CN115140992A

CN115140992A - Concrete raw material, autoclaved aerated concrete plate and preparation method thereof

Info

Publication number: CN115140992A
Application number: CN202210592635.XA
Authority: CN
Inventors: 陈传明; 陈刚; 刘玉亭; 张光红; 孙思文; 田野; 姚华彦; 徐兴雅; 涂劲松; 李中辉; 章卫东
Original assignee: Anhui Gaodi Circular Economy Industrial Park Co ltd
Current assignee: Anhui Gaodi Circular Economy Industrial Park Co ltd
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2022-10-04

Abstract

The invention provides a concrete raw material, an autoclaved aerated concrete plate and a preparation method thereof, and belongs to the technical field of buildings. The concrete raw materials comprise, by mass, 0.56-0.65:1, dry materials and water; the dry material comprises the following components in parts by weight: 60-70 parts of slag with 8-10% of carbon content percentage, 2-5 parts of tailing sand, 1-2 parts of sludge, 2-3 parts of concrete waste, 3-5 parts of desulfurized gypsum, 0.01-0.1 part of microfiber, 0.5-1.5 parts of nano calcium carbonate, 10-15 parts of cement, 12-20 parts of lime, 0.3-0.7 part of foam stabilizer, 0.5-1.2 parts of dispersant and 0.5-0.8 part of aluminum paste. The autoclaved aerated concrete plate prepared by utilizing the concrete raw material has the advantages of high strength, low water absorption and strong bearing capacity, and the appearance of the autoclaved aerated concrete plate is grayish white or whitish yellow by carrying out carbon reduction treatment on furnace slag.

Description

Concrete raw material, autoclaved aerated concrete plate and preparation method thereof

Technical Field

The invention relates to the technical field of buildings, in particular to a concrete raw material, an autoclaved aerated concrete plate and a preparation method thereof.

Background

An Autoclaved Aerated Concrete (AAC) plate is a porous Concrete forming plate which is formed by curing silica sand, cement, lime or fly ash and the like serving as main raw materials through high-pressure steam.

At present, the autoclaved aerated concrete plate comprises two types of sand aerated concrete and ash aerated concrete, wherein the ash aerated concrete plate mainly takes fly ash, lime and cement as main raw materials.

However, the current autoclaved aerated concrete slab of the "ash aerated" type has at least the following technical problems: the appearance is grayish, the strength is low, the water absorption is high, and the like.

Disclosure of Invention

In view of the above, the invention provides a concrete raw material, an autoclaved aerated concrete slab and a preparation method thereof, which can solve the technical problems.

Specifically, the method comprises the following technical scheme:

in one aspect, a concrete raw material is provided, and the concrete raw material comprises a dry material and water, wherein the mass ratio of the water to the dry material is 0.56-0.65:1;

the dry material comprises the following components in parts by weight:

60-70 parts of furnace slag, 2-5 parts of tailing sand, 1-2 parts of sludge, 2-3 parts of concrete waste, 3-5 parts of desulfurized gypsum, 0.01-0.1 part of microfiber, 0.5-1.5 parts of nano calcium carbonate, 10-15 parts of cement, 12-20 parts of lime, 0.3-0.7 part of foam stabilizer, 0.5-1.2 parts of dispersant and 0.5-0.8 part of aluminum paste;

the carbon content of the slag is 8-10% by mass, and the slag is subjected to carbon reduction treatment when the concrete raw material is used for preparing an autoclaved aerated concrete plate.

In some possible implementations, the slag includes the following components in mass percent: 8 to 10 percent of carbon, 5 to 7 percent of calcium oxide, 6 to 8 percent of calcium carbonate and the balance of silicon dioxide.

In some possible implementations, the tailings sand includes the following components in mass percent: 1% -5% of alumina, 2% -18% of ferric oxide and 60% -74% of silicon dioxide;

the sludge comprises the following components in percentage by mass: 21 to 30 percent of silicon dioxide, 1 to 19 percent of aluminum oxide and 1 to 21 percent of ferric oxide, and the loss on ignition is 20 to 50 percent.

In some possible implementations, the concrete waste comprises the following components in percentage by mass: 0-30% of alumina, 0-30% of ferric oxide and 30-60% of silicon dioxide.

In some possible implementations, the microfibers are selected from at least one of polypropylene monofilament fibers, cellulosic fibers, basalt fibers, glass fibers;

the foam stabilizer is selected from at least one of silicone polyether emulsion, fatty alcohol-polyoxyethylene ether, fatty acid, palmitic acid, silicone amide and sodium dodecyl benzene sulfonate;

the dispersing agent is selected from at least one of bentonite, sodium polyacrylate, sodium hexametaphosphate and hydroxypropyl methyl cellulose.

In another aspect, a preparation method of an autoclaved aerated concrete plate is provided, and the preparation method comprises the following steps: preparing a raw material slurry by using any one of the concrete raw materials; wherein the preparing the raw material slurry comprises: mixing slag and water and preparing the slag slurry through wet grinding, wherein the slag slurry comprises slag ash and water, and the slag slurry is subjected to carbon reduction treatment so that the mass percent of carbon in the slag ash is less than or equal to 3%;

and sequentially carrying out steel bar mesh cage pouring, standing maintenance, cutting and marshalling and autoclaved maintenance on the raw material slurry to obtain the autoclaved aerated concrete plate.

In some possible implementations, the preparing the feedstock slurry further comprises:

wet grinding the tailing sand, the sludge and water to prepare silicon mortar; sequentially crushing, grinding and adding water to stir the concrete waste to prepare waste slurry; mixing and stirring desulfurized gypsum and water to prepare desulfurized gypsum slurry; mixing and stirring the foam stabilizer, the dispersing agent, the aluminum powder paste and water to prepare an aluminum powder paste suspension;

uniformly mixing the slag mortar subjected to carbon reduction treatment, the silicon mortar, the waste slurry, the desulfurized gypsum slurry, microfibers, nano calcium carbonate and water to form a first mixed slurry;

adding cement and lime into the first mixed slurry for stirring, and raising the temperature to 40-50 ℃ by steam in the stirring process until the mixture is uniformly stirred to form second mixed slurry;

and adding the aluminum powder paste suspension into the second mixed slurry and uniformly stirring to obtain the raw material slurry.

In some possible implementations, the static maintenance includes:

and placing the first blank obtained by the operation of casting the steel reinforcement mesh cage in a curing room, and carrying out the static curing on the first blank for 2-5 hours under the conditions that the temperature is 50-60 ℃ and the humidity is 60-70%.

In some possible implementations, the autoclave curing includes:

placing the second blank obtained by the cutting and grouping operation in an autoclave, and sequentially carrying out pollution discharge, vacuum pumping, pressure boosting maintenance and constant pressure maintenance until the pressure of the autoclave is reduced to 0MPa to obtain the autoclaved aerated concrete plate;

the boosting maintenance comprises the following steps: and (2) conducting air guide and pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide and pressure boosting stage, the flow of steam inlet air is 500 kg, and the inlet air is gradually increased in stages after the air guide and pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam enters 1000 kilograms of air flow and enters 30 minutes; the steam enters the air flow of 2000 kilograms and the air enters the air for 30 minutes; steam is fed for 30 minutes at the inlet flow of 3000 kg; the steam inlet flow is 4000 kilograms, and the air inlet is 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and the boosting time length when the internal pressure of the still kettle is raised to the target pressure is controlled to be 4-4.5 hours;

the constant-pressure maintenance comprises the following steps: the target pressure is maintained for 8 hours to 10 hours, and condensed water is discharged every hour during constant pressure.

In another aspect, an autoclaved aerated concrete plate is provided, and is prepared from any one of the concrete raw materials of the autoclaved aerated concrete plate, or is prepared by any one of the preparation methods of the autoclaved aerated concrete plate.

The technical scheme provided by the embodiment of the invention at least has the following beneficial effects:

the embodiment of the invention provides a concrete raw material and a method for preparing a concrete plate based on the concrete raw material. The slag ash after carbon reduction is matched with tailing sand, sludge, concrete waste, desulfurized gypsum, microfiber, nano calcium carbonate, cement, lime, a foam stabilizer, a dispersing agent and aluminum powder paste in a certain ratio, and the concrete raw material is suitable for preparing an autoclaved aerated concrete plate by adopting an autoclaved aerated process through synergistic action among the components, so that the prepared autoclaved aerated concrete plate at least has the following advantages: high strength, low water absorption and high bearing capacity. And because the carbon reduction treatment is carried out on the slag with high carbon content, the color of the prepared autoclaved aerated concrete plate is whitened, and the appearance color of the autoclaved aerated concrete plate is similar to the gray white or white yellowish appearance of the sand aerated concrete plate. Therefore, the embodiment of the invention takes the high-carbon furnace slag as the raw material, reduces the carbon of the high-carbon furnace slag to prepare the concrete plate, solves the problem that the concrete plate prepared by using the conventional high-carbon furnace slag has navy blue or gray-blue black color by controlling the carbon content of the furnace slag, and simultaneously realizes the effective recycling of the high-carbon furnace slag, so that the energy utilization is maximized, and the energy conservation and emission reduction are facilitated.

Detailed Description

In order to make the technical solutions and advantages of the present application more clear, the following will describe the embodiments of the present application in further detail. In embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

In one aspect, an embodiment of the present invention provides a concrete raw material, where the concrete raw material includes a dry material and water, and a mass ratio of the water to the dry material is 0.56-0.65:1, for example, the mass ratio of water to dry matter is 0.56: 1. 0.57: 1. 0.58:1. 0.59: 1. 0.60: 1. 0.61: 1. 0.62:1. 0.63: 1. 0.64: 1. 0.65:1, etc.

As for the dry material, the material comprises the following components in parts by weight: 60-70 parts of furnace slag with 8-10% of carbon, 2-5 parts of tailing sand, 1-2 parts of sludge, 2-3 parts of concrete waste, 3-5 parts of desulfurized gypsum, 0.01-0.1 part of microfiber, 0.5-1.5 parts of nano calcium carbonate, 10-15 parts of cement, 12-20 parts of lime, 0.3-0.7 part of foam stabilizer, 0.5-1.2 parts of dispersant and 0.5-0.8 part of aluminum paste. Wherein, the mass percent of the carbon in the slag is 8-10%, and the slag is subjected to carbon reduction treatment when the concrete raw material is used for preparing the autoclaved aerated concrete plate.

The embodiment of the invention provides a concrete raw material and a method for preparing a concrete plate based on the concrete raw material. The slag ash after carbon reduction is matched with tailing sand, sludge, concrete waste, desulfurized gypsum, microfiber, nano calcium carbonate, cement, lime, a foam stabilizer, a dispersing agent and aluminum powder paste in a certain ratio, and the concrete raw material is suitable for preparing an autoclaved aerated concrete plate by adopting an autoclaved aerated process through synergistic action among the components, so that the prepared autoclaved aerated concrete plate at least has the following advantages: high strength, low water absorption and high bearing capacity. And because the carbon reduction treatment is carried out on the slag with high carbon content, the color of the prepared autoclaved aerated concrete plate is whitened, and the appearance color of the autoclaved aerated concrete plate is similar to the gray white or white yellowish appearance of the sand aerated concrete plate. Therefore, in the embodiment of the invention, the high-carbon furnace slag is used as the raw material, the carbon is reduced to prepare the concrete plate, the problem that the concrete plate prepared by using the conventional high-carbon furnace slag has a navy blue color or a dark gray color is solved by controlling the carbon content of the furnace slag, and meanwhile, the effective recycling of the high-carbon furnace slag is realized, so that the energy utilization is maximized, and the energy conservation and emission reduction are facilitated.

The composition of the individual components involved in the above concrete raw materials and their effects will be further described below:

the slag involved in the embodiment of the invention is high carbon slag, usually, the high carbon slag is one of solid wastes of a coal-fired power plant, and the slag directly generated by the coal-fired power plant is the high carbon slag, if the slag is directly used for preparing a concrete plate, the color of the plate is grey, and the slag is difficult to popularize and apply in the market. According to the embodiment of the invention, the carbon content of the high-carbon slag from the coal-fired power plant is controlled to be 3% or less, for example, 1% or less by performing carbon reduction treatment on the high-carbon slag, so that the high-carbon slag can be effectively utilized, and the problem that the color of a plate is grey is solved.

In some examples, the slag used in embodiments of the present invention is derived from coal fired power plant solid waste, wherein the mass percentage of carbon contained therein includes, but is not limited to, 8%, 8.5%, 9%, 9.5%, 10%, etc. The weight parts of the slag in the concrete raw material include but are not limited to: 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts and the like.

In some examples, the slag used in embodiments of the present invention comprises the following components in weight percent: 8 to 10 percent of carbon, 5 to 7 percent of calcium oxide, 6 to 8 percent of calcium carbonate and the balance of silicon dioxide. Wherein, the balance of the silicon dioxide means that the mass percentage of the silicon dioxide and the sum of the mass percentages of the carbon, the calcium oxide and the calcium carbonate are 100 percent.

Further, the high carbon slag may be mixed with water and wet ground to form a slurry at the time of use, so that the slag forms fine ashes, wherein the ash has a fineness of: the 80 micron screen residue is 10-15 percent, namely 0.1-0.15 screen pore residue, so as to achieve the effect of optimizing the comprehensive performance of the autoclaved aerated concrete plate.

As described above, the slag according to the embodiment of the present invention exists in the form of mortar when used, and may be subjected to a carbon reduction treatment when the mortar is formed.

For example, the high-carbon slag with 8-10% of carbon by mass can be subjected to carbon reduction treatment by the following method when used for preparing concrete plates:

high carbon slag from a coal-fired power plant is used as a raw material and water is ground in a wet grinding machine according to a certain proportion to prepare high carbon slag wet grinding mortar, and then the high carbon slag wet grinding mortar is subjected to carbon separation by utilizing fly ash flotation separation equipment to form low carbon content slag mortar which can be directly collected for later use. For example, the slag slurry may have a moisture content of 35% to 45%, for example 40%.

Fly ash flotation separation equipment is common in the art, for example, as shown in chinese patent CN205095968U, fly ash flotation separation equipment can be applied, and details thereof are not repeated here. When the device is used, the high-carbon slag wet-grinding mortar can be uniformly poured into a flotation tank which is fully filled with water in advance, an electric stirrer is started at the same time, after a flotation agent is added, the stirring is continued for a plurality of minutes, then the stirring is stopped, at the moment, an operator releases a nylon rope and holds the nylon rope with one hand, the other hand holds a steel fork to fork a plastic hose and collect carbon granules to a fine carbon collecting tank under the liquid level of slurry, the carbon granules containing water are filtered by a filter screen to realize separation, after the flotation separation work is finished, a gate valve on a plastic hard pipe is closed, the upper tank body is rotationally disassembled, the anhydrous carbon granules fall into an annular storage tank, then the upper tank body is rotationally installed, sewage is discharged after the drainage pipe is opened, the flotation separation work is continuously carried out, and meanwhile, the carbon granules are manually taken out of the annular storage tank; after continuous flotation treatment for a plurality of times, opening a gate valve at the bottom of the flotation tank, and collecting the slag mortar with low carbon content deposited after the treatment for a plurality of times into a collection tank.

Of course, for ease of transportation and storage, the low carbon content slag mortar may be dried again to form a low carbon dry slag ash for storage.

Alternatively, the carbon reduction treatment of the high carbon slag may be performed by some decarburization techniques known in the art, for example, see the decarburization techniques of "progress and prospect of research on decarburization of fly ash" disclosed in "clean coal technology" volume 23, volume 1, such as zhuangli, etc., and all of the above techniques can achieve the purpose of carbon reduction of the high carbon slag.

Further, it is desirable for the embodiment of the present invention that the mass percentage of carbon of the slag ash in the carbon-reduced slag ash slurry is less than or equal to 3%, for example, further less than or equal to 2%, further less than or equal to 1%, or the like.

In order to ensure that the carbon content in the slag ash subjected to carbon reduction treatment meets the requirements, a carbon reduction experiment can be performed in advance before a formal carbon reduction operation is performed on slag wet-grinding mortar with high carbon content, so as to test the carbon content of the corresponding slag ash under each carbon reduction operation condition, and then the carbon reduction operation conditions meeting the requirements are obtained through screening. In this way, when the carbon reduction treatment is carried out on the blast furnace slag in the main form, the carbon reduction operation conditions may be directly performed in accordance with the above screening. For the test of the carbon content, reference can be made to a determination-correction method (reference method) of the ignition loss of the portland slag cement shown in GB/T176-2017, and the carbon content can be accurately and correspondingly obtained by determining the ignition loss through the test.

In the embodiment of the invention, the tailing sand is an industrial byproduct in the process of mining iron ore, and in the embodiment of the invention, the tailing sand comprises the following components in percentage by mass: 1% -5% alumina, 2% -18% iron oxide and 60% -74% silica, with the balance being impurities, wherein the alumina, iron oxide and silica compositions are desirable for embodiments of the present invention.

For example, the mass percentages of alumina include, but are not limited to: 1%, 2%, 3%, 4%, 5%, etc., the mass percentages of iron oxide include but are not limited to: 3%, 5%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

In the embodiment of the invention, the sludge can be derived from industrial waste sludge finally discharged from municipal sewage treatment plants and tap water purification plants, and in some examples, the sludge comprises the following components in percentage by mass: 21% -30% of silicon dioxide, 1% -19% of aluminum oxide, 1% -21% of ferric oxide and the balance of impurities, and the loss on ignition is 20% -50%. Where alumina, iron oxide and silica components are desired for embodiments of the present invention.

For example, the mass percentages of silica include, but are not limited to: 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, etc.; the mass percentages of alumina include, but are not limited to: 1%, 5%, 10%, 13%, 15%, 16%, 17%, 18%, etc.; the mass percentages of iron oxide include, but are not limited to: 3%, 5%, 8%, 10%, 12%, 15%, 17%, 19%, 20%, etc.

In the embodiment of the invention, the concrete waste refers to industrial waste such as waste aerated concrete blocks.

In some examples, the concrete waste comprises the following components in mass percent: 0% -30% of alumina, 0% -30% of ferric oxide, 30% -60% of silicon dioxide and the balance of some impurities. Where alumina, iron oxide and silica components are desired for embodiments of the present invention.

For example, the mass percentages of alumina include, but are not limited to: 1%, 5%, 10%, 15%, 20%, 25%, 30%, etc.; the mass percentages of iron oxide include, but are not limited to: 1%, 5%, 10%, 15%, 20%, 25%, 30%, etc.; the mass percentages of silica include, but are not limited to: 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.

In some examples, the concrete waste according to embodiments of the present invention is in the form of slurry, for example, the concrete waste is crushed, ground, and mixed with water to form the concrete waste slurry.

In some examples, the desulfurized gypsum of the embodiments of the invention belongs to one of solid wastes of coal-fired power plants, and comprises dihydrate gypsum (CaSO) with a mass fraction higher than 90% ₄ ·2H ₂ And O), the desulfurized gypsum is used as a regulator for the gas generation process when the concrete plate is prepared by the autoclaved aerated process.

In some examples, the microfibers are selected from at least one of polypropylene monofilament fibers, cellulosic fibers, basalt fibers, and glass fibers.

The polypropylene monofilament fiber has a length of 2mm-8mm and an equivalent diameter of 0.01mm-0.03mm, for example, a polypropylene monofilament fiber having a length of 6mm, an equivalent diameter of 0.02mm and a tensile strength of 800MPa is selected, and for example, a fiber product manufactured by seiran bohope new material science and technology limited may be used as the polypropylene monofilament fiber.

The cellulose fibers have a length of 2mm to 8mm and an equivalent diameter of 0.01mm to 0.03mm, for example, the cellulose fibers having a length of 2mm, an equivalent diameter of 0.015mm and a tensile strength of 900MPa are selected, and further for example, cellulose fiber products manufactured by new material Tokyo Haoda may be used as the cellulose fibers.

The length of the basalt fiber is 2mm-8mm, the equivalent diameter can be 0.05mm-0.08mm, for example, the basalt fiber with the length of 7mm, the equivalent diameter of 6mm and the tensile strength of 1100MPa is selected, and for example, the basalt fiber can be a basalt fiber product produced by Taian hong concrete New Material Co.

The glass fiber has a length of 5mm to 15mm and an equivalent diameter of 0.01mm to 0.05mm, and for example, a glass fiber having a length of 11mm, an equivalent diameter of 0.03mm and a tensile strength of 2000MPa is used, and for further example, a glass fiber product manufactured by Henan high-gloss durable materials Co.

The nano calcium carbonate according to the embodiment of the present invention has an average particle size of, for example, 40nm to 60nm, such as 40nm, 42nm, 45nm, 48nm, 50nm, 53nm, 55nm, 58nm, 60nm, and the like.

For example, the nano calcium carbonate may be ultrafine activated nano calcium carbonate having an average particle size of 54.3nm, which is manufactured by Baole powder Co., ltd.

The micro-fiber and nano calcium carbonate are added into the concrete raw material, so that the concrete has at least the following beneficial effects: the microfibers can penetrate through macroscopic air holes of the autoclaved aerated concrete plate and hole wall frameworks around the air holes, and the microfibers are mixed in the plate matrix and distributed disorderly, so that a network-shaped three-dimensional support reinforcing system can be formed, and the integrity of the interior of the autoclaved aerated concrete plate is improved.

If the micro-fibers and the nano calcium carbonate are not added, when the prepared autoclaved aerated concrete plate is subjected to external force, a large amount of stress concentration is generated at the end part of the micro-crack part of the pore wall framework, so that cracks are rapidly expanded, and finally the plate is brittle and damaged. The doping of the micro-fiber can effectively reduce the stress concentration, change the crack direction and slow down the expansion of the micro-crack. If the matrix of the concrete plate is damaged, the microfibers have a certain effect of being involved in the concrete block particles in a separated state, and the microfibers are peeled off from the concrete plate or pulled to break, which consumes a large amount of energy, thus inhibiting the breakage of the concrete plate.

In addition, the contact area between the microfibers and the concrete plate is increased through the network-shaped three-dimensional supporting and reinforcing system, the microfibers are well bonded in the autoclaved aerated concrete plate, and the internal structure of the autoclaved aerated concrete plate is more compact due to the high elastic modulus and the relatively small diameter of the microfibers, so that the strength of the autoclaved aerated concrete plate is effectively improved, and the compression performance of the autoclaved aerated concrete plate is remarkably enhanced.

And for the addition of the nano calcium carbonate, on one hand, the nano calcium carbonate can be filled in a concrete plate, so that the filling pores are filled, a micro-aggregate effect is generated, the pore structure is improved, on the other hand, the crystallization of certain crystals in the concrete plate is promoted, the compactness of the autoclaved aerated concrete plate is improved due to the micro-aggregate effect, and some hydrothermal reaction products are limited by space in the production process, so that small crystals are easier to form and are mutually connected in the space to form a network, the compressive strength of the autoclaved aerated concrete plate is increased, and the drying shrinkage value of the autoclaved aerated concrete is reduced.

In the embodiment of the invention, the cement and the lime are common in the field, for example, the cement can be P.II 525 Portland cement which is produced by Anhui conch Cement Ltd and meets the GB175-2007 requirement.

In order to improve the comprehensive performance of the concrete plate, the lime involved in the embodiment of the invention is lime powder, for example, the fineness of the lime powder is 10-20% of the screen residue with the particle diameter of 80um, the effective calcium content of the lime powder is 75-95%, the digestion rate is 5-15 min, and the digestion temperature is 70-100 ℃.

In some examples, the foam stabilizer is selected from at least one of silicone polyether emulsion, fatty alcohol-polyoxyethylene ether, fatty acid, palmitic acid, silicone amide, and sodium dodecyl benzene sulfonate.

In some examples, the dispersant is selected from at least one of bentonite, sodium polyacrylate, sodium hexametaphosphate, hydroxypropyl methylcellulose.

In some examples, aluminum paste is used as the gas generating material, and may be selected from those commonly used in the art, for example, GLS-65 aqua type aluminum paste manufactured by the south china silver peng building materials ltd.

On the other hand, the embodiment of the invention also provides a preparation method of the autoclaved aerated concrete plate, which comprises the following steps: the raw material slurry is prepared by using any one of the concrete raw materials. Wherein, the preparation of the raw material slurry comprises the following steps: slag and water are mixed and wet-milled to prepare a slag slurry, the slag slurry comprising slag ash and water, and the slag slurry is subjected to a carbon-reducing treatment so that the mass percentage of carbon in the slag ash is 3% or less. The carbon reduction treatment can be referred to the above description about the concrete raw material, and is not repeated herein.

And (3) sequentially carrying out reinforcement cage pouring, static curing, cutting and grouping and autoclaved curing by using the raw material slurry to obtain the autoclaved aerated concrete plate.

The concrete plate is prepared by the preparation method of the autoclaved aerated concrete plate, and the preparation method has the advantages of simple process, high efficiency, low production cost and the like, and is suitable for large-scale production.

In some examples, the preparing the feedstock slurry further comprises:

step 101, wet grinding the tailing sand, the sludge and water to prepare silicon mortar; sequentially crushing, grinding and adding water to stir the concrete waste to prepare waste slurry; mixing and stirring desulfurized gypsum and water to prepare desulfurized gypsum slurry; and mixing and stirring the foam stabilizer, the dispersing agent, the aluminum powder paste and water to prepare the aluminum powder paste suspension. Among them, lime may be used by crushing and ball-milling to an appropriate particle size.

Step 102, uniformly mixing the slag mortar subjected to carbon reduction treatment, silicon mortar, waste slurry, desulfurized gypsum slurry, microfibers, nano calcium carbonate and water to form first mixed slurry. For example, the above components are added to a mixer and mixed for a certain time, for example, 30 seconds to 1 minute to obtain a first mixed slurry.

103, adding cement and lime into the first mixed slurry for stirring, and raising the temperature to 40-50 ℃ by using steam in the stirring process until the mixture is uniformly stirred to form second mixed slurry. For example, steam heating is performed from the start of stirring until the temperature is raised to 40 ℃ to 50 ℃ and the temperature is maintained, for example, the temperature after heating includes, but is not limited to, 40 ℃, 42 ℃, 45 ℃, 46 ℃, 48 ℃, 50 ℃ and the like.

And step 104, adding the aluminum powder paste suspension into the second mixed slurry and uniformly stirring to obtain raw material slurry. For example, the stirring time may be 30 seconds to 1 minute, such as 40 seconds.

For the steel reinforcement cage pouring process, the raw material slurry is poured into the steel reinforcement cage by a stirrer (namely, empty mold), the reinforcement cage can be prepared in advance or after the preparation of the raw material slurry is finished.

For the embodiment of the invention, the preparation of the raw material slurry and the pouring of the steel reinforcement net cage can be automatically controlled by a computer system through PLC.

For static maintenance, it includes: placing a first blank obtained by the operation of pouring the steel reinforcement cage in a curing room, and standing and curing the blank for 2-5 hours under the conditions that the temperature is 50-60 ℃ and the humidity is 60-70%.

For example, the temperature of the static curing is 50 ℃, 52 ℃, 54 ℃, 55 ℃, 58 ℃, 60 ℃ or the like, the humidity is 60%, 62%, 65%, 66%, 68%, 70% or the like, and the time of the static curing is 2 hours, 2.5 hours, 3 hours, 3.5 hours or the like.

Through static maintenance, the first green body has certain strength before steaming so as to resist stress caused by temperature change and migration during maintenance and temperature rise and prevent product cracks; meanwhile, particles such as lime and the like which are not completely digested are continuously and fully digested before maintenance, and green body cracking caused by continuous digestion of lime during maintenance is prevented. In addition, when the molding moisture of the first green body is too large, the residual moisture is too much, the rapid evaporation of the moisture during the temperature rise is easy to cause cracking, and the static stop dehydration can be realized through static stop maintenance, so that the first green body has proper water content before steaming and strength before steaming.

For autoclave curing, it includes: and (3) placing the second blank obtained by cutting and grouping operation in an autoclave, and performing pollution discharge, vacuum pumping, pressure boosting maintenance and constant pressure maintenance in sequence until the pressure of the autoclave is reduced to 0MPa to obtain the autoclaved aerated concrete plate.

The autoclave is a common device in the field, and is not described herein again, and the steam used in the autoclave curing process may be saturated waste steam from a power plant, for example, saturated waste steam from a sika-hua power plant.

For the processes of pollution discharge, vacuum pumping and pressure boosting maintenance, the operation can be carried out through the following steps: the method comprises the steps of firstly introducing main pipe steam into a sealing ring before boosting of the still kettle, switching a valve after boosting to working pressure, enabling the steam in the kettle to directly pass through a sealing ring groove, starting a vacuum pump, opening a water gate, opening a kettle body vacuumizing sealing door of the still kettle, carrying out vacuumizing operation, and stopping the pump and closing a vacuumizing door after reaching a specified vacuum degree.

After the vacuum pumping is finished, air is guided and pressurized through the air distributing cylinder, a manual drain valve is required to drain water in the early stage of pressurization, the autoclave automatically drains the sewage when the pressure in the autoclave reaches 0.5MPa, and when the pressure reaches 0.3-0.4 MPa, an air inlet valve of the air ring is closed, and a communication valve in the autoclave is opened to keep discharging the condensed water every 15 min.

When the manual blowoff valve drains water, the blowoff valve is fully opened at the initial stage of steam guiding; when the pressure in the kettle reaches 0.01MPa, the drain valve is closed by one third; when the pressure in the kettle reaches 0.07MPa, the drain valve is closed by two thirds; when the pressure in the kettle reaches 0.5MPa, the drain valve is fully closed.

For pressurized maintenance, it includes: the method comprises the following steps of conducting air guide pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide pressure boosting stage, the flow of steam inlet air is 500 kilograms, and the inlet air is gradually increased in stages after the air guide pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam inlet flow is 1000 kg, and the air is introduced for 30 minutes; the steam inlet flow is 2000 kg, and the air inlet time is 30 minutes; the steam inlet flow is 3000 kg, and the air is fed for 30 minutes; the steam inlet flow is 4000 kg, and the air is introduced for 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and the pressure-raising time period when the internal pressure of the autoclave is raised to the target pressure is controlled to be 4 hours to 4.5 hours.

For constant pressure maintenance, it includes: the target pressure was maintained for 8 hours to 10 hours, and condensed water was discharged every hour during the constant pressure.

For example, the target pressure is 1.2MPa to 1.5MPa, for example, 1.25MPa, for example, when the pressure in the autoclave is increased to 1.25MPa, the pressure is kept for 8 hours, and the pressure in the autoclave during the process of keeping constant pressure is greater than or equal to 1.2MPa, for example, if the pressure in the autoclave is decreased, pressure needs to be timely supplemented.

After constant pressure maintenance is finished, pressure is reduced through the air distributing cylinder, after the pressure in the kettle is reduced to 0MPa, the safety device is opened to completely discharge residual gas in the kettle, the manual speed reducer is rotated to separate the kettle cover from the sealing ring, the kettle door is opened by 30cm-50cm, and the kettle door is completely opened after 5 min.

According to the preparation method of the autoclaved aerated concrete plate, the power plant saturated waste steam is used for autoclaved curing, on one hand, the waste steam of the power plant is fully utilized, and the energy utilization maximization is realized, on the other hand, the energy efficiency is high due to the power plant saturated waste steam, the autoclaved curing time can be obviously shortened, and the strength of the blank body is improved; the kettle body is subjected to pollution discharge and vacuum pumping measures, so that the heat exchange condition of the inner layer and the outer layer of the green body is improved, the core generation phenomenon is prevented, and the temperature rise time is shortened; by utilizing the autoclaved curing system, the hydration reaction of the aerated concrete can be strengthened by utilizing the autoclaved curing damp-heat condition, and the condition that the hydrothermal reaction is not facilitated or the curing effect and the product quality are damaged in the autoclaved curing process can be effectively avoided. The preparation method of the concrete plate is simple, high in efficiency, low in production cost and suitable for continuous large-scale production.

The autoclaved aerated concrete plate prepared by the preparation method of the autoclaved aerated concrete plate provided by the embodiment of the invention has excellent comprehensive performance, and has the advantages of high strength, low water absorption, strong bearing capacity and the like.

Compared with the prior art, the autoclaved aerated concrete plate and the preparation method thereof provided by the embodiment of the invention mainly have the following advantages:

(1) The autoclaved aerated concrete plate is prepared by utilizing the high-carbon slag, and the technology of flotation and carbon removal of wet-milled mortar of the high-carbon slag is utilized, so that the current situation of the color of the ash aerated appearance, namely 'ash', is changed, a new way for applying the high added value of the solid wastes of the high-carbon slag is developed, the product quality is ensured, and the production cost is effectively reduced.

(2) By doping the micro-fibers and the nano calcium carbonate into the autoclaved aerated concrete, the compressive strength and the compressive property of the concrete plate are obviously improved, and the problems that the autoclaved aerated concrete plate is easy to dry, shrink, crack and the like are optimized.

(3) The method not only can strengthen the hydration reaction of the aerated concrete by using the autoclaved curing damp-heat condition, but also can effectively avoid the condition which is possibly unfavorable for the hydrothermal reaction or is harmful to the curing effect and the product quality in the autoclaved curing process.

On the other hand, the embodiment of the invention also provides an autoclaved aerated concrete plate, which is prepared from any one of the concrete raw materials, or any one of the preparation methods of the autoclaved aerated concrete plate.

The autoclaved aerated concrete plate provided by the embodiment of the invention at least has the following advantages: the autoclaved aerated concrete plate has the advantages of high strength, low water absorption and strong bearing capacity, and has a whitening effect, so that the appearance color of the autoclaved aerated concrete plate is similar to the gray white or white to yellow appearance of the sand aerated concrete plate.

In some examples, the autoclaved aerated concrete slab can be used as a floor slab, a roof slab, or the like.

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Those skilled in the art will recognize that the specific techniques or conditions, not specified in the examples, are according to the techniques or conditions described in the literature of the art or according to the product specification. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.

Example 1

The embodiment 1 provides an autoclaved aerated concrete plate, which adopts concrete raw materials comprising a dry material and water, wherein the mass ratio of the water to the dry material is 0.58:1. the dry material comprises the following components in parts by weight: 65 parts of furnace slag, 3 parts of tailing sand, 1 part of sludge, 3 parts of concrete waste, 4 parts of desulfurized gypsum, 0.02 part of microfiber, 1 part of nano calcium carbonate, 12 parts of cement, 15 parts of lime, 0.4 part of a foam stabilizer, 0.7 part of a dispersant and 0.7 part of aluminum paste.

Wherein the slag comprises the following components in percentage by mass: 8% carbon, 5% calcium oxide, 6% calcium carbonate and the balance silica. The slag is subjected to carbon reduction treatment by the following method: the slag is used as raw material and water are ground in a wet grinding machine according to a certain proportion to prepare wet grinding slag mortar with high carbon content, then the wet grinding slag mortar with high carbon content is subjected to carbon separation by utilizing a fly ash flotation separation device to form slag mortar with low carbon content, the slag mortar can be directly collected for standby, and the fineness of the slag mortar with low carbon content is as follows: the 80 micron screen residue is 12 percent, the water content is 40 percent, and the carbon content of the slag ash contained in the slag ash is lower than 1 percent.

The tailings are industrial byproducts in the process of mining iron ores, and comprise 65% of silicon dioxide, 3% of aluminum oxide and 10% of iron oxide. The content of silicon dioxide in the sludge is 25%, the content of aluminum oxide is 10%, the content of ferric oxide is 12% and the loss on ignition is 30%. The concrete waste contains 40% of silica, 10% of alumina and 12% of iron oxide. The microfiber is polypropylene monofilament fiber produced by New science and technology Limited of Xian Bo Wang New Material, and the polypropylene monofilament fiber has a length of 6mm, an equivalent diameter of 0.02mm and a tensile strength of 800MPa. The nano calcium carbonate is produced by Baolai powder company Limited in Pozhou, and the average grain diameter is 54.3nm. The desulfurized gypsum contains more than 90 percent of dihydrate gypsum (CaSO) ₄ ·2H ₂ O). The cement is selected from P.II 525 Portland cement which is produced by Anhui conch cement corporation and meets the GB175-2007 requirement. Lime is powder with fineness of 80um and 14 percent of screen residue, effective calcium content is 82 percent, digestion speed is 9min, and digestion temperature is 88 ℃. The foam stabilizer is silicone polyether emulsion. The dispersant is bentonite. The aluminum powder paste is produced by Jinan Yinpeng building material Co., ltdThe GLS-65 aqueous aluminum powder paste.

The autoclaved aerated concrete plate is prepared by the following method:

using the concrete raw material provided in example 1, a raw material slurry was prepared. And sequentially carrying out steel bar mesh cage pouring, standing maintenance, cutting and marshalling and autoclaved maintenance by using the raw material slurry to obtain the autoclaved aerated concrete plate. The method specifically comprises the following steps:

wet grinding the slag and water to prepare slag mortar with low carbon content; wet grinding the tailing sand, the sludge and water to prepare silicon mortar; sequentially crushing, grinding and adding water to stir the concrete waste to prepare waste slurry; mixing and stirring the desulfurized gypsum and water to prepare desulfurized gypsum slurry; and mixing and stirring the foam stabilizer, the dispersing agent, the aluminum powder paste and water to prepare the aluminum powder paste suspension.

Blast furnace slag is used as a raw material, mixed with water and subjected to wet grinding and decarbonization separation to form slag mortar. Uniformly mixing the slag mortar, the silicon mortar, the waste slurry, the desulfurized gypsum slurry, the microfibers, the nano calcium carbonate and the water, and stirring for 30 seconds to form a first mixed slurry. Adding cement and lime into the first mixed slurry for stirring, and raising the temperature to 42 ℃ by using steam in the stirring process. And adding the aluminum powder paste suspension into the second mixed slurry and uniformly stirring for 40 seconds to obtain raw material slurry.

And pouring the raw material slurry into the steel reinforcement mesh cage by a stirrer. The preparation of the raw material slurry and the pouring of the steel mesh cage can be automatically controlled by a computer system through PLC.

And placing the first blank obtained by the operation of casting the steel reinforcement mesh cage in a curing room, and standing and curing the blank for 2.5 hours under the conditions that the temperature is 55 ℃ and the humidity is 70%.

Cutting off and grouping the first green body, placing the second green body obtained by cutting off and grouping operation in the still kettle, introducing main pipe steam into a sealing ring before boosting of the still kettle, converting a valve after boosting to working pressure, enabling the steam in the kettle to be directly communicated with a sealing ring groove, starting a vacuum pump, opening a water gate, opening a kettle body vacuumizing sealing door of the still kettle, performing vacuumizing operation, and stopping the pump and closing a vacuumizing door after reaching a specified vacuum degree.

After the vacuum pumping is finished, air is guided and pressurized through the air distributing cylinder, a manual drain valve is required to drain water in the early stage of pressurization, the autoclave automatically drains the sewage after the pressure in the autoclave reaches 0.5MPa, when the pressure reaches 0.3MPa, an air inlet valve of the air ring is closed, and a communication valve in the autoclave is opened to ensure that condensed water is discharged every 15 min.

The method comprises the following steps of conducting air guide pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide pressure boosting stage, the flow of steam inlet air is 500 kilograms, and the inlet air is gradually increased in stages after the air guide pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam inlet flow is 1000 kg, and the air inlet time is 30 min; the steam inlet flow is 2000 kg, and the air inlet time is 30 minutes; the steam inlet flow is 3000 kg, and the air is fed for 30 minutes; the steam inlet flow is 4000 kg, and the air is introduced for 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and the pressure-increasing time period when the internal pressure of the autoclave was increased to 1.25MPa was controlled to 4.5 hours.

And (3) continuously keeping for 8 hours when the pressure in the autoclave is increased to 1.25MPa, and keeping the pressure in the autoclave to be more than or equal to 1.2MPa in the constant pressure process, if the pressure in the autoclave is reduced, timely pressure supplement is needed.

After constant pressure maintenance is finished, pressure reduction is carried out through the branch air cylinder, after the pressure in the kettle is reduced to 0MPa, the safety device is opened to completely discharge residual air in the kettle, the manual speed reducer is rotated to separate the kettle cover from the sealing ring, the kettle door is firstly opened by 35cm, and after 5min, the kettle door is completely opened.

Example 2

The embodiment 2 provides an autoclaved aerated concrete plate, which comprises concrete raw materials including a dry material and water, wherein the mass ratio of the dry material to the dry material is 0.6:1. the dry material comprises the following components in parts by weight: 65 parts of furnace slag, 3 parts of tailing sand, 1 part of sludge, 2 parts of concrete waste, 4 parts of desulfurized gypsum, 0.03 part of microfiber, 1 part of nano calcium carbonate, 13 parts of cement, 16 parts of lime, 0.3 part of a foam stabilizer, 0.5 part of a dispersant and 0.7 part of aluminum paste.

Wherein the slag comprises the following components in percentage by mass: 9% carbon, 6% calcium oxide, 7% calcium carbonate and the balance silica. The slag is subjected to carbon reduction treatment by the following method: the slag is used as raw material and water are ground in a wet grinding machine according to a certain proportion to prepare wet grinding slag mortar with high carbon content, then the wet grinding slag mortar with high carbon content is subjected to carbon separation by utilizing a fly ash flotation separation device to form slag mortar with low carbon content, the slag mortar can be directly collected for standby, and the fineness of the slag mortar with low carbon content is as follows: the 80 micron screen residue is 11 percent, the water content is 40 percent, and the carbon content of the slag ash contained in the slag ash is lower than 1 percent.

The content of silica in the tailings sand is 65%, the content of alumina is 3%, and the content of iron oxide is 10%. The content of silicon dioxide in the sludge is 25%, the content of aluminum oxide is 9%, the content of ferric oxide is 6%, and the loss on ignition is 23%. The concrete waste contains 40% of silica, 10% of alumina and 12% of iron oxide. The microfiber is basalt fiber produced by Taian hong concrete new material company Limited, and has a length of 7mm, an equivalent diameter of 6mm and a tensile strength of 1100MPa. The nano calcium carbonate is produced by Baole powder company Limited in pool state, and the average grain diameter is 54.3nm. The desulfurized gypsum contains more than 90 percent of dihydrate gypsum (CaSO) ₄ ·2H ₂ O). The cement is selected from P.II 525 Portland cement which is produced by Anhui conch cement corporation and meets the GB175-2007 requirement. Lime is powder with fineness of 80um and residue sieve of 12%, effective calcium content of 82%, digestion rate of 9min, and digestion temperature of 88 deg.C. The foam stabilizer is sodium dodecyl benzene sulfonate. The dispersant is sodium hexametaphosphate. The aluminum powder paste is GLS-65 aqueous aluminum powder paste produced by the Jinan Yinpeng building material company Limited.

The preparation method of the autoclaved aerated concrete slab is basically the same as that in example 1, and the difference is the difference of the autoclaved curing process, which can be seen as follows:

after the vacuum pumping is finished, air is guided and pressurized through the air distributing cylinder, a manual drain valve is required to drain water in the early stage of pressurization, the autoclave automatically drains the sewage after the pressure in the autoclave reaches 0.5MPa, when the pressure reaches 0.35MPa, an air inlet valve of the air ring is closed, and a communication valve in the autoclave is opened to ensure that condensed water is discharged every 15 min.

The method comprises the following steps of conducting air guide pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide pressure boosting stage, the flow of steam inlet air is 500 kilograms, and the inlet air is gradually increased in stages after the air guide pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam inlet flow is 1000 kg, and the air is introduced for 30 minutes; the steam inlet flow is 2000 kg, and the air inlet time is 30 minutes; the steam inlet flow is 3000 kg, and the air is fed for 30 minutes; the steam inlet flow is 4000 kg, and the air is introduced for 30 minutes; before the internal pressure of the autoclave reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kg; and the pressure-increasing time period when the internal pressure of the autoclave was increased to 1.25MPa was controlled at 4 hours.

After constant pressure maintenance is finished, pressure is reduced through the air distributing cylinder, after the pressure in the kettle is reduced to 0MPa, the safety device is opened to completely discharge residual gas in the kettle, the manual speed reducer is rotated to separate the kettle cover from the sealing ring, the kettle door is opened 40cm firstly, and the kettle door is opened completely after 5 min.

Example 3

The embodiment 3 provides an autoclaved aerated concrete plate, which adopts concrete raw materials comprising a dry material and water, wherein the mass ratio of the water to the dry material is 0.6:1. as for the dry material, the material comprises the following components in parts by weight: 65 parts of furnace slag, 3 parts of tailing sand, 1 part of sludge, 2.5 parts of concrete waste, 4 parts of desulfurized gypsum, 0.1 part of microfiber, 1 part of nano calcium carbonate, 14 parts of cement, 17 parts of lime, 0.5 part of a foam stabilizer, 0.4 part of a dispersant and 0.7 part of aluminum paste.

Wherein the slag comprises the following components in percentage by mass: 8.5% carbon, 6% calcium oxide, 7% calcium carbonate and the balance silica. The slag is subjected to carbon reduction treatment by the following method: grinding the slag as a raw material and water in a wet grinding machine in a certain proportion to form a high carbon content wet-ground slag mortar, and then subjecting the high carbon content wet-ground slag mortar to carbon separation by means of a fly ash flotation separation plant to form a low carbon content slag mortar which can be directly collected for later use, and wherein the low carbon content slag mortar has a fineness of: the 80 micron screen residue is 11 percent, the water content is 40 percent, and the carbon content of the slag ash contained in the slag ash is less than 1.5 percent.

The content of silica, alumina and iron oxide in the tailings sand are 65%, 3% and 10%, respectively. The content of silicon dioxide, aluminum oxide, iron oxide and loss on ignition in the sludge is 25%, 9%, 6% and 23%. The concrete waste contains 40% of silica, 10% of alumina and 12% of iron oxide. The microfiber is glass fiber produced by Henan high-gloss refractory Co., ltd, and the glass fiber has a length of 11mm, an equivalent diameter of 0.03mm and a tensile strength of 2000MPa. The nano calcium carbonate is produced by Baole powder company Limited in pool state, and the average grain diameter is 54.3nm. The desulfurized gypsum contains more than 90 percent of dihydrate gypsum (CaSO) ₄ ·2H ₂ O). The cement is selected from P.II 525 Portland cement which is produced by Anhui conch cement corporation and meets the GB175-2007 requirement. Lime is powder with fineness of 80um and residue sieve of 12%, effective calcium content of 82%, digestion rate of 9min, and digestion temperature of 88 deg.C. The foam stabilizer is sodium dodecyl benzene sulfonate. The dispersant is sodium hexametaphosphate. The aluminum powder paste is GLS-65 aqueous aluminum powder paste produced by the Jinan Yinpeng building material company Limited.

The preparation method of the autoclaved aerated concrete plate is basically the same as that in the embodiment 1, and the difference is the difference between the static curing process and the autoclaved curing process, which can be seen as follows:

the static maintenance comprises the following steps: and placing the first blank obtained by the operation of casting the steel reinforcement mesh cage in a curing room, and carrying out the static curing on the first blank for 3 hours under the conditions that the temperature is 58 ℃ and the humidity is 68%.

The steam pressure curing comprises the following steps: after the vacuum pumping is finished, air is guided and pressurized through the air distributing cylinder, a manual drain valve is required to drain water in the early stage of pressurization, the autoclave automatically drains the sewage after the pressure in the autoclave reaches 0.5MPa, when the pressure reaches 0.4MPa, an air inlet valve of the air ring is closed, and a communication valve in the autoclave is opened to ensure that condensed water is discharged every 15 min.

When the manual blowoff valve drains water, the blowoff valve is fully opened at the initial stage of steam guiding; when the pressure in the kettle reaches 0.01MPa, the blow-off valve is closed by one third; when the pressure in the kettle reaches 0.07MPa, the drain valve is closed by two thirds; when the pressure in the kettle reaches 0.5MPa, the drain valve is fully closed.

The method comprises the following steps of conducting air guide pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide pressure boosting stage, the flow of steam inlet air is 500 kilograms, and the inlet air is gradually increased in stages after the air guide pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam inlet flow is 1000 kg, and the air is introduced for 30 minutes; the steam inlet flow is 2000 kg, and the air inlet time is 30 minutes; the steam inlet flow is 3000 kg, and the air is fed for 30 minutes; the steam inlet flow is 4000 kg, and the air is introduced for 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and the pressure-increasing time period when the internal pressure of the autoclave was increased to 1.25MPa was controlled at 4 hours.

And when the pressure in the autoclave is increased to 1.25MPa, continuously maintaining for 8 hours, and maintaining the pressure in the autoclave to be more than or equal to 1.2MPa in the constant pressure process, if the pressure in the autoclave is reduced, timely pressure supplement is needed.

After constant pressure maintenance is finished, pressure is reduced through the air dividing cylinder, after the pressure in the kettle is reduced to 0MPa, the safety device is opened to completely discharge residual gas in the kettle, the manual speed reducer is rotated to separate the kettle cover from the sealing ring, the kettle door is opened at first, and after 8min, the kettle door is completely opened.

Example 4

The embodiment 4 provides an autoclaved aerated concrete plate, which adopts concrete raw materials comprising a dry material and water, wherein the mass ratio of the water to the dry material is 0.62:1. the dry material comprises the following components in parts by weight: 66 parts of furnace slag, 3 parts of tailing sand, 1 part of sludge, 3 parts of concrete waste, 4 parts of desulfurized gypsum, 0.08 part of microfiber, 1.2 parts of nano calcium carbonate, 14 parts of cement, 14 parts of lime, 0.4 part of foam stabilizer, 0.7 part of dispersant and 0.8 part of aluminum paste.

Wherein the slag comprises the following components in percentage by mass: 9% carbon, 6% calcium oxide, 7% calcium carbonate and the balance silica. The slag is subjected to carbon reduction treatment by the following method: grinding the slag as a raw material and water in a wet grinding machine in a certain proportion to form a high carbon content wet-ground slag mortar, and then subjecting the high carbon content wet-ground slag mortar to carbon separation by means of a fly ash flotation separation plant to form a low carbon content slag mortar which can be directly collected for later use, and wherein the low carbon content slag mortar has a fineness of: the 80 micron screen residue is 13 percent, the water content is 40 percent, and the carbon content of the slag ash contained in the slag ash is lower than 2 percent.

The content of silica in the tailings sand is 65%, the content of alumina is 3%, and the content of iron oxide is 10%. The content of silicon dioxide in the sludge is 25%, the content of aluminum oxide is 10%, the content of ferric oxide is 10%, and the loss on ignition is 30%. The content of silica, alumina and iron oxide in the concrete waste is 40%, 10% and 12%, respectively. The microfiber is glass fiber produced by Henan high-gloss refractory Co., ltd, and the glass fiber has a length of 11mm, an equivalent diameter of 0.03mm and a tensile strength of 2000MPa. The nano calcium carbonate is produced by Baolai powder company Limited in Pozhou, and the average grain diameter is 54.3nm. The desulfurized gypsum contains more than 90 percent of dihydrate gypsum (CaSO) ₄ ·2H ₂ O). The cement is selected from P.II 525 Portland cement which is produced by Anhui conch cement corporation and meets the GB175-2007 requirement. Lime is powder with fineness of 80um and residue on sieve of 13%, effective calcium content of 82%, digestion rate of 9min and digestion temperature of 88 ℃. The foam stabilizer is palmitic acid. The dispersant is hydroxypropyl methylcellulose. Aluminum powder pasteIs GLS-65 aqueous aluminum powder paste produced by Jinan Yinpeng building material Co.

The preparation method of the autoclaved aerated concrete slab is basically the same as that in example 1, and the difference is the difference between the static curing process and the autoclaved curing process, which can be seen as follows:

the static maintenance comprises the following steps: and placing the first blank obtained by the operation of casting the steel reinforcement mesh cage in a curing room, and carrying out the static curing on the first blank for 4 hours under the conditions that the temperature is 60 ℃ and the humidity is 64%.

When the manual blowoff valve drains water, the blowoff valve is fully opened at the initial stage of steam guiding; when the pressure in the kettle reaches 0.01MPa, the drain valve is closed by one third; when the pressure in the kettle reaches 0.07MPa, the blow-off valve is closed by two thirds; when the pressure in the kettle reaches 0.5MPa, the drain valve is fully closed.

The method comprises the following steps of conducting air guide pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide pressure boosting stage, the flow of steam inlet air is 500 kilograms, and the inlet air is gradually increased in stages after the air guide pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam inlet flow is 1000 kg, and the air is introduced for 30 minutes; the steam inlet flow is 2000 kg, and the air inlet time is 30 minutes; the steam inlet flow is 3000 kg, and the air inlet lasts for 30 minutes; the steam inlet flow is 4000 kg, and the air is introduced for 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and the pressure-increasing time period when the internal pressure of the autoclave was increased to 1.25MPa was controlled at 4.5 hours.

And (3) continuously keeping for 9 hours when the pressure in the autoclave is increased to 1.25MPa, and keeping the pressure in the autoclave to be more than or equal to 1.2MPa in the constant pressure process, if the pressure in the autoclave is reduced, timely pressure supplement is needed.

After constant pressure maintenance is finished, pressure is reduced through the air distributing cylinder, after the pressure in the kettle is reduced to 0MPa, the safety device is opened to completely discharge residual gas in the kettle, the manual speed reducer is rotated to separate the kettle cover from the sealing ring, the kettle door is opened 30cm firstly, and the kettle door is opened completely after 5 min.

Comparative example

The comparative example provides an autoclaved aerated concrete plate, and concrete raw materials adopted by the autoclaved aerated concrete plate comprise a dry material and water, wherein the mass ratio of the dry material to the dry material is 0.58:1.

the dry material comprises the following components in parts by weight: 65 parts of fly ash, 3 parts of tailing sand, 1 part of sludge, 3 parts of concrete waste, 4 parts of desulfurized gypsum, 12 parts of cement, 15 parts of lime, 0.4 part of foam stabilizer, 0.7 part of dispersant and 0.7 part of aluminum paste.

Test example

The test example tests the performances of the autoclaved aerated concrete slabs provided in examples 1 to 4 and the comparative example, and the specific test results can be seen in the following table 1:

TABLE 1

As can be seen from table 1, the autoclaved aerated concrete slabs provided in embodiments 1 to 4 of the present invention use slag as a main raw material, so that the slabs are gray white, have substantially the same color as sand aerated autoclaved aerated concrete slabs, have a compressive strength significantly higher than that of common gray aerated concrete slabs, and have the advantages of low water absorption rate, etc.

The above description is only for the convenience of understanding the technical solutions of the present invention by those skilled in the art, and is not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The concrete raw material is characterized by comprising a dry material and water, wherein the mass ratio of the water to the dry material is 0.56-0.65:1;

the dry material comprises the following components in parts by weight:

wherein the mass percent of carbon in the slag is 8-10%, and the slag is subjected to carbon reduction treatment when the concrete raw material is used for preparing the autoclaved aerated concrete plate.

2. The concrete raw material according to claim 1, wherein the slag comprises the following components in percentage by mass: 8 to 10 percent of carbon, 5 to 7 percent of calcium oxide, 6 to 8 percent of calcium carbonate and the balance of silicon dioxide.

3. The concrete raw material according to claim 1, wherein the tailings sand comprises the following components in percentage by mass: 1% -5% of alumina, 2% -18% of ferric oxide and 60% -74% of silicon dioxide;

4. The concrete raw material as claimed in claim 1, wherein the concrete waste comprises the following components in percentage by mass: 0-30% of alumina, 0-30% of ferric oxide and 30-60% of silicon dioxide.

5. The concrete raw material as claimed in claim 1, wherein the micro fibers are selected from at least one of polypropylene monofilament fibers, cellulose fibers, basalt fibers, glass fibers;

6. The preparation method of the autoclaved aerated concrete plate is characterized by comprising the following steps: preparing a raw material slurry using the concrete raw material according to any one of claims 1 to 5; wherein the preparing the raw material slurry comprises: mixing slag and water and preparing the slag slurry through wet grinding, wherein the slag slurry comprises slag ash and water, and the slag slurry is subjected to carbon reduction treatment so that the mass percent of carbon in the slag ash is less than or equal to 3%;

7. The preparation method of the autoclaved aerated concrete plate according to claim 6, wherein the preparation of the raw material slurry further comprises:

8. The preparation method of the autoclaved aerated concrete slab as set forth in claim 6, wherein the static curing comprises:

9. The method for preparing an autoclaved aerated concrete slab as claimed in claim 6, wherein the autoclave curing comprises:

the boosting maintenance comprises the following steps: and (2) conducting air guide and pressure boosting on the autoclave, wherein slow air inlet is maintained within 40 minutes of an air guide and pressure boosting stage, the flow of steam inlet air is 500 kg, and the inlet air is gradually increased in stages after the air guide and pressure boosting stage is carried out for 40 minutes, and the method comprises the following steps: the steam enters 1000 kilograms of air flow and enters 30 minutes; the steam enters the air flow of 2000 kg and the air enters the air for 30 minutes; steam flows into 3000 kg and enters for 30 min; the steam inlet flow is 4000 kilograms, and the air inlet is 30 minutes; before the internal pressure of the still kettle reaches 0.5MPa, keeping the steam inlet flow less than or equal to 6000 kilograms; and controlling the pressure rise time when the internal pressure of the still kettle rises to the target pressure within 4-4.5 hours;

the constant pressure maintenance comprises: the target pressure is maintained for 8 hours to 10 hours, and condensed water is discharged every hour during constant pressure.

10. An autoclaved aerated concrete panel, characterized in that the autoclaved aerated concrete panel is prepared from the concrete raw material according to any one of claims 1 to 5, or the method for preparing the autoclaved aerated concrete panel according to any one of claims 6 to 9.