A method for preparing non-burning bricks by harmless treatment of aluminum ash, and non-burning bricks

Abstract

The application relates to the field of solid waste recycling, in particular to a method for preparing non-burning bricks from harmless aluminum ash and the non-burning bricks. The method comprises the following steps: grinding the harmless aluminum ash, then screening to obtain first aluminum-based raw materials; microwave activating the first aluminum-based raw materials to obtain second aluminum-based raw materials; using acid liquid to stimulate the second aluminum-based raw materials to obtain third aluminum-based raw materials; mixing the third aluminum-based raw materials, inorganic cementing materials, aggregates, water reducing agents and water to obtain grouting materials; and performing mold shaping and post-processing on the grouting materials to obtain the non-burning bricks. The first aluminum-based raw materials are screened through the grinding and screening mode, microwave activation is used to provide energy for the first aluminum-based raw materials and reduce the activation energy of the subsequent reaction, and in the subsequent acid liquid stimulation process, the effective components in the harmless aluminum ash can be more easily converted into aluminum salt adhesives, the physical performance of the aluminum-based non-burning bricks can be optimized, and high-value utilization of solid waste is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solid waste recycling, in particular to a method for preparing non-burning bricks from harmless aluminum ash and the non-burning bricks. BACKGROUND

[0002] Aluminum ash is a kind of dregs produced in the process of aluminum smelting or casting. It is listed in the National Hazardous Waste List due to its reactivity and leaching toxicity. Harmless aluminum ash is a kind of waste produced by the safe dissociation of unstable substances such as AlN and Al3C4 in aluminum ash. It contains a large amount of aluminum resources, so it has potential utilization value. Currently, harmless aluminum ash can be used in high-aluminum refractory materials, aluminate materials, water purifying agents, etc., but there is no report on its use in the preparation of non-burning bricks.

[0003] Currently, the methods for preparing non-burning bricks from aluminum ash include: (1) using aluminum ash as raw material to prepare non-burning bricks, which includes 70-80 parts of aluminum ash, 1-5 parts of calcium oxide, 1-5 parts of hydrogen peroxide, 1-3 parts of sodium carbonate, 1-3 parts of portland cement, 1-5 parts of peroxyacetic acid, 1-10 parts of acetic acid, 1-5 parts of anhydrous calcium sulfate, 1-5 parts of fly ash, 5-10 parts of crushed stone, 1-2 parts of additives, and 10-15 parts of water. This method uses aluminum ash as raw material, but there is a problem of ammonia gas emission during the preparation of non-burning bricks, and the physical properties of the prepared non-burning bricks are generally poor.

[0004] (2) A method for preparing polyaluminum chloride and co-producing non-burning environment-friendly bricks from aluminum ash, which includes: ball milling and sieving the aluminum ash; adding the undersize to water to obtain an aluminum ash slurry; adding hydrochloric acid to the aluminum ash slurry to separate an acid leaching liquid and an acid leaching residue; adjusting the pH of the acid leaching liquid, then polymerizing and curing to obtain polyaluminum chloride; and using the acid leaching residue as raw material to prepare non-burning environment-friendly bricks. However, this method mainly uses hydrochloric acid to polymerize and cure to form polyaluminum chloride, and does not involve the principle of phosphoric acid excitation. In addition, the aluminum ash raw material needs to be safely dissociated.

[0005] (3) A process for preparing non-burning bricks from secondary aluminum ash under high pressure, which includes: using secondary aluminum ash as the main material, adding active waste residue and a small amount of active activator to the main material, mixing, and then high-pressure pressing to form non-burning bricks, which includes the following steps: pretreatment, mixing, molding, and steam curing. However, the preparation of non-burning bricks in this method requires high-pressure molding.

[0006] Therefore, using harmless aluminum ash as raw material to prepare high-performance non-burning bricks can not only expand the utilization way of harmless aluminum ash, but also fully utilize the effective components in harmless aluminum ash to realize the high-value utilization of solid waste. SUMMARY

[0007] The application provides a method for preparing non-burning bricks by using harmless aluminum ash and the non-burning bricks, so as to solve the technical problem that there is no method for preparing high-performance non-burning bricks by using harmless aluminum ash as raw materials in the prior art.

[0008] In a first aspect, the application provides a method for preparing non-burning bricks by using harmless aluminum ash, which comprises the following steps:

[0009] Grinding the harmless aluminum ash, and then performing screening to obtain a first aluminum-based raw material;

[0010] Performing microwave activation on the first aluminum-based raw material to obtain a second aluminum-based raw material;

[0011] Performing acid liquid excitation on the second aluminum-based raw material by using an acid liquid to obtain a third aluminum-based raw material;

[0012] Mixing the third aluminum-based raw material, inorganic cementing material, aggregate, water reducing agent and water to obtain a grouting material;

[0013] Performing mold shaping and post-processing on the grouting material to obtain non-burning bricks.

[0014] Optionally, the power of the microwave activation is 400 W to 1200 W, and the time of the microwave activation is 1 min to 10 min.

[0015] Optionally, the mass ratio of the acid liquid to the second aluminum-based raw material is ≤5%.

[0016] Optionally, the acid liquid comprises phosphoric acid, and the mass concentration of the phosphoric acid is 60% to 90%.

[0017] Optionally, the acid liquid excitation is performed by adding the acid liquid while stirring, the time of the acid liquid excitation is 1 min to 5 min, and the stirring speed of the acid liquid excitation is 100 r / min to 400 r / min.

[0018] Optionally, the target particle size of the screening is <60 mesh.

[0019] Optionally, the post-processing comprises demolding and curing, the time of the curing is 1 day to 4 days, the temperature of the curing is 20°C to 40°C, and the humidity of the curing is 40% to 70%.

[0020] In a second aspect, the application provides non-burning bricks, which are prepared by the method in the first aspect.

[0021] Optionally, the raw materials of the non-burning bricks comprise, in terms of weight parts, the third aluminum-based raw material: 10 parts to 40 parts, the inorganic cementing material: 10 parts to 20 parts, the aggregate: 30 parts to 60 parts, the water: 10 parts to 25 parts and the water reducing agent: 0.5 part to 2 parts.

[0022] Optionally, the aggregate comprises at least one of:

[0023] Natural sand, artificial sand, pebbles, gravel and ceramsite.

[0024] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0025] The method for preparing the unfired brick from the harmless aluminum ash slag provided by the embodiments of the present application first screens out the first aluminum-based raw material with sufficient particle size distribution through the grinding and screening method, then provides energy for the first aluminum-based raw material through the microwave activation method, and reduces the activation energy of the subsequent reaction, so that the effective components in the harmless aluminum ash slag can be more easily converted into the aluminum salt adhesive in the subsequent acid liquid excitation process. Due to the existence of the aluminum salt adhesive, the raw materials of the grouting material can be directly glued and fixed to form the aluminum-based unfired brick, so that the physical properties of the aluminum-based unfired brick can be optimized, and the high-value utilization of the solid waste can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings incorporated into the specification and constituting a part of the specification show embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 The flowchart of the method for preparing the unfired brick from the harmless aluminum ash slag provided by the embodiments of the present application is shown in the figure.

[0029] Figure 2 The actual production flowchart of the method for preparing the unfired brick from the harmless aluminum ash slag provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment, etc. used in the present application can be purchased from the market or can be prepared by the existing method.

[0032] As Figure 1 shown in the embodiments of the present application, a method for preparing non-burning bricks from harmless aluminum ash slag is provided, and the method comprises the following steps:

[0033] S1. Grinding the harmless aluminum ash slag, and then screening to obtain a first aluminum-based raw material;

[0034] S2. Microwave activating the first aluminum-based raw material to obtain a second aluminum-based raw material;

[0035] S3. Acid liquid excitation of the second aluminum-based raw material with an acid liquid to obtain a third aluminum-based raw material;

[0036] S4. Mixing the third aluminum-based raw material, inorganic cementitious material, aggregate, water reducing agent and water to obtain a grouting material;

[0037] S5. Molding and post-processing the grouting material to obtain non-burning bricks.

[0038] It should be noted that the harmless aluminum ash slag refers to the waste slag produced by safe dissociation of unstable substances such as AlN and Al3C4 in aluminum ash. The harmless aluminum ash slag can be inert high-aluminum material, or inert residue after nitrogen and fluorine removal of primary aluminum ash, or inert residue after nitrogen and fluorine removal of secondary aluminum ash.

[0039] In some optional embodiments, the power of microwave activation is 400W-1200W, and the time of microwave activation is 1min-10min.

[0040] In the embodiments of the present application, the specific power and time of microwave activation are limited, which can ensure that the energy generated by microwave activation is sufficient to reduce the activation energy of the first aluminum-based raw material, so that the effective components in the harmless aluminum ash slag can be more easily converted into aluminum salt adhesive in the subsequent acid liquid excitation process. In this way, non-burning bricks can be directly formed without applying pressure during the film formation stage of the grouting material.

[0041] The power of microwave activation can be 400W, 500W, 600W, 700W, 800W, 900W, 1000W, 1100W or 1200W.

[0042] The time of microwave activation can be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min.

[0043] In some optional embodiments, the mass ratio of the acid solution to the second aluminum-based raw material is ≤5%.

[0044] In the embodiments of the present application, by limiting the specific mass ratio of the acid solution to the second aluminum-based raw material, the aluminum element in the harmless aluminum ash slag can be excited by the acid solution, and the aluminum element can be converted into an aluminum salt adhesive, so that the pressing step can be omitted in the subsequent preparation of the no-burning brick, and the no-burning brick product can be directly obtained.

[0045] It should be noted that the acid solution can use phosphoric acid. When the phosphoric acid is used, the effective components in the harmless aluminum ash slag can be converted into aluminum dihydrogen phosphate in the acid solution excitation process, and the aluminum dihydrogen phosphate not only can avoid the pressing in the traditional preparation process of the no-burning brick, but also can improve the mechanical properties of the no-burning brick.

[0046] In some optional embodiments, the acid solution includes phosphoric acid, and the mass concentration of the phosphoric acid is 60%-90%.

[0047] In the embodiments of the present application, by limiting the specific mass concentration of the phosphoric acid, the effective components in the harmless aluminum ash slag can be fully converted into aluminum dihydrogen phosphate in the excitation process, and a sufficient amount of aluminum dihydrogen phosphate can be produced.

[0048] The mass concentration of the phosphoric acid can be 60%, 65%, 70%, 75%, 80%, 85%, or 90%.

[0049] In some optional embodiments, the acid solution excitation is performed by adding the acid solution while stirring, the acid solution excitation time is 1 min-5 min, and the stirring speed of the acid solution excitation is 100 r / min-400 r / min.

[0050] In the embodiments of the present application, by limiting the specific time of the acid solution excitation and the stirring speed of the acid solution excitation state, the acid solution and the first aluminum-based raw material can be fully contacted, and the effective components in the harmless aluminum ash slag can be more easily converted into the aluminum salt adhesive.

[0051] The acid solution excitation time can be 1 min, 2 min, 3 min, 4 min, or 5 min.

[0052] The stirring speed of the acid solution excitation can be 100 r / min, 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, or 400 r / min.

[0053] In some optional embodiments, the target particle size of the screening is <60 mesh.

[0054] In the embodiment of the present application, the specific target particle size of the screening can determine the specific particle size distribution of the first aluminum-based raw material, facilitate the subsequent microwave activation process to be fully performed, and thus can effectively reduce the reaction activation energy of the harmless aluminum ash residue.

[0055] In some optional embodiments, the post-processing includes demolding and curing, the curing time is 1-4 days, the curing temperature is 20-40°C, and the curing humidity is 40-70%.

[0056] In the embodiment of the present application, the specific steps of the post-processing include demolding and curing, and the specific time, temperature and humidity of the curing can make the grouting material gradually form and obtain the excellent performance of the baking-free brick during the curing process.

[0057] As shown in Figure 2 Based on the overall inventive concept, the embodiment of the present application provides a baking-free brick prepared by the method.

[0058] The baking-free brick is realized based on the above preparation method, and the specific steps of the preparation method can be referred to the above embodiments. Since the baking-free brick adopts part or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0059] In some optional embodiments, the raw materials of the baking-free brick include, in terms of weight parts, 10-40 parts of the third aluminum-based raw material, 10-20 parts of the inorganic cementitious material, 30-60 parts of the aggregate, 10-25 parts of water and 0.5-2 parts of the water reducing agent.

[0060] In the embodiment of the present application, the specific composition of the baking-free brick is limited, the aggregate is used as the framework, and the inorganic cementitious material and the third aluminum-based raw material are combined. The use of the aluminum salt adhesive in the third aluminum-based raw material and the bonding performance of the inorganic cementitious material can make the bonding between different aggregates sufficient, and at the same time, the solid particles in the third aluminum-based raw material can be fixed on the framework of the aggregate. Compared with the traditional baking-free brick which needs to be pressed to make the bonding between the aggregates sufficient, the present application only needs to realize the forming of the baking-free brick by the third aluminum-based raw material and the inorganic cementitious material at normal temperature and pressure, and finally adjusts the water content of the baking-free brick by the action of water and the water reducing agent, so that the excellent performance of the baking-free brick can be obtained.

[0061] It should be noted that the inorganic cementitious material can be 425 ordinary portland cement.

[0062] It should be noted that the water reducing agent can be FS65 of Wuhan Shanda.

[0063] In some alternative embodiments, the aggregate comprises at least one of:

[0064] Natural sand, artificial sand, pebbles, gravel and ceramsite.

[0065] In the embodiments of the present application, the specific types of aggregate can form a large enough framework structure in the non-burned brick and make the reaction between the inorganic cementitious material and the third aluminum-based raw material complete, so as to make the non-burned brick quickly form, and finally adjust the moisture of the non-burned brick by the water reducing agent and water, so that the non-burned brick product with excellent performance can be obtained.

[0066] The present application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. The experimental methods not specified in the following examples are generally determined according to the national standards. If there is no corresponding national standard, the general international standard, the conventional condition, or the condition suggested by the manufacturer is used.

[0067] Example 1

[0068] A method for preparing non-burned brick from harmless aluminum ash residue, comprising:

[0069] S1. Grinding the harmless aluminum ash residue, and then screening to obtain a first aluminum-based raw material;

[0070] S2. Microwave activating the first aluminum-based raw material to obtain a second aluminum-based raw material;

[0071] S3. Acid liquid excitation of the second aluminum-based raw material with an acid liquid to obtain a third aluminum-based raw material;

[0072] S4. Mixing the third aluminum-based raw material, inorganic cementitious material, aggregate, water reducing agent and water to obtain a grouting material;

[0073] S5. Molding and shaping the grouting material for 48h and post-processing to obtain a non-burned brick.

[0074] The chemical composition of the harmless aluminum ash residue is shown in Table 1.

[0075] Table 1 Chemical composition of harmless aluminum ash residue

[0076] Chemical composition Al2O3 MgO Na2O K2O SiO2 CaO TiO2 Fe2O3 Others Percentage content (%) 81.47 9.21 0.48 0.36 1.63 1.20 0.46 1.54 3.65

[0077] The power of microwave activation is 400W, and the time of microwave activation is 5min.

[0078] The mass ratio of the acid liquid to the second aluminum-based raw material is 3%.

[0079] The acid liquid comprises phosphoric acid, and the mass concentration of the phosphoric acid is 60%.

[0080] The acid liquid excitation includes acid liquid excitation by stirring while adding acid liquid, the acid liquid excitation time is 5 min, and the acid liquid excitation stirring speed is 100 r / min.

[0081] The post-processing includes demolding and curing, the curing time is 3 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0082] The raw materials of the baking-free brick include, in terms of weight parts, the third aluminum-based raw material: 20 parts, the inorganic cementing material: 20 parts, the aggregate: 40 parts, the water: 10 parts, and the water reducing agent: 0.5 part.

[0083] The aggregate is natural sand.

[0084] Example 2

[0085] Comparing example 2 with example 1, the difference between example 2 and example 1 is that:

[0086] The microwave activation power is 1200 W, and the microwave activation time is 5 min.

[0087] The mass ratio of the acid liquid to the second aluminum-based raw material is 3%.

[0088] The acid liquid includes phosphoric acid, and the mass concentration of the phosphoric acid is 90%.

[0089] The acid liquid excitation includes acid liquid excitation by stirring while adding acid liquid, the acid liquid excitation time is 5 min, and the acid liquid excitation stirring speed is 100 r / min.

[0090] The post-processing includes demolding and curing, the curing time is 3 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0091] The raw materials of the baking-free brick include, in terms of weight parts, the third aluminum-based raw material: 20 parts, the inorganic cementing material: 20 parts, the aggregate: 40 parts, the water: 10 parts, and the water reducing agent: 0.5 part.

[0092] The aggregate is natural sand.

[0093] Example 3

[0094] Comparing example 3 with example 1, the difference between example 3 and example 1 is that:

[0095] The microwave activation power is 400 W, and the microwave activation time is 5 min.

[0096] The mass ratio of the acid liquid to the second aluminum-based raw material is 3%.

[0097] The acid liquid includes phosphoric acid, and the mass concentration of the phosphoric acid is 60%.

[0098] Acid activation involves adding acid while stirring for 5 minutes, with a stirring speed of 100 r / min.

[0099] Post-treatment includes demolding and curing. The curing time is 3 days, the curing temperature is 25℃, and the curing humidity is 60%.

[0100] By weight, the raw materials for non-fired bricks include: 20 parts of third aluminum-based raw material, 20 parts of inorganic cementitious material, 40 parts of aggregate, 10 parts of water, and 0.5 parts of water-reducing agent.

[0101] The aggregate is natural sand.

[0102] Example 4

[0103] Comparing Example 4 with Example 1, the difference between Example 4 and Example 1 is as follows:

[0104] The microwave activation power was 400W, and the microwave activation time was 5 minutes.

[0105] The mass ratio of acid solution to the second aluminum-based raw material is 3%.

[0106] The acid solution includes phosphoric acid, with a mass concentration of 60%.

[0107] Acid activation involves adding acid while stirring for 5 minutes, with a stirring speed of 100 r / min.

[0108] Post-treatment includes demolding and curing. The curing time is 3 days, the curing temperature is 25℃, and the curing humidity is 40%.

[0109] By weight, the raw materials for non-fired bricks include: 20 parts of third aluminum-based raw material, 20 parts of inorganic cementitious material, 40 parts of aggregate, 10 parts of water, and 1.0 part of water-reducing agent.

[0110] The aggregate is natural sand.

[0111] Example 5

[0112] Comparing Example 5 with Example 1, the difference between Example 5 and Example 1 is as follows:

[0113] The microwave activation power was 800W, and the microwave activation time was 5 minutes.

[0114] The mass ratio of acid solution to the second aluminum-based raw material is 5%.

[0115] The acid solution includes phosphoric acid, with a mass concentration of 60%.

[0116] The acid liquid activation includes adding the acid liquid while stirring, the acid liquid activation time is 3 minutes, and the stirring speed of the acid liquid activation is 400 r / min.

[0117] The target particle size of the screening is 80 mesh.

[0118] The post-processing includes demolding and curing, the curing time is 34 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0119] The raw materials of the baking-free brick include, by weight fraction, the third aluminum-based raw material 40 parts, the inorganic cementing material 20 parts, the aggregate 40 parts, water 10 parts, and the water reducing agent 0.5 parts.

[0120] The aggregate is the ceramsite.

[0121] Example 6

[0122] Comparing the example 6 with the example 1, the difference between the example 6 and the example 1 is that:

[0123] The microwave activation power is 400 W, and the microwave activation time is 5 minutes.

[0124] The mass ratio of the acid liquid to the second aluminum-based raw material is 3%.

[0125] The acid liquid includes the phosphoric acid, and the mass concentration of the phosphoric acid is 60%.

[0126] The acid liquid activation includes adding the acid liquid while stirring, the acid liquid activation time is 5 minutes, and the stirring speed of the acid liquid activation is 100 r / min.

[0127] The post-processing includes demolding and curing, the curing time is 3 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0128] The raw materials of the baking-free brick include, by weight fraction, the third aluminum-based raw material 20 parts, the inorganic cementing material 20 parts, the aggregate 40 parts, water 10 parts, and the water reducing agent 0.5 parts.

[0129] The aggregate is the natural sand.

[0130] Example 7

[0131] Comparing the example 7 with the example 1, the difference between the example 7 and the example 1 is that:

[0132] The microwave activation power is 400 W, and the microwave activation time is 5 minutes.

[0133] The mass ratio of the acid liquid to the second aluminum-based raw material is 3%.

[0134] The acid liquid includes the phosphoric acid, and the mass concentration of the phosphoric acid is 60%.

[0135] The acid liquid activation is performed by adding the acid liquid while stirring, the acid liquid activation time is 5 min, and the acid liquid activation stirring speed is 100 r / min.

[0136] The post-processing includes demolding and curing, the curing time is 3 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0137] The raw materials of the baking-free brick include, by weight fraction, the third aluminum-based raw material: 20 parts, the inorganic cementing material: 10 parts, the aggregate: 40 parts, the water: 10 parts, and the water reducing agent: 0.5 parts.

[0138] The aggregate is natural sand.

[0139] Example 8

[0140] Comparing example 8 with example 1, the difference between example 8 and example 1 is that:

[0141] The microwave activation power is 1000 W, and the microwave activation time is 10 min.

[0142] The mass ratio of the acid liquid to the second aluminum-based raw material is 1.5%.

[0143] The acid liquid includes phosphoric acid, and the mass concentration of the phosphoric acid is 80%.

[0144] The acid liquid activation is performed by adding the acid liquid while stirring, the acid liquid activation time is 5 min, and the acid liquid activation stirring speed is 200 r / min.

[0145] The post-processing includes demolding and curing, the curing time is 3 days, the curing temperature is 25 DEG C, and the curing humidity is 40%.

[0146] The raw materials of the baking-free brick include, by weight fraction, the third aluminum-based raw material: 20 parts, the inorganic cementing material: 20 parts, the aggregate: 40 parts, the water: 10 parts, and the water reducing agent: 0.5 parts.

[0147] The aggregate is crushed stone.

[0148] Comparative example 1

[0149] Comparing comparative example 1 with example 1, the difference between comparative example 1 and example 1 is that:

[0150] A method for preparing a baking-free brick from a harmless aluminum ash residue includes:

[0151] S1. grinding the harmless aluminum ash residue, and then screening to obtain a first aluminum-based raw material;

[0152] S2. The first aluminum-based raw material is subjected to acid liquid excitation with an acid liquid to obtain a second aluminum-based raw material;

[0153] S3. The second aluminum-based raw material, inorganic cementitious material, aggregate, water reducing agent and water are mixed to obtain a grouting material;

[0154] S4. The grouting material is subjected to mold setting for 48 hours and post-processing to obtain the non-burning brick.

[0155] The mass ratio of the acid liquid to the first aluminum-based raw material is 3%.

[0156] The acid liquid comprises phosphoric acid, and the mass concentration of the phosphoric acid is 60%.

[0157] The acid liquid excitation comprises acid liquid excitation by stirring while adding the acid liquid, the acid liquid excitation time is 5 minutes, and the stirring speed of the acid liquid excitation is 100 r / min.

[0158] The post-processing comprises demolding and curing, the curing time is 3 days, the curing temperature is 25°C, and the curing humidity is 40%.

[0159] The raw materials of the non-burning brick comprise, in parts by weight, the second aluminum-based raw material: 20 parts, the inorganic cementitious material: 20 parts, the aggregate: 40 parts, the water: 10 parts and the water reducing agent: 0.5 parts.

[0160] The aggregate is natural sand.

[0161] Comparative Example 2

[0162] Comparative Example 2 and Example 1 are compared, and the difference between Comparative Example 2 and Example 1 is that:

[0163] A method for preparing a non-burning brick from harmless aluminum ash slag comprises:

[0164] S1. The harmless aluminum ash slag is ground and then screened to obtain a first aluminum-based raw material;

[0165] S2. The first aluminum-based raw material is subjected to microwave activation to obtain a second aluminum-based raw material;

[0166] S3. The second aluminum-based raw material, inorganic cementitious material, aggregate, water reducing agent and water are mixed to obtain a grouting material;

[0167] S4. The grouting material is subjected to mold setting for 48 hours and post-processing to obtain the non-burning brick.

[0168] The power of the microwave activation is 400 W, and the microwave activation time is 5 minutes.

[0169] The post-processing comprises demolding and curing, the curing time is 3 days, the curing temperature is 25°C, and the curing humidity is 40%.

[0170] The raw materials of the unfired brick include, by weight fraction, a second aluminum-based raw material: 20 parts, an inorganic cementing material: 20 parts, aggregate: 40 parts, water: 10 parts, and water reducing agent: 0.5 parts.

[0171] The aggregate is natural sand.

[0172] Related experiments and effect data:

[0173] The compressive strength of the unfired bricks obtained in Examples 1-8 and Comparative Examples 1-2 after 7 days was detected, and the results are shown in Table 2.

[0174] Table 2 Compressive strength of unfired bricks obtained in each example and comparative example

[0175]

[0176] As can be seen from Table 1, the method for preparing unfired bricks from the harmless aluminum ash provided in the embodiments of the present application first increases the specific surface area of the harmless aluminum ash by using a ball milling and screening pretreatment process, then improves the activity of the harmless aluminum ash by a microwave activation method, then makes the harmless aluminum ash generate a new chemical component, aluminum dihydrogen phosphate, by a phosphoric acid excitation method, and finally prepares the unfired bricks by metering the harmless aluminum ash and other raw materials. The entire process fully utilizes the effective components in the harmless aluminum ash, and the high-performance unfired bricks prepared thereby bring considerable benefits to the project and also expand the channel for the harmless aluminum ash.

[0177] Meanwhile, the method for preparing unfired bricks from the harmless aluminum ash provided in the embodiments of the present application not only expands the utilization way of the harmless aluminum ash, but also the high-performance unfired bricks prepared from the harmless aluminum ash can create considerable benefits.

[0178] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is merely for the convenience and brevity, and should not be understood as a hard limitation on the scope of the present application; therefore, it should be considered that the range described has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) within the indicated range.

[0179] In the present application, the orientation words such as "upper" and "lower" are specific to the drawing surface direction in the drawings. In addition, in the description of the specification of the present application, the terms "include", "contain" and the like mean "include but are not limited to".

[0180] In this document, relational terms such as "first" and "second", and the like can be used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. In this document, the term "and / or" describes association between name objects. It is used to represent the following three cases: A alone, both A and B, and B alone. Where A and B are names of objects. In this document, the term "at least one" means one or more and the term "multiple" means two or more. The term "at least one of A, B, and C" covers A, B, C, A-B, A-C, B-C, and A-B-C. Where A, B, and C are names of objects.

[0181] The foregoing is merely illustrative of the principles of this application and various modifications can be made by those skilled in the art without departing from the spirit and scope of the application. The above embodiments are illustrative, and not restrictive, of the scope of the application.

Claims

1. A method for preparing non-fired bricks from harmless aluminum ash slag, characterized in that, The method includes: The harmless aluminum ash residue was ground and then sieved to obtain the first aluminum-based raw material. The first aluminum-based raw material was microwave activated to obtain the second aluminum-based raw material; The second aluminum-based raw material is activated by acid solution to convert the effective component in the second aluminum-based raw material into aluminum dihydrogen phosphate, thus obtaining the third aluminum-based raw material. The third aluminum-based raw material, inorganic cementitious material, aggregate, water-reducing agent and water are mixed to obtain grouting material; The grouting material is molded, shaped, and post-treated to obtain non-fired bricks; The microwave activation power is 400W to 1200W, and the microwave activation time is 1min to 10min; The mass ratio of the acid solution to the second aluminum-based raw material is ≤5%; The acid solution includes phosphoric acid, wherein the mass concentration of the phosphoric acid is 60% to 90%. The acid activation includes adding acid while stirring, the acid activation time is 1 min to 5 min, and the stirring speed is 100 r / min to 400 r / min. The target particle size for sieving is <60 mesh.

2. The method according to claim 1, characterized in that, The post-processing includes demolding and curing, with the curing time being 1 to 4 days, the curing temperature being 20°C to 40°C, and the curing humidity being 40% to 70%.

3. A type of non-fired brick, characterized in that, The unfired bricks include those prepared by the method as described in any one of claims 1-2.

4. The non-fired brick according to claim 3, characterized in that, By weight, the raw materials of the non-fired bricks include: 10 to 40 parts of third aluminum-based raw material, 10 to 20 parts of inorganic cementitious material, 30 to 60 parts of aggregate, 10 to 25 parts of water, and 0.5 to 2 parts of water-reducing agent.

5. The non-fired brick according to claim 4, characterized in that, The aggregate includes at least one of the following: Natural sand, artificial sand, pebbles, gravel, and ceramsite.

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