CN110540435A

CN110540435A - autoclaved aerated concrete prepared by utilizing waste FCC catalyst and preparation method thereof

Info

Publication number: CN110540435A
Application number: CN201910929342.4A
Authority: CN
Inventors: 张童鑫; 马韵升; 史庆苓; 汪君华; 崔东波; 王明军; 胡建; 朱庆强; 赵春花
Original assignee: Shandong Jingbo Environmental Protection Material Co Ltd
Current assignee: Shandong Jingbo Environmental Protection Material Co Ltd
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2019-12-06

Abstract

The invention relates to the field of aerated concrete, in particular to autoclaved aerated concrete prepared by utilizing a waste FCC catalyst and a preparation method thereof. According to the invention, the autoclaved aerated concrete product is prepared by optimizing and improving the formula and pulping and grinding the waste FCC catalyst to meet certain process requirements, the effective components of the autoclaved aerated concrete product are fully utilized to participate in hydration reaction, and the active components have the adjusting effect on the cementing material, so that the performance of the aerated concrete product is brought into full play, the resource utilization of the waste FCC catalyst is maximized, the circular economic clean production is realized, the land is saved, and the concrete product with excellent performance is obtained, and the autoclaved aerated concrete product is worthy of wide popularization and use.

Description

autoclaved aerated concrete prepared by utilizing waste FCC catalyst and preparation method thereof

Technical Field

The invention relates to the field of aerated concrete, in particular to autoclaved aerated concrete prepared by utilizing a waste FCC catalyst and a preparation method thereof.

Background

spent FCC catalyst is a solid waste produced during the most important secondary processing of the oil refining industry. With the upgrading and deterioration of petroleum resources, the quality of raw materials is worse and worse, the catalyst replacement period is obviously shortened, the amount of discharged waste FCC catalyst is also increased year by year, and most of the waste FCC catalyst cannot be reused. At present, the landfill method is mostly adopted to treat the waste FCC catalyst in China, but the main components of the waste FCC catalyst are Al2O3, SiO2 and certain amount of metal oxides such as Ca, Fe, Mg and the like. Therefore, such practices not only occupy a large amount of land resources, but also waste resources.

Although the current approaches for recycling the FCC catalyst have been developed, the application scope is still narrow, the consumption of the FCC catalyst is low, and the like, and there is still a need to develop a new more efficient and more cyclic economic approach for reducing the FCC catalyst and the adverse impact on the environment caused by the FCC catalyst.

The rock wool is made up by using basalt and other natural ore as main raw material through the processes of high-temp. melting and forming fibre, and possesses excellent heat-insulating property, convenient construction and installation and obvious energy-saving effect, so that it is a high-quality heat-insulating material with low heat conductivity, and possesses good tensile strength, heat-insulating property and corrosion-resisting property, and is not easy to burn, so that it is extensively used. However, the waste heat-insulating rock wool generated in the process of maintenance and technical improvement of the industrial production device is difficult to degrade, so that large-area waste rock wool is piled for a long time, occupies land resources, or is dumped and buried in a large amount, and serious environmental pollution is caused. However, the rock wool is light in weight, small in heat conductivity coefficient and excellent in heat preservation performance.

Disclosure of Invention

in order to overcome the technical defects, the inventor titrates the chemical components of the waste FCC catalyst, and finds that the main chemical components of the waste FCC catalyst comprise Al2O3 which is more than or equal to 40 percent, SiO2 which can replace partial silicon-containing tailing sand, and metal ions such as Ca, Fe, Mg and the like and negative ions such as sulfate radical and the like. The reaction principle of the autoclaved aerated concrete is that Ca (OH)2, SiO2 and Al2O3 are subjected to hydration synthesis reaction under saturated vapor pressure to generate calcium silicate hydrate and calcium aluminate hydrate, so that the strength of the product is generated; the calcium sulfate formed by combining calcium ions and sulfate radicals has the same components as desulfurized gypsum and can be used as a regulating material for reaction. Therefore, the doping of the waste FCC catalyst can be used as part of raw materials to participate in the reaction, and can be used as a regulator to respectively regulate the gas generation and thickening speeds of the aluminum powder paste and the cementing material, so that the gas generation and thickening speeds of the blank are consistent, the production is stable, and the drying shrinkage value of the product is greatly reduced on the basis of meeting the product strength. The method can digest a large amount of deactivated catalyst, save cultivated land, protect environment, utilize a large amount of industrial waste residue, and has great significance of environmental protection and waste utilization.

therefore, aiming at the characteristics of low activity, difficult treatment and excellent performance of the waste FCC catalyst, the invention provides a method for preparing autoclaved aerated concrete by recycling the waste FCC catalyst by combining the characteristics of light weight, small heat conductivity coefficient, excellent heat preservation performance and the like of rock wool. Compared with the conventional autoclaved aerated concrete, the method has the advantages that part of the waste FCC catalyst is added, and part of the silicon-containing tailing sand can be replaced by optimizing the process and adjusting the proportion, so that part of the raw material cost is reduced, and the utilization value of the waste FCC catalyst is maximized.

The autoclaved aerated concrete prepared by utilizing the waste FCC catalyst comprises the following raw materials in parts by weight: 36-52 parts of silicon-containing tailing sand, 10-13 parts of lime, 11-14 parts of cement, 5-6 parts of desulfurized gypsum, 6-8 parts of waste FCC catalyst, 0.15-0.20 part of aluminum powder paste, 10-15 parts of furnace slag and 5-10 parts of waste rock wool fiber.

The autoclaved aerated concrete prepared by the formula has the average dry density of 480-3 kg/m, the average compressive strength of 4.0-4.5MPa, the single-group minimum value of 3.3-3.6MPa, the dry shrinkage value of 0.20-0.30mm/m by a standard method and the thermal conductivity of 0.10-0.11W/(m.k).

the inventor further discloses a preparation method of the autoclaved aerated concrete prepared by using the waste FCC catalyst, which comprises the following specific steps:

1) Adding water into the silicon-containing tailing sand according to the proportion, mixing, simultaneously adding furnace slag and treated waste rock wool fiber into the mixture, and grinding the mixture to a specified fineness by a wet ball mill to obtain silicon-containing tailing mortar;

Crushing the lime blocks with the proportion by a jaw crusher, and then grinding the crushed lime blocks into lime powder with certain fineness by a dry ball mill;

Uniformly mixing the desulfurization gypsum and the waste FCC catalyst in proportion, adding water, and wet-grinding to prepare mixed slurry with certain fineness;

adding water into the aluminum powder paste according to the proportion and uniformly stirring to obtain aluminum powder paste slurry;

2) adding the silicon-containing tailing mortar and the mixed slurry obtained in the step 1) into a pouring stirrer to be stirred, controlling the temperature to be about 35 ℃, then sequentially discharging cement and lime powder into the pouring stirrer to be stirred for 40-45s, controlling the temperature to be 38-39 ℃, finally adding the aluminum powder paste slurry, uniformly stirring for 20-30s, pouring, controlling the pouring temperature to be 40-45 ℃, finishing by a bubble finishing machine, and then feeding into a pre-curing chamber, controlling the temperature in the chamber to be 45-50 ℃, controlling the humidity in the chamber to be 60-70%, and controlling the pre-curing time to be 150-180 min;

3) demoulding and cutting the blank after the precuring to obtain a blank with required specification, putting the blank into a steam curing kettle for high-temperature high-pressure steam curing for 11-12 hours, taking the blank out of the kettle, sampling and detecting, packaging the blank into a warehouse, stacking the blank in stages, and naturally curing for 10 days to obtain a finished product;

in the step 1), the adding amount of water in the silicon-containing tailing mortar is 61-72% of the mass of the silicon-containing tailing sand, and the density of the final silicon-containing tailing mortar is 1580-1620kg/m 3;

The siliceous tailings have too high density, thick slurry, difficult transportation, large equipment loss and easy uneven stirring of the slurry; the siliceous tailings sand has the advantages of over-low density, thinner slurry, unavailable viscosity, easy sedimentation, relatively large using amount of each mold, limited storage amount, obvious reduction of production efficiency, improvement of labor amount of preparation personnel and certain influence on pre-curing gas evolution of blanks. The particle size of the siliceous tailing sand requires 25 to 30 percent of the residue of a square-hole sieve with 0.080mm, the particle size is too large, the specific surface area of the siliceous tailing sand is small, the amount of silicon dioxide participating in the reaction is small, and the product strength is influenced by the sedimentation, delamination and the like of the product; the particle size is too small, the energy consumption of equipment is high, the loss is large, the water demand is large, and slurry is sticky, so that the gas forming and thickening process of the slurry is influenced.

in the step 1), the fineness of the lime powder is 0.080mm, the residue of the square-hole sieve is not more than 20 percent of the powder, and the lime powder is too fine and is easy to agglomerate, so that the material is not uniform and the hydrothermal reaction depth is influenced; the fineness is too coarse, the specific surface area of the lime powder is small, the calcium oxide participating in the reaction is less, and the strength is influenced. The content of the effective calcium oxide in the lime powder is more than 75 percent, and the content of the effective calcium oxide is the mass percentage of the active free calcium oxide in the lime to the lime sample. The effective calcium oxide is calcium oxide which really participates in the reaction, the content is too low, namely the heat release is little when the effective calcium oxide reacts with water, the pre-curing time is prolonged, the hydrothermal reaction depth is influenced, and the product strength is influenced

the fineness of the mixed slurry in the step 1) is 0.080mm, the screen residue of the square-hole sieve is 20-25%, and the passivation layer on the surface of the catalyst is mainly removed to increase the specific surface area of the catalyst. The density of the mixed slurry is controlled to be 1450-1500kg/m3, and the excessive density is not beneficial to the transportation of the slurry; the density is too low, the pre-curing and gas-forming time is prolonged, and the physical strength is influenced.

in the step 1), the mass ratio of the aluminum powder paste to water is controlled to be 1:10, the water consumption is too low, and the aluminum powder paste is not uniformly stirred; the water consumption is excessive, the adding time is prolonged, the aluminum powder paste can react when contacting the slurry, the waste of the aluminum powder paste is caused, the total gas evolution of the aluminum powder paste in a green body is reduced, and the green body is not high in severe cases.

The pouring temperature mentioned in the step 2) is controlled to be 40-45 ℃, which is beneficial to the pouring process, so that the blank has a proper initial temperature, the pre-curing gas-forming time is shortened, and the blank is beneficial to forming a good air hole structure to ensure the strength. When the temperature is too high, the gas generation speed of the cast blank is too high, the gas is exhausted too early and too violent, the internal pore structure is seriously damaged, the collapse is serious, and even the mould is directly wasted.

in the pre-curing chamber, the aluminum powder paste generates hydrogen under an alkaline condition, and the hydrogen is uniformly filled and distributed in the pre-curing chamber under the shearing stress of the slurry, so that the aerated concrete has a porous structure; and simultaneously, cement in the slurry is hydrated and initially solidified, lime absorbs water, is digested and releases heat, so that the slurry is thickened, and the thickening speed of the slurry and the gas generating speed of the aluminum powder paste are synchronously carried out. In the pre-curing gas-forming process, the temperature of the center of the blank is higher due to the heat released by lime digestion, the temperature of the periphery of the blank is lower, the temperature in the pre-curing chamber is controlled to be 45-50 ℃, the temperature difference between the center and the periphery of the blank can be ensured to be small, and the cracking caused by temperature difference stress can be reduced. The pre-curing time is 150-180min, so that sufficient thickening and hardening time is ensured, only certain initial strength is reached, the product cannot collapse during turning over during cutting, the cut surface is uniform and attractive, and the defects of fish scale marks and the like are avoided; too hard blank body too long time also can appear cutting knife belting, appear cutting hole, lead to the appearance quality unqualified.

preferably, demolding and cutting are carried out after the precuring is finished to obtain a blank body with required specification and size; after the blank is cut, the blank is sent into a pre-kettle static curing chamber, the temperature is controlled to be 40-50 ℃, the humidity is 60% -70%, pre-kettle curing is carried out for 0-180min, heat and moisture loss in the blank is reduced, and temperature stress and dry-wet stress generated in the blank are avoided. And then, conveying the blank in the static curing chamber in front of the kettle into the steam curing kettle, if the steam curing kettle is not used for a long time, keeping the internal temperature low, properly introducing steam to increase the temperature in the steam curing kettle to 70-90 ℃, stopping introducing the steam, closing a kettle door and valves on the kettle, starting a vacuum pump, vacuumizing for 40-60min to-0.06 MPa, closing the vacuum pump, and continuously introducing the steam to heat up. Then, slowly raising the temperature in the autoclave to 130 ℃ at the speed of 20-25 ℃/h; and raising the temperature in the autoclave to 185-190 ℃ at the speed of 25-30 ℃/h, gradually raising the pressure from negative pressure to 1.1-1.2MPa along with the temperature, and keeping the constant temperature and the constant pressure for 5-6 hours to obtain the autoclaved aerated concrete with the density of below 500kg/m 3.

In the high-temperature high-pressure steam curing stage, redundant steam in the kettle can be led into other steam curing kettles or into the inverted air bag for storage, so that the steam utilization rate is improved, and the energy consumption is reduced. Residual gas which is not led out in the autoclave can be discharged to the outside, the gas is guided, and the process of discharging the residual gas needs 2 to 3 hours.

The silicon-containing tailing sand is mainly glass raw material ore dressing tailing and gold ore dressing tailing, the average SiO2 content is more than 85%, the main function of the silicon-containing tailing sand is to improve the content of silicon dioxide in slurry, and the silicon dioxide and calcium hydroxide participate in hydration reaction to generate calcium silicate hydrate to improve the product strength. The unreacted quartz particles as fine aggregate are jointed with the initial hydration product of the cementing material into a whole, are uniformly distributed in the product and play a role in supporting a framework. According to the parts by weight, the dosage of the silicon-containing tailing sand is generally 36-52 parts, the dosage is too low, the main reactant silicon dioxide is lacked, the content of the generated hydrated calcium silicate is low, and the product quality is seriously influenced; the use amount of the silicon-containing tailing sand is too high, namely the powder amount is reduced, the calcium-silicon ratio is reduced, the product strength is reduced, meanwhile, the reaction temperature in the blank body is low, the thickening is slow, the gas evolution is unstable, the maintenance time is long, and the pore structure in the product is damaged.

The spent FCC catalyst is a solid waste generated during the most important secondary process catalytic cracking process in the oil refining industry. The fineness is about 30 percent, the dried product is white powdery solid, the content of silicon dioxide is more than or equal to 35 percent, and the content of aluminum oxide is more than or equal to 40 percent. The silicoaluminate in the waste FCC catalyst is subjected to hydrothermal reaction in a high-temperature and high-pressure alkaline environment to generate CaO & SiO2 & nH2O and CaO & Al2O3 & nH2O, so that the product has strength. And because the calcium sulfate in the waste FCC catalyst can react with C3A in cement slurry to form a protective layer on the surface of C3A, the further hydration of C3A is prevented, the protective layer and the desulfurized gypsum play a role in retarding coagulation, the gas generation and thickening process of slurry is stabilized, the hardening of a green body in the static stopping process is accelerated, the compressive strength of a product is improved, and the shrinkage of the product is reduced, so that the waste FCC catalyst can replace part of silicon-containing tailing sand to be used for preparing autoclaved aerated concrete. In addition, because the surface substances of the waste FCC catalyst are inactivated to prevent the internal substances from fully reacting and reduce the reaction rate, the waste FCC catalyst and the desulfurized gypsum are jointly ground by a wet ball mill before use to achieve a certain process index and then prepare the autoclaved aerated concrete product, and the method not only removes the surface passivation layer of the waste FCC catalyst, improves the activity, increases the specific surface area, but also improves the uniformity and the integrity of the mixed slurry; the adding method does not need to increase equipment investment, improves production benefits while realizing solid waste utilization, realizes circular economic clean production, saves land, and is beneficial to improving product quality. According to the weight portion, the dosage of the waste FCC catalyst is generally 6-8 parts, the dosage is too much, and the substituted siliceous tailing sand is too much, so that the product quality is fluctuated, and the content of silicon dioxide in the waste FCC catalyst is lower; the consumption is too little, the cost of the raw materials of the product is increased, and the production benefit is reduced. The waste FCC catalyst is used for replacing part of siliceous tailings, so that the product shrinkage can be effectively reduced on the premise of ensuring the product quality.

the lime is medium-speed lime, the digestion time is 5-15min, the digestion temperature is 70-90 ℃, and the digestion temperature and time of the lime adopted by the invention ensure that the body thickening speed is consistent with the gas generation speed. The main function of the lime is to react with water to generate calcium hydroxide, and provide a main reactant to participate in hydrothermal reaction during autoclave curing to generate hydration products such as calcium silicate hydrate and the like so as to improve the strength of the product. The lime is digested in the early stage to release a large amount of heat, so that heat is provided for pre-curing hair-growing gas in the early stage of the blank, and the blank is promoted to be hardened into a die. According to the parts by weight, the lime consumption is generally controlled to be 10-13 parts, the lime consumption is too high, the lime releases too much heat in the early stage, the gas generation and thickening speeds are inconsistent, the exhaust is violent, the blank body is boiled when the exhaust is serious, the blank body structure is damaged, the waste mold is caused, and the production is not suitable to be controlled; the using amount is too low, the early reaction temperature of the blank is too low, the gas generation is slow, the thickening speed cannot be kept up with the thickening speed, the pre-curing time is prolonged, the content of hydration products in the later steam-pressure curing process is low, and the physical strength of the product is influenced.

The cement is P.O 42.5 ordinary Portland cement, and the hydration of the cement provides initial strength for the green body and ensures the normal densification of the green body. The tricalcium silicate in the cement, C-S-H gel precipitated during hydration of dicalcium silicate and Ca (OH)2 generate hydrothermal reaction in the later period, and the physical strength of the product is improved. According to the parts by weight, the using amount of the cement is generally controlled to be 11-14 parts, the using amount is too low, the early strength is increased too slowly, the green body collapses seriously, the internal structure of the green body is influenced, and the pre-curing time is prolonged; when the using amount is too high, the thickening hardness of the blank is too high, and phenomena of large air holes, air blocking, layered fracture and the like are easily caused in the blank.

the waste rock wool fiber is rock wool fiber with the length below 2mm and obtained by treating waste rock wool, the main components of the waste rock wool fiber are silicon dioxide and aluminum oxide, in the whole production process of the product, the rock wool fiber can be well fused with slurry and uniformly distributed in the slurry, in the process of autoclaved curing, the waste rock wool fiber can participate in hydration reaction, and can also be well drawn together with generated hydration products and silicon-containing tailing sand particles to form a whole body, so that the waste rock wool fiber plays a role in a skeleton, the internal structure tensile force is increased, the product strength is improved, meanwhile, the rock wool heat conductivity coefficient is small, the whole heat conductivity coefficient of the product can be reduced, and the heat insulation performance is improved. The dosage of the waste rock wool fiber is generally controlled to be 5-10 parts by weight, the dosage is too low, the product superiority brought by the rock wool is not obvious, the treatment amount is small, and the method is meaningless; when the amount is too high, the wet grinding process consumes much energy, or the pipeline can be blocked due to the fact that the stirring cannot be carried out.

the aluminum powder paste is GLS-65 oil solution type aluminum powder paste;

The desulfurized gypsum is a thermoelectric desulfurization byproduct, and is doped into the aerated concrete for the purposes of adjusting the cement setting time, inhibiting lime digestion, participating in aluminum powder gas-forming reaction, reducing blank shrinkage and the like.

the slag is industrial solid waste generated by a thermoelectric company, the main components of the slag comprise 30-40% of calcium ion and 35-43% of silicon, the slag can replace part of silicon-containing tailing sand to participate in hydration reaction, and the slag is light, so that the mortar is more uniform and light after the slag and the silicon-containing tailing sand are ground in proportion, and the mixing effect is better.

In conclusion, the invention adopts the waste FCC catalyst, the waste rock wool fiber, the silicon-containing tailing sand, the lime, the cement, the desulfurized gypsum and the aluminum powder paste as the main raw materials, and the waste FCC catalyst is utilized to the maximum extent possible by treating and adjusting the corresponding preparation process, thereby ensuring the normal operation of production. Compared with the conventional aerated concrete product, the indexes of the autoclaved aerated concrete prepared by the method, such as drying shrinkage performance, compressive strength, dry density and the like, are greatly improved. According to tests of GB 11969-2008 & ltautoclaved aerated concrete test method & gt and GB 6566 & lt2010 & ltradionuclide limit for building materials & gt, all indexes of the autoclaved aerated concrete obtained by the invention can meet the B05 grade requirement, and the autoclaved aerated concrete has the advantages of average dry density of 480 & lt/m & gt 3, average compressive strength of 4.0-4.5MPa, single-group minimum value of 3.3-3.6MPa, drying shrinkage value (standard method) of 0.20-0.30mm/m and heat conductivity coefficient of 0.10-0.11W/(m & k). According to the product grade judgment in GB11968-2006 autoclaved aerated concrete block, the autoclaved aerated concrete produced by adding the waste FCC catalyst completely meets the requirements of superior products (dry density is less than or equal to 500kg/m3, average compressive strength is more than or equal to 3.5MPa, single-group minimum value is more than or equal to 2.8MPa, and drying shrinkage value is less than or equal to 0.5mm/m) in quality, and the autoclaved aerated concrete has higher average compressive strength and lower drying shrinkage value. Compared with the common autoclaved aerated concrete, the autoclaved aerated concrete prepared by the invention has high compressive strength and small drying shrinkage value, is applied to heat-insulating wall materials, has a particularly remarkable effect, and has better earthquake resistance of buildings using the autoclaved aerated concrete.

Detailed Description

The present invention will be described in further detail with reference to the following examples, but it should not be construed that the scope of the above subject matter is limited to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention, and the following embodiments are all completed by adopting the conventional prior art except for the specific description.

Example 1

The waste FCC catalyst used in the invention is solid white powdery waste with ineffective activity after being recycled by the petrochemical company of our group, the main components of the waste FCC catalyst are silicon dioxide (about 37%) and aluminum oxide (about 45%), and the addition of the waste FCC catalyst can ensure the strength of the product, reduce the drying shrinkage value of the aerated concrete product and stabilize the application performance of the product.

the method for preparing the autoclaved aerated concrete by recycling the waste FCC catalyst is characterized by comprising the following steps: the raw materials by weight portion are: 40 parts of silicon-containing tailing sand, 8 parts of waste FCC catalyst, 12 parts of lime, 12 parts of cement, 5 parts of desulfurized gypsum, 0.15 part of aluminum paste, 15 parts of furnace slag and 8 parts of waste rock wool fiber;

the waste FCC catalyst is white powdery solid waste which loses activity after being recycled in the petrochemical industry of our group, and the main components of the waste FCC catalyst are silicon dioxide (about 37%) and aluminum oxide (about 45%);

The density of the autoclaved aerated concrete prepared by recycling the waste FCC catalyst is 485kg/m3, the average compressive strength is 4.0MPa, the single-group minimum value is 3.3MPa, and the drying shrinkage value is 0.2 mm/m.

The preparation method comprises the following specific steps:

Weighing the raw materials in proportion for later use;

adding water into the silicon-containing tailing sand, mixing, simultaneously adding slag and waste rock wool fibers which are processed (crushed, ground, screened, demagnetized, dedusted and the like) and meet the requirements, and grinding by a wet ball mill until the fineness (0.080mm standard sieve residue) is 26% to obtain silicon-containing tailing mortar;

Crushing the lime blocks by using a jaw crusher, and then grinding the crushed lime blocks to a certain fineness by using a dry ball mill to obtain lime powder; the fineness (the residue of a square-hole sieve with 0.080 mm) is 8.9 percent, the content of effective calcium oxide is 76.3 percent, the digestion time is 13.5min, and the digestion temperature is 72.8 ℃;

Uniformly mixing desulfurized gypsum and waste FCC catalyst according to a proportion, adding water, and wet-grinding to prepare mixed slurry with a certain fineness, wherein the fineness (0.080mm standard sieve residue) of the mixed slurry is 24%, and the volume weight is 1489kg/m 3;

Adding water into the aluminum powder paste, and uniformly mixing and stirring; the mass of the water is 10 times of that of the aluminum powder paste;

Adding the silicon-containing tailing mortar obtained in the step (2) and the mixed slurry obtained in the step (4) into a pouring stirrer to stir for 10s, controlling the temperature to be 35.5 ℃, then sequentially discharging cement and the lime powder obtained in the step (3) into the stirrer to stir for 40s, controlling the temperature to be 38 ℃, finally adding the mixed slurry prepared in the step (5), pouring after stirring for 30s, controlling the pouring temperature to be 42 ℃, finishing by using a bubble finishing machine, then feeding into a pre-curing chamber, controlling the temperature in the pre-curing chamber to be 46 ℃, controlling the humidity to be 65% and pre-curing for 180 min;

demoulding and cutting to obtain a blank body with required specification after precuring is finished (namely certain strength is achieved), then putting the blank body into a steam curing kettle for high-temperature high-pressure steam curing for 12 hours, taking out the blank body from the kettle, sampling and detecting, packaging and warehousing the broken plates, stacking the broken plates in a grading way, and naturally curing for 10 days to obtain a finished product;

the high-temperature high-pressure steam curing process in the step (7) comprises the following steps:

The cut blank body enters a pre-kettle static curing room to wait for entering the kettle, the indoor temperature is 45 ℃, the humidity is 63 percent, and pre-kettle curing is carried out for 180 min;

And (3) vacuumizing stage: feeding the mixture into a steam curing kettle from a static curing chamber, closing a kettle door and valves, starting a vacuum pump, vacuumizing for 40min to-0.06 MPa, and turning off the vacuum pump to start introducing steam for heating;

a temperature raising and pressure raising stage: slowly raising the temperature in the autoclave to 130 ℃ at the speed of 20-25 ℃/h; then the temperature in the autoclave is increased to 189 ℃ at the speed of 25-30 ℃/h; at the moment, the pressure in the kettle is 1.15 MPa;

And (3) a constant temperature and pressure stage: and (4) keeping the temperature and the pressure in the step (3), and keeping the temperature and the pressure for 6 hours.

and (3) cooling and depressurizing: and after the heat preservation and pressure maintenance are finished, the temperature is reduced to 90 ℃ at the speed of 35-45 ℃/h, the pressure in the kettle is reduced to normal pressure, and the high-temperature high-pressure steam curing process is finished.

Example 2

the method for preparing the autoclaved aerated concrete by recycling the waste FCC catalyst is characterized by comprising the following steps: the raw materials by weight portion are: 45 parts of silicon-containing tailing sand, 7 parts of a waste FCC catalyst, 13 parts of lime, 13 parts of cement, 5 parts of desulfurized gypsum, 0.15 part of aluminum paste, 12 parts of furnace slag and 5 parts of waste rock wool fiber;

The waste FCC catalyst is white powdery solid waste which loses activity after being recycled in petrochemical industry;

the density of the autoclaved aerated concrete prepared by recycling the waste FCC catalyst is 487kg/m3, the average compressive strength is 4.3MPa, the single-group minimum value is 3.4MPa, and the drying shrinkage value is 0.25 mm/m.

The preparation method comprises the following specific steps:

weighing the raw materials in proportion for later use;

adding water into the silicon-containing tailing sand, mixing, simultaneously adding furnace slag and waste rock wool fibers which are processed (crushed, ground, screened, demagnetized, dedusted and the like) and meet the requirements, and grinding by a wet ball mill until the fineness (0.080mm standard sieve residue) is 27% to obtain silicon-containing tailing mortar;

Crushing the lime blocks by using a jaw crusher, and then grinding the crushed lime blocks to a certain fineness by using a dry ball mill to obtain lime powder; 9.50 percent of screen residue of a square-hole sieve with the fineness of 0.080mm, 77.5 percent of effective calcium oxide, 11.5min of digestion time and 72 ℃;

uniformly mixing desulfurized gypsum and waste FCC catalyst (by weight) at a ratio of 1:1, adding water, and wet-grinding to prepare mixed slurry with a certain fineness, wherein the fineness (0.080mm standard sieve residue) of the mixed slurry is 24.6%, and the volume weight is 1493kg/m 3;

adding the silicon-containing tailing mortar obtained in the step (2) and the mixed slurry obtained in the step (4) into a pouring stirrer, stirring for 10s, controlling the temperature of the pouring stirrer to be 36 ℃, then sequentially discharging cement and the lime powder obtained in the step (3) into the stirrer, stirring for 40s, controlling the temperature to be 38.5 ℃, finally adding the mixed slurry prepared in the step (5), pouring after stirring for 30s, controlling the pouring temperature to be 41 ℃, finishing by using a bubble finishing machine, then feeding into a pre-curing chamber, controlling the temperature in the pre-curing chamber to be 48 ℃, the humidity to be 63% and the pre-curing time to be 175 min;

feeding the cut blank into a pre-kettle static curing room to wait for entering the kettle, and performing pre-kettle curing for 175min at the indoor temperature of 46 ℃ and the humidity of 63.7%;

and (3) vacuumizing stage: feeding the mixture into a steam curing kettle from a static curing chamber, closing a kettle door and valves, starting a vacuum pump, vacuumizing for 50min to-0.06 MPa, and turning off the vacuum pump to start introducing steam for heating;

A temperature raising and pressure raising stage: slowly raising the temperature in the autoclave to 130 ℃ at the speed of 20-25 ℃/h; then the temperature in the autoclave is increased to 190 ℃ at the speed of 25-30 ℃/h; at the moment, the pressure in the kettle is 1.19 MPa;

example 3

the method for preparing the autoclaved aerated concrete by recycling the waste FCC catalyst is characterized by comprising the following steps: the raw materials by weight portion are: 48 parts of silicon-containing tailing sand, 6 parts of waste FCC catalyst, 10 parts of lime, 11 parts of cement, 6 parts of desulfurized gypsum, 0.15 part of aluminum paste, 10 parts of furnace slag and 9 parts of waste rock wool fiber;

the density of the autoclaved aerated concrete prepared by recycling the waste FCC catalyst is 490kg/m3, the average compressive strength is 4.5MPa, the single-group minimum value is 3.6MPa, and the drying shrinkage value is 0.30 mm/m.

The preparation method comprises the following specific steps:

weighing the raw materials in proportion for later use;

Adding water into the silicon-containing tailing sand, mixing, simultaneously adding slag and waste rock wool fibers which are processed (crushed, ground, screened, demagnetized, dedusted and the like) and meet the requirements, and grinding by a wet ball mill until the fineness (0.080mm standard sieve residue) is 28% to obtain silicon-containing tailing mortar;

crushing the lime blocks by using a jaw crusher, and then grinding the crushed lime blocks to a certain fineness by using a dry ball mill to obtain lime powder; the screen residue of a square-hole sieve with the fineness of 0.080mm is 10.3 percent, the content of effective calcium oxide is 76.25 percent, the digestion time is 12min, and the digestion temperature is 73.5 ℃;

uniformly mixing desulfurized gypsum and waste FCC catalyst (by weight) at a ratio of 1:1, adding water, and wet-grinding to prepare mixed slurry with a certain fineness, wherein the fineness (0.080mm standard sieve residue) of the mixed slurry is 23.6%, and the volume weight is 1488kg/m 3;

Adding the silicon-containing tailing mortar obtained in the step (2) and the mixed slurry obtained in the step (4) into a pouring stirrer to stir for 10s, controlling the temperature to be 34.3 ℃, then sequentially discharging cement and lime powder obtained in the step (3) into the stirrer to stir for 40s, controlling the temperature to be 38.2 ℃, finally adding the mixed slurry prepared in the step (5), pouring after stirring for 30s, controlling the pouring temperature to be 42.4 ℃, finishing by using a bubble finishing machine, then entering a pre-curing chamber, controlling the temperature in the pre-curing chamber to be 49.5 ℃, the humidity to be 65% and the pre-curing time to be 170 min;

Feeding the cut blank into a pre-kettle static curing room to wait for entering the kettle, and performing pre-kettle curing for 170min at the indoor temperature of 44 ℃ and the humidity of 62%;

and (3) vacuumizing stage: entering a steam curing kettle from a static curing chamber, closing a kettle door and valves, starting a vacuum pump, vacuumizing for 55min to-0.06 MPa, closing the vacuum pump, and starting introducing steam to heat;

a temperature raising and pressure raising stage: slowly raising the temperature in the autoclave to 130 ℃ at the speed of 20-25 ℃/h; then the temperature in the autoclave is increased to 186 ℃ at the speed of 25-30 ℃/h; at the moment, the pressure in the kettle is 1.12 MPa;

The average value of B05 grade products in the embodiment is compared with the common B05 grade superior products on the market, and the following table is provided:

product name	³Average dry Density, kg/m3	average compressive strength, MPa	average shrinkage on drying, mm/m
				BO5 grade of the invention	490	4.5	0.25
general grade B05 super-grade product	498	3.6	0.35

The invention fully utilizes the characteristics of the waste FCC catalyst, prepares the waste FCC catalyst according to a certain process and adds the waste FCC catalyst to prepare the aerated concrete, and the solid waste catalyst in the product not only participates in hydration reaction, but also is used as an adjusting material to stabilize the gas generating thickening process. The product of the invention has high strength and small drying shrinkage value, the radioactivity meets the requirements of national standards, the waste FCC catalyst can be safely and efficiently recycled, and the method is worthy of popularization and application.

Claims

1. the autoclaved aerated concrete prepared by utilizing the waste FCC catalyst is characterized by comprising the following raw materials in parts by weight: 36-52 parts of silicon-containing tailing sand, 10-13 parts of lime, 11-14 parts of cement, 5-6 parts of desulfurized gypsum, 6-8 parts of waste FCC catalyst, 0.15-0.20 part of aluminum powder paste, 10-15 parts of furnace slag and 5-10 parts of waste rock wool fiber.

2. The autoclaved aerated concrete prepared by using the waste FCC catalyst as claimed in claim 1, wherein the average dry density is 480-kg/m 3, the average compressive strength is 4.0-4.5MPa, the single-component minimum value is 3.3-3.6MPa, the standard method dry shrinkage value is 0.20-0.30mm/m, and the thermal conductivity is 0.10-0.11W/(m.k).

3. a preparation method of autoclaved aerated concrete prepared by using a waste FCC catalyst is characterized by comprising the following specific steps:

1) Adding water into the silicon-containing tailing sand according to the proportion, mixing, simultaneously adding furnace slag and waste rock wool fibers, and grinding by a wet ball mill to obtain silicon-containing tailing mortar;

Grinding the lime with the proportion into lime powder;

Uniformly mixing the desulfurization gypsum and the waste FCC catalyst in proportion, adding water, and wet-grinding to prepare mixed slurry;

2) Adding the silicon-containing tailing mortar and the mixed slurry obtained in the step 1) into a pouring stirrer to be stirred, controlling the temperature of the pouring stirrer to be 35 ℃, then sequentially discharging cement and lime powder into the pouring stirrer to be stirred for 40-45s, controlling the temperature to be 38-39 ℃, finally adding the aluminum powder paste slurry, uniformly stirring for 20-30s, then pouring, finishing by a bubble finishing machine, and then feeding into a pre-curing chamber;

3) Demoulding and cutting to obtain a blank body after the precuring is finished, then putting the blank body into a steam curing kettle for high-temperature high-pressure steam curing for 11-12 hours, taking the blank body out of the kettle, packaging the blank plate, warehousing the packaged blank plate, stacking the packaged blank plate in a grading way, and naturally curing the blank plate for 10 days to obtain a finished product.

4. The method for preparing the autoclaved aerated concrete by using the waste FCC catalyst according to claim 3, wherein the amount of the water added into the silicon-containing tailing mortar in the step 1) is 61-72% of the mass of the silicon-containing tailing sand, and the density of the final silicon-containing tailing mortar is 1580-1620kg/m 3; the fineness of the mixed pulp is 0.080mm, the residue on a square-hole sieve is 20-25%, and the density of the mixed pulp is controlled at 1450-; the mass ratio of the aluminum powder paste to the water in the step 1) is controlled to be 1: 10.

5. the preparation method of the autoclaved aerated concrete prepared by utilizing the waste FCC catalyst according to claim 3, wherein the siliceous tailings sand has an average SiO2 content of more than 85%, and the particle size of the siliceous tailings sand requires 0.080mm square-hole sieve residue of 25-30%; in the step 1), the powder with the fineness of 0.080mm square-hole sieve residue not more than 20 percent is obtained, and the content of effective calcium oxide in the lime powder is more than 75 percent; the content of silicon dioxide in the waste FCC catalyst is more than or equal to 35 percent, and the content of aluminum oxide is more than or equal to 40 percent; the waste rock wool fiber is rock wool fiber with the length of below 2mm, which is obtained after the waste rock wool is treated; the main components of the slag comprise 30-40 percent of calcium ion and 35-43 percent of silicon.

6. the method for preparing autoclaved aerated concrete by using the waste FCC catalyst according to claim 3, wherein the casting temperature in the step 2) is controlled to 40-45 ℃.

7. The method for preparing autoclaved aerated concrete by using the waste FCC catalyst as claimed in claim 3, wherein the temperature in the pre-curing chamber is controlled at 45-50 ℃, the humidity is controlled at 60% -70%, and the pre-curing time is controlled at 150-.

8. the method for preparing autoclaved aerated concrete by using the waste FCC catalyst as claimed in claim 3, wherein the step 3) further comprises feeding the embryo into a pre-autoclave static curing chamber before entering the steam curing autoclave, controlling the temperature at 40-50 ℃ and the humidity at 60% -70%, and performing pre-autoclave curing for 0-180 min.

9. the preparation method of the autoclaved aerated concrete prepared by using the waste FCC catalyst according to claim 3, wherein the specific steps of high-temperature high-pressure steam curing in the step 3) are as follows: firstly, introducing steam to increase the temperature in the steam curing kettle to 70-90 ℃, stopping introducing the steam, closing a kettle door and valves on the kettle, starting a vacuum pump, vacuumizing for 40-60min to-0.06 MPa, closing the vacuum pump, continuously introducing the steam to increase the temperature, and then slowly increasing the temperature in the steam curing kettle to 130 ℃ at the speed of 20-25 ℃/h; and then the temperature in the autoclave is increased to 185-190 ℃ at the speed of 25-30 ℃/h, the pressure is gradually increased from negative pressure to 1.1-1.2MPa along with the temperature, and the constant temperature and the constant pressure are maintained for 5-6 hours.