Harmless treatment process for secondary aluminum ash

Abstract

The invention relates to the technical field of waste treatment processes, and discloses a secondary aluminum ash harmless treatment process, which comprises the following steps: collecting secondary aluminum ash for pretreatment, calculating the proportion range of secondary aluminum ash substitute raw materials required by cement production after pretreatment, feeding the secondary aluminum ash in the proportion range into a cement kiln or a cement kiln for calcination, and discharging the secondary aluminum ash into a furnace. According to the reaction characteristics of the secondary aluminum ash, a proper storage container is determined through comparison and analysis of multiple groups of data, the secondary aluminum ash is subjected to fast burning treatment, schemes A, B, C and D are set by controlling the addition of calcium salt, the roasting temperature and the duration, then the components of the calcined aluminum ash A, B and C are measured to adjust the mineral composition of the cement clinker, and meanwhile, a quenching process is adopted to adjust the mineral composition of the cement clinker. And the cement is produced by simulating an aluminum-containing raw material in actual cement production according to the replacement proportion of the optimal calcined secondary aluminum ash, and the treatment amount of the secondary aluminum ash can be maximized through the technological process.

Description

Technical Field

[0001] The present invention relates to the technical field of waste treatment processes, and particularly to a harmless treatment process for secondary aluminum ash. Background Art

[0002] With the acceleration of the urbanization process and the rapid development of industrialization. Among them, in the cement industry, the large output and difficult disposal of secondary aluminum ash have become a prominent problem. Aluminum ash slag and secondary aluminum ash react with water to produce harmful gases such as ammonia, and are listed in the "National Hazardous Waste List" due to their reactivity.

[0003] In traditional aluminum ash treatment methods, there are problems such as low hydrolysis rate and incomplete hydrolysis, which cannot meet the requirements and need to be handed over to units with hazardous waste qualifications for compliance disposal, resulting in the insufficient decomposition and utilization of aluminum nitride in secondary aluminum ash. This not only causes waste of resources, but also pollutes the environment.

[0004] To solve these problems, the present invention proposes a harmless treatment method for aluminum ash. This method can not only effectively reduce the generation of harmful gases, but also convert aluminum ash into aluminum correction materials required for cement production, thereby reducing the batching cost of cement plants. In addition, this method can also achieve the coordinated cost reduction and efficiency improvement of cement kilns, and improve production efficiency. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a harmless treatment process for secondary aluminum ash, which has the advantages of effectively reducing the generation of harmful gases, improving resource utilization rate and reducing costs, and solves the problem that a large amount of harmful gases are generated during the water reaction of aluminum ash slag and secondary aluminum ash in the existing harmless treatment process.

[0007] (2) Technical Solutions

[0008] To achieve the above object, the present invention provides the following technical solutions: A harmless treatment process for secondary aluminum ash, comprising the following steps:

[0009] Step 1: Raw material preparation and pretreatment: Collect secondary aluminum ash and perform pretreatment;

[0010] Step 2: Calculate the mixing ratio range of secondary aluminum ash: Calculate the mixing ratio range of raw materials required for cement production;

[0011] Step 3: High-temperature calcination treatment: Feed the secondary aluminum ash within the mixing ratio range into a cement kiln or the like for calcination;

[0012] Step 4: Optimize storage container: According to the reaction characteristics of secondary aluminum ash, determine the appropriate storage container through comparative analysis of multiple groups of data;

[0013] Step 5: Improve the strength of cement clinker: Perform fast burning treatment on the secondary aluminum ash, set up A, B, C, D schemes by controlling the addition of calcium salt, controlling the roasting temperature and controlling the duration, and measure the components of the aluminum ash A, B, C after calcination to adjust the mineral composition of cement clinker, and adopt a rapid cooling process to improve the strength of the clinker;

[0014] Step 6. Determine the best ratio: Use the best secondary aluminum ash replacement ratio after calcination to simulate the aluminum-containing raw materials in actual cement production to produce cement.

[0015] Preferably, in the step 1, the secondary aluminum ash is pretreated by passing the secondary aluminum ash through a 100-mesh sieve, placing it in a ball mill, and controlling the ball-milled particle size to be between 85-90 meshes.

[0016] Preferably, the high temperature calcination treatment conditions in step 3 are as follows: the proportioned secondary aluminum ash is fed into a cement kiln, and 5% to 10% CaCl is added. 2 The high-temperature calcination was carried out for 2.5-3.5 hours at a temperature controlled at 1000-1300°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the release of harmful gases was reduced to below 2mL / g, the concentration of soluble fluoride ions was reduced to below 6.71mg / L, the weight loss range of aluminum ash was 13.00-13.24%, and the α-Al 2 O 3 The content is between 90-100%.

[0017] Preferably, the storage container is optimized in step four: the secondary aluminum ash is placed in containers made of plastic, glass, and metal for 7-14 days respectively, and the temperature change, humidity change, and chemical reaction rate data of the secondary aluminum ash in containers made of different storage materials during 7-14 days are collected.

[0018] Preferably, in the scheme A of step 5, the proportioned secondary aluminum ash is sent to the cement kiln, and 5% by mass of CaCl is added. 2 The high-temperature calcination was carried out for 2.5 hours at a temperature controlled at 1100°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was 0%, the harmful gas release was 1.8 mL / g, the soluble fluoride ion concentration was 5.84 mg / L, the aluminum ash weight loss was 13.06%, and the α-Al 2 O 3 The content is 93.3%.

[0019] Preferably, in the scheme B of step 5: the proportioned secondary aluminum ash is sent to the cement kiln, and CaCl with a mass fraction of 8% is added. 2 The high-temperature calcination was carried out for 3 hours at a temperature controlled at 1250°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the harmful gas release was 2 mL / g, the soluble fluoride ion concentration was 6.02 mg / L, the aluminum ash weight loss was 13.14%, and the α-Al 2 O 3 The content is 91%.

[0020] Preferably, in the scheme C of step 5, the proportioned secondary aluminum ash is sent to the cement kiln, and 10% by mass fraction of CaCl is added. 2 The high-temperature calcination was carried out for 2 hours at a temperature controlled at 1300°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the harmful gas release was 1.50 mL / g, the soluble fluoride ion concentration was 4.98 mg / L, the aluminum ash weight loss was 13.18%, and the α-Al 2 O 3 The content is 95%.

[0021] Preferably, in the scheme D of step 5, the proportioned secondary aluminum ash is sent to the cement kiln, and 5% by mass of CaCl is added. 2 The high-temperature calcination was carried out for 2.5 hours at a temperature controlled at 1300°C. The emission of harmful gases was monitored using online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was 0%, the harmful gas release was 1.9 mL / g, the soluble fluoride ion concentration was 5.21 mg / L, the aluminum ash weight loss was 13.14%, and the α-Al 2 O 3 The content is 92%.

[0022] Preferably, in the quenching process in step five, the calcined secondary aluminum ash is quenched using a liquid helium-free dilution refrigerator, and the quenching temperature is set to be below 10 mK.

[0023] Preferably, the step six determines the optimal ratio: in a laboratory environment, secondary aluminum ash is mixed with other raw materials in different proportions to prepare cement raw material, and the influence on the quality and performance of cement clinker is observed by adjusting the proportion of secondary aluminum ash, and a step test is carried out to explore the influence of the proportion of secondary aluminum ash disposal on the quality of cement finished product, and the optimal ratio is determined by comparative analysis based on the content of harmful components in aluminum ash.

[0024] Compared with the prior art, the present invention provides a secondary aluminum ash harmless treatment process, which has the following beneficial effects:

[0025] 1. The present invention fully decomposes and solidifies the harmful gases and heavy metals in the secondary aluminum ash through high-temperature calcination in a cement kiln, thereby achieving the purpose of no secondary waste generation. It solves the problem that when aluminum ash slag and secondary aluminum ash are treated in the existing harmless treatment process, a large amount of harmful gases will be generated during the reaction with water, thereby achieving a cleaning effect.

[0026] 2. The present invention utilizes the high aluminum content of secondary aluminum ash to replace cement aluminum materials, thereby maximizing the comprehensive utilization of resources, and explores the content of harmful components in aluminum ash through step-by-step experiments to determine the optimal ratio, which can ensure the quality of cement clinker products while maximizing the disposal volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 A secondary aluminum ash harmless treatment process comprises the following steps:

[0030] Step 1: Raw material preparation and pretreatment: collect secondary aluminum ash and pretreat it;

[0031] Step 2: Calculate the ratio range of secondary aluminum ash: Calculate the ratio range of raw materials required for cement production;

[0032] Step 3: high temperature calcination treatment: send the secondary aluminum ash within the ratio range into a cement kiln or for calcination;

[0033] Step 4: Optimize storage container: According to the reaction characteristics of secondary aluminum ash, determine the appropriate storage container through comparative analysis of multiple groups of data;

[0034] Step 5: Improve the strength of cement clinker: Perform fast burning treatment on the secondary aluminum ash, set up A, B, C, D schemes by controlling the addition of calcium salt, controlling the roasting temperature and controlling the duration, and measure the components of the aluminum ash A, B, C after calcination to adjust the mineral composition of cement clinker, and adopt a rapid cooling process to improve the strength of the clinker;

[0035] Step 6. Determine the optimal ratio: In a laboratory environment, mix secondary aluminum ash with other raw materials in different proportions to prepare cement raw materials. By adjusting the proportion of secondary aluminum ash, observe its effect on the quality and performance of cement clinker. Conduct step tests to explore the effect of the proportion of secondary aluminum ash disposal on the quality of cement products. Determine the optimal ratio based on comparative analysis of the harmful component content of aluminum ash.

[0036] Specifically, in step 1, the secondary aluminum ash is pretreated by passing the secondary aluminum ash through a 100-mesh sieve to remove large impurities and foreign matter, and then put into a ball mill to control the ball milling particle size to be between 85-90 meshes to reduce its particle size and refine its particle size.

[0037] Specifically, the high temperature calcination treatment conditions in step 3 are as follows: the proportioned secondary aluminum ash is sent to the cement kiln, and 5%-10% CaCl is added. 2 The high-temperature calcination was carried out for 2.5-3.5 hours at a temperature controlled at 1000-1300°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the release of harmful gases was reduced to below 2mL / g, the concentration of soluble fluoride ions was reduced to below 6.71mg / L, the weight loss range of aluminum ash was 13.00-13.24%, and the α-Al 2 O 3 The content is between 90-100%. This step helps to evaluate the behavior of secondary aluminum ash under high temperature conditions and to monitor whether the requirements for harmless treatment are met during the treatment process. For example, the secondary aluminum ash can remain stable in high temperature experiments and will not release harmful substances.

[0038] Specifically, in step 4, the storage containers are optimized: the secondary aluminum ash is placed in containers made of plastic, glass, and metal for 7-14 days respectively, and the temperature change, humidity change, and chemical reaction rate data of the secondary aluminum ash in containers of different storage materials are collected during 7-14 days (the temperature, humidity, and chemical reaction rate of the secondary aluminum ash in each container are recorded every day, measured using a thermometer and a hygrometer, and the chemical reaction rate is evaluated by chemical analysis methods).

[0039] Specifically, step six determines the best ratio: in a laboratory environment, secondary aluminum ash is mixed with other raw materials in different proportions to prepare cement raw material. By adjusting the proportion of secondary aluminum ash, its effect on the quality and performance of cement clinker is observed. A step test is carried out to explore the effect of the proportion of secondary aluminum ash disposal on the quality of cement finished products. A comparative analysis is performed based on the content of harmful components in aluminum ash to determine the best ratio.

[0040] Specifically, in step seven: the optimal secondary aluminum ash replacement ratio after calcination is used to simulate the aluminum-containing raw materials in actual cement production to produce cement.

[0041] Example 1

[0042] Plan A: Send the proportioned secondary aluminum ash into the cement kiln and add 5% CaCl 2 The high-temperature calcination was carried out for 2.5 hours at a temperature controlled at 1100°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was 0%, the harmful gas release was 1.8 mL / g, the soluble fluoride ion concentration was 5.84 mg / L, the aluminum ash weight loss was 13.06%, and the α-Al 2 O 3 The content is 93.3%.

[0043] Comparative Example 1

[0044] Plan B: Send the proportioned secondary aluminum ash into the cement kiln and add 8% CaCl 2 The high-temperature calcination was carried out for 3 hours at a temperature controlled at 1250°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the harmful gas release was 2 mL / g, the soluble fluoride ion concentration was 6.02 mg / L, the aluminum ash weight loss was 13.14%, and the α-Al 2 O 3 The content is 91%.

[0045] Example 2

[0046] Plan C: Send the proportioned secondary aluminum ash into the cement kiln and add 10% CaCl 2 The high-temperature calcination was carried out for 2 hours at a temperature controlled at 1300°C. The emission content of harmful gases was monitored by online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was reduced to 0%, the harmful gas release was 1.50 mL / g, the soluble fluoride ion concentration was 4.98 mg / L, the aluminum ash weight loss was 13.18%, and the α-Al 2 O 3 The content is 95%.

[0047] Comparative Example 2

[0048] Plan D: Send the proportioned secondary aluminum ash into the cement kiln and add 5% CaCl 2 The high-temperature calcination was carried out for 2.5 hours at a temperature controlled at 1300°C. The emission of harmful gases was monitored using online monitoring instruments throughout the process. The nitrogen content of the secondary aluminum ash after calcination was 0%, the harmful gas release was 1.9 mL / g, the soluble fluoride ion concentration was 5.21 mg / L, the aluminum ash weight loss was 13.14%, and the α-Al2 O 3 The content is 92%.

[0049] According to the nitrogen element, harmful gas release, soluble fluorine ion concentration, aluminum ash weight loss and α-Al 2 O 3 By comparing the contents of , the best calcination conditions are shown in Example 2 (Scheme C).

[0050] Example 3

[0051] 15 parts by mass of aluminum raw material in the cement raw material was replaced with 13 parts by mass of secondary aluminum ash.

[0052] Comparative Example 3

[0053] 15 parts by mass of secondary aluminum ash are used to replace 15 parts by mass of aluminum raw material in the cement raw material.

[0054] Example 4

[0055] 18 parts by mass of aluminum raw material in the cement raw material was replaced by 14 parts by mass of secondary aluminum ash.

[0056] Comparative Example 4

[0057] 18 parts by mass of the aluminum raw material in the cement raw material was replaced with 18 parts by mass of the secondary aluminum ash.

[0058] Example 5

[0059] 19 parts by mass of aluminum raw material in the cement raw material was replaced with 17 parts by mass of secondary aluminum ash.

[0060] Comparative Example 5

[0061] 17 parts by mass of secondary aluminum ash are used to replace 17 parts by mass of aluminum raw material in the cement raw material.

[0062] According to Examples 3, 4, 5 and the corresponding Examples 3, 4, 5, the secondary aluminum ash replaces the aluminum raw material in the cement raw material, and the data on the influence of the quality and performance of cement clinker are obtained. A step test is carried out to obtain the data on the influence of the secondary aluminum ash disposal ratio on the quality of the cement finished product. The comparative data are obtained in the following table:

[0063]

[0064]

[0065] From the above data, it can be seen that while maintaining or improving the performance of cement clinker, Example 5 reduces the content of harmful components to the greatest extent, and compared with other examples, its performance improvement is the most significant (strength increased by 10%, setting time extended by 4 minutes, and harmful components reduced by 20%). Therefore, it can be concluded that the best ratio is Example 5.

[0066] This conclusion is based on the evaluation of the performance improvement of cement clinker and the reduction of harmful components. Example 5 not only improves the strength and setting time, but also significantly reduces harmful components, meeting the goal of dual optimization of environmental protection and performance.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A secondary aluminum ash harmless treatment process, characterized in that: The following steps are involved: Step 1: Raw material preparation and pretreatment: collect secondary aluminum ash and pretreat it; Step 2: Calculate the ratio range of secondary aluminum ash: Calculate the ratio range of raw materials required for cement production; Step 3: high temperature calcination treatment: send the secondary aluminum ash within the ratio range into a cement kiln or for calcination; Step 4: Optimize storage container: According to the reaction characteristics of secondary aluminum ash, determine the appropriate storage container through comparative analysis of multiple groups of data; Step 5: Improve the strength of cement clinker: Perform fast burning treatment on the secondary aluminum ash, set up A, B, C, D schemes by controlling the addition of calcium salt, controlling the roasting temperature and controlling the duration, and measure the components of the aluminum ash A, B, C after calcination to adjust the mineral composition of cement clinker, and adopt a rapid cooling process to improve the strength of the clinker; Step 6. Determine the best ratio: Use the best secondary aluminum ash replacement ratio after calcination to simulate the aluminum-containing raw materials in actual cement production to produce cement.

2. A secondary aluminum ash harmless treatment process according to claim 1, characterized in that: The secondary aluminum ash is pretreated in step 1: the secondary aluminum ash is passed through a 100-mesh sieve and placed in a ball mill, and the ball-milled particle size is controlled to be between 85-90 meshes.

3. A secondary aluminum ash harmless treatment process according to claim 1, characterized in that: The high-temperature calcination treatment conditions in the step three are as follows: the proportioned secondary aluminum ash is sent into a cement kiln, CaCl2 with a mass fraction of 5%-10% is added, and a high-temperature calcination is carried out for 2.5-3.5 hours and the temperature is controlled at 1000-1300°C. An online monitoring instrument is used to monitor the emission content of harmful gases throughout the process. It is measured that the nitrogen content of the secondary aluminum ash after calcination is reduced to 0%, the release of harmful gases is reduced to below 2mL / g, the concentration of soluble fluoride ions is reduced to below 6.71mg / L, the weight loss range of aluminum ash is 13.00-13.24%, and the content of α-Al2O3 is between 90-100%.

4. A secondary aluminum ash harmless treatment process according to claim 1, characterized in that: The storage container is optimized in step 4: the secondary aluminum ash is placed in plastic, glass, and metal containers for 7-14 days respectively, and the temperature change, humidity change, and chemical reaction rate data of the secondary aluminum ash in the containers of different storage materials during 7-14 days are collected.

5. The secondary aluminum ash harmless treatment process according to claim 3 is characterized by: Plan A in the step five: the proportioned secondary aluminum ash is sent into a cement kiln, 5% CaCl2 is added, and a high-temperature calcination is carried out for 2.5 hours at a temperature controlled at 1100°C. An online monitoring instrument is used to monitor the emission content of harmful gases throughout the process. The nitrogen content of the secondary aluminum ash after calcination is measured to be 0%, the harmful gas release is 1.8 mL / g, the soluble fluoride ion concentration is 5.84 mg / L, the weight loss of aluminum ash is 13.06%, and the content of α-Al2O3 is 93.3%.

6. A secondary aluminum ash harmless treatment process according to claim 3, characterized in that: Plan B in the step five: the proportioned secondary aluminum ash is sent into a cement kiln, CaCl2 with a mass fraction of 8% is added, and high-temperature calcination is carried out for 3 hours at a temperature controlled at 1250°C. An online monitoring instrument is used to monitor the emission content of harmful gases throughout the process. The nitrogen content of the secondary aluminum ash after calcination is reduced to 0%, the release of harmful gases is 2 mL / g, the concentration of soluble fluoride ions is 6.02 mg / L, the weight loss of aluminum ash is 13.14%, and the content of α-Al2O3 is 91%.

7. The secondary aluminum ash harmless treatment process according to claim 3 is characterized by: In the scheme C of step five, the proportioned secondary aluminum ash is sent into a cement kiln, CaCl2 with a mass fraction of 10% is added, and high-temperature calcination is carried out for 2 hours at a temperature controlled at 1300°C. An online monitoring instrument is used to monitor the emission content of harmful gases throughout the process. The nitrogen content of the secondary aluminum ash after calcination is reduced to 0%, the release of harmful gases is 1.50 mL / g, the concentration of soluble fluoride ions is 4.98 mg / L, the weight loss of aluminum ash is 13.18%, and the content of α-Al2O3 is 95%.

8. The secondary aluminum ash harmless treatment process according to claim 3 is characterized by: In the scheme D of step five, the proportioned secondary aluminum ash is sent into a cement kiln, 5% CaCl2 is added, and high-temperature calcination is carried out for 2.5 hours at a temperature controlled at 1300°C. An online monitoring instrument is used to monitor the emission content of harmful gases throughout the process. The nitrogen content of the secondary aluminum ash after calcination is measured to be 0%, the harmful gas release is 1.9 mL / g, the soluble fluoride ion concentration is 5.21 mg / L, the weight loss of aluminum ash is 13.14%, and the content of α-Al2O3 is 92%.

9. The secondary aluminum ash harmless treatment process according to claim 1, characterized in that: The rapid cooling process in step 5 is as follows: the calcined secondary aluminum ash is rapidly cooled using a liquid helium-free dilution refrigerator, and the rapid cooling temperature is set to be below 10 mK.

10. The secondary aluminum ash harmless treatment process according to claim 1, characterized in that: The step six is ​​to determine the best ratio: in a laboratory environment, secondary aluminum ash is mixed with other raw materials in different proportions to prepare cement raw material, and the influence on the quality and performance of cement clinker is observed by adjusting the proportion of secondary aluminum ash. A step test is carried out to explore the influence of the proportion of secondary aluminum ash disposal on the quality of cement finished product, and a comparative analysis is carried out based on the content of harmful components in aluminum ash to determine the best ratio.

Images