Sintered brick and method for preparing sintered brick from lithium slag

Abstract

The invention discloses a sintered brick and a method for preparing the sintered brick by utilizing lithium slag, and relates to the technical field of lithium slag recovery treatment and building materials. The method comprises the following steps: adding an activation treatment agent into the lithium slag, wherein the activation treatment agent comprises sodium hexametaphosphate, phosphogypsum and bentonite; mixing the lithium slag with an internal combustion material and shale, and crushing to obtain a brick making raw material mixture, wherein the mass percentages of the lithium slag, the internal combustion material and the shale are respectively (40%-50%), (10%-15%) and (40%-50%); carrying out aging treatment for 2-3 days; water and a reinforcing material are added, the materials are mixed to be uniform, and the reinforcing material comprises aluminum oxide, ferrum dioxide and silica powder; performing extrusion molding and drying to obtain a brick blank; the highest roasting temperature ranges from 800 DEG C to 850 DEG C, the most heat preservation time is 3 h, and a sintered brick is obtained after cooling; according to the method, a large amount of lithium slag is recycled and applied, various performance indexes of the sintered brick meet the requirements, the brick making cost is low, and waste resources are recycled.

Description

Technical Field

[0001] The invention relates to the technical field of lithium slag recovery and construction materials, and in particular to a sintered brick and a method for preparing the sintered brick by using lithium slag. Background Art

[0002] Lithium is a key material to support the sustainable development of the new energy vehicle industry. It is also widely used in aerospace, glass ceramics, nuclear industry and many other fields. It is known as "new energy metal", "aerospace alloy metal" and "industrial MSG". With the rapid development of the global new energy industry, the demand for lithium resources has increased dramatically. Lithium slag is a by-product of the production of lithium carbonate from spodumene ore. The current output of lithium slag in my country is particularly large. The current treatment method is mainly stacking, with few utilization methods and low utilization rate.

[0003] At present, although there are some technologies that use lithium slag to produce cement, concrete and other building materials, its proportion in the material is small and the overall utilization rate is low, making it impossible to achieve large-scale application. The random stacking of lithium slag not only occupies a large amount of land resources, but the sulfur elements it contains will also pollute the surrounding soil with soil erosion. The discharged and stored lithium slag will also produce dust pollution, which brings great pressure to the environment.

[0004] Based on this, the present invention provides a sintered brick and a method for preparing the sintered brick using lithium slag, so as to achieve harmless treatment of lithium slag and realize large-scale application of lithium slag. Summary of the invention

[0005] The present invention aims to solve the technical problems of environmental pollution caused by the accumulation of lithium slag and how to realize resource recovery by applying it in large quantities. The present invention aims to provide a sintered brick and a method for preparing sintered brick using lithium slag, so that the proportion of lithium slag in the raw materials for sintered bricks reaches 40%-50%, which is recovered and applied in large quantities, and various performance indicators of sintered bricks meet the requirements, the brick making cost is low, and the waste resources are recycled, so the market potential is huge and the prospects are broad.

[0006] The present invention is achieved through the following technical solutions.

[0007] The first object of the present invention is to provide a method for preparing sintered bricks using lithium slag, comprising the following steps: S1, adding an activation agent to the lithium slag for pretreatment, wherein the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite; S2, mixing the pretreated lithium slag with internal combustion materials and shale, and crushing them to obtain a brick-making raw material mixture; wherein the mass percentages of lithium slag, internal combustion materials, and shale in the brick-making raw material mixture are: (40%-50%), (10%-15%), and (40%-50%), respectively; S3, aging the brick-making raw material mixture for 2-3 days; S4, adding water and reinforcing materials to the brick-making raw material mixture and stirring evenly, wherein the reinforcing materials include aluminum oxide, iron dioxide and silica powder; S5, extruding and drying to obtain a brick embryo; S6. Brick embryos are roasted, with the highest roasting temperature at 800°C-850°C and the highest temperature insulation time being 3-5h. Sintered bricks are obtained after cooling.

[0008] As a further technical solution of the present invention, the amount of the activation agent added is 0.2%-0.3% of the total mass of the mixture obtained in step S1.

[0009] As a further technical solution of the present invention, in the activation treatment agent, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is (3-8): (25-45): (55-75).

[0010] As a further technical solution of the present invention, the internal combustion material is any one of coal and coal gangue or a mixture thereof.

[0011] As a further technical solution of the present invention, the amount of reinforcing material added is 5%-7% of the total mass of the mixture obtained in step S4.

[0012] As a further technical solution of the present invention, in the reinforcing material, the mass ratio of aluminum oxide, iron dioxide and silica powder is (45-65): (30-45): (15-35).

[0013] As a further technical solution of the present invention, the mass ratio of aluminum oxide, iron dioxide and silica powder is (50-60): (35-40): (20-30).

[0014] As a further technical solution of the present invention, during the forming process, the moisture content of the brick blank needs to be controlled within the range of 9%-13%.

[0015] As a further technical solution of the present invention, the drying temperature is in the range of 80°C-100°C, and the drying time is 20h-24h.

[0016] The second object of the present invention is to provide a sintered brick prepared by the above method.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention adds an activation agent to the lithium slag, wherein the activation agent is a mixture of sodium hexametaphosphate, phosphogypsum and bentonite, so that clay minerals in lithium slag particles can be separated, and the plasticity of the lithium slag can be increased, so that the lithium slag can meet the raw material requirements for preparing sintered bricks; and by adding a reinforcing material to the brick-making raw material mixture, wherein the reinforcing material is a mixture of aluminum oxide, iron dioxide and silica powder, the sintering temperature can be reduced and the strength of the sintered brick products can be increased; 2. The present invention adds an activation agent and a reinforcing material, and the sintered bricks finally obtained have high compressive strength and low water absorption, and various performance indicators meet the standard requirements. The amount of lithium slag in the raw materials for sintered bricks reaches 40%-50%, so that lithium carbonate waste residues are recycled and applied in large quantities, and the brick making cost is low, and the waste resources are recycled, which has huge market potential and broad prospects; 3. The drying and calcining temperatures of the present invention are relatively low, the maximum calcining temperature is between 800°C and 850°C, the sintering time is short, the energy consumption is reduced, and the production cost is reduced. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present invention are clearly and completely described below in conjunction with embodiments. Obviously, the schematic implementation modes of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0019] The following is a detailed description of the embodiments of a sintered brick and a method for preparing a sintered brick using lithium slag according to the present invention. However, there are cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions and repeated descriptions of well-known matters are omitted. This is to avoid the following description from becoming unnecessarily lengthy and facilitate the understanding of those skilled in the art.

[0020] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range.

[0021] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0022] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0023] Unless otherwise specified, the terms "include" and "comprising" mentioned in this application may be open-ended or closed-ended. For example, the terms "include" and "comprising" may mean that other substances not listed may also be included or only the listed substances may be included.

[0024] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0025] Based on the fact that the current amount of lithium slag is particularly large, although it can be used to produce cement and concrete, replace a small part of mineral resources and save costs, its comprehensive utilization rate is less than 20%. The large amount of accumulated lithium slag still occupies land and causes environmental pollution. Although some technologies use lithium slag to produce cement, concrete and other building materials, its proportion in the material is small, the overall utilization rate is low, and it cannot be used in large quantities, which brings great pressure to the environment. If the content of lithium slag is increased, the performance of the prepared sintered bricks cannot meet the requirements. Therefore, the present invention provides a new method for preparing sintered bricks using lithium slag to solve these problems.

[0026] The technical solution of the present invention is to provide a method for preparing sintered bricks using lithium slag, comprising the following steps: S1, adding an activation agent to the lithium slag for pretreatment, wherein the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite; S2, mixing the pretreated lithium slag with internal combustion materials and shale, and crushing them to obtain a brick-making raw material mixture; wherein the mass percentages of lithium slag, internal combustion materials, and shale in the brick-making raw material mixture are: (40%-50%), (10%-15%), and (40%-50%), respectively; S3, aging the brick-making raw material mixture for 2-3 days; S4, adding water and reinforcing materials to the brick-making raw material mixture and stirring evenly, wherein the reinforcing materials include aluminum oxide, iron dioxide and silica powder; S5, extruding and drying to obtain a brick embryo; S6. Brick embryos are roasted, with the highest roasting temperature at 800°C-850°C and the highest temperature insulation time being 3-5h. Sintered bricks are obtained after cooling.

[0027] The present invention adds an activation agent into the lithium slag, wherein the activation agent is a mixture of sodium hexametaphosphate, phosphogypsum and bentonite, so that clay minerals in lithium slag particles can be separated, and the plasticity of the lithium slag can be increased, so that the lithium slag can meet the raw material requirements for preparing sintered bricks; and adds a reinforcing material into the brick-making raw material mixture, wherein the reinforcing material is a mixture of aluminum oxide, iron dioxide and silica powder, so that the sintering temperature can be reduced and the strength of the sintered brick product can be increased.

[0028] In summary, by adding the activation treatment agent and the reinforcing material, the sintered bricks finally obtained by the present invention have high compressive strength and low water absorption, and various performance indicators meet the standard requirements. The proportion of lithium slag in the raw materials for sintered bricks reaches 40%-50%, so that the lithium carbonate waste slag is recycled and applied in large quantities, and the brick-making cost is low, and the recycling of waste resources is realized. The market potential is huge and the prospects are broad.

[0029] As a further technical solution of the present invention, the amount of the activation agent added is 0.2%-0.3% of the total mass of the mixture obtained in step S1. By adding the activation agent to pretreat the raw materials, clay minerals in the lithium slag particles can be separated, the plasticity of the lithium slag can be increased, and the lithium slag can meet the raw material requirements for preparing sintered bricks.

[0030] As a further technical solution of the present invention, in the activation treatment agent, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is (3-8): (25-45): (55-75). Preferably, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is (3-8): (30-40): (60-70), more preferably, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is (4-6): (32-37): (62-67), and most preferably, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is 5:35:65.

[0031] As a further technical solution of the present invention, the internal combustion material is any one of coal and coal gangue or a mixture thereof.

[0032] As a further technical solution of the present invention, the amount of reinforcing material added is 5%-7% of the total mass of the mixture obtained in step S4. For example, the amount of reinforcing material added is 5%, 6%, or 7% of the total mass of the mixture obtained in step S4.

[0033] As a further technical solution of the present invention, in the reinforcing material, the mass ratio of aluminum oxide, iron dioxide and silica powder is (45-65): (30-45): (15-35).

[0034] Preferably, the mass ratio of aluminum oxide, iron dioxide and silica powder is (50-60):(35-40):(20-30), and more preferably, the mass ratio of aluminum oxide, iron dioxide and silica powder is 55:40:25.

[0035] As a further technical solution of the present invention, during the forming process, the moisture content of the brick blank needs to be controlled within the range of 9%-13%.

[0036] As a further technical solution of the present invention, the drying temperature is in the range of 80°C-100°C, and the drying time is 20h-24h.

[0037] The present invention sets the drying temperature in the range of 80-100°C, the drying time is 20h-24h, and then performs calcination after drying. The maximum calcination temperature is 800-850°C, the heating rate is 4-6°C / min, the maximum temperature holding time is 3-5h, and sintered bricks are obtained after cooling. The drying and calcination temperatures of the present invention are relatively low, the maximum calcination temperature is 800-850°C, the sintering time is short, the energy consumption is reduced, and the production cost is reduced.

[0038] The technical solution of the present invention is further described in detail below in conjunction with embodiments.

[0039] It should be noted that the experimental methods used in the examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained by those skilled in the art through commercial channels.

[0040] Example 1

[0041] A method for preparing sintered bricks using lithium slag comprises the following steps: 1) pre-treating the lithium slag, specifically adding an activation agent with a mass fraction of 0.2% to increase the plasticity of the lithium slag for easy molding, wherein the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite, and the mass ratio of the three is 5:35:65; 2) mixing the pretreated lithium slag in a designed proportion (lithium slag accounts for 40% of the mixture) with internal combustion materials (accounting for 10% of the mixture) and shale (accounting for 50% of the mixture), crushing and sieving, and obtaining a raw material mixture for brick making; 3) After obtaining the raw material mixture for brick making, place it in an aging bin for aging treatment for 2-3 days; 4) Add water and 5% by mass of reinforcing material to the brick-making raw material mixture, and stir it thoroughly to make it uniform; wherein the reinforcing material includes aluminum oxide, iron dioxide and silica powder, and the mass ratio of the three is 55:40:25; 5) Extrusion molding of fired brick embryos. During the molding process, the moisture content of the embryos is controlled within the range of 9%-13%, making them easy to extrude and not easy to deform; 6) The bricks are dried in the drying kiln using the waste heat from the roasting kiln. During the drying process, attention should be paid to the drying temperature and drying time. The drying temperature is within the range of 80℃-100℃ and the drying time is 20h-24h. 7) After the brick embryo is dried, it is fired. The maximum firing temperature is 850℃, the heating rate is 5℃ / min, and the maximum temperature holding time is 3h. After sintering, sintered brick products are obtained.

[0042] The obtained products were tested according to the sintered ordinary brick standard GB / T5101-2017, and their main performance indicators met the standard requirements, including compressive strength of 25.8MPa (standard requirement ≥10MPa), water absorption of 16% (standard requirement ≤20%), saturation coefficient of 0.76 (standard requirement ≤0.78), radioactivity Ira of 0.2, Ir of 0.5 (standard requirements Ira≤1.0, Ir≤1.0), moderate frosting (standard requirements no severe frosting), and lime bursting met the standard requirements.

[0043] Example 2

[0044] A method for preparing sintered bricks using lithium slag comprises the following steps: 1) pre-treating the lithium slag, specifically adding an activation agent with a mass fraction of 0.3% to increase the plasticity of the lithium slag for easy molding, wherein the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite, and the mass ratio of the three is 5:35:65; 2) mixing the pretreated lithium slag in a designed proportion (lithium slag accounts for 50% of the mixture) with internal combustion materials (accounting for 10% of the mixture) and shale (accounting for 40% of the mixture), crushing and sieving, and obtaining a brick-making raw material mixture; 3) After obtaining the raw material mixture for brick making, place it in an aging bin for aging treatment for 2-3 days; 4) adding water and 7% by mass of reinforcing material to the brick-making raw material mixture, and stirring the mixture thoroughly to make it uniform; wherein the reinforcing material comprises aluminum oxide, iron dioxide and silica powder, and the mass ratio of the three is 55:40:25; 5) Extrusion molding of fired brick embryos. During the molding process, the moisture content of the embryos is controlled within the range of 9%-13%, making them easy to extrude and not easy to deform; 6) The bricks are dried in the drying kiln using the waste heat from the roasting kiln. During the drying process, attention should be paid to the drying temperature and drying time. The drying temperature is in the range of 80℃-100℃ and the drying time is 20h-24h. 7) After the brick embryo is dried, it is fired. The maximum firing temperature is 850℃, the heating rate is 5℃ / min per minute, and the maximum temperature insulation time is 3h. After sintering, sintered brick products are obtained.

[0045] The obtained products were tested according to the sintered ordinary brick standard GB / T5101-2017, and their main performance indicators met the standard requirements, including compressive strength of 24.4MPa (standard requirement ≥10MPa), water absorption of 16% (standard requirement ≤20%), saturation coefficient of 0.77 (standard requirement ≤0.78), radioactivity Ira of 0.2, Ir of 0.5 (standard requirements Ira≤1.0, Ir≤1.0), moderate frosting (standard requirements no severe frosting), and lime bursting met the standard requirements.

[0046] Comparative Example 1: In this comparative example 1, no activation treatment agent is added.

[0047] A method for preparing sintered bricks using lithium slag comprises the following steps: 1) mixing lithium slag in a designed ratio (lithium slag accounts for 40% of the mixture) with internal combustion materials (accounting for 10% of the mixture) and shale (accounting for 50% of the mixture), crushing and sieving to obtain a brick-making raw material mixture; 2) After obtaining the raw material mixture for brick making, place it in an aging bin for aging treatment for 2-3 days; 3) Add water and 5% by mass of reinforcing material to the brick-making raw material mixture, and stir it thoroughly to make it uniform; wherein the reinforcing material includes aluminum oxide, iron dioxide and silica powder, and the mass ratio of the three is 55:40:25; 4) Extrusion molding of fired brick embryos. During the molding process, the moisture content of the embryos is controlled within the range of 9%-13%, making them easy to extrude and not easy to deform; 5) The bricks are dried in the drying kiln using the waste heat from the roasting kiln. During the drying process, attention should be paid to the drying temperature and drying time. The drying temperature is in the range of 80℃-100℃ and the drying time is 20h-24h. 6) After the brick embryo is dried, it is fired. The maximum firing temperature is 850℃, the heating rate is 5℃ per minute, and the maximum temperature insulation time is 3h. After sintering, sintered brick products are obtained.

[0048] The obtained products were tested according to the sintered ordinary brick standard GB / T5101-2017, and their main performance indicators are: compressive strength of 17.2MPa (standard requirement ≥10MPa), water absorption of 22% (standard requirement ≤20%), saturation coefficient of 0.82 (standard requirement ≤0.78), radioactivity Ira of 0.2, Ir of 0.5 (standard requirements Ira≤1.0, Ir≤1.0), moderate frosting (standard requirements no severe frosting), and lime bursting met the standard requirements.

[0049] It can be seen from the performance index data that the sintered brick products obtained without adding the activation treatment agent have a certain decrease in strength compared with the examples, and the water absorption rate and saturation coefficient do not meet the standard requirements.

[0050] Comparative Example 2: In this comparative example 1, no reinforcing material is added.

[0051] A method for preparing sintered bricks using lithium slag comprises the following steps: 1) pre-treating the lithium slag, specifically adding an activation agent with a mass fraction of 0.2% to increase the plasticity of the lithium slag for easy molding; the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite, and the mass ratio of the three is 5:35:65; 2) mixing the pretreated lithium slag in a designed proportion (lithium slag accounts for 40% of the mixture) with internal combustion materials (accounting for 10% of the mixture) and shale (accounting for 50% of the mixture), crushing and sieving, and obtaining a raw material mixture for brick making; 3) After obtaining the raw material mixture for brick making, place it in an aging bin for aging treatment for 2-3 days; 4) Add water to the brick-making raw material mixture and stir it thoroughly to make it uniform; 5) Extrusion molding of fired brick embryos. During the molding process, the moisture content of the embryos is controlled within the range of 9%-13%, making them easy to extrude and not easy to deform; 6) The bricks are dried in the drying kiln using the waste heat from the roasting kiln. During the drying process, attention should be paid to the drying temperature and drying time. The drying temperature is in the range of 80℃-100℃ and the drying time is 20h-24h. 7) After the brick embryo is dried, it is fired. The maximum firing temperature is 850℃, the heating rate is 5℃ per minute, and the maximum temperature insulation time is 3h. After sintering, sintered brick products are obtained.

[0052] The obtained products were tested according to the sintered ordinary brick standard GB / T5101-2017, and their main performance indicators met the standard requirements, including compressive strength of 14.1MPa (standard requirement ≥10MPa), water absorption of 18% (standard requirement ≤20%), saturation coefficient of 0.83 (standard requirement ≤0.78), radioactivity Ira of 0.2, Ir of 0.5 (standard requirement Ira≤1.0, Ir≤1.0), moderate frosting (standard requirement no severe frosting), and lime bursting met the standard requirements.

[0053] It can be seen from the performance index data that the product obtained without adding reinforcing materials has a significant decrease in strength compared with the example, and the saturation coefficient increases significantly, and does not meet the standard requirements.

[0054] Comparative Example 3: This comparative example reduces the amount of activation treatment agent and reinforcing material added.

[0055] A method for preparing sintered bricks using lithium slag comprises the following steps: 1) pre-treating the lithium slag, specifically adding an activation agent with a mass fraction of 0.05% to increase the plasticity of the lithium slag for easy molding; the activation agent includes sodium hexametaphosphate, phosphogypsum and bentonite, and the mass ratio of the three is 5:35:65; 2) mixing the pretreated lithium slag in a designed proportion (lithium slag accounts for 40% of the mixture) with internal combustion materials (accounting for 10% of the mixture) and shale (accounting for 50% of the mixture), crushing and sieving, and obtaining a raw material mixture for brick making; 3) After obtaining the raw material mixture for brick making, place it in an aging bin for aging treatment for 2-3 days; 4) Add water and 2% by mass of reinforcing material to the brick-making raw material mixture, and stir it thoroughly to make it uniform; wherein the reinforcing material includes aluminum oxide, iron dioxide and silica powder, and the mass ratio of the three is 55:40:25; 5) Extrusion molding of fired brick embryos. During the molding process, the moisture content of the embryos is controlled within the range of 9%-13%, making them easy to extrude and not easy to deform; 6) The bricks are dried in the drying kiln using the waste heat from the roasting kiln. During the drying process, attention should be paid to the drying temperature and drying time. The drying temperature is in the range of 80℃-100℃ and the drying time is 20h-24h. 7) After the brick embryo is dried, it is fired. The maximum firing temperature is 850℃, the heating rate is 5℃ / min per minute, and the maximum temperature insulation time is 3h. After sintering, sintered brick products are obtained.

[0056] The obtained products were tested according to the sintered ordinary brick standard GB / T5101-2017, and their main performance indicators are: compressive strength of 15.3MPa (standard requirement ≥10MPa), water absorption of 19% (standard requirement ≤20%), saturation coefficient of 0.81 (standard requirement ≤0.78), radioactivity Ira of 0.2, Ir of 0.5 (standard requirements Ira≤1.0, Ir≤1.0), moderate frosting (standard requirements no severe frosting), and lime bursting met the standard requirements.

[0057] It can be seen from the performance index data that when the amount of activation treatment agent and reinforcing material added is reduced, the strength of sintered brick products decreases to a certain extent, and the saturation coefficient does not meet the standard requirements.

[0058] In summary, the present invention adds an activation agent and a reinforcing material and controls them within a suitable proportion range, while optimizing the ratio of the raw materials, and finally prepares sintered bricks with a lithium slag content of 40%-50%, and has high strength, low water absorption, and various performance indicators meet the standard requirements. It can be seen from the performance test data of the comparative example that the activation agent, the reinforcing material and the proportion range thereof have a great influence on the product, which also proves that only by adopting the preparation method of the present invention can sintered brick products that meet the requirements be obtained.

[0059] Finally, it should be noted that the above specific embodiments are only used to explain in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific implementation method of the present invention and is not used to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the above specific embodiments, ordinary technicians in this field should understand that it is still possible to modify the technical solutions recorded in the above embodiments, or to replace or improve some or all of the technical features therein. These modifications, equivalent replacements and improvements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for preparing sintered bricks using lithium slag, characterized in that: The following steps are involved: S1, adding an activation agent to the lithium slag for pretreatment, wherein the activation agent comprises sodium hexametaphosphate, phosphogypsum and bentonite; S2, mixing the pretreated lithium slag with internal combustion materials and shale, and crushing them to obtain a brick-making raw material mixture; wherein the mass percentages of lithium slag, internal combustion materials, and shale in the brick-making raw material mixture are: (40%-50%), (10%-15%), and (40%-50%), respectively; S3, aging the brick-making raw material mixture for 2-3 days; S4, adding water and reinforcing materials to the brick-making raw material mixture and stirring evenly, wherein the reinforcing materials include aluminum oxide, iron dioxide and silica powder; S5, extruding and drying to obtain a brick embryo; S6. Brick embryos are roasted, with the highest roasting temperature at 800°C-850°C and the highest temperature insulation time being 3-5h. Sintered bricks are obtained after cooling.

2. The method for preparing sintered bricks using lithium slag according to claim 1, characterized in that: The amount of the activation agent added is 0.2%-0.3% of the total mass of the mixture obtained in step S1.

3. A method for preparing sintered bricks using lithium slag according to claim 1 or 2, characterized in that: In the activation treatment agent, the mass ratio of sodium hexametaphosphate, phosphogypsum and bentonite is (3-8): (25-45): (55-75).

4. The method for preparing sintered bricks using lithium slag according to claim 1, characterized in that: The internal combustion material is any one of coal and coal gangue or a mixture thereof.

5. The method for preparing sintered bricks using lithium slag according to claim 1, characterized in that: The amount of the reinforcing material added is 5%-7% of the total mass of the mixture obtained in step S4.

6. A method for preparing sintered bricks using lithium slag according to claim 1 or 5, characterized in that: In the reinforcing material, the mass ratio of aluminum oxide, iron dioxide and silica powder is (45-65): (30-45): (15-35).

7. The method for preparing sintered bricks using lithium slag according to claim 6, characterized in that: The mass ratio of aluminum oxide, iron dioxide and silica powder is (50-60): (35-40): (20-30).

8. The method for preparing sintered bricks using lithium slag according to claim 1, characterized in that: During the forming process, the moisture content of the brick embryo needs to be controlled within the range of 9%-13%.

9. The method for preparing sintered bricks using lithium slag according to claim 1, characterized in that: The drying temperature is in the range of 80°C-100°C, and the drying time is 20h-24h.

10. A fired brick, characterized in that: The method is prepared by any one of claims 1 to 9.