Secondary aluminum ash recycling product as well as preparation method and application thereof

Abstract

The invention provides a secondary aluminum ash resourceful treatment method, and relates to the technical field of industrial solid waste resourceful treatment. The secondary aluminum ash recycling product is obtained through pelletizing, self-propagating combustion and cooling of raw materials, and the raw materials comprise, by mass, 80-100 parts of secondary aluminum ash and 10-20 parts of fly ash. The preparation process does not need to add auxiliaries such as acid, alkali and calcium oxide, treatment is completed through aluminothermy self-propagating reaction by utilizing reaction heat, and the method has the advantages of low energy consumption and low cost. The power consumption of the method is about 120 kilowatt-hour per ton, and the energy efficiency is higher than that of a traditional process. No waste gas, waste water and waste residues are discharged in the whole treatment process, potassium sodium villiaumite in the flue gas is collected through the high-temperature filter, and the added value of the product is increased. The finally obtained secondary aluminum ash recycling product can be widely applied to the fields of building materials, refractory materials, water purifying agents and the like, has good economic benefits and environmental friendliness, and is wide in application prospect.

Description

Technical Field

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

[0002] Aluminum ash is waste generated during the production process of the aluminum industry. It is divided into primary aluminum ash and secondary aluminum ash according to the degree of treatment and disposal. Primary aluminum ash is mainly aluminum ash directly produced in the electrolytic aluminum section and the secondary aluminum melting section. It is reflected in the aluminum slag directly discharged from the melting section and the scum produced by the electrolytic alumina section. No metallic aluminum has been extracted. The main components are metallic aluminum, fluoride salts, aluminum oxide, aluminum nitride and other substances. It has a high value for the recycling of metallic aluminum. Secondary aluminum ash is the waste after the primary aluminum ash is melted to extract metallic aluminum or the aluminum-containing waste slag produced in the aluminum refining process. The metallic aluminum content is significantly lower than that of the primary aluminum ash, and the total aluminum content is generally around 65% calculated as alumina.

[0003] Secondary aluminum ash has a wide range of sources and complex components. The chemical components in secondary aluminum ash are harmful to the environment and human health. When secondary aluminum ash comes into contact with water or humid air, the aluminum nitride contained in it is very easy to undergo hydrolysis reaction to generate ammonia with a pungent odor, which pollutes the air; the metallic aluminum contained in it reacts with water to generate hydrogen, and the aluminum carbide reacts with water to generate methane. Both hydrogen and methane have the risk of combustion and explosion. Secondary aluminum ash contains a high level of alkali metal oxides, as well as fluorides, chlorides, etc. Long-term accumulation will pollute the soil and groundwater, seriously affecting the ecological environment and people's health and safety. Due to its obvious toxicity (T) and reactivity (R), it has been included in the list of hazardous wastes.

[0004] After a lot of exploration and research, there are currently two relatively mature process routes for the treatment of secondary aluminum ash: wet treatment and pyrolysis.

[0005] The wet treatment uses water, acid and alkali solutions as solvents, removes the reactivity in the secondary aluminum ash through wet hydrolysis and leaching, and reacts the active components such as AlN and Al in the aluminum ash to produce ammonia, hydrogen and other gases through hydrolysis. The leached salt is purified and crystallized to be formulated into an aluminum refining agent, and the dehydrated filter cake is dried to obtain an inert high-aluminum material. However, during the wet treatment process, the ammonia absorption rate produced is not high and is easy to leak, and the cost of making the product into ammonium salt is too high, and the tail gas is not easy to meet the emission standards. Inflammable and explosive gases such as hydrogen and methane are easily produced in the entire treatment process, which poses a safety hazard. In addition, the entire process is relatively long, the equipment investment is large, and it is easy to corrode and has a short service life.

[0006] The core of pyrometallurgical treatment is to convert AlN into N2 and Al2O3 through roasting reaction. The most common application case is the use of secondary aluminum ash to prepare calcium aluminate refined slag for steelmaking. This technology is to prepare qualified particle size products after ball milling, homogenization, sintering, cooling and processing of secondary aluminum ash and limestone and other raw materials. The main phase of the product calcium aluminate refined slag is 12CaO·7Al2O3, which can be used for molten steel desulfurization, removal of inclusions, and purification of molten steel. However, the current pyrometallurgical treatment generally has problems such as high energy consumption, poor production environment, and relatively difficult flue gas treatment. A few low-temperature pyrometallurgical treatment processes have problems such as maintaining a low device temperature, resulting in incomplete denitrification rate and difficulty in removing fluorine and chlorine in secondary aluminum ash. Summary of the invention

[0007] In view of this, the present invention provides a secondary aluminum ash resource product and its preparation method and application. The preparation method of the secondary aluminum ash resource product provided by the present invention does not require the addition of additives, and the treatment is completed by using the reaction heat through the aluminum heat self-propagating reaction, which has the advantages of low energy consumption and low cost. There is no waste gas, waste water and waste residue emission during the treatment process, which has the advantage of being environmentally friendly. The secondary aluminum ash resource product finally obtained can be widely used in the fields of building materials, refractory materials and water purifiers, and has good application prospects.

[0008] The secondary aluminum ash resource product of the present invention is obtained by pelletizing, self-propagating combustion and cooling the raw materials, and the raw materials, calculated by mass, include:

[0009] 80-100 parts of secondary aluminum ash and 10-20 parts of dust removal ash.

[0010] Preferably, the secondary aluminum ash is low calorific value secondary aluminum ash and / or high calorific value secondary aluminum ash. More preferably, the secondary aluminum ash is composed of low calorific value secondary aluminum ash and high calorific value secondary aluminum ash in a mass ratio of (3-7):(3-7).

[0011] Preferably, the secondary aluminum ash is activated before use, specifically: the secondary aluminum ash is de-ironized, crushed, pulverized and then sieved, and then the aluminum and powder are separated until the aluminum content is 1% to 5%, completing the activation of the secondary aluminum ash.

[0012] The present invention provides a method for preparing a secondary aluminum ash resource product, which specifically comprises the following steps:

[0013] The first raw materials are mixed evenly in proportion and then pelletized. The obtained pellets are subjected to self-propagating combustion and cooled after the combustion is completed to obtain secondary aluminum ash resource products.

[0014] Preferably, the ball material has a length of 40 to 50 mm, a width of 25 to 35 mm, a thickness of 15 to 25 mm, a moisture content of ≤3%, and a compressive strength of ≥10N.

[0015] Preferably, the self-propagating combustion temperature is 1100°C to 1500°C, and the self-propagating combustion time is 6 to 8 hours. More preferably, the self-propagating combustion temperature is 1100°C to 1300°C.

[0016] The present invention provides a secondary aluminum ash resource product for preparing building materials, refractory materials and water purifiers. The secondary aluminum ash resource product is the secondary aluminum ash resource product described in the above technical solution.

[0017] The secondary aluminum ash resource processing method provided by the present invention does not require the addition of additional additives such as acid, alkali, calcium oxide, etc., has low energy consumption, and can complete the processing by using the heat generated by the self-propagating reaction of aluminum heat. Only a fan is needed to supply air during the whole process. The power consumption of processing 1 ton of secondary aluminum ash is about 120 kWh. Compared with conventional processes, the energy consumption is lower, the cost is lower, and the economic benefits are significant. In addition, the method has a high conversion rate and a high denitrification rate for aluminum nitride. There is no waste gas, wastewater, and waste residue emission during the treatment process, which is environmentally friendly. The high-temperature integrated filter is used to control different temperatures to separate and capture dust and salt, collect potassium, sodium, and fluoride salts volatilized at high temperatures in the flue gas for industrial reuse, increase the added value of the product, and the processing process has a high degree of automation, is easy to operate, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 This is the denitrification rate test result. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with 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.

[0021] The present invention provides a secondary aluminum ash resource product, which is obtained by pelletizing, self-propagating combustion and cooling the raw materials, and the raw materials, calculated by mass, include:

[0022] 80-100 parts of secondary aluminum ash and 10-20 parts of dust removal ash.

[0023] The secondary aluminum ash of the present invention is preferably low calorific value secondary aluminum ash and / or high calorific value secondary aluminum ash. In some preferred embodiments of the present invention, the secondary aluminum ash is composed of low calorific value secondary aluminum ash and high calorific value secondary aluminum ash in a mass ratio of (3-7):(3-7).

[0024] The composition of the low calorific value secondary aluminum ash of the present invention is as follows:

[0025] AlN 5.09wt.%, SiO2 2.01wt.%, Cl 0.91wt.%, MgO 1.16wt.%, SO3 0.15wt.%, CaO 0.52wt.%, Fe2O3 0.67wt.%, K2O 0.72wt.%, MnO 1.64wt.%, CuO 0.13wt.%, and the balance is Al2O3.

[0026] The composition of the high calorific value secondary aluminum ash of the present invention is as follows:

[0027] AlN 5.210wt.%, SiO2 6.81wt.%, Cl 3.71wt.%, MgO 2.76wt.%, SO3 1.86wt.%, CaO 1.53wt.%, Fe2O3 1.49wt.%, K2O 0.88wt.%, MnO 0.54wt.%, CuO 0.45wt.%, and the balance is Al2O3.

[0028] The present invention uses a mixture of a specific ratio of low calorific value secondary aluminum ash and a high calorific value secondary aluminum ash as a raw material to prepare a secondary aluminum ash resource product, which can achieve a balance between heat and reaction stability, and is an important means of taking into account the quality of the product and the energy efficiency of the process. The low calorific value aluminum ash has a low calorific value, and the heat generated during the aluminothermic reaction is limited. If the proportion is too high, the reaction cannot maintain self-propagating combustion, affecting the treatment effect. The high calorific value aluminum ash has a high calorific value and can provide sufficient heat to maintain the reaction, but if the proportion is too high, the reaction process will be difficult to control, and the uniformity of the combustion process cannot be operated, and the expected quality of the resource product cannot be obtained. Therefore, the present invention adopts a method of controlling the ratio of low calorific value secondary aluminum ash and high calorific value secondary aluminum ash to adjust the reactivity of the secondary aluminum ash raw material, and comprehensively combines its calorific value characteristics to make the self-propagating combustion stably carried out within the ideal heat range, and can also avoid the waste of resources caused by the high content of high calorific value aluminum ash, or the increase of additional energy consumption due to the high content of low calorific value aluminum ash, and always ensure that the energy consumption of the treatment process is maintained at a low level. In addition, the performance of the secondary aluminum ash resource product of the present invention is closely related to the chemical composition of the raw materials. The low calorific value aluminum ash and the high calorific value aluminum ash have significant differences in composition. After mixing in a reasonable proportion, the components in the final product can be balanced to meet the performance requirements of subsequent use as building materials, refractory materials and water purifiers.

[0029] The present invention can adjust the ratio of low calorific value and high calorific value aluminum ash within a specific range according to the actual needs of the raw materials to ensure the stability of the process and the quality of the product, specifically based on the calorific value of the secondary aluminum ash after mixing being 450 to 1300 kcal / kg. During the research process of the present invention, it was found that the secondary aluminum ash within this calorific value range has good reactivity, and the obtained product also has good comprehensive performance, which can meet the production needs of most building materials, refractory materials and water purifiers.

[0030] The secondary aluminum ash of the present invention is activated before use, specifically: the secondary aluminum ash is de-ironized, crushed, pulverized and then sieved, and then the aluminum and powder are separated until the aluminum content is 1% to 5%, completing the activation of the secondary aluminum ash.

[0031] The activation treatment of secondary aluminum ash can improve the purity of aluminum ash, ensure the quality of raw materials, reduce the waste of aluminum, and reduce the risk of excessive oxidation of aluminum in subsequent reactions. During the activation treatment, the uniformity of the raw material particle size distribution can be improved, the contact area of ​​the reactants can be optimized, and the efficiency of the aluminothermic reaction can be improved through crushing, pulverizing and screening operations. The separation process can also control the content of active components (such as aluminum and aluminum nitride) in the aluminum ash to avoid certain components being too high or too low to affect the reaction balance, thereby ensuring the stability of the reaction. In addition, the self-propagating combustion of the present invention has high requirements for the particle size, calorific value and component uniformity of the raw materials. The secondary aluminum ash that has not been activated has the problem of excessive particle size and uneven component distribution, which will lead to incomplete reaction and uneven reaction speed, generate by-products, and affect the overall treatment effect. Through activation treatment, the particle size of aluminum ash can meet the process requirements of self-propagating combustion, and ensure that the calorific value of the reactants is within a reasonable range to meet the requirements of combustion temperature control (1100℃~1300℃). At the same time, activation treatment can reduce the unreacted aluminum content in aluminum ash, reduce the release of large amounts of heat caused by large amounts of aluminum oxidation during combustion, and improve the safety and controllability of the reaction.

[0032] In some specific embodiments of the present invention, the secondary aluminum ash is deironed, crushed, and pulverized before passing through a 120-150 mesh sieve.

[0033] The raw materials of the present invention also include a certain amount of dust ash. The dust ash of the present invention is dust ash collected from aluminum ash recycling and ash roasting or smelting, and also belongs to the scope of hazardous waste. Its particle size is small, the salt content and carbon content are high, and it has a high specific surface area and calorific value. In the aluminum ash processing process, the dust ash is used to improve the physical properties of the raw materials, increase the uniformity of the reactants, and promote the stability and balance of the combustion process.

[0034] The present invention provides a method for preparing a secondary aluminum ash resource product, which specifically comprises the following steps:

[0035] The first raw materials are mixed evenly in proportion and then pelletized. The obtained pellets are subjected to self-propagating combustion and cooled after the combustion is completed to obtain secondary aluminum ash resource products.

[0036] The ball material of the invention has a length of 40 to 50 mm, a width of 25 to 35 mm, a thickness of 15 to 25 mm, a moisture content of ≤3%, and a compressive strength of ≥10N.

[0037] The self-propagating combustion temperature of the present invention is 1100° C. to 1500° C. In some preferred embodiments of the present invention, the self-propagating combustion temperature is 1100° C. to 1300° C. The present invention activates the secondary aluminum ash of the raw material and performs raw material proportioning, so that the self-propagating combustion temperature of the raw material is maintained at 1100° C. to 1500° C., so that the raw material is fully burned and denitrified, and the reactivity and combustibility of the secondary aluminum ash are removed.

[0038] In some specific embodiments of the present invention, the self-propagating combustion process is carried out in a self-propagating reactor, and the reactor is also provided with a high-temperature integrated filter, and Roots blowers are provided at the bottom and sides of the furnace. The raw materials are delivered to the furnace by automatic conveying equipment, and the oxygen-enriched side blowing process technology of the self-propagating combustion process allows the raw materials to be fully burned at a specific temperature and release sufficient heat, so that the temperature of the heat storage furnace can be maintained between 1100℃ and 1500℃ for 6 to 8 hours, so as to fully denitrify, dechlorinate and defluorinate, thereby removing the reactivity and toxicity of secondary aluminum ash and obtaining high-quality resource products. During the combustion process, potassium, sodium and fluoride salts in the flue gas volatilize at high temperatures, and the high-temperature integrated filter can separate and capture the dust according to different temperature controls, so that the gaseous salt is condensed and captured and recovered for use as industrial salt. The Roots blower plays the role of providing oxygen support, adjusting the reaction temperature, promoting airflow circulation, taking away exhaust gas and heat, improving the filter efficiency, and promoting gas cooling and purification during the reaction process.

[0039] The material that has completed the reaction in the furnace is cooled and classified to finally obtain a qualified secondary aluminum ash resource product, which can be used as a raw material in the fields of building materials, refractory materials and water purifiers.

[0040] In order to further illustrate the present invention, the following examples are provided for detailed description.

[0041] The compositions of the low calorific value secondary aluminum ash, high calorific value secondary aluminum ash, and dust removal ash used in the embodiments and comparative examples of the present invention are as follows:

[0042] Low calorific value secondary aluminum ash: AlN 5.09wt.%, SiO22.01wt.%, Cl 0.91wt.%, MgO1.16wt.%, SO30.15wt.%, CaO 0.52wt.%, Fe2O30.67wt.%, K2O 0.72wt.%, MnO1.64wt.%, CuO0.13wt.%, the balance is Al2O3;

[0043] High calorific value secondary aluminum ash: AlN 5.210wt.%, SiO26.81wt.%, Cl 3.71wt.%, MgO2.76wt.%, SO31.86wt.%, CaO 1.53wt.%, Fe2O31.49wt.%, K2O 0.88wt.%, MnO0.54wt.%, CuO 0.45wt.%, the balance is Al2O3;

[0044] Dust removal ash: AlN 6.605wt.%, SiO22.529wt.%, Cl 1.485wt.%, MgO 0.937wt.%, SO30.830wt.%, CaO 0.657wt.%, Fe2O30.557wt.%, K2O 0.366wt.%, MnO0.173wt.%, CuO0.028.%, and the balance is Al2O3.

[0045] Unless otherwise specified, all experiments were repeated three times. SPSS 21.0 was used for analysis of variance (ANOVA) and Duncan's multiple comparison analysis. The results were expressed as mean ± standard deviation, and P < 0.05 indicated a significant difference.

[0046] Example 1 A method for preparing a secondary aluminum ash resource product, the steps are as follows:

[0047] S1. De-ironize, crush and pulverize the low calorific value secondary aluminum ash and the high calorific value secondary aluminum ash respectively, and then pass through a 150-mesh sieve, and then separate the aluminum and powder until the aluminum content is 5% and 5% respectively, and complete the activation of the secondary aluminum ash;

[0048] S2, weigh 80 parts by weight of activated secondary aluminum ash (low calorific value secondary aluminum ash: high calorific value secondary aluminum ash = 7:3, calorific value is 854 kcal / kg) and 20 parts by weight of dust removal ash, mix them evenly and send them to a high-pressure ball press through a screw conveyor for ball making to obtain a ball material with a length of 45±2mm, a width of 30±2mm, a thickness of 20±2mm, an average moisture content of 3%, and a compressive strength of 10N;

[0049] S3, the ball material is sent to the feeder on the top of the kiln through the feeding belt, and a material layer is formed in the kiln through the feeder. A small amount of coal and wood are needed to ignite the furnace for the first time to ignite the local material layer. The Roots blower at the bottom and side of the kiln is used to continuously ventilate and supply oxygen to maintain an oxygen-rich environment so that the material burns violently. The heat generated spreads outward from the ignition area through heat conduction until the self-propagating combustion reaction is complete. The self-propagating combustion temperature is 1200°C and the duration is 7h;

[0050] S4. After the combustion is completed, cooling is performed to obtain secondary aluminum ash resource products.

[0051] Example 2

[0052] Same as Example 1, except that the raw material composition is as follows:

[0053] 90 parts by weight of secondary aluminum ash (low calorific value secondary aluminum ash: high calorific value secondary aluminum ash = 3:7, calorific value is 1297 kcal / kg), and 10 parts by weight of dust removal ash.

[0054] Comparative Example 1

[0055] Same as Example 1, except that no dust removal ash is added.

[0056] Comparative Example 2

[0057] Same as Example 1, except that the dust removal ash is replaced with an equal amount of waste incineration fly ash.

[0058] Comparative Example 3

[0059] Same as Example 1, except that: low calorific value secondary aluminum ash: high calorific value secondary aluminum ash = 1:9.

[0060] Comparative Example 4

[0061] Same as Example 1, except that: low calorific value secondary aluminum ash: high calorific value secondary aluminum ash = 9:1.

[0062] Since the content of low calorific value secondary aluminum ash is too high in this comparative example, a complete self-propagating combustion reaction cannot be achieved and resource products that can be used for the preparation of subsequent products cannot be obtained. Therefore, no further research will be carried out.

[0063] The denitrification rates of the raw materials of Examples 1-2 and Comparative Examples 1-3 were measured, and the results are shown in Table 1.

[0064] Table 1

[0065] project Denitrification rate, % Example 1 96.17±0.37b Example 2 97.62±0.62a Comparative Example 1 93.06±0.54c Comparative Example 2 92.98±0.78c Comparative Example 3 92.45±0.45c

[0066] Note: Different lowercase letters in the same column in the table indicate significant differences between the two groups, P < 0.05.

[0067] It can be seen from Table 1 that the raw material composition of secondary aluminum ash affects the denitrification rate of the raw material, but the overall denitrification rate is maintained at a relatively high level. In comparative examples 1-3, the denitrification rate of the raw material is reduced to varying degrees, and compared with example 1-2, the degree of reduction is more significant.

[0068] Test Example 1

[0069] The products obtained in Examples 1-2 and Comparative Examples 1-3 were used to prepare high alumina bricks. The preparation method was based on Example 1 of CN110304908A, except that the products obtained in the Examples and Comparative Examples of the present invention were used instead of alumina powder. The specific method was as follows:

[0070] S1. Raw material selection: select high-quality raw materials;

[0071] S2, crushing: crushing the raw materials in the first step respectively;

[0072] S3, screening: the crushed raw materials are respectively passed through a 180-mesh sieve to obtain iron sheet powder, mullite powder and alumina powder; then the screened iron sheet is passed through a 3mm sieve, and the remaining iron sheet is passed through a sieve with a mesh size of 5mm to obtain iron sheet with a particle size of 3-5mm; similarly, mullite particles with a particle size of 1-3mm and high alumina with a particle size of 0.5-1mm are obtained;

[0073] S4, batching: 8 parts of iron sheet material, 30 parts of mullite particles, 22 parts of high aluminum material, 21 parts of iron sheet material powder, 7 parts of mullite powder, 5 parts of secondary aluminum ash resource product, and 7 parts of Guangxi white mud are prepared. First, add iron sheet material, mullite and high aluminum material to stir, then add 3 parts of water and iron sheet material powder, mullite powder, and alumina powder, and continue to stir until uniform; prepare the ingredients, first add iron sheet material, mullite and high aluminum material to stir, then add 3 parts of water and iron sheet material powder, mullite powder, and alumina powder, and continue to stir until uniform;

[0074] S5, molding: the mixed raw materials are pressed 6 times by a 400-ton press;

[0075] S6, drying: drying the semi-finished product after forming at 110° C. for 20 hours;

[0076] S7, Semi-finished product inspection: Screen out semi-finished products that do not meet the requirements;

[0077] S8, firing: When the ambient temperature is controlled at about 30°C, the semi-finished product that has passed the inspection is heated to 1490°C at 5°C / min, and then kept at this temperature for 8 hours to obtain the finished product.

[0078] The performance of the obtained high alumina bricks was tested, and the specific indicators were:

[0079] Refractoriness (℃): ≥1790;

[0080] Load softening temperature (℃) 0.2MPa×0.6%: ≥1510;

[0081] Bulk density (g / cm 3 ): ≥2.48;

[0082] Apparent porosity (%): ≤20;

[0083] High temperature compressive strength (MPa): ≥55.06;

[0084] High temperature creep rate% (0.2MPa, 1280℃, 2h)≤: 0.7;

[0085] Reburning line change, 1500℃×2h%: ±0.3;

[0086] Thermal stability (1100℃ water cooling) ≥15.

[0087] The performance test results of each high alumina brick are shown in Table 2.

[0088] Table 2 High alumina brick performance test results

[0089]

[0090] It can be seen from Table 2 that dust removal ash and low calorific value secondary aluminum ash and high calorific value secondary aluminum ash

[0091] Test Example 2

[0092] The products obtained in Examples 1-2 and Comparative Examples 1-3 were used to prepare fused cast alumina refractory products for glass melting furnaces. The preparation method was based on Example 1 of CN 112110716A, except that the alumina was replaced with an equal amount of the products obtained in Examples 1-2 and Comparative Examples 1-3. The specific method was as follows:

[0093] S1. Mixing: Weigh 32 kg of secondary aluminum ash resource product, add 26.3 kg of zircon sand, 10 kg of desiliconized zirconium, 1 kg of soda ash, 2.5 kg of calcium silicate and 1.2 kg of ferric oxide, mix well, crush with a crusher, sieve with a sieve with an aperture of 700 μm, continue to crush particles larger than 700 μm until they are no larger than 700 μm, and obtain a mixture;

[0094] S2 melting: the mixture is transferred into an electric arc furnace, heated to 2000°C with a graphite electrode, melted for 130 minutes, and a molten liquid is obtained. The outlet end of the oxygen gun is inserted 40 cm below the surface of the molten liquid, and oxygen is blown into the molten liquid with an oxygen gun for 8 minutes. The oxygen pressure is 0.4 MPa, and the oxygen flow rate is 450 L / h. The oxygen blowing is stopped, and the refining is continued at 2000°C for 18 minutes. Then, oxygen is blown into the molten liquid for a second time for 8 minutes to obtain a casting liquid.

[0095] S3 casting: Take 1.8kg yttrium oxide and 3kg tetragonal nano zirconium oxide, mix them evenly, transfer them into a sand mold placed in an insulation box, inject the casting liquid into the mold, cool it down to 60°C in 10 days, and obtain a fused-cast alumina refractory product for a glass melting furnace with a size of 80cm*40cm*10cm.

[0096] The test results of the fused-cast alumina refractory products for various glass melting furnaces are shown in Table 3.

[0097] Table 3 Performance test results of fused cast alumina refractory products for glass melting furnace

[0098] Room temperature compressive strength, MPa, Flexural strength at room temperature, MPa Example 1 31.55±0.55a 7.38±0.38a Example 2 32.03±0.57a 7.46±0.46a Comparative Example 1 27.76±0.24c 6.79±0.21ab Comparative Example 2 28.08±0.42c 6.64±0.36b Comparative Example 3 30.29±0.29b 6.94±0.56ab

[0099] Note: Different lowercase letters in the same column in the table indicate significant differences between the two groups, P < 0.05.

[0100] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A secondary aluminum ash resource product, characterized in that: The raw materials are pelletized, self-propagating burned and cooled, and the raw materials are calculated by weight and include: 80-100 parts of secondary aluminum ash and 10-20 parts of dust removal ash.

2. The secondary aluminum ash resource product according to claim 1, characterized in that: The secondary aluminum ash is low calorific value secondary aluminum ash and / or high calorific value secondary aluminum ash.

3. The secondary aluminum ash resource product according to claim 2, characterized in that: The secondary aluminum ash is composed of calorific value secondary aluminum ash and high calorific value secondary aluminum ash in a mass ratio of (3-7):(3-7).

4. The secondary aluminum ash resource product according to claim 1, characterized in that: The secondary aluminum ash is activated before use, specifically: the secondary aluminum ash is de-ironized, crushed, pulverized and then sieved, and then the aluminum and powder are separated until the aluminum content is 1% to 5%, completing the activation of the secondary aluminum ash.

5. The secondary aluminum ash resource product according to claim 1, characterized in that: The raw materials also include 5 parts by mass of a fluorine-fixing agent.

6. The method for preparing the secondary aluminum ash resource product according to any one of claims 1 to 5, specifically comprising the following steps: The first raw materials are mixed evenly in proportion and then pelletized. The obtained pellets are subjected to self-propagating combustion and cooled after the combustion is completed to obtain secondary aluminum ash resource products.

7. The preparation method according to claim 6, characterized in that: The length of the ball material is 40-50 mm, the width is 25-35 mm, the thickness is 15-25 mm, the moisture content is ≤3%, and the compressive strength is ≥10N.

8. The preparation method according to claim 6, characterized in that: The self-propagating combustion temperature is 1100° C. to 1500° C., and the self-propagating combustion time is 6 to 8 hours.

9. The preparation method according to claim 8, characterized in that: The self-propagating combustion temperature is 1100°C to 1300°C.

10. Application of secondary aluminum ash resource products in the preparation of building materials, refractory materials and water purifiers, characterized in that: The secondary aluminum ash resource product is the secondary aluminum ash resource product described in any one of claims 1 to 5 or the secondary aluminum ash resource product prepared by the method described in any one of claims 6 to 9.

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