A lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof

Abstract

The present invention relates to a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof, belonging to the technical field of lightweight non-fired ceramsite. In order to use agricultural biomass waste for the preparation of non-fired ceramsite and make the prepared non-fired ceramsite meet the requirements of lightweight porosity and mechanical strength, the present invention provides a lightweight porous non-fired ceramsite based on a biomass core, and the raw materials include lightweight balls of agricultural biomass waste, slag powder, pulverized coal, an alkaline activator and water. The present invention uses lightweight balls of agricultural biomass waste as a sacrificial core to prepare lightweight porous non-fired ceramsite, which not only realizes the harmless resource utilization of agricultural biomass waste, but also has the advantages of energy conservation, consumption reduction, and environmental friendliness. The ceramsite prepared by the present invention has medium and small pores with controllable sizes inside, and closed pores are formed because the pores do not communicate with each other, so that the obtained ceramsite has better mechanical strength and heat preservation and sound insulation effects, and can meet the requirements of different fields for lightweight porous non-fired ceramsite.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightweight non-fired ceramsite, and particularly relates to a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof. Background Art

[0002] Ceramsite has a spherical shape, with a smooth and hard surface and a honeycomb-like interior. It has the characteristics of light weight, corrosion resistance, frost resistance, earthquake resistance, and good insulation, so it is widely used in the fields of building materials, horticulture, food, refractory insulation materials, chemical industry, petroleum, etc.

[0003] The sintering method is the most common ceramsite preparation process at present. During the sintering process, the raw materials melt with the increase of temperature to form a solid-liquid mixed phase with viscosity, and at the same time, gas is released. The gas escapes, causing the solid-liquid mixed phase to foam and expand. After stabilization, the gas generation gradually decreases, forming many closed and semi-closed pores inside the ceramsite, and finally cooling to form a typical honeycomb-like structure. The ceramsite prepared by the sintering method has the characteristics of high hardness, rich pores, large expansion coefficient, and stable chemical properties, but this process often has high energy consumption, complex process, and large production cost.

[0004] Non-fired ceramsite is prepared by granulating raw materials and natural curing. Compared with the sintering method, it has the advantages of low energy consumption and small construction investment. However, most of the existing non-fired ceramsites use solid waste as the core. The core forming process is complex and its apparent density is relatively large, which is difficult to meet the requirements of lightweight aggregate use. Moreover, it often has low strength and small expansion coefficient, so its application fields are relatively narrow.

[0005] At the same time, with the development of agriculture and the increase of population, the output of agricultural waste is increasing day by day. The harmless and resource utilization of agricultural waste has become a research hotspot and development trend. How to apply agricultural waste to the preparation of non-fired ceramsite while still meeting the requirements of lightweight porosity and mechanical strength of ceramsite is still an urgent problem to be solved in this field. Summary of the Invention

[0006] In order to use agricultural biomass waste for the preparation of non-fired ceramsite and make the prepared non-fired ceramsite meet the requirements of lightweight porosity and mechanical strength, the present invention provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0007] The technical solution of the present invention:

[0008] A lightweight porous non-fired ceramsite based on a biomass core, comprising the following raw materials in parts by mass:

[0009] 5-10 parts of lightweight small balls of agricultural biomass waste, 30-50 parts of slag powder, 10-15 parts of fly ash, 16-48.75 parts of alkaline activator, and 20-45.5 parts of water.

[0010] Furthermore, the particle size of the lightweight pellets of agricultural biomass waste is 0.1 - 5.0 mm, and the moisture content is 10 - 60%.

[0011] Furthermore, the inorganic matter content of the slag powder is not less than 30%, and the activity index at 28 days ≥ 95%; the particle size of the fly ash is 0.5 - 300 μm.

[0012] Furthermore, the alkaline activator is sodium hydroxide, potassium hydroxide, sodium silicate with a modulus of 1.0 - 3.2, or sodium potassium silicate with a modulus of 1.0 - 3.2.

[0013] A preparation method of lightweight porous non - fired ceramsite based on a biomass core is as follows:

[0014] Step 1: Prepare lightweight pellets of agricultural biomass waste:

[0015] Crush the agricultural biomass waste into powder, add a plant adhesive to the obtained powder to prepare spheres of different particle sizes, and after drying the obtained spheres, screen out lightweight pellets of agricultural biomass waste with different particle sizes;

[0016] Step 2: Prepare an alkali - activated slurry:

[0017] Mix the slag powder, fly ash, and alkaline activator with water evenly to obtain an alkali - activated slurry;

[0018] Step 3: Prepare green ceramsite balls:

[0019] Add the lightweight pellets of agricultural biomass waste obtained in Step 1 to the alkali - activated slurry obtained in Step 2, mix evenly, and extrude and granulate to obtain green ceramsite balls;

[0020] Step 4: Prepare lightweight porous non - fired ceramsite based on a biomass core:

[0021] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing to obtain lightweight porous non - fired ceramsite based on a biomass core.

[0022] Furthermore, the agricultural biomass waste in Step 1 is a plant material containing cellulose, lignin, hemicellulose, pectin, and starch, including one or a combination of several of straw, vine, fruit shell, rice husk, corn cob, edible mushroom residue, Chinese medicine residue, sugarcane bagasse, fruit peel, or wood chips.

[0023] Furthermore, the plant adhesive is a natural adhesive based on plant protein, cellulose, lignin, or glucose derivative, including one of cellulose adhesive, starch adhesive, dextrin adhesive, lignin adhesive, tannin adhesive, fir adhesive, peach gum, or sodium alginate; the addition amount of the plant adhesive is 0.3% of the mass of the obtained powder.

[0024] Further, the drying in Step 1 is to dry the light balls to the required moisture content at 40 - 150°C.

[0025] Further, the temperature for static curing in Step 4 is 20 - 50°C, the humidity ≥ 95%, and the curing time is 5 - 12 h.

[0026] Further, the autoclave curing pressure in Step 4 is 1.0 - 1.5 MPa, the temperature is 60 - 120°C, and the curing time is 6 - 12 h.

[0027] Advantages of the present invention:

[0028] The lightweight porous non - fired ceramsite based on biomass core provided by the present invention uses the light balls prepared from agricultural biomass waste as sacrificial cores. During the curing process, the light balls gradually degrade in an alkaline environment, generating gas or forming pores due to changes in physical properties, and finally forming lightweight porous ceramsite. The present invention scientifically develops and comprehensively utilizes agricultural biomass waste, solving the problem of harmless resource utilization of agricultural biomass waste; at the same time, the non - fired preparation process without foaming agent provided by the present invention has the advantages of cost saving, energy conservation and consumption reduction, and environmental friendliness.

[0029] By regulating the particle size and moisture content of the sacrificial core light balls, the present invention can form medium and small pores with controllable sizes inside the ceramsite. The structure with pore size composite blending obtained by the way of sacrificial core forms closed pores because the pores do not communicate with each other, making the obtained ceramsite have better mechanical strength, heat preservation and sound insulation effects, and can meet the requirements of lightweight porous non - fired ceramsite in different fields, having a wide application prospect. The average particle size of the lightweight porous ceramsite obtained by the present invention is 8.0 - 9.0 mm, the cylinder compressive strength is 12.7 - 14.5 MPa, the bulk density is 880 - 1050 kg / m 3 , the water absorption rate is 2.3 - 3.3%, and the porosity is 23.63 - 29.60%. Specific embodiments

[0030] The technical solutions of the present invention will be further described below in conjunction with embodiments, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically indicated, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically indicated, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0031] Example 1

[0032] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0033] In this embodiment, the agricultural biomass waste is corn straw, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% at 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.0.

[0034] The steps of the preparation method of the lightweight porous non-fired ceramsite based on a biomass core in this embodiment are as follows:

[0035] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0036] Mechanically crush the corn straw into powder, add cellulose adhesive to the obtained corn straw powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 60 °C until the moisture content is 30%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0037] Step 2: Prepare an alkali-activated slurry:

[0038] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 120 g of sodium silicate with a modulus of 1.0 and 60 g of water in sequence, and continue to stir until the appropriate consistency is obtained to obtain an alkali-activated slurry.

[0039] Step 3: Prepare green ceramsite balls:

[0040] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut the corresponding amount according to the size of the forming machine orifice, put it into the extrusion orifice to extrude into cakes, then put the obtained cakes into the strip pressing orifice to extrude into strips, then put the obtained thin strips into the ball forming orifice to obtain green ceramsite ball blanks, and finally put the green ceramsite ball blanks into a drum to roll and polish to obtain green ceramsite balls.

[0041] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0042] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature of static curing is 20 °C, the humidity ≥95%, and the curing time is 8 h; the pressure of autoclave curing is 1.0 MPa, the temperature is 90 °C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0043] Example 2

[0044] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0045] In this embodiment, the agricultural biomass waste is corn straw, and the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% in 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.3.

[0046] The preparation method of the lightweight porous non-fired ceramsite based on a biomass core in this embodiment is as follows:

[0047] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0048] Mechanically crush the corn straw into powder, add a starch adhesive to the obtained corn straw powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 60°C until the moisture content is 30%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0049] Step 2: Prepare an alkali-activated slurry:

[0050] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 140 g of sodium silicate with a modulus of 1.3 and 50 g of water in sequence, and continue to stir until the appropriate consistency is obtained to get an alkali-activated slurry;

[0051] Step 3: Prepare green ceramsite balls:

[0052] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut an appropriate amount according to the size of the forming machine mouth, put it into the extrusion port and extrude it into a cake, then put the obtained cake into the strip pressing port and extrude it into a strip, then put the obtained thin strip into the ball forming port to get a green ceramsite blank, and finally put the green ceramsite blank into a drum and roll it round and polished to obtain green ceramsite balls;

[0053] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0054] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature of static curing is 20°C, the humidity ≥95%, and the curing time is 8 h; the pressure of autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0055] Example 3

[0056] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0057] In this embodiment, the agricultural biomass waste is corn straw, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% at 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.6.

[0058] The steps of the preparation method of the lightweight porous non-fired ceramsite based on the biomass core in this embodiment are as follows:

[0059] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0060] Mechanically crush the corn straw into powder, add a starch adhesive to the obtained corn straw powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 60°C until the moisture content is 30%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0061] Step 2: Prepare an alkali-activated slurry:

[0062] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 160 g of sodium silicate with a modulus of 1.6 and 40 g of water in sequence, and continue to stir until the appropriate consistency is obtained to obtain an alkali-activated slurry.

[0063] Step 3: Prepare green ceramsite balls:

[0064] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut the corresponding amount according to the size of the forming machine orifice, put it into the extrusion orifice to extrude into a cake, then put the obtained cake into the strip-forming orifice to extrude into a strip, then put the obtained thin strip into the ball-forming orifice to obtain a green ceramsite blank, and finally put the green ceramsite blank into a drum to roll and polish to obtain green ceramsite balls.

[0065] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0066] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature of the static curing is 20°C, the humidity is ≥95%, and the curing time is 8 h; the pressure of the autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0067] Example 4

[0068] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0069] In this embodiment, the agricultural biomass waste is sweet potato vines, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% at 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.0.

[0070] The steps of the preparation method of the lightweight porous non-fired ceramsite based on the biomass core in this embodiment are as follows:

[0071] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0072] Mechanically crush the sweet potato vines into powder, add a starch adhesive to the obtained sweet potato vine powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 80°C until the moisture content is 25%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0073] Step 2: Prepare an alkali-activated slurry:

[0074] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 120 g of sodium silicate with a modulus of 1.0 and 60 g of water in sequence, and continue to stir until the appropriate consistency is obtained to obtain an alkali-activated slurry.

[0075] Step 3: Prepare green ceramsite balls:

[0076] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut the corresponding amount according to the size of the forming machine mouth, put it into the extrusion port to extrude into cakes, then put the obtained cakes into the strip pressing port to extrude into strips, then put the obtained thin strips into the ball forming port to obtain green ceramsite ball blanks, and finally put the green ceramsite ball blanks into a drum to roll and polish to obtain green ceramsite balls.

[0077] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0078] The green ceramsite balls obtained in Step 3 are sequentially subjected to static curing and autoclave curing. Among them, the temperature of static curing is 20°C, the humidity ≥95%, and the curing time is 8 h; the pressure of autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0079] Example 5

[0080] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0081] In this embodiment, the agricultural biomass waste is sweet potato vines, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% in 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.3.

[0082] The preparation method of the lightweight porous non-fired ceramsite based on a biomass core in this embodiment is as follows:

[0083] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0084] Mechanically crush the sweet potato vines into powder, add a starch adhesive to the obtained sweet potato vine powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 80°C until the moisture content is 25%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0085] Step 2: Prepare an alkali-activated slurry:

[0086] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 140 g of sodium silicate with a modulus of 1.3 and 50 g of water in sequence, and continue to stir until the appropriate consistency is obtained to obtain an alkali-activated slurry;

[0087] Step 3: Prepare green ceramsite balls:

[0088] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut an appropriate amount according to the size of the orifice of the ball forming machine, put it into the extrusion port to extrude into a cake, then put the obtained cake into the strip pressing port to extrude into a strip, then put the obtained thin strip into the ball forming port to obtain a green blank, and finally put the green blank into a drum to roll and polish to obtain green ceramsite balls;

[0089] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0090] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature of static curing is 20°C, the humidity ≥95%, and the curing time is 8 h; the pressure of autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0091] Example 6

[0092] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method thereof.

[0093] In this embodiment, the agricultural biomass waste is sweet potato vines, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% in 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.6.

[0094] The preparation method of the lightweight porous non-fired ceramsite based on the biomass core in this embodiment is as follows:

[0095] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0096] Mechanically crush the sweet potato vines into powder, add a starch adhesive to the obtained sweet potato vine powder according to a mass ratio of 1000:3, make spheres of different diameters using a granulator, dry the obtained spheres at 80°C until the moisture content is 25%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0097] Step 2: Prepare an alkali-activated slurry:

[0098] Mix 500 g of slag powder and 100 g of fly ash evenly in a blender, then slowly add 160 g of sodium silicate with a modulus of 1.6 and 40 g of water in sequence, and continue to stir until the appropriate consistency is obtained to get the alkali-activated slurry.

[0099] Step 3: Prepare green ceramsite balls:

[0100] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut an appropriate amount according to the size of the forming machine mouth, put it into the extrusion port to extrude into cakes, then put the obtained cakes into the strip-forming port to extrude into strips, then put the obtained thin strips into the ball-forming port to get green ceramsite ball blanks, and finally put the green ceramsite ball blanks into a drum to roll and polish to obtain green ceramsite balls.

[0101] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0102] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature of the static curing is 20°C, the humidity ≥95%, and the curing time is 8 h; the pressure of the autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0103] Example 7

[0104] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method therefor.

[0105] In this embodiment, the agricultural biomass waste is coconut shell, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index is ≥95% at 28 days; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.2.

[0106] The steps for the preparation method of the lightweight porous non-fired ceramsite based on a biomass core in this embodiment are as follows:

[0107] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0108] Mechanically crush the coconut shell into powder, add a starch adhesive to the obtained coconut shell powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 40°C until the moisture content is 35%, and after screening, obtain lightweight balls with a mixed particle size distribution range of 1 - 3 mm.

[0109] Step 2: Prepare an alkali-activated slurry:

[0110] Mix 400 g of slag powder and 150 g of fly ash evenly in a blender, then slowly add 130 g of sodium silicate with a modulus of 1.2 and 70 g of water in sequence, and continue to stir until the appropriate consistency is obtained to get the alkali-activated slurry.

[0111] Step 3: Prepare green ceramsite balls:

[0112] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut an appropriate amount according to the size of the forming machine mouth, put it into the extrusion port to extrude into a cake, then put the obtained cake into the pressing port to extrude into a strip, and then put the obtained thin strip into the forming port to get a green ceramsite blank. Finally, put the green ceramsite blank into a drum to roll and polish to obtain green ceramsite balls.

[0113] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0114] The green ceramsite balls obtained in Step 3 are successively subjected to static curing and autoclave curing. Among them, the temperature for static curing is 20°C, the humidity is ≥95%, and the curing time is 12 h; the pressure for autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0115] Example 8

[0116] This embodiment provides a lightweight porous non-fired ceramsite based on a biomass core and a preparation method therefor.

[0117] In this embodiment, the agricultural biomass waste is coconut shell, the plant adhesive is a cellulose adhesive, specifically a hydroxypropyl methylcellulose adhesive, purchased from Hebei Hongyuan Cellulose Co., Ltd. The content of inorganic substances such as active calcium, silicon, and aluminum in the slag powder is greater than 30%, and the activity index at 28 days ≥ 95%; the particle size of the fly ash is 0.5 - 300 μm; the alkaline activator is sodium silicate with a modulus of 1.5.

[0118] The preparation method of the lightweight porous non-fired ceramsite based on a biomass core in this embodiment is as follows:

[0119] Step 1: Prepare lightweight balls of agricultural biomass waste:

[0120] Mechanically crush the coconut shell into powder, add starch adhesive to the obtained coconut shell powder according to a mass ratio of 1000:3, use a granulator to make spheres of different diameters, dry the obtained spheres at 40°C until the moisture content is 35%, and after screening, obtain lightweight balls with a particle size distribution range of 1 - 3 mm and different particle sizes mixed.

[0121] Step 2: Prepare an alkali-activated slurry:

[0122] Mix 400 g of slag powder and 150 g of fly ash evenly in a mixer, then slowly add 160 g of sodium silicate with a modulus of 1.5 and 50 g of water in sequence, and continue to stir until the appropriate consistency is obtained to obtain an alkali-activated slurry.

[0123] Step 3: Prepare green ceramsite balls:

[0124] Add 500 g of the lightweight balls of agricultural biomass waste obtained in Step 1 to the alkali-activated slurry obtained in Step 2, stir evenly, take it out from the stirring tank, cut the corresponding amount according to the size of the forming machine mouth and put it into the extrusion port to be extruded into a cake, then put the obtained cake into the pressing port to be extruded into a strip, then put the obtained thin strip into the forming port to obtain a green blank, and finally put the green blank into a drum to be rolled and polished to obtain green ceramsite balls.

[0125] Step 4: Prepare a lightweight porous non-fired ceramsite based on a biomass core:

[0126] The green ceramsite balls obtained in Step 3 are sequentially subjected to static curing and autoclave curing. Among them, the temperature of static curing is 20°C, the humidity ≥ 95%, and the curing time is 12 h; the pressure of autoclave curing is 1.0 MPa, the temperature is 90°C, and the curing time is 8 h; to obtain a lightweight porous non-fired ceramsite based on a biomass core.

[0127] The performance of the lightweight porous non - fired ceramsite based on biomass core prepared in the above - mentioned examples was tested, and the test results are shown in Table 1.

[0128] Table 1

[0129] Example Number Average Diameter Cylinder Compressive Strength Bulk Density Water Absorption Rate Porosity Example 1 8.4mm 12.7MPa <![CDATA[893Kg / m 3 > 3.1％ 29.21％ Example 2 8.7mm 12.7MPa <![CDATA[934Kg / m 3 > 2.9％ 27.53％ Example 3 7.9mm 13.5MPa <![CDATA[953 Kg / m 3 > 3.3％ 26.87％ Example 4 8.9mm 13.6MPa <![CDATA[885 Kg / m 3 > 2.9％ 29.60％ Example 5 8.1mm 12.7MPa <![CDATA[897 Kg / m 3 > 3.0％ 29.27％ Example 6 8.4mm 12.9MPa <![CDATA[932 Kg / m 3 > 3.2％ 27.79％ Example 7 7.7mm 13.2MPa <![CDATA[992 Kg / m 3 > 2.3％ 26.15％ Example 8 8.7mm 14.5MPa <![CDATA[1043 Kg / m 3 > 2.4％ 23.63％

[0130] In the preparation process of the lightweight porous non - fired ceramsite based on biomass core of the present invention, the particle size and moisture content of the agricultural biomass waste lightweight pellets directly affect the pore structure of the final ceramsite. By controlling these parameters, the microstructure of the ceramsite can be predicted and regulated to a certain extent to optimize its physical and chemical properties. The structure with a compound - adjusted pore diameter obtained by sacrificing the core forms closed pores because the pores do not communicate with each other, making the obtained ceramsite have better mechanical strength, heat - insulation and sound - insulation effects, and can meet the requirements of lightweight porous non - fired ceramsite in different fields, having a wide application prospect.

[0131] By using agricultural waste, the present invention reduces the energy consumption in the production process, reduces the pressure on the ecological environment, realizes the resource utilization of waste, and meets the important considerations of environmental protection and sustainable development. In addition, the low - energy - consumption and low - cost nature of the non - fired process itself has significant advantages.

[0132] The advantages of the present invention in terms of low energy consumption and low cost will be reflected through preliminary energy - consumption measurement and ecological - impact assessment below, and the specific measurement data are as follows:

[0133] Producing one ton of lightweight porous non - fired ceramsite based on biomass core includes the following key steps:

[0134] 1. Production process analysis

[0135] · Raw material collection: including the collection of agricultural waste and transportation to the factory.

[0136] · Mixing and forming: mixing agricultural waste, alkali activator, water, etc., and forming.

[0137] · Curing process: including static curing and autoclave curing.

[0138] 2. Energy types

[0139] · Electric energy: used for mechanical crushing, mixing, forming, transportation, etc.

[0140] · Thermal energy: used for drying raw materials and autoclave curing process.

[0141] 3. Energy - consumption assumptions

[0142] For the sake of simplifying the analysis, the following assumptions are made:

[0143] · Drying: 100 kWh of electrical energy is consumed per ton of raw materials.

[0144] · Machining (crushing, mixing, forming): 50 kWh of electrical energy is consumed per ton of raw materials.

[0145] · Autoclave curing: 300 kWh of thermal energy is consumed per ton of raw materials.

[0146] 4. Calculation method

[0147] Total energy consumption in the whole process:

[0148] · Total electrical energy consumption = drying electrical energy + machining electrical energy

[0149] · Total energy consumption = total electrical energy consumption + autoclave curing thermal energy

[0150] Energy consumption calculation:

[0151] · Drying electrical energy: 100 kWh / ton × 1 ton = 100 kWh

[0152] · Machining electrical energy: 50 kWh / ton × 1 ton = 50 kWh

[0153] · Autoclave curing thermal energy: 300 kWh / ton × 1 ton = 300 kWh

[0154] · Total electrical energy consumption: 100 kWh + 50 kWh = 150 kWh

[0155] · Total energy consumption: 150 kWh (electrical energy) + 300 kWh (thermal energy) = 450 kWh

[0156] 5. Comparative analysis

[0157] The production of each ton of traditional sintered ceramsite generally consumes about 1050 kWh of energy.

[0158] The above data shows that the preparation process of the non-fired ceramsite of the present invention significantly reduces energy consumption, which not only helps to reduce production costs, but also reduces carbon emissions, is environmentally friendly, and has significant advantages.

Claims

1. A lightweight porous unburned ceramsite based on biomass core, characterized in that: Including the following raw materials by mass: 5-10 parts of light pellets of agricultural biomass waste, 30-50 parts of slag powder, 10-15 parts of fly ash, 16-48.75 parts of alkaline activator and 20-45.5 parts of water; the particle size of the light pellets of agricultural biomass waste is 0.1-5.0 mm, and the moisture content is 10-60%; The lightweight porous unburned ceramsite based on biomass core is prepared by the following method steps, which are as follows: Step 1: Preparation of lightweight pellets from agricultural biomass waste: The agricultural biomass waste is crushed into powder, a plant adhesive is added to the obtained powder to prepare spheres of different particle sizes, and the obtained spheres are dried and then sieved to obtain lightweight spheres of agricultural biomass waste of different particle sizes; The agricultural biomass waste is plant material containing cellulose, lignin, hemicellulose, pectin, starch, including straw, vines, fruit shells, rice husks, corn cobs, edible fungus residues, Chinese medicine residues, bagasse, peels or sawdust, or a combination of several thereof; The plant adhesive is a natural adhesive based on plant protein, cellulose, lignin or glucose derivatives, including one of cellulose adhesive, starch adhesive, dextrin adhesive, lignin adhesive, tannin adhesive, fir adhesive, peach gum or sodium alginate; the amount of the plant adhesive added is 0.3% of the mass of the obtained powder; Step 2: Prepare alkali activated slurry: Add water to slag powder, fly ash and alkali activator and stir evenly to obtain alkali activated slurry; Step 3: Prepare ceramsite raw balls: Adding the light pellets of agricultural biomass waste obtained in step 1 to the alkali-activated slurry obtained in step 2, mixing them evenly, and then extruding and granulating them to obtain ceramsite green pellets; Step 4: Preparation of lightweight porous unburned ceramsite based on biomass core: The ceramsite raw balls obtained in step 3 are subjected to static curing and autoclaving curing in sequence to obtain lightweight, porous, unfired ceramsite based on the biomass core.

2. The lightweight porous unburned ceramsite based on biomass core according to claim 1, characterized in that: The inorganic content of the slag powder is not less than 30%, and the activity index is ≥95% after 28 days; the particle size of the fly ash is 0.5-300 μm.

3. The lightweight porous unburned ceramsite based on biomass core according to claim 2, characterized in that: The alkaline activator is sodium hydroxide, potassium hydroxide, sodium silicate with a modulus of 1.0 to 3.2, or sodium silicate or potassium silicate with a modulus of 1.0 to 3.

2.

4. The lightweight porous unburned ceramsite based on biomass core according to claim 3 is characterized in that: The drying in step 1 is to dry the lightweight balls to the required moisture content at 40-150°C.

5. The lightweight porous unburned ceramsite based on biomass core according to claim 4, characterized in that: The temperature of the static curing in step 4 is 20-50°C, the humidity is ≥95%, and the curing time is 5-12 hours.

6. The lightweight porous unburned ceramsite based on biomass core according to claim 5, characterized in that: The pressure of the autoclave curing in step 4 is 1.0-1.5 MPa, the temperature is 60-120°C, and the curing time is 6-12 h.