阅读说明：本技术 延缓快速生石灰消解的石灰改性剂、方法、改性生石灰、蒸压加气混凝土砌块及其制备方法 (Lime modifier and method for delaying rapid quicklime digestion, modified quicklime, autoclaved aerated concrete block and preparation method thereof ) 是由 李小军 陈强娃 马永东 王勇 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种延缓快速生石灰消解的石灰改性剂、方法、改性生石灰、蒸压加气混凝土砌块及其制备方法,改性剂的原料配方包括：三乙醇胺和水,三乙醇胺与水的质量份数比为1：(10～500)。本实施例中的延缓快速生石灰消解的石灰改性剂及方法,对快速生石灰进行调节,延缓快速生石灰与水接触后发生反应的速度,使得快速生石灰的消解速度延长,得到改性生石灰,改性生石灰中的A-CaO含量相对较低,且价格相对中速生石灰低,改性生石灰消解平稳达到延长快速生石灰消解的效果,利于在蒸压加气混凝土砌块生产中保证料浆稠化速度与铝粉发气速度的相互适应,稳定了蒸压加气混凝土砌块的生产工艺,能够平稳控制生产质量,提升产品合格率。(The invention discloses a lime modifier for delaying rapid quicklime digestion, a method, modified quicklime, an autoclaved aerated concrete block and a preparation method thereof, wherein the raw material formula of the modifier comprises the following components: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: (10-500). In the embodiment, the lime modifier and the method for delaying quick lime digestion delay the quick lime, the reaction speed of the quick lime after the quick lime contacts water is delayed, the digestion speed of the quick lime is prolonged, the modified lime is obtained, the A-CaO content in the modified lime is relatively low, the price is relatively low compared with that of medium-speed lime, the digestion of the modified lime stably achieves the effect of prolonging the digestion of the quick lime, the mutual adaptation of the slurry thickening speed and the aluminum powder gas generating speed in the production of autoclaved aerated concrete blocks is facilitated, the production process of the autoclaved aerated concrete blocks is stabilized, the production quality can be stably controlled, and the product percent of pass is improved.)

1. A lime modifier for delaying quick lime digestion is characterized in that the raw material formula comprises: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: (10-500).

2. A method for delaying quick lime digestion is characterized by comprising the following steps:

the lime modifier disclosed in claim 1 is added into quick quicklime to delay the quick quicklime digestion to obtain modified quicklime, wherein the addition amount of the lime modifier is 0.005-0.3% of the mass of the quick quicklime.

3. The method for delaying rapid quicklime digestion according to claim 2, wherein the lime modifier is added at a faster rate when the rapid quicklime digestion is fast than when the rapid quicklime digestion is slow.

4. The method for delaying the digestion of quick lime according to claim 2, wherein the grain size of the quick lime is 100 mesh or more.

5. A modified quicklime, characterized in that it is prepared by the method of any one of claims 2 to 4.

6. The autoclaved aerated concrete block is characterized by comprising the following raw materials: 5-25 wt% of cement, 5-25 wt% of modified quicklime as described in claim 5, 2-6 wt% of gypsum, 0.07-0.12 wt% of aluminum powder, 50-75 wt% of fly ash and the balance of water.

7. The preparation method of the autoclaved aerated concrete block as set forth in claim 6, characterized in that the raw material formulation in the preparation method of the autoclaved aerated concrete block is according to the raw material formulation as set forth in claim 6, and the preparation method comprises the following steps:

1) mixing fly ash and water to obtain fly ash mortar, and mixing gypsum and water to obtain gypsum slurry;

2) mixing fly ash mortar, the modified quicklime as claimed in claim 5, cement and gypsum slurry, adding aluminum powder, and casting;

3) and then carrying out static curing, cutting and autoclaved curing to obtain the autoclaved aerated concrete block.

8. The preparation method of the autoclaved aerated concrete block according to claim 7, wherein in the step 1), the diffusivity of the fly ash mortar is 22-45 cm, the temperature of the fly ash mortar is 10-40 ℃, and the specific gravity of the gypsum slurry is 1.4-1.6 kg/L.

9. The preparation method of the autoclaved aerated concrete block according to claim 7, wherein the pouring temperature in the step 2) is 30-60 ℃, and the pouring diffusivity is 12-26 cm.

10. The preparation method of the autoclaved aerated concrete block according to claim 7, wherein in the step 3), the static curing temperature is 50-60 ℃, the static curing time is 1-2.5 hours, and cutting is performed when the surface hardness of the blank obtained by static curing is 450-500N.

11. The preparation method of the autoclaved aerated concrete block according to claim 7, wherein the autoclave curing in the step 3) is performed under saturated steam pressure at a temperature of 178-207 ℃, and the steam pressure is 1.1-1.5 MPa.

12. The preparation method of the autoclaved aerated concrete block according to claim 7, wherein the autoclaved curing in the step 3) is performed in a steam curing kettle, the evacuation time is 15-30 minutes after the autoclaved curing kettle is entered, the pressure rise is performed for 0-0.2 MPa for 1-2 hours, the manual drainage is performed once at 0.1-0.3 MPa, the manual drainage is performed once at 0.2-0.5 MPa for 1-2 hours, the pressure rise is performed for 0.5-1.1 MPa for 0.5-1 hours, the pressure is kept at a constant pressure for 2-6 hours, and the pressure is released for 1-3 hours.

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to a lime modifier and a method for delaying rapid quicklime digestion, modified quicklime, an autoclaved aerated concrete block and a preparation method thereof.

Background

The autoclaved aerated block concrete is a novel light porous building material, and has the advantages of light weight, good heat preservation, processability, no combustion and the like. The light porous silicate product is produced by taking cement, quicklime and fly ash as main raw materials, adding a foaming agent, and carrying out the processes of proportioning, stirring, pouring, static curing, cutting, autoclaved curing and the like.

In the production of autoclaved aerated block concrete, the slaking speed of quicklime has great influence on the pouring stability, and in the process of producing the block by aerated concrete equipment, the used quicklime is mainly divided into two types, one type is planar and can be directly used; one is in block form. Main component CaCO of quicklime₃After high-temperature calcination, the quicklime is decomposed to release CO₂However, the sintered quicklime mainly contains CaO as a chemical component and also contains a small amount of MgO and Fe₂O₃And SiO₂And the like. Due to CaCO during calcination₃Often not very safe, the quicklime often contains undecomposed CaCO₃And other compounds. Therefore, the quicklime composition can be divided into two parts: from CaCO₃The decomposed CaO in a free state (non-dead burning) is an active part and is an active ingredient participating in a hydrothermal synthesis reaction in the aerated concrete, so the CaO is also called as effective calcium oxide (expressed by A-CaO);the other part being a non-reactive part, comprising non-decomposed CaCO₃Dead burned CaO, etc., which does not participate in the reaction with water at the time of casting. According to the digestion speed, the quicklime can be divided into: quick lime with digestion speed within 10 min; quick lime with a digestion speed of 10-30min is added at a medium speed; slowly producing lime, wherein the slaking speed is more than 30 min. Digestion rate refers to the time to reach maximum temperature when the sample of lime is digested in a standard container. Factors influencing the quicklime digestion speed are mainly the calcination temperature and time of the quicklime. In general, normalized lime (calcination temperature 800-; the burnt lime (the calcining temperature is 1200-1400 ℃) is slow lime; and the content of A-CaO and the digestion temperature of the lime which is short of fire are lower. The quicklime is mainly used in the steel industry, the sugar industry, the calcium carbide production, the chlor-alkali production, the building industry, the agriculture, the forestry, the environmental sanitation industry and the like, the manufacturing industry mainly uses the quick quicklime as the main material, the proportion is 75-90 percent, because of the restriction of the using range and the limitation of the production regionality, the quicklime manufacturing enterprises mainly use the quick quicklime as the main material, the annual quantity of the medium-speed quicklime and the slow-speed quicklime is less and the price is higher, so that the market is not good, the temperature required by the production of the quick quicklime is low, the burning time is short, meanwhile, the usage amount of fuel coal is correspondingly lower than that of the medium-speed quicklime and the slow-speed quicklime, the environmental protection responsibility of the manufacturing enterprises is that the waste gas discharge treatment reaches the standard, the quicklime manufacturing enterprises more wish to produce the quick lime with lower production, the quick quicklime is purchased for production in order to reduce the production cost.

In the production of aerated concrete, quicklime is required to ensure the mutual adaptation of the slurry thickening speed and the aluminum powder gas forming speed, and generally, medium-speed quicklime is better for producing aerated concrete gas blocks. The content of A-CaO in the quicklime is a component directly participating in hydration reaction, so the higher the requirement is, the better the requirement is. However, the content of A-CaO in the medium-speed quicklime is relatively low, and the price is high, so that the wide application of the medium-speed quicklime is restricted.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a lime modifier and a method for delaying the digestion of quick quicklime, modified quicklime, an autoclaved aerated concrete block and a preparation method thereof.

The technical scheme adopted for solving the technical problem of the invention is to provide a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: (10-500). According to the digestion speed, the quicklime can be divided into: quick lime with digestion speed within 10 min; quick lime with a digestion speed of 10-30min is added at a medium speed; slowly producing lime, wherein the slaking speed is more than 30 min.

The invention also provides a method for delaying quick quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.005-0.3% of the mass of the quick quicklime.

The content of calcium oxide in the quick lime is not lower than 80mas percent, and the digestion temperature is not lower than 80 ℃.

The content of calcium oxide in the modified quicklime is not lower than 80 mas%, and the digestion temperature is not lower than 70 ℃.

Preferably, the lime modifier is added at a faster rate when the rapid quicklime digestion rate is fast than when the rapid quicklime digestion rate is slow.

Preferably, the particle size of the quick quicklime is 100 mesh or more.

Preferably, the quick quicklime is ground by a ball mill after being ground by a grinder, and the ground grain size is 25 +/-10% of the residual amount of a 0.008 square-hole sieve.

Preferably, the lime modifier is added into the quick quicklime within 1-10 minutes of the digestion range of the quick quicklime. Specifically, the lime modifier is uniformly added into the quick quicklime at a feed opening of a lime ball mill.

Preferably, the digestion time of the modified quicklime is 10-30 minutes.

The invention also provides modified quicklime which is prepared by the method.

The invention also provides an autoclaved aerated concrete block which comprises the following raw materials: 5 to 25 weight percent of cement, 5 to 25 weight percent of the modified quicklime, 2 to 6 weight percent of gypsum, 0.07 to 0.12 weight percent of aluminum powder, 50 to 75 weight percent of fly ash and the balance of water.

The invention also provides a preparation method of the autoclaved aerated concrete block, wherein the raw material formula in the preparation method of the autoclaved aerated concrete block is as follows, and the preparation method comprises the following steps:

1) mixing fly ash and water to obtain fly ash mortar, and mixing gypsum and water to obtain gypsum slurry;

2) mixing fly ash mortar, the modified quicklime, cement and gypsum slurry, and adding aluminum powder for pouring;

3) and then carrying out static curing, cutting and autoclaved curing to obtain the autoclaved aerated concrete block.

Preferably, the diffusivity of the fly ash slurry in the step 1) is 22-45 cm, the temperature of the fly ash slurry is 10-40 ℃, and the specific gravity of the gypsum slurry is 1.4-1.6 kg/L.

Preferably, the fly ash mortar is added into a pouring stirring tank, cement and gypsum slurry are added, modified quicklime is added and stirred for 30-180 s, then aluminum powder is added and stirred for 20-60 s, then the mixture is poured into a mold box, and the distance between the slurry level after pouring and the edge of the top end of the mold box is 15-42 cm.

Preferably, the casting temperature in the step 2) is 30-60 ℃, and the casting diffusivity is 12-26 cm.

Preferably, in the step 3), the static curing temperature is 50-60 ℃, the static curing time is 1-2.5 hours, and cutting is carried out when the surface hardness of the blank obtained by static curing is 450-500N.

Preferably, the steam pressure curing in the step 3) is performed under saturated steam pressure at the temperature of 178-207 ℃, and the steam pressure is 1.1-1.5 MPa.

Preferably, the steam curing in the step 3) is performed in the steam curing kettle, the emptying time is 15-30 minutes after the steam curing kettle enters the steam curing kettle, the pressure is increased by 0-0.2 MPa for 1-2 hours, manual drainage is performed once at 0.1-0.3 MPa, manual drainage is performed once at the pressure increased by 0.2-0.5 MPa for 1-2 hours, the pressure increased by 0.5-1.1 MPa for 0.5-1 hour, the pressure is constant for 2-6 hours, and the pressure is released for 1-3 hours.

Preferably, the blank body cut from the building block of the floor skin is required to be placed for 30-240 minutes in front of the autoclave in order to ensure that the bottom sticking condition does not occur.

The lime modifier and the method for delaying quick lime digestion delay the quick lime digestion, which are disclosed by the invention, adjust the quick lime, delay the reaction speed of the quick lime after contacting with water, prolong the digestion speed of the quick lime to obtain the modified lime, wherein the A-CaO content in the modified lime is relatively low, the price is relatively low compared with that of the medium-speed lime, the digestion of the modified lime is stable to achieve the effect of prolonging the digestion of the quick lime, the mutual adaptation of the slurry thickening speed and the aluminum powder gas generating speed in the production of autoclaved aerated concrete blocks is favorably ensured, the production process of the autoclaved aerated concrete blocks is stabilized, the production quality can be stably controlled, the product qualification rate is improved, and the losses such as die collapse, gas cracks caused by asynchronous thickening and gas generating and cutting fracture caused by different hardness of blanks due to high pouring temperature caused by the too fast digestion of the quick lime in the prior art are avoided, reduces the waste materials in the production, has high quality qualification rate, and is used for environment-friendly novel manufacturing industry.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the present invention will be further described in detail with reference to the following detailed description.

The invention provides a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: (10-500).

The invention also provides a method for delaying quick quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.005-0.3% of the mass of the quick quicklime.

The quick quicklime produced in the prior art can not be returned to the kiln to be produced into medium-speed quicklime, and the purchase price of the quick quicklime is 10-20% lower than that of the medium-speed quicklime. The purity of the triethanolamine used in the invention is 99%, and the unit price of the industrial grade is 30 yuan/kg. The cost comparison of medium speed quicklime produced in the prior art and modified quicklime of the present invention is shown in table 1 below, analyzed according to the maximum addition of 0.3 mas% of lime modifier:

TABLE 1

The content of effective calcium oxide (A-CaO) in the modified quicklime is the same as that of the effective calcium oxide in the corresponding quick quicklime modified by the lime modifier, and is far higher than that of the effective calcium oxide in the medium-speed quicklime, but the price is lower than that of the medium-speed quicklime, and the digestion speed of the modified quicklime stably achieves the effect of prolonging the digestion of the quick quicklime.

Example 1

The embodiment provides a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: (10-500).

The embodiment also provides a method for delaying rapid quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.005-0.3% of the mass of the quick quicklime.

The content of calcium oxide in the quick lime is not lower than 80mas percent, and the digestion temperature is not lower than 80 ℃.

The content of calcium oxide in the modified quicklime is not lower than 80 mas%, and the digestion temperature is not lower than 70 ℃.

Preferably, the lime modifier is added at a faster rate when the rapid quicklime digestion rate is fast than when the rapid quicklime digestion rate is slow.

Preferably, the particle size of the quick quicklime is 100 mesh or more.

Specifically, the mass part ratio of triethanolamine to water in this example is 1: 100.

The embodiment provides a method for delaying quick lime digestion, the digestion time of quick lime is correspondingly prolonged by adding a lime modifier according to the condition that the digestion time of the quick lime is 1-8 minutes, the addition amount of the lime modifier required to be added is 0.005-0.3% of the mass of the quick lime, all the embodiments use the quick lime produced by the same factory, and the lime modifiers added in the following table 2 and the lime modifiers in the embodiments 5, 6 and 7 are all prepared according to the mass part ratio of triethanolamine to water of 1: 100.

The following experimental comparisons are made for the same batch of quicklime, the same batch of lime modifier data when no addition is made and the data when different proportions of addition are made as shown in table 2 below:

TABLE 2

As can be seen from Table 2, the addition of the lime modifier to quick lime delayed the quick lime digestion.

In the method for delaying rapid quicklime digestion in the embodiment, the length of the mold box is 4.2 meters, the height of the mold box is 0.65 meter, the width of the mold box is 1.25 meters, the digestion speed of the rapid quicklime is 2min, the digestion temperature is 95 ℃, the starting temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, and the ambient temperature is 27 ℃.

The embodiment also provides modified quicklime which is prepared by the method. The effective calcium oxide in the modified quicklime in this example is 90.86 mas%.

Example 2

The embodiment provides a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: 10.

the embodiment also provides a method for delaying rapid quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.005 percent of the mass of the quick quicklime.

The embodiment also provides modified quicklime which is prepared by the method.

In the embodiment, the digestion speed of the quick lime is 2min, the digestion temperature is 95 ℃, the starting temperature is 86 ℃, the effective calcium oxide is 90.86mas percent, and the environmental temperature is 27 ℃.

The digestion speed of the modified quicklime in the embodiment is 11.8min, the digestion temperature is 78 ℃, the starting temperature is 35.8 ℃, and the effective calcium oxide is 88.46 mas%.

Example 3

The embodiment provides a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: 500.

the embodiment also provides a method for delaying rapid quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.3 percent of the mass of the quick quicklime.

The embodiment also provides modified quicklime which is prepared by the method.

In the embodiment, the digestion speed of the quick lime is 2min, the digestion temperature is 95 ℃, the starting temperature is 86 ℃, the effective calcium oxide is 90.86mas percent, and the environmental temperature is 27 ℃.

The digestion speed of the modified quicklime in the embodiment is 14min, the digestion temperature is 77.8 ℃, the starting temperature is 35.5 ℃, and the effective calcium oxide is 87.98 mas%.

Example 4

The embodiment provides a lime modifier for delaying quick quicklime digestion, which comprises the following raw materials in formula: triethanolamine and water, wherein the weight part ratio of the triethanolamine to the water is 1: 250.

the embodiment also provides a method for delaying rapid quicklime digestion, which comprises the following steps:

and adding the lime modifier into the quick quicklime to delay the quick quicklime digestion to obtain the modified quicklime, wherein the addition amount of the lime modifier is 0.01 percent of the mass of the quick quicklime.

The embodiment also provides modified quicklime which is prepared by the method.

In the embodiment, the digestion speed of the quick lime is 2min, the digestion temperature is 95 ℃, the starting temperature is 86 ℃, the effective calcium oxide is 90.86mas percent, and the environmental temperature is 27 ℃.

The digestion speed of the modified quicklime in the embodiment is 10min, the digestion temperature is 79 ℃, the starting temperature is 37 ℃, and the effective calcium oxide is 88.98 mas%.

Example 5

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the fineness of the rapid quicklime is 20% of the residue after passing through a 0.008 square-hole sieve, the digestion speed of the rapid quicklime is detected for 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) This batch of quick lime uses the ball mill to grind, adds the lime modifier of 0.045% of quick lime quality through lime ball mill feed opening in grinding, and add in quick lime's digestion scope 1 ~ 10 minutes, the lime modifier is the lime modifier in embodiment 1, because the time of digesting the lime that the production autoclaved aerated concrete block used is most stable in 8 minutes and above, consequently the proportion of adding the lime modifier sets for 0.045mas in the experiment. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 10.8 minutes, the digestion temperature is 78.2 ℃, the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable, the later-stage pouring temperature is reduced, the gas generation speed of a green body is reduced, and the production is stable.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 10.88% of cement, 15% of modified quicklime, 6% of gypsum, 0.12% of aluminum powder, 60% of fly ash and the balance of water. The fly ash and water are stirred to obtain a gypsum slurry with the diffusivity of 34cm and the fly ash mortar temperature of 35 ℃, and the gypsum and the water are mixed to obtain the gypsum slurry with the specific gravity of 1.55 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 60 seconds, adding the aluminum powder, stirring for 40 seconds, pouring into a mold box, wherein the pouring temperature is 50 ℃, the pouring diffusivity is 17cm, and the distance between the poured slurry and the edge of the top end of the mold box is 32 cm.

4) And (3) conveying the mold box into a static maintenance room with the environment temperature of 50-60 ℃, wherein the static maintenance time is 90min, the cutting is carried out when the surface hardness of the blank is 450-500N, and the quality of the cut blank is not broken or has no inclined crack. The cut blank body is required to be placed for 2 hours before a steam curing kettle to ensure that the bottom sticking condition does not occur, the steam curing is performed under the saturated steam pressure at the temperature of 178-197 ℃, the steam pressure is 1.1-1.4 MPa, the evacuation time is 15 minutes after the blank body enters the steam curing kettle, the pressure is increased by 0-0.2 MPa for 1 hour, the manual drainage of 0.2MPa is performed once, the pressure increase time of 0.2-0.5 MPa is 1 hour, the manual drainage of 0.5-1.1 MPa is performed once, the pressure increase time of 0.5-1.1 MPa is 45 minutes, the pressure is maintained for 3 hours, the pressure is released for 1.5 hours, the condition that 3 circulations of the steam curing kettle can be carried out (1 kettle can produce 3 kettle products within 24 hours) is ensured, the strength of the steam-cured aerated concrete block discharged from the kettle is 5.2MPa, the quality is stable, the surface has no cracks, the strength is 5.7 MPa.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

The quicklime is the main calcareous material for producing aerated concrete, and the main function of the quicklime is to provide effective calcium oxide to react with SiO in siliceous materials under hydrothermal conditions₂、Al₂O₃The function is to generate hydrated calcium silicate, so that the product obtains strength, quicklime also provides gas forming condition of the aluminum powder, the aluminum powder is subjected to gas forming reaction, a large amount of heat release capacity is released when the quicklime is hydrated, a heat source is provided for aerated concrete slurry, the temperature of a blank can be raised to 80-90 ℃ in the blank hardening stage, further condensation and hardware formation of a cementing material in the blank are promoted, so that the strength of the blank is promoted to be rapidly improved, the volume of the quicklime expands about 44% when the quicklime is hydrated, for the levigated quicklime, most of the expansion process occurs within 30min after the hydration is started, therefore, the heat release and the volume expansion promote the hardening of the aerated concrete blank on one hand, and meanwhile, excessive heat release due to improper regulation and control is possible, the temperature is too high or the volume expansion occurs when the blank has certain strength and loses plasticity, causing cracking of the green body, etc. (by delaying the quicklime digestion time, the quicklime digestion time is best within 8-15 minutes, and the usage amount of the quicklime can play a role in adjusting the green body according to the usage amount range in the embodiment so as to avoid the green body from cracking)

In the production of aerated concrete, ground quicklime powder is generally adopted, but slaked lime is not suitable to be used. When slaking quicklime powder, a large amount of heat is released, the generation of hydrated gel is promoted, the control of the production process is facilitated, and the product quality is ensured. And the adoption of slaked lime greatly improves the water demand and can not provide the digestion heat. Therefore, the hardening of the green body is delayed, the good green body is not easy to form, the process control difficulty is increased, the product quality is reduced, and the quicklime digestion speed has great influence on the pouring stability of the aerated concrete in the production of the aerated concrete. At the initial stage of the aerated concrete slurry after casting, a large amount of aluminum powder is gasified, the slurry is slowly thickened, enough fluidity is kept, the foaming is smooth, and a good air pore structure is formed. Once the gas evolution is finished, the slurry is thickened rapidly to stabilize the bubbles and support the slurry to form a green body with certain strength.

The lime modifier and the method for delaying quick lime digestion in the embodiment adjust the quick lime, delay the reaction speed of the quick lime after contacting with water, prolong the digestion speed of the quick lime to obtain the modified lime, wherein the A-CaO content in the modified lime is relatively low, the price is relatively low compared with the medium-speed lime, the digestion of the modified lime stably achieves the effect of prolonging the digestion of the quick lime, are favorable for ensuring the mutual adaptation of the slurry thickening speed and the aluminum powder gas generating speed in the production of autoclaved aerated concrete blocks, stabilize the production process of the autoclaved aerated concrete blocks, can stably control the production quality, improve the product qualification rate, and avoid the loss of die collapse, gas hold-out cracks caused by asynchronous thickening and gas generating and cutting fracture caused by inconsistent blank hardness due to the high pouring temperature caused by the excessively quick lime digestion in the prior art, reduces the waste materials in the production, has high quality qualification rate, and is used for environment-friendly novel manufacturing industry.

Example 6

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the fineness of the rapid quicklime is 20% of the residue after passing through a 0.008 square-hole sieve, the digestion speed of the rapid quicklime is detected for 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) This batch of quick lime uses the ball mill to grind, adds the lime modifier of 0.045% of quick lime quality through lime ball mill feed opening in grinding, and add in quick lime's digestion scope 1 ~ 10 minutes, the lime modifier is the lime modifier in embodiment 1, because the time of digesting the lime that the production autoclaved aerated concrete block used is most stable at 7 minutes and above, consequently the proportion of adding the lime modifier sets for 0.045mas in the experiment. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 10.8 minutes, the digestion temperature is 78.2 ℃, the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable, the later-stage pouring temperature is reduced, the gas generation speed of a green body is reduced, and the production is stable.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 10.9% of cement, 15% of modified quicklime, 6% of gypsum, 0.1% of aluminum powder, 50% of fly ash and the balance of water. The fly ash and water are stirred to obtain a gypsum slurry with the diffusivity of 34cm and the fly ash mortar temperature of 35 ℃, and the gypsum and the water are mixed to obtain the gypsum slurry with the specific gravity of 1.55 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 60 seconds, adding the aluminum powder, stirring for 40 seconds, pouring into a mold box, wherein the pouring temperature is 48 ℃, the pouring diffusivity is 20cm, and the distance between the poured slurry and the top edge of the mold box is 28 cm.

4) And (3) conveying the mold box into a static maintenance room with the environment temperature of 50-60 ℃, wherein the static maintenance time is 110min, the cutting is carried out when the surface hardness of the blank is 450-500N, and the quality of the cut blank is not broken or has no inclined crack. The cut blank body is required to be placed for 2 hours before a steam curing kettle to ensure that the bottom sticking condition does not occur, the steam curing is performed under the saturated steam pressure at the temperature of 178-197 ℃, the steam pressure is 1.1-1.4 MPa, the evacuation time is 15 minutes after the blank body enters the steam curing kettle, the pressure is increased by 0-0.2 MPa for 1 hour, the manual drainage of 0.2MPa is performed once, the pressure increase time of 0.2-0.5 MPa is 1 hour, the manual drainage of 0.5-1.1 MPa is performed once, the pressure increase time of 0.5-1.1 MPa is 45 minutes, the pressure is maintained for 3 hours, the pressure is released for 1.5 hours, the condition that 3 circulations of the steam curing kettle can be carried out (1 kettle can produce 3 kettle products within 24 hours) is ensured, the strength of the steam-cured aerated concrete block discharged from the kettle is 4.1MPa, the quality is stable, the surface has no cracks, the strength is 4.8 MPa.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

Example 7

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the fineness of the rapid quicklime is 20% of the residue after passing through a 0.008 square-hole sieve, the digestion speed of the rapid quicklime is detected for 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) This batch of quick lime uses the ball mill to grind, adds the lime modifier of 0.045% of quick lime quality through lime ball mill feed opening in grinding, and add in quick lime's digestion scope 1 ~ 10 minutes, the lime modifier is the lime modifier in embodiment 1, because the time of digesting the lime that the production autoclaved aerated concrete block used is most stable at 7 minutes and above, consequently the proportion of adding the lime modifier sets for 0.045mas in the experiment. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 10.8 minutes, the digestion temperature is 78.2 ℃, the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable, the later-stage pouring temperature is reduced, the gas generation speed of a green body is reduced, and the production is stable.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 15% of cement, 12.91% of modified quicklime, 2% of gypsum, 0.09% of aluminum powder, 62% of fly ash and the balance of water. The fly ash and water are stirred to obtain a gypsum slurry with the diffusivity of 34cm and the fly ash mortar temperature of 35 ℃, and the gypsum and the water are mixed to obtain the gypsum slurry with the specific gravity of 1.55 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 60 seconds, adding the aluminum powder, stirring for 40 seconds, pouring into a mold box, wherein the pouring temperature is 45 ℃, the pouring diffusivity is 21.5cm, and the distance between the slurry after pouring and the edge of the top end of the mold box is 30 cm.

4) And (3) conveying the mold box into a static maintenance room with the environment temperature of 50-60 ℃, wherein the static maintenance time is 135min, the cutting is carried out when the surface hardness of the blank is 440-480N, and the quality of the cut blank is not broken or has no inclined crack. The cut blank body is required to be placed for 2 hours before a steam curing kettle to ensure that bottom sticking does not occur, steam pressure curing is performed under the saturated steam pressure at the temperature of 178-197 ℃, the steam pressure is 1.1-1.4 MPa, evacuation is performed for 15 minutes after the blank body enters the steam curing kettle, then pressure boosting is performed for 0-0.2 MPa for 1 hour, manual drainage is performed once at 0.2MPa, manual drainage is performed once at the pressure boosting time of 0.2-0.5 MPa for 1 hour, the pressure boosting time of 0.5-1.1 MPa is 45 minutes, constant pressure is performed for 3 hours, pressure relief is performed for 1.5 hours, 3 turnover of the steam curing kettle is ensured, the strength of the steam-cured aerated concrete block discharged from the kettle is 4.1MPa, the quality is stable, the surface has no cracks, the strength is increased to 4.8MPa after the blank body is placed for 15 days, and the surface of the steam-.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

Comparative example 1

The comparative example provides a preparation method of an autoclaved aerated concrete block, which is different from the preparation method of the autoclaved aerated concrete block in example 5 in that:

the raw material formula of the autoclaved aerated concrete block in the preparation method of the comparative example uses the quick quicklime instead of the modified quicklime, and the quick quicklime is the corresponding quick quicklime before the modified quicklime is modified in the example 5. The rapid quicklime was directly added to produce a block, and the rest was completely the same as in example 5.

The method is characterized in that the fineness of quicklime is measured to be 20% of the allowance of a 0.008 square-hole sieve on site, the digestion time of rapid quicklime is detected to be 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, the digestion process is violent in heat release, the prepared green body is quick in gas release, the edge collapse and the sinking occur, the internal stress damage of the green body is caused by quick moisture dissipation of the green body due to quick temperature rise, the stability of slurry is influenced, the forming is unstable, and the green body is broken and has more inclined cracks during.

Comparative example 2

The comparative example provides a preparation method of an autoclaved aerated concrete block, which is different from the preparation method in the example 6 in that:

the raw material formula of the autoclaved aerated concrete block in the preparation method of the comparative example uses the quick quicklime instead of the modified quicklime, and the quick quicklime is the corresponding quick quicklime before the modified quicklime is modified in the example 5. The rapid quicklime was directly added to produce a block, and the rest was completely the same as in example 6.

The method is characterized in that the fineness of quicklime is measured to be 20% of the allowance of a 0.008 square-hole sieve on site, the digestion time of rapid quicklime is detected to be 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, the digestion process is violent in heat release, the prepared green body is quick in gas release, the edge collapse and the sinking occur, the internal stress damage of the green body is caused by quick moisture dissipation of the green body due to quick temperature rise, the stability of slurry is influenced, the forming is unstable, and the green body is broken and has more inclined cracks during.

Comparative example 3

The comparative example provides a preparation method of an autoclaved aerated concrete block, which is different from that in example 7 in that:

the raw material formula of the autoclaved aerated concrete block in the preparation method of the comparative example uses the quick quicklime instead of the modified quicklime, and the quick quicklime is the corresponding quick quicklime before the modified quicklime is modified in the example 5. The rapid quicklime was directly added to produce a block, and the rest was completely the same as in example 7.

The fineness of the quick lime is measured to be 20% of the allowance of a 0.008 square-hole sieve on site, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas% when the quick lime is detected, the digestion speed is too high, the digestion process is violent in heat release, the prepared green body is quick in gas release, the edge collapse and the sinking occur, the internal stress damage of the green body is caused by quick moisture dissipation of the green body due to quick temperature rise, the stability of slurry is influenced, the forming is unstable, and the phenomena of breakage, inclined cracking and unstable quality occur during cutting.

Example 8

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the rapid quicklime with the grain size of 200 meshes is obtained through grinding and screening, the digestion speed of the rapid quicklime is detected for 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) The batch of quick lime is ground by using a ball mill, a lime modifier which accounts for 0.005 percent of the mass of the quick lime is added through a feed opening of the lime ball mill during grinding, the lime modifier is added within 1-10 minutes of the digestion range of the quick lime, the lime modifier is the lime modifier in the embodiment 2, and the digestion time of lime used for producing the autoclaved aerated concrete block is most stable within 7 minutes or more, so the proportion of adding the lime modifier in an experiment is set to be 0.005mas percent. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 11.8 minutes, the digestion temperature is 78 ℃, and the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable compared with that before modification, the later pouring temperature is reduced, the gas generation speed of a green body is reduced, and the production is stable.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 10% of cement, 5% of modified quicklime, 4% of gypsum, 0.12% of aluminum powder, 75% of fly ash and the balance of water. The fly ash and water are stirred to prepare gypsum slurry with the diffusivity of 22cm and the fly ash mortar temperature of 40 ℃, and the gypsum and the water are mixed to obtain the gypsum slurry with the specific gravity of 1.4 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 30 seconds, adding the aluminum powder, stirring for 20 seconds, pouring into a mold box, wherein the pouring temperature is 60 ℃, the pouring diffusivity is 26cm, and the distance between the poured slurry and the top edge of the mold box is 15 cm.

4) And (3) conveying the mold box into a static maintenance chamber with the environment temperature of 55 ℃, wherein the static maintenance time is 2 hours, the cutting is carried out when the surface hardness of the blank is 470N, and the quality of the cut blank is the inclined crack fracture condition. The cut blank body is required to be placed for 30min before a steam curing kettle to ensure that the bottom sticking condition does not occur, the steam curing is performed under the saturated steam pressure at the temperature of 178 ℃, the steam pressure is 1.1MPa, the evacuation time is 15 minutes after the blank body enters the steam curing kettle, the pressure is increased by 0.2MPa for 2 hours, the manual drainage of 0.2MPa is performed once, the pressure increasing time of 0.2MPa is 1 hour, the manual drainage is performed once, the pressure increasing time of 0.8MPa is 1 hour, the pressure is maintained for 6 hours at constant pressure, the pressure is released for 3 hours, the condition that the steam curing kettle can be turned over is ensured, the strength of the steam-cured aerated concrete block which is taken out of the kettle is 5.2MPa, the quality is stable, the surface has no cracks, the strength is increased to 5.7MPa after the blank body.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

Example 9

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the rapid quicklime with the grain size of 500 meshes is obtained through grinding and screening, the digestion speed of the rapid quicklime is detected for 2.5min, the digestion temperature is 91.5 ℃, the starting temperature is 80 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) The batch of quick lime is ground by using a ball mill, a lime modifier which accounts for 0.1% of the mass of the quick lime is added through a feed opening of the lime ball mill during grinding, the lime modifier is added within 1-10 minutes of the digestion range of the quick lime, the lime modifier is the lime modifier in the embodiment 3, and the digestion time of lime used for producing the autoclaved aerated concrete block is most stable within 7 minutes or more, so that the proportion of adding the lime modifier in an experiment is set to be 0.1 mas%. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 14 minutes, the digestion temperature is 77.8 ℃, the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable, the later-stage pouring temperature is reduced, the gas generation speed of a green body is reduced, and the stable production is ensured.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 25% of cement, 15% of modified quicklime, 2% of gypsum, 0.07% of aluminum powder, 50% of fly ash and the balance of water. Stirring fly ash and water to obtain a gypsum slurry with the diffusivity of 45cm and the fly ash mortar temperature of 30 ℃, and mixing gypsum and water to obtain the gypsum slurry with the specific gravity of 1.5 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 180 seconds, adding the aluminum powder, stirring for 40 seconds, pouring into a mold box, wherein the pouring temperature is 50 ℃, the pouring diffusivity is 18cm, and the distance between the poured slurry and the top edge of the mold box is 42 cm.

4) And (3) conveying the mold box into a static maintenance chamber with the environment temperature of 50 ℃, wherein the static maintenance time is 1h, the cutting is carried out when the surface hardness of the blank is 450N, and the quality of the cut blank is not broken or has no inclined crack. The cut blank body is required to be placed for 120 minutes before a steam curing kettle to ensure that the bottom sticking condition does not occur, steam pressure curing is performed under the saturated steam pressure at the temperature of 188 ℃, the steam pressure is 1.5MPa, evacuation is performed for 30 minutes after the blank body enters the steam curing kettle, then boosting is performed for 0MPa to 1 hour, manual drainage is performed once at 0.1MPa, boosting is performed for 2 hours at 0.4MPa, manual drainage is performed once at 0.5MPa, boosting is performed for 0.8 hour at 0.5MPa, constant pressure is performed for 4 hours, pressure relief is performed for 2 hours, the condition that the steam curing kettle can be turned over for 3 hours is ensured, the strength of the steam-cured aerated concrete block discharged from the kettle is 4.6MPa, the quality is stable, no crack exists on the surface, the strength is increased to 4.8MPa after the blank body is.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

Example 10

The embodiment provides a preparation method of an autoclaved aerated concrete block, which comprises the following steps:

1) the rapid quicklime is adopted on site, the rapid quicklime with the grain size of 800 meshes is obtained through grinding and screening, the digestion speed of the rapid quicklime is detected for 2min, the digestion temperature is 95 ℃, the initial temperature is 86 ℃, the effective calcium oxide is 90.86 mas%, the digestion speed is too high, and the heat release in the digestion process is severe.

2) The batch of quick lime is ground by using a ball mill, a lime modifier which accounts for 0.3% of the mass of the quick lime is added through a feed opening of the lime ball mill during grinding, the lime modifier is added within 1-10 minutes of digestion of the quick lime, the lime modifier is the lime modifier in the embodiment 4, and the digestion time of lime used for producing the autoclaved aerated concrete block is most stable within 7 minutes or more, so that the proportion of adding the lime modifier in an experiment is set to be 0.3 mas%. The fineness of the ground lime is 20%, the digestion time of the modified quicklime after the lime modifier is used is 10 minutes, the digestion temperature is 79 ℃, and the digestion time of the modified quicklime is prolonged compared with that before adjustment, so that the production is more stable, the later-stage pouring temperature is reduced, the gas generation speed of a green body is reduced, and the production is stable.

3) The autoclaved aerated concrete block is produced by using modified quicklime, and comprises the following components in percentage by weight, wherein the total weight of the base material is 100 percent: 5% of cement, 25% of modified quicklime, 6% of gypsum, 0.09% of aluminum powder, 60% of fly ash and the balance of water. The fly ash and water are stirred to prepare gypsum slurry with the diffusivity of 35cm and the fly ash mortar temperature of 30 ℃, and the gypsum and the water are mixed to obtain the gypsum slurry with the specific gravity of 1.6 kg/L. Adding the fly ash mortar into a pouring stirring tank, adding the modified quicklime, the cement and the gypsum slurry, stirring for 100 seconds, adding the aluminum powder, stirring for 60 seconds, pouring into a mold box, wherein the pouring temperature is 30 ℃, the pouring diffusivity is 12cm, and the distance between the poured slurry and the edge of the top end of the mold box is 30 cm.

4) And (3) conveying the mold box into a static maintenance chamber with the environment temperature of 60 ℃, wherein the static maintenance time is 2.5h, the cutting is carried out when the surface hardness of the blank is 500N, and the quality of the cut blank is not broken or has no inclined crack. The cut blank body is required to be placed for 240 minutes before a steam curing kettle to ensure that the bottom sticking condition does not occur, steam pressure curing is performed under the saturated steam pressure at the temperature of 207 ℃, the steam pressure is 1.3MPa, evacuation is performed for 20 minutes after the blank body enters the steam curing kettle, then pressure boosting is performed for 0.1MPa for 1.5 hours, manual drainage is performed for 0.3MPa once, manual drainage is performed for 1.5 hours at the pressure boosting time of 0.5MPa once, the pressure boosting time of 1.1MPa is 0.5 hour, constant pressure is performed for 2 hours, pressure relief is performed for 1 hour, the condition that the steam curing kettle can be turned over for 3 hours is ensured, the strength of the steam-cured aerated concrete block discharged from the kettle is 5.5MPa, the quality is stable, the surface has no cracks, the strength is increased to 6.1MPa after the blank body is placed for 15 days, the quality grade of the national standard BO.

The embodiment provides an autoclaved aerated concrete block which is prepared by the method.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.