Environment-friendly shale-based non-sintered brick and preparation method thereof

Abstract

The application discloses an environment-friendly shale-based non-sintered brick and a preparation method thereof. The non-sintered brick body formula comprises shale 50-95%, solid waste 0-40%, cementing material 5-25%, additive A 0.1-0.8%, additive B 0.01-0.06%, and additive C 0.02-0.1% by weight percentage. The raw materials are prepared, crushed, sieved, dry-mixed, wet-mixed, extruded and naturally maintained to obtain the non-sintered brick product. The non-sintered brick product has the advantages of high strength, heat insulation, sound insulation, fireproofing and the like, effectively meets the requirements of energy saving and emission reduction of the building industry, and has a wide market prospect.

Description

Technical Field

[0001] This invention belongs to the field of building ceramics, specifically relating to an environmentally friendly shale-based non-sintered brick and its preparation method. Background Technology

[0002] Non-sintered new wall materials are a type of energy-saving and environmentally friendly building material with advantages such as high strength, heat insulation, sound insulation, and fire resistance. With the ban on the use of solid clay bricks in my country, many sintered brick factories in the Jiangnan and South China regions have switched to using the region's abundant low-grade argillaceous shale as raw material. Meanwhile, the market demand and social value of non-sintered new wall materials are increasingly prominent, but their production technology and equipment still face some problems and bottlenecks that urgently need to be overcome.

[0003] Currently, non-sintered new wall materials cannot be plastically extruded and are mainly produced using compression molding. The advantages of compression molding are high pressure, low requirements for the plasticity of the raw material, and high product strength. The disadvantages are that compression molding is an intermittent process, resulting in low efficiency, low production capacity, high equipment cost, and large investment. It can only produce simple, solid square products and is difficult to produce complex porous and hollow products. Sintered bricks are generally formed using plastic extrusion. Its advantages are continuous molding, high efficiency, high production capacity, and the ability to produce porous, hollow, and other irregularly shaped products with diverse forms, low cost, and high added value. The disadvantages are low molding pressure, high requirements for the plasticity of the raw material to ensure no cracking during molding. Furthermore, after extrusion, the brick blanks are cut into standard bricks using wire cutting. If the raw material contains coarse aggregates, it will obstruct the cutting line and cause breakage. Therefore, the particle size of the raw material is generally required to be less than 3.8mm. How to fully utilize existing equipment to achieve plastic molding of non-sintered bricks is an urgent need facing many brick factories.

[0004] The research team of this invention has a strong research foundation in the field of green non-sintering materials. In 2019, with Jingdezhen Ceramic University as the author's affiliation, we published an article entitled "Study on the Influence of Curing System on Strength of Fly Ash-Based Geological Polymers" in the journal "Bulletin of the Chinese Ceramic Society". The article discussed in detail the influence of different curing systems on the strength of the samples and successfully prepared high-strength non-sintering geopolymer materials (Ding Erbao, Cao Chun'e, Hu Haiquan, Chen Yunxia, ​​Lu Xilong. (2019). Study on the Influence of Curing System on Strength of Fly Ash-Based Geological Polymers. Bulletin of the Chinese Ceramic Society, 38(4), 7.). In 2020, we again published a research paper entitled "Application of central composite design to the optimization of fly ash-based geopolymers" in *Construction and Building Materials*, with Jingdezhen Ceramic University as the first affiliated institution (Erbao Ding, Chune Cao, Haiquan Hu, Yunxia Chen, Xilong Lu (2020). Application of central composite design to the optimization of fly ash-based geopolymers. Construction and Building Materials, 230, 116960.). This paper further optimized the preparation process of non-sintered geopolymer materials and successfully obtained non-sintered materials with excellent performance. These research results provide important theoretical basis and practical guidance for our further exploration in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an environmentally friendly shale-based non-sintered brick with simple process, low cost, and green environmental protection and its preparation method.

[0006] This invention is achieved through the following technical solution: an environmentally friendly shale-based non-sintered brick, characterized in that: the weight percentage composition of the non-sintered brick body formula is: shale 50-95%, solid waste 0-40%, cementing material 5-25%, and additives A 0.1-0.8%, B 0.01-0.06%, and C 0.02-0.1%.

[0007] The solid waste is one of the following: construction waste, coal gangue, and waste concrete.

[0008] The cementing material is one or a mixture of two of the following: PO 42.5R grade early-strength ordinary Portland cement and sodium metasilicate pentahydrate.

[0009] Additive A is one of XP-type alumina and pseudoboehmite.

[0010] Additive B is one of vinyltriethoxysilane, isobutylenetriethoxysilane, methyltriethoxysilane, n-propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, n-dodecyltriethoxysilane, dimethyldimethoxysilane, hexadecyltrimethoxysilane, and epoxy-modified polysiloxane.

[0011] The additive C is one of sodium humate, sodium hexametaphosphate, American hyaluronic acid, sodium secondary alkyl sulfonate, sodium dodecyl sulfate, and disodium lauryl ether sulfosuccinate.

[0012] The above-mentioned method for preparing environmentally friendly shale-based non-sintered bricks is characterized by the following steps:

[0013] Step 1: Crush and sieve the shale and solid waste according to the specified ratio;

[0014] Step 2: Add the gelling material, additive A, and additive B to the raw materials after sieving in Step 1 according to the proportions and perform dry mixing;

[0015] Step 3: Mix additive C with tap water in the specified proportions and then add it to the dry mixture from Step 2 for wet mixing.

[0016] Step 4: Form the wet mixture from Step 3 using an extruder;

[0017] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0018] In step one, the maximum particle size of the raw material after sieving is less than 3.8 mm. In step four, the moisture content of the wet mixture is 14%. In step five, the extrusion molding pressure is 4 MPa.

[0019] The natural curing humidity in step five is ≥95%.

[0020] The natural curing time in step five is as follows: when the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0021] The compressive strength of the non-sintered brick product obtained in step five can reach 32.7 MPa.

[0022] Additive A is highly active alumina with fine particles that can fill the gaps between pores, increasing bulk density and thus providing reinforcement. Furthermore, additive A can better combine with additives B and C to form an organic / inorganic composite material, which can increase the strength and surface hardness of unsintered bricks, reduce water absorption, and decrease shrinkage.

[0023] Additive B is an organosilicon compound, which has good compatibility with shale and can be adsorbed between fine clay particles, thereby achieving a reinforcing effect.

[0024] Additive C can reduce the thickness of the hydration film of particles, increase the surface activity of shale and cement particles, and facilitate the adsorption of additive B.

[0025] This patent uses shale as the main raw material and adopts a plastic extrusion molding method. Appropriate modifiers and additives are added to the raw material to improve the plasticity and stability of the billet and prevent defects such as cracking during the molding process. The resulting non-sintered bricks have advantages such as high strength, heat insulation, sound insulation and fire resistance, effectively meeting the energy conservation and emission reduction requirements of the construction industry and have broad market prospects. Attached Figure Description

[0026] Appendix Figure 1 The image shown is a scanning electron microscope image of Example 5, magnified 500 times.

[0027] Appendix Figure 2 The image shown is a scanning electron microscope image of Example 5, magnified 10,000 times. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the present invention will be described in detail below with reference to preferred embodiments: Example 1

[0029] A method for preparing environmentally friendly shale-based non-sintered bricks, the method specifically including the following steps:

[0030] Step 1: Crush and sieve 85% shale and 10% waste concrete by weight percentage, controlling the maximum particle size to be less than 3.8mm;

[0031] Step 2: Add 5% PO 42.5R grade early-strength ordinary Portland cement, 0.4% XP type alumina, and 0.01% vinyltriethoxysilane to the raw materials after sieving in Step 1 by weight percentage, and perform dry mixing;

[0032] Step 3: Mix 0.1% sodium humate with tap water by weight and add it to the dry mixture from Step 2 for wet mixing. Control the moisture content of the wet mixture to 14%.

[0033] Step 4: The wet mixture from Step 3 is extruded using an extruder at a pressure of 4 MPa.

[0034] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0035] The natural curing humidity in step five is ≥95%.

[0036] Natural curing time: When the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0037] The compressive strength of the non-sintered brick product obtained in step five is 12.5 MPa. Example 2

[0038] A method for preparing environmentally friendly shale-based non-sintered bricks, the method specifically including the following steps:

[0039] Step 1: Crush and sieve 90% of the shale by weight percentage, controlling the maximum particle size to be less than 3.8mm;

[0040] Step 2: Add 10% PO 42.5R grade early-strength ordinary Portland cement, 0.3% pseudoboehmite, and 0.03% n-dodecyltriethoxysilane to the raw materials after sieving in Step 1 by weight percentage, and perform dry mixing;

[0041] Step 3: Mix 0.09% of the American Fairy Water with tap water by weight percentage, then add it to the dry mixture from Step 2 for wet mixing, controlling the moisture content of the wet mixture to 14%.

[0042] Step 4: The wet mixture from Step 3 is extruded using an extruder at a pressure of 4 MPa.

[0043] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0044] The natural curing humidity in step five is ≥95%.

[0045] Natural curing time: When the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0046] The compressive strength of the non-sintered brick product obtained in step five is 16.8 MPa. Example 3

[0047] A method for preparing environmentally friendly shale-based non-sintered bricks, the method specifically including the following steps:

[0048] Step 1: Crush and sieve 60% shale and 35% waste concrete by weight percentage, controlling the maximum particle size to be less than 3.8mm;

[0049] Step 2: Add 5% PO 42.5R grade early-strength ordinary Portland cement, 0.5% XP type alumina, and 0.02% epoxy modified polysiloxane to the raw materials after sieving in Step 1 by weight percentage, and perform dry mixing;

[0050] Step 3: Mix 0.05% disodium lauryl ether sulfosuccinate with tap water according to the weight percentage ratio, and then add it to the dry mixture in Step 2 for wet mixing. Control the moisture content of the wet mixture to 14%.

[0051] Step 4: The wet mixture from Step 3 is extruded using an extruder at a pressure of 4 MPa.

[0052] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0053] The natural curing humidity in step five is ≥95%.

[0054] Natural curing time: When the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0055] The compressive strength of the non-sintered brick product obtained in step five is 12.7 MPa. Example 4

[0056] A method for preparing environmentally friendly shale-based non-sintered bricks, the method specifically including the following steps:

[0057] Step 1: Crush and sieve 80% of the shale by weight percentage, controlling the maximum particle size to be less than 3.8mm;

[0058] Step 2: Add 13% PO 42.5R grade early-strength ordinary Portland cement, 7% sodium metasilicate pentahydrate, 0.6% boehmite, and 0.06% n-dodecyltriethoxysilane to the raw materials after sieving in Step 1 by weight percentage and perform dry mixing;

[0059] Step 3: Mix 0.04% sodium secondary alkyl sulfonate with tap water according to the weight percentage, and then add it to the dry mixture from Step 2 for wet mixing. Control the moisture content of the wet mixture to 14%.

[0060] Step 4: The wet mixture from Step 3 is extruded using an extruder at a pressure of 4 MPa.

[0061] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0062] The natural curing humidity in step five is ≥95%.

[0063] Natural curing time: When the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0064] The compressive strength of the non-sintered brick product obtained in step five is 30.6 MPa. Example 5

[0065] A method for preparing environmentally friendly shale-based non-sintered bricks, the method specifically including the following steps:

[0066] Step 1: Crush and sieve 55% shale and 20% coal gangue by weight percentage, controlling the maximum particle size to be less than 3.8mm;

[0067] Step 2: Add 15% PO 42.5R grade early-strength ordinary Portland cement, 10% sodium metasilicate pentahydrate, 0.8% XP type alumina, and 0.01% hexadecyltrimethoxysilane to the raw materials after sieving in Step 1 by weight percentage for dry mixing;

[0068] Step 3: Mix 0.1% sodium dodecyl sulfate with tap water according to the weight percentage ratio, and then add it to the dry mixture from Step 2 for wet mixing. Control the moisture content of the wet mixture to 14%.

[0069] Step 4: The wet mixture from Step 3 is extruded using an extruder at a pressure of 4 MPa.

[0070] Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

[0071] The natural curing humidity in step five is ≥95%.

[0072] Natural curing time: When the temperature is above 20℃, the curing time shall not be less than 14 days; when the temperature is below 20℃, the curing time shall not be less than 28 days.

[0073] The compressive strength of the non-sintered brick product obtained in step five is 32.7 MPa.

[0074] The SEM images show that a large number of plate-like crystals were formed in the sample, with a diameter of approximately 2–3 μm and a thickness of approximately 20–50 nm. These plate-like nanocrystals are randomly and tightly arranged in the bulk phase of the sample, while on the surface they tend to align parallel to the sample surface. They have extremely low porosity and high bulk density. This microstructure greatly increases the compressive strength of the sample, while also enhancing its surface hardness, scratch resistance, and wear resistance. The sample is also less prone to dust generation, making it suitable for use as an excellent green new wall material.

Claims

1. An environmentally friendly shale-based non-sintered brick, characterized in that: The non-sintered brick body formulation has the following weight percentage composition: shale 50-90%, solid waste 0-40%, cementitious materials 5-25%, and additives A 0.1-0.8%, B 0.01-0.06%, and C 0.02-0.1%. The cementing material is P·O42.5R grade early-strength ordinary Portland cement or a mixture of P·O42.5R grade early-strength ordinary Portland cement and sodium metasilicate pentahydrate; The additive A is one of XP-type alumina and pseudoboehmite; The additive B is one of vinyltriethoxysilane, isobutylenetriethoxysilane, methyltriethoxysilane, n-propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, n-dodecyltriethoxysilane, dimethyldimethoxysilane, hexadecyltrimethoxysilane, and epoxy-modified polysiloxane. The additive C is one of sodium humate, sodium hexametaphosphate, American hyaluronic acid, sodium secondary alkyl sulfonate, sodium dodecyl sulfate, and disodium lauryl ether sulfosuccinate. The environmentally friendly shale-based non-sintered bricks are manufactured using a plastic extrusion molding method.

2. The environmentally friendly shale-based non-sintered brick according to claim 1, characterized in that: The solid waste is one of the following: construction waste, coal gangue, and waste concrete.

3. The method for preparing environmentally friendly shale-based non-sintered bricks according to claim 1, characterized in that: The preparation method specifically includes the following steps: Step 1: Crush and sieve the shale and solid waste according to the specified ratio; Step 2: Add the gelling material, additive A, and additive B to the raw materials after sieving in Step 1 according to the proportions and perform dry mixing; Step 3: Mix additive C with tap water in the specified proportions and then add it to the dry mixture from Step 2 for wet mixing. Step 4: Form the wet mixture from Step 3 using an extruder; Step 5: Extrude the green body from Step 4 and allow it to cure naturally to obtain a non-sintered brick product.

4. The preparation method according to claim 3, characterized in that: In step one, the maximum particle size of the raw material after sieving is less than 3.8 mm; in step three, the moisture content of the wet mixture is 14%; and in step four, the extrusion molding pressure is 4 MPa.

5. The preparation method according to claim 3, characterized in that: In step five, the natural curing humidity is ≥95%; the natural curing time is: when the temperature is greater than 20℃, the curing time is not less than 14 days, and when the temperature is less than 20℃, the curing time is not less than 28 days.

6. The preparation method according to claim 3, characterized in that: The compressive strength of the non-sintered brick product obtained in step five is 32.7 MPa.

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