Method for preparing insulating brick based on gasification coarse slag

Abstract

The embodiment of the invention provides a method for preparing an insulating brick based on gasification coarse slag, and relates to the technical field of insulating brick preparation. Ning coal coarse slag and sludge are used; the heat-insulating brick is prepared from the raw materials including the bentonite and the pore-forming agent, and the prepared heat-insulating brick is relatively high in compressive strength, relatively low in heat conductivity and volume density and relatively good in heat-insulating effect. The method comprises the following steps: S1, taking coarse slag and sludge in a ratio of 5: 1 as main raw materials; s2, weighing a pore-forming agent according to 5% of the main raw material, and weighing bentonite accounting for 15%-18% of the total mass of the main raw material and the pore-forming agent as a binder; s3, fully and uniformly mixing the weighed raw materials, and aging in a sealed environment for 24 hours; s4, pouring the aged raw material into a mortar, adding a 1mol / L NaOH solution which accounts for 13-15% of the total mass, and stirring to form a pressed raw material; s5, the pressed raw materials are placed in a mold to be pressed and formed; s6, drying the formed semi-finished product in a drying oven for 12 hours; and S7, the dried bricks are placed in a muffle furnace to be sintered to prepare the heat preservation bricks, reduction and resource utilization of the gasified slag are achieved, and the bricks with the good heat preservation performance are prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal insulation brick preparation, and in particular relates to a method for preparing thermal insulation bricks based on gasified coarse slag. Background Art

[0002] As an important way to utilize coal resources cleanly and efficiently, the widespread promotion and application of coal gasification technology has greatly promoted the optimization of energy structure and the progress of environmental protection. However, along with the popularization of this technology comes the significant growth of gasification slag (especially crude gasification slag, which accounts for as much as 70%-80%), and its proper treatment and utilization have become environmental challenges that need to be urgently addressed. Traditional storage and landfill methods not only occupy a large amount of precious land resources, but also easily cause dust pollution. What is more serious is that harmful trace elements in gasification slag may leach out after contacting water, posing a long-term threat to the soil and groundwater environment, which is directly related to human health and ecological safety. Therefore, exploring and realizing the reduction, resource utilization and harmless treatment technology of gasification slag has become a key strategy for enterprises to pursue a win-win situation of environmental protection and economic benefits.

[0003] Chinese patent application number 202311730042.6 discloses a method for producing perforated thermal insulation and energy-saving bricks, which use cement and construction waste as the main raw materials, and mainly make holes by adding foaming agents and foam stabilizers. Chinese patent application number 202410259406.5 discloses a high-temperature and wear-resistant polymer cement composite insulation brick and its preparation method, whose main raw materials are magnesium oxide and calcium oxide, and one or more of activator, fly ash, mineral powder, steel slag powder, aluminum ash, mullite powder, and corundum powder as mixed powder. In the preparation process of the above two patents, raw materials other than solid waste are added, and full solid waste utilization is not achieved, and the utilization rate of solid waste is low. The raw materials added in the preparation process of this article are all solid waste. The prepared brick body can not only meet the requirements of national standards, but also improve the utilization rate of solid waste to a certain extent. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems of improving the utilization rate of solid waste in the prior art. To this end, the present application proposes a method for preparing thermal insulation bricks based on gasified coarse slag.

[0005] To achieve the above object, the specific technical solution of the present invention is as follows: A method for preparing thermal insulation bricks based on gasified coarse slag, characterized in that it comprises the following steps:

[0006] S1. Weigh gasification crude slag and chemical sludge in a mass ratio of 5:1;

[0007] S2. Weigh 5% of the mass of the gasified crude slag and the chemical sludge to obtain a pore-forming agent, and weigh 15%-18% of the mass of the gasified crude slag, the sludge and the pore-forming agent to obtain a bentonite as a binder;

[0008] S3, the weighed raw materials are fully mixed and aged in a sealed environment for 24 hours;

[0009] S4, pouring the aged raw material into a mortar, adding 1 mol / L NaOH solution, and stirring to form a pressed raw material;

[0010] S5, placing the pressed raw material in a mold and pressing it into shape;

[0011] S6, placing the pressed semi-finished product in an oven to dry for 12 hours;

[0012] S7, placing the dried bricks in a sintering device, heating them to a target temperature at a set heating rate, and sintering them into finished insulation bricks.

[0013] Preferably: in the step S1, the mesh size of the coarse slag and chemical sludge after grinding is greater than or equal to 180 meshes.

[0014] Preferably, the pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks.

[0015] Preferably: in step S4, 1 mol / L NaOH solution is added to account for 13%-15% of the mass of the raw material.

[0016] Preferably: in step S5, the pressure required for compression molding is 30-45 MPa.

[0017] Preferably, in step S7, the specific steps are: heating to 500°C at a set heating rate of 3°C / min, keeping warm for 1 hour, then heating to the target temperature at a rate of 10°C / min, and keeping warm for 2 hours.

[0018] Preferably: in step S7, the target temperature is 950°C-1100°C.

[0019] The method for preparing thermal insulation bricks based on gasified coarse slag of the present invention has the following advantages:

[0020] 1. This application proposes an innovative method for preparing thermal insulation bricks based on the coordinated utilization of gasified crude slag and sludge. This method cleverly combines gasified slag, a solid waste, with sludge. Through scientific proportioning and advanced technology, it not only achieves significant reduction, efficient resource utilization and environmentally friendly treatment of gasified slag, but also significantly improves the utilization rate of sludge, giving thermal insulation bricks more excellent performance. More importantly, this preparation method effectively enhances the thermal resistance of thermal insulation bricks, that is, reduces their thermal conductivity, thereby showing broad application prospects in the field of building insulation and contributing new solutions to energy conservation and environmental protection.

[0021] 2. This application proposes an innovative and environmentally friendly method for preparing thermal insulation bricks based on gasified coarse slag, which significantly breaks through the limitation of the existing thermal insulation brick preparation technology that is highly dependent on red clay resources. Specifically, this method cleverly introduces bentonite as an effective substitute for red clay, and through carefully designed proportions and production processes, it successfully achieves a significant reduction or even replacement of the amount of red clay used in the preparation process of thermal insulation bricks. This technological innovation not only reduces the raw material cost of thermal insulation brick production, but more importantly, it effectively alleviates the ecological and environmental damage caused by red clay mining activities, such as land degradation, soil erosion, etc., thereby realizing the resource utilization of waste while promoting the green production and sustainable development of building materials. This research result provides new ideas and practical paths for the green transformation of the insulation materials industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of compressive strength in Examples 1-4 of the present invention;

[0024] Figure 2 It is a schematic diagram of thermal conductivity in Examples 1-4 of the present invention;

[0025] Figure 3 It is a schematic diagram of volume density in Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0027] Embodiment 1:

[0028] The method for preparing thermal insulation bricks based on gasified coarse slag in this embodiment comprises the following steps:

[0029] S1. Weigh the coarse slag and chemical sludge with a mesh size greater than or equal to 180 after grinding at a mass ratio of 5:1;

[0030] S2, weighing 5% of the mass of the gasification crude slag and the chemical sludge as a pore-forming agent, and weighing 15%-18% of the mass of the gasification crude slag, the sludge and the pore-forming agent as a binder, wherein the pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks;

[0031] S3, after fully mixing the weighed raw materials, ageing them in a sealed environment for 24 hours;

[0032] S4. Pour the aged raw materials into a mortar, add 1 mol / L NaOH solution accounting for 13%-15% of the total mass of the raw materials, and stir to form a pressed raw material. Too much NaOH solution will be detrimental to demoulding, and too little NaOH solution will have a significant impact on the compressive strength of the brick body, so the added NaOH solution is 13%-15% of the mass of the raw materials;

[0033] S5, placing the pressed raw material in a mold, subjecting it to a pressure of 30-45 MPa for pressing and molding. Specifically, the pressing machine used in this embodiment is a tablet press;

[0034] S6, placing the pressed semi-finished product in an oven to dry for 12 hours;

[0035] S7. Place the dried bricks in a muffle furnace and heat them to 500°C at a heating rate of 3°C / min, keep them warm for 1 hour, then heat them to 950°C at a heating rate of 10°C / min, keep them warm for 2 hours, and sinter them to form finished insulation bricks.

[0036] Depend on Figure 1-3 It can be seen that the insulation brick prepared by the method disclosed in this embodiment has a compressive strength of 10.78 MPa, a thermal conductivity of 0.4381 w / m·k, and a bulk density of 1.3551 g / cm at room temperature. 3 , all meet the requirements of GB / T 29060-2012.

[0037] Embodiment 2:

[0038] The method for preparing thermal insulation bricks based on gasified coarse slag in this embodiment comprises the following steps:

[0039] S1. Weigh the coarse slag and chemical sludge with a mesh size greater than or equal to 180 after grinding at a mass ratio of 5:1;

[0040] S2, weighing 5% of the mass of the gasification crude slag and the chemical sludge as a pore-forming agent, and weighing 15%-18% of the mass of the gasification crude slag, the sludge and the pore-forming agent as a binder, wherein the pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks;

[0041] S3, after fully mixing the weighed raw materials, ageing them in a sealed environment for 24 hours;

[0042] S4. Pour the aged raw materials into a mortar, add 1 mol / L NaOH solution accounting for 13%-15% of the total mass of the raw materials, and stir to form a pressed raw material. Too much NaOH solution will be detrimental to demoulding, and too little NaOH solution will have a significant impact on the compressive strength of the brick body, so the added NaOH solution is 13%-15% of the mass of the raw materials;

[0043] S5, placing the pressed raw material in a mold, subjecting it to a pressure of 30-45 MPa for pressing and molding. Specifically, the pressing machine used in this embodiment is a tablet press;

[0044] S6, placing the pressed semi-finished product in an oven to dry for 12 hours;

[0045] S7. Place the dried bricks in a muffle furnace and heat them to 500°C at a heating rate of 3°C / min, keep them warm for 1 hour, then heat them to 1000°C at a heating rate of 10°C / min, keep them warm for 2 hours, and sinter them to form finished insulation bricks.

[0046] Depend on Figure 1-3 It can be seen that the insulation brick prepared by the method disclosed in this embodiment has a compressive strength of 10.78 MPa, a thermal conductivity of 0.4381 w / m·k, and a bulk density of 1.3551 g / cm at room temperature. 3 , all meet the requirements of GB / T 29060-2012.

[0047] Depend on Figure 1-3 It can be seen that the insulation brick prepared by the method disclosed in this embodiment has a compressive strength of 12.44 MPa, a thermal conductivity of 0.4653 w / m·k, and a bulk density of 1.4261 g / cm at room temperature. 3 , all meet the requirements of GB / T 29060-2012.

[0048] Embodiment 3:

[0049] The method for preparing thermal insulation bricks based on gasified coarse slag in this embodiment comprises the following steps:

[0050] S1. Weigh the coarse slag and chemical sludge with a mesh size greater than or equal to 180 after grinding at a mass ratio of 5:1;

[0051] S2, weighing 5% of the mass of the gasification crude slag and the chemical sludge as a pore-forming agent, and weighing 15%-18% of the mass of the gasification crude slag, the sludge and the pore-forming agent as a binder, wherein the pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks;

[0052] S3, after fully mixing the weighed raw materials, ageing them in a sealed environment for 24 hours;

[0053] S4. Pour the aged raw materials into a mortar, add 1 mol / L NaOH solution accounting for 13%-15% of the total mass of the raw materials, and stir to form a pressed raw material. Too much NaOH solution will be detrimental to demoulding, and too little NaOH solution will have a significant impact on the compressive strength of the brick body, so the added NaOH solution is 13%-15% of the mass of the raw materials;

[0054] S5, placing the pressed raw material in a mold, subjecting it to a pressure of 30-45 MPa for pressing and molding. Specifically, the pressing machine used in this embodiment is a tablet press;

[0055] S6, placing the pressed semi-finished product in an oven to dry for 12 hours;

[0056] S7. Place the dried bricks in a muffle furnace and heat them to 500°C at a heating rate of 3°C / min, keep them warm for 1 hour, then heat them to 1050°C at a heating rate of 10°C / min, keep them warm for 2 hours, and sinter them to form finished insulation bricks.

[0057] Depend on Figure 1-3 It can be seen that the insulation brick prepared by the method disclosed in this embodiment has a compressive strength of 13.18 MPa, a thermal conductivity of 0.4877 w / m·k, and a bulk density of 1.4983 g / cm at room temperature. 3 , all meet the requirements of GB / T 29060-2012.

[0058] Embodiment 4:

[0059] The method for preparing thermal insulation bricks based on gasified coarse slag in this embodiment comprises the following steps:

[0060] S1. Weigh the coarse slag and chemical sludge with a mesh size greater than or equal to 180 after grinding at a mass ratio of 5:1;

[0061] S2, weighing 5% of the mass of the gasification crude slag and the chemical sludge as a pore-forming agent, and weighing 15%-18% of the mass of the gasification crude slag, the sludge and the pore-forming agent as a binder, wherein the pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks;

[0062] S3, after fully mixing the weighed raw materials, ageing them in a sealed environment for 24 hours;

[0063] S4. Pour the aged raw materials into a mortar, add 1 mol / L NaOH solution accounting for 13%-15% of the total mass of the raw materials, and stir to form a pressed raw material. Too much NaOH solution will be detrimental to demoulding, and too little NaOH solution will have a significant impact on the compressive strength of the brick body, so the added NaOH solution is 13%-15% of the mass of the raw materials;

[0064] S5, placing the pressed raw material in a mold, subjecting it to a pressure of 30-45 MPa for pressing and molding. Specifically, the pressing machine used in this embodiment is a tablet press;

[0065] S6, placing the pressed semi-finished product in an oven to dry for 12 hours;

[0066] S7. Place the dried bricks in a muffle furnace and heat them to 500°C at a heating rate of 3°C / min, keep them warm for 1 hour, then heat them to 1100°C at a heating rate of 10°C / min, keep them warm for 2 hours, and sinter them to form finished insulation bricks.

[0067] Depend on Figure 1-3 It can be seen that the insulation brick prepared by the method disclosed in this embodiment has a compressive strength of 15.32MPa, a thermal conductivity of 0.4954w / m·k, and a bulk density of 1.5028g / cm at room temperature. 3 , all meet the requirements of GB / T 29060-2012.

[0068] In summary, the test results of Examples 1-4 are shown in Table 1 below:

[0069]

[0070] In summary, it can be seen from Examples 1-4 that at different sintering target temperatures, specifically within 950°C-1100°C, the thermal insulation bricks prepared by the method disclosed in this application have good compressive strength (MPa), thermal conductivity (w / m·k), and bulk density (g / cm2). 3 ) in all three tests, they all meet the requirements of GB / T 29060-2012, meet the national standard requirements of sintered composite insulation bricks (SBR), and have good compressive strength (MPa), thermal conductivity (w / m·k), and bulk density (g / cm2). 3 )As the sintering temperature increases, various properties gradually increase.

[0071] Therefore, through Figure 1-3 As well as the test data shown in Table 1, it can be determined that the composite insulation bricks prepared by the method disclosed in this application can not only meet the utilization of solid waste such as gasification coarse slag and avoid damage to the environment, but also meet the national standard requirements of GB / T 29060-2012 for sintered composite insulation bricks (SBR).

[0072] Moreover, this method cleverly combines gasification slag, a solid waste, with sludge. By adopting this method, not only the significant reduction, efficient resource utilization and environmentally friendly treatment of gasification slag are achieved, but also the utilization rate of sludge is significantly improved, giving the insulation bricks more excellent performance.

[0073] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A method for preparing thermal insulation bricks based on gasified coarse slag, characterized in that: The following steps are involved: S1. Weigh gasification crude slag and chemical sludge in a mass ratio of 5:1; S2. Weigh 5% of the mass of the gasified crude slag and the chemical sludge to obtain a pore-forming agent, and weigh 15%-18% of the mass of the gasified crude slag, the sludge and the pore-forming agent to obtain a bentonite as a binder; S3, the weighed raw materials are fully mixed and aged in a sealed environment for 24 hours; S4, pouring the aged raw material into a mortar, adding 1 mol / L NaOH solution, and stirring to form a pressed raw material; S5, placing the pressed raw material in a mold and pressing it into shape; S6, placing the pressed semi-finished product in an oven to dry for 12 hours; S7, placing the dried bricks in a sintering device, heating them to a target temperature at a set heating rate, and sintering them into finished insulation bricks.

2. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 1, characterized in that: In the step S1, the mesh size of the coarse slag and chemical sludge after grinding is greater than or equal to 180 meshes.

3. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 2, characterized in that: The pore-forming agent is one or more of silicon carbide, sawdust, corn stalks, and rice husks.

4. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 2, characterized in that: In step S4, 1 mol / L NaOH solution is added in an amount of 13%-15% of the raw material mass.

5. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 4, characterized in that: In step S5, the pressure required for compression molding is 30-45 MPa.

6. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 5, characterized in that: In step S7, the specific steps are: heating to 500°C at a set heating rate of 3°C / min, keeping the temperature for 1 hour, then heating to the target temperature at a rate of 10°C / min, and keeping the temperature for 2 hours.

7. The method for preparing thermal insulation bricks based on gasified coarse slag according to claim 6, characterized in that: In step S7, the target temperature is 950°C-1100°C.

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