash to water is 1:2.

[0029] Example 3: This example is different from Example 1 in that the mass ratio of the fine secondary aluminum ash to water is 1:5.

[0030] Example 4: This example is different from Example 1 in that the ball mill system is heated to 500°C, the ball mill speed is controlled at 300 r / min for 10 min, and then the temperature is lowered to 120°C.

[0031] Example 5: This example is different from Example 1 in that the ball mill system is heated to 600°C, the ball mill speed is controlled at 500 r / min for 10 min, and then the temperature is lowered to 150°C.

[0032] Example 6: This example is different from Example 1 in that the amount of sodium carbonate added is 8wt% of the mass of the crude secondary aluminum ash; and the amount of NaOH added is 1wt% of the mass of the crude secondary aluminum ash.

[0033] Example 7: This example is different from Example 1 in that the amount of sodium carbonate added is 12 wt% of the mass of the crude secondary aluminum ash; and the amount of NaOH added is 3 wt% of the mass of the crude secondary aluminum ash.

[0034] Example 8: This example is different from Example 1 in that the method of adding the mixed liquid material to the ball milling system is: The mixed liquid material is equally divided into n mixed liquid separations, wherein a single mixed liquid separation must satisfy the requirement that the temperature of the ball milling system can be reduced to 85°C within 90s after being added to the ball milling system. Taking this embodiment as an example, n is 4, and a single mixed liquid separation of 15°C and 500mL can satisfy the cooling requirement of the corresponding amount of the ball milling system; When the temperature of the ball mill system reaches 135°C, add a single portion of the mixed liquid to reduce the temperature of the ball mill system to 85°C, then reheat the temperature of the ball mill system to 135°C, and repeat this operation until the addition of the mixed liquid is completed. At the same time, the NaOH is added into the ball milling system along with the first single mixed material separation.

[0035] Example 9: This example is different from Example 8 in that when the temperature of the ball milling system reaches 135°C, a single portion of the mixed material is added to separate the liquid to reduce the temperature of the ball milling system to 80°C, and then the temperature of the ball milling system is restored to 135°C.

[0036] Example 10: This example is different from Example 8 in that when the temperature of the ball milling system reaches 135°C, a single portion of the mixed material is added to separate the liquid to reduce the temperature of the ball milling system to 90°C, and then the temperature of the ball milling system is restored to 135°C.

[0037] Example 11: This example is different from Example 8 in that the NaOH is divided into n equal parts, n is 4, and each part of NaOH is added to the ball milling system together with each liquid separation of a single part of the mixture.

[0038] Example 12: This example is different from Example 8 in that the sodium carbonate is doped with calcium oxide accounting for 4% of its mass.

[0039] Example 13: This example is different from Example 12 in that the sodium carbonate is doped with calcium oxide accounting for 2% of its mass.

[0040] Example 14: This example is different from Example 12 in that the sodium carbonate is doped with calcium oxide accounting for 5% of its mass.

[0041] Example 15: This example is different from Example 1 in that the high-aluminum material can be processed to obtain a refractory material, and the processing method is: kaolin with an Al content of 20% and high-aluminum material are mixed in a mass ratio of 4:6 and pressed into a billet, and then fired in a tunnel kiln at 1550°C for 24 hours to obtain a refractory material.

[0042] Example 16: This example is different from Example 1 in that the high-aluminum material can be processed to obtain a refractory material, and the processing method is: kaolin with an Al content of 30% and high-aluminum material are mixed in a mass ratio of 4:6 and pressed into a billet, and then fired at 1560°C for 32 hours in a tunnel kiln to obtain a refractory material.

[0043] Experimental Example 1: Based on the "Hazardous Waste Identification Standard - Leaching Toxicity Identification" (GB5085.3-2007), the high aluminum materials prepared by the methods of Examples 1 to 14 of the present invention were tested for leaching toxicity content. The leaching toxicity content was lower than the limit in the "Hazardous Waste Identification Standard - Leaching Toxicity Identification" (GB5085.3-2007), meeting the requirements.

[0044] Experimental Example 2: Experiment on the effect of aluminum resource recovery in secondary aluminum ash Experimental reagents: 20% hexamethylenetetramine solution, 0.02 mol / L EDTA solution, 1% NaOH solution, methyl orange indicator, 0.1% 1-(2-pyridyl azo)-2-naphthol, 0.01 mol / L copper standard solution, HCl-HNO mixed acid; The copper standard solution is 2.5g CuSO4·5H2O weighed in a 1000mL beaker, 3 drops of 1:1 H2SO4 are added, dissolved in distilled water and diluted to 1L; HCl-HNO mixed acid is prepared by adding 400 mL HCl and 100 mL HNO3 to 500 mL water and mixing evenly.

[0045] Experimental method: Based on the EDTA method, firstly, the high aluminum material (same mass) prepared in each example is added with an excess of EDTA solution (no need to be quantitative), then the pH is adjusted to 3.5, and methyl orange indicator can be used for indication, and boiled for 3 minutes to make Al 3+ Completely complexed with EDTA; At the same time, other interfering ions will also react with EDTA. Hexamethylenetetramine is used to adjust the pH to 5.5, and 1-(2-pyridyl azo)-2-naphthol is used for indication. The excess EDTA is removed with a copper standard solution while it is still hot. At this time, an appropriate amount of NH4F is added to - With Al 3+ The property of forming a more stable complex replaces the Al 3+ After heating and boiling, an equal amount of EDTA is titrated to the end point using a copper standard solution. The reaction is as follows: Y - +6F - =AlF6 3- +Y 4- Y 4- +Cu 2+ =CuY 2- The aluminum content in the high-aluminum material is calculated from this.

[0046] Analysis method: Accurately weigh 0.10g (accurate to 0.0002g) of the sample into a small beaker, add 5mL HCl-HNO3 mixed acid and 5mL water, and carefully heat on a hot plate to dissolve. Remove and cool, then slowly transfer to a 100mL volumetric flask, add water to the volume, and shake well.

[0047] Pipette 25.00mL of test solution into a 250mL conical flask, add 20mL of water and 15.00mL of 0.02 molL EDTA. Use methyl orange as an indicator and slowly add 1% NaOH solution until the solution turns orange. Heat and boil for 2~3 min, remove, immediately add 10mL of hexamethylenetetramine solution, 4~6 drops of 1-(2-pyridylazo)-2-naphthol, and add CuSO4 standard solution while hot until the solution turns purple-red. Add 1g of NH4F, continue heating and boiling for 2min, add 6 drops of 1-(2-pyridylazo)-2-naphthol, and titrate with 0.01molL copper standard solution until the solution changes from green to purple, which is the end point. Record the volume V of the consumed CuSO4 standard solution, and calculate the aluminum content in the sample: ; The results are shown in Table 1 below: Table 1 Statistical table of aluminum content of high aluminum materials in various examples ; It can be seen from the results in Table 1 above that when the method of the present invention is used to treat secondary aluminum ash, the aluminum content of the prepared high-aluminum materials is greater than 96%. At the same time, there are some differences in the high-aluminum materials prepared under different process conditions. The following analysis is made based on the data comparison in Table 1 above: 1) Effect of different proportions of coarse and fine secondary aluminum ash on the product By comparing Example 2 and Example 3 with Example 1, it can be seen that the use of different proportions of coarse and fine secondary aluminum ash has a certain impact on the aluminum content of the prepared product. On the basis of Example 1, reducing or increasing the proportion of coarse and fine secondary aluminum ash can reduce the aluminum content of the prepared product to a certain extent. Therefore, the product prepared in Example 1 is relatively optimal.

[0048] At the same time, in order to further explore the effects of coarse and fine secondary aluminum ash, a control was set up. Based on the method of Example 1, the residual material was not screened, the residual material was used as coarse secondary aluminum ash, and water was used as mixed liquid. The other processes remained unchanged. The results are shown in Table 2 below: Table 2 Statistical table of aluminum content of high aluminum materials ; It can be seen from the results in Table 2 above that the treatment of secondary aluminum ash using the method of the present invention is significantly better than the control. By adopting the treatment methods of coarse and fine secondary aluminum ash, under the same parameter conditions, the aluminum content of the prepared high-aluminum material is increased from 96.27% to 97.81%.

[0049] 2) Effects of different ball milling speeds and calcination temperatures on the products By comparing Example 4 and Example 5 with Example 1, it can be seen that the use of different ball mill speeds and temperature reduction gradients has a certain impact on the prepared products. On the basis of Example 1, the ball mill speed and the calcination temperature are reduced, and the aluminum content of the prepared product is reduced to a certain extent. On the other hand, by increasing the ball mill speed and the calcination temperature, the aluminum content of the prepared product is increased to a certain extent but not significantly. Therefore, from the perspective of economy and other aspects, the product prepared in Example 1 is relatively better.

[0050] 3) Effects of different sodium carbonate and NaOH addition amounts on the product By comparing Example 6 and Example 7 with Example 1, it can be seen that the use of different amounts of sodium carbonate and NaOH addition has a certain impact on the prepared product. On the basis of Example 1, the amount of sodium carbonate and NaOH added is reduced, so that the aluminum content of the prepared product is reduced to a certain extent. On the basis of Example 1, the amount of sodium carbonate and NaOH added is increased, so that the aluminum content of the prepared product is improved to a certain extent but not significantly. Therefore, from the perspective of economy, Example 1 uses less raw materials to achieve similar effects, so the product prepared in Example 1 is relatively better.

[0051] Experimental Example 3: Effect of Optimization of Mixed Liquid Addition Method on Aluminum Resource Recovery in Secondary Aluminum Ash The aluminum content of high aluminum materials prepared under different processes was measured by referring to the above experimental method. The results are shown in Table 3 below: Table 3 Statistical table of aluminum content of high aluminum materials in various examples ; It can be seen from the results in Table 3 above that the aluminum content of the prepared high-aluminum material has increased to a certain extent after the gradual addition and doping of calcium oxide. After the method of optimizing the mixed liquid material to be added to the ball milling system, the aluminum content of the prepared high-aluminum material is >98%. After doping with calcium oxide, the aluminum content of the prepared high-aluminum material is further improved, and the aluminum content is >99%. At the same time, there are some differences in the high-aluminum materials prepared under different process conditions. The following analysis is made based on the data comparison in Table 3 above: 1) Effects of different mixed liquid addition methods on the product By comparing Example 8 with Example 1, it can be seen that different mixed liquid addition methods have a certain impact on the aluminum content of the prepared product, among which the product prepared in Example 8 is relatively optimal.

[0052] At the same time, through the comparison between Example 9 and Example 10 and Example 8, it can be seen that when using different temperature differences for treatment, reducing or increasing the stage temperature difference on the basis of Example 1, the aluminum content of the prepared products is reduced to a certain extent. Therefore, the product prepared in Example 8 is relatively optimal.

[0053] Further, in order to verify the advantages of the addition method, a control is now set up. The control is based on Example 8. Under a pressurized environment, the mixed material at the same temperature is added to the system for separation, and the time difference between each time is 90s. The other parameters remain unchanged. The results are shown in Table 4: Table 4 Statistical table of aluminum content of high aluminum materials ; It can be seen from the results in Table 4 above that the treatment of secondary aluminum ash using the addition method of the present invention is significantly better than the control. By adopting the temperature difference mixing treatment method, under the same parameter conditions, the aluminum content of the prepared high aluminum material is increased from 98.07% to 98.75%.

[0054] 2) Effects of different NaOH addition methods on the product By comparing Example 11 with Example 8, it can be seen that the use of different NaOH addition methods has a certain impact on the prepared product. When adding gradually, the aluminum content of the prepared product is reduced to a certain extent compared with the full addition of NaOH, but the difference is not very obvious. It can be seen that the full addition of NaOH will cause the mixed system of the ball mill system and the mixture separation to be at a high NaOH concentration content at the beginning, and the subsequent continued addition of the mixture separation will cause the alkali solution concentration in the entire mixed system to decrease in a direction. The gradual addition of NaOH will cause the mixed system of the ball mill system and the mixture separation to be at a relatively low NaOH concentration content at the beginning, but the subsequent continued addition of the mixture separation and NaOH will make the alkali solution concentration in the entire mixed system relatively stable, which can make the ball milling water washing treatment effect more stable, but compared with the full addition, NaOH needs to be added gradually, and the operation steps are relatively complicated. Therefore, the two addition methods can be selected according to actual production needs.

[0055] 3) Effect of different amounts of sodium carbonate doped with calcium oxide on the product By comparing Example 12 with Example 8, it can be seen that the use of sodium carbonate doped with different calcium oxides has a certain impact on the prepared product. The introduction of calcium oxide can reduce the temperature and alkali amount required for the process system, thereby improving the treatment effect at the current temperature and alkali amount. Therefore, the product prepared in Example 12 is relatively better.

[0056] At the same time, through the comparison of Example 13, Example 14 and Example 12, it can be seen that when using different amounts of sodium carbonate doped with calcium oxide for treatment, on the basis of Example 12, reducing or increasing the amount of doped calcium oxide, the aluminum content of the prepared product is reduced to a certain extent. Therefore, the product prepared in Example 12 is relatively optimal.

Claims

1. A method for rapid detoxification and resource utilization of secondary aluminum ash, characterized in that: The following steps are involved: S1, ball-milling the secondary aluminum ash and performing magnetic separation to obtain iron-rich material and residual material, then sieving the residual material to obtain coarse secondary aluminum ash and fine secondary aluminum ash, and then mixing the fine secondary aluminum ash with water to obtain a mixed liquid material; S2. Mix the crude secondary aluminum ash and sodium carbonate to form a ball milling system, wherein the amount of sodium carbonate added is 8-12wt% of the mass of the crude secondary aluminum ash; and heat the ball milling system to 500-600°C and roast for 10 min, during which the ball milling speed is controlled at 300-500r / min, and the generated ammonia and combustible gas are collected; then cool down to 120-150°C, add the mixed liquid to the ball milling system, and add NaOH to wash the ball milling to obtain a washed liquid, wherein the amount of NaOH added is 1-3wt% of the mass of the crude secondary aluminum ash; S3, the collected ammonia is absorbed by an ammonia absorption system to prepare a 20wt% ammonia water product, and the collected combustible gas is collected by a gas collection system and used as a secondary fuel; S4. The water washing liquid obtained in S2 is subjected to filter pressing treatment to obtain wet ash and waste liquid with a water content of 10-15wt%, and the waste liquid is subjected to purification and evaporation and crystallization treatment to obtain a salt-containing product and water; the wet ash is dried to prepare a high-aluminum material.

2. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The mass ratio of the fine secondary aluminum ash to water is 1:2-5.

3. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The method of adding the mixed liquid material to the ball milling system is: The mixed liquid material is equally divided into n mixed liquid separations, wherein a single mixed liquid separation must satisfy the requirement that the temperature of the ball milling system can be reduced to 80-90° C. within 90 seconds after being added to the ball milling system. When the temperature of the ball milling system reaches 120-150°C, add a single portion of the mixed liquid to reduce the temperature of the ball milling system to 80-90°C, then warm the ball milling system to 120-150°C, and repeat this operation until the addition of the mixed liquid is completed.

4. The method for rapid detoxification and resource utilization of secondary aluminum ash as claimed in claim 3, characterized in that: The NaOH is added into the ball milling system together with the first single mixed material separation.

5. The method for rapid detoxification and resource utilization of secondary aluminum ash as claimed in claim 3, characterized in that: The NaOH is divided into n equal parts, and each part of NaOH is added into the ball milling system together with each liquid separation of a single mixed material.

6. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The sodium carbonate is doped with calcium oxide accounting for 2-5% of its mass.

7. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The residual material is separated into coarse secondary aluminum ash and fine secondary aluminum ash by vibrating screening, the particle size of the coarse secondary aluminum ash is ≥0.3mm, and the particle size of the fine secondary aluminum ash is <0.3mm.

8. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The method for purification and evaporation crystallization treatment in S4 is: filtering the waste liquid using liquid filter paper and then introducing it into an MVR evaporator for evaporation to obtain a salt-containing product and water.

9. The method for rapid detoxification and resource utilization of secondary aluminum ash according to claim 1, characterized in that: The high-aluminum material is processed to obtain a refractory material. The processing method is: kaolin with an Al content of 20-30% and high-aluminum material are mixed in a mass ratio of 4:6 and pressed into a billet, and then fired in a tunnel kiln at 1550-1560° C. for 24-32 hours to obtain a refractory material.