CN106630801A - Baking-free brick, method for preparing same and raw materials for baking-free brick - Google Patents

Abstract

The invention provides a baking-free brick, a method for preparing the same and raw materials for the baking-free brick. The method for preparing the baking-free brick includes smashing black cotton soil and volcanic ash; forming ingredients from the smashed black cotton soil, the smashed volcanic ash, cement and calcium hydroxide according to proportions and uniformly grinding the ingredients; adding water into the ingredients and uniformly stirring the water and the ingredients to obtain mixtures; carrying out compression molding on the mixtures and aging the mixtures at the room temperature to obtain an initial green brick; curing the initial green brick in a steam curing kettle; cooling the initial green brick until the temperature of the initial green brick reaches the room temperature so as to obtain the baking-free brick. The baking-free brick, the method and the raw materials have the advantage that the baking-free brick prepared by the aid of the method is high in strength and low in water absorption and can be used a widely applied engineering building material.

Description

Preparation method of burn-free brick, burn-free brick and raw material of burn-free brick

technical field

The invention relates to the field of building materials, in particular to a method for preparing unburned bricks, unburned bricks and raw materials for unburned bricks.

Background technique

Since the reform of burning clay to make bricks in the Qin and Han Dynasties, the wall materials in our country have not changed substantially. For thousands of years, clay bricks have played an inestimable role in human life and production as the largest and most widely used building material. Clay bricks are refractory materials or strength materials made by firing clay as the main raw material. Its production raw materials are extensive and can be obtained locally. Although various new building materials have emerged in recent years, clay bricks are still widely used in many areas of our country, and they are still the main wall materials in our country, accounting for more than 90% of the total wall materials. Clay bricks have strong vitality, and the reasons why they have endured for thousands of years mainly include the following aspects:

First, the raw materials are plentiful and easy to obtain. Water and soil are gifts from nature. Wherever human beings live, there is water and soil;

Second, the process is simple, the technical requirements for firing bricks are low, and firing does not require special high temperatures;

Third, the performance is good, the clay brick is durable, beautiful and generous, and the physical performance is reliable;

In addition, due to low raw material requirements, low price, and simple production technology, brick products are cheap. However, the production of sintered clay bricks not only destroys cultivated land, pollutes the environment, and wastes energy, but also the clay bricks themselves are small in size, heavy in weight, and low in construction efficiency, which does not meet the requirements of high-rise buildings, on-site construction, and multifunctional building materials.

As our country pays more and more attention to the environment and resources, unburned bricks will replace sintered bricks and become the mainstream of wall materials. This is an irreversible trend. Compared with sintered bricks, unburned bricks have the following advantages:

1. Save land resources and utilize industrial waste. According to statistics, burning bricks consumes about 1 million mu of land every year, of which 20,000 mu are destroyed to make bricks, reducing grain production by nearly 80 million tons. There are about 110,000 brick and tile enterprises across the country, covering an area of more than 6 million mu.

2. Save energy consumption in production and protect the environment. The production of sintered clay bricks requires a large amount of coal and other fuels. Our country is relatively short of energy. Every year, a large part of our energy is used to produce sintered clay bricks. It takes 10,000 tons of standard coal to produce 1 billion solid clay bricks. Because the combustion of coal produces a large amount of waste residue and harmful gas at the same time, there are many brick and tile enterprises near the suburbs of the city. The smokestacks of the brick and tile factories produce a large amount of harmful gas, which seriously pollutes the air in the city and affects people's physical and mental health. .

3. The production process of unburned bricks is simple and the economic cost is low.

Compared with sintered bricks, unfired bricks use industrial waste slag as raw materials, and do not need sintering and steaming, so the production cost is lower than that of sintered bricks; the amount of "eating" slag is large, and the social and environmental benefits are outstanding; the edges and corners are neat, the size is standard, The compressive strength is higher than 7.5MPa; the density is high, the water absorption is small, and the durability is good. Overall, its product quality and overall performance are not inferior to those of fired bricks.

However, unfired bricks have high molding pressure and compactness, so the bulk density is larger than that of fired bricks, and the surface is too smooth; secondly, if the production process is not well controlled, the stability of unfired bricks to water and to the atmosphere will be poor.

Black cotton soil is a kind of tropical common hydration highly expansive clay, which is distributed all over the world, such as: 26% of India's land is this kind of clay; most of the central and southern Africa are this kind of expansive soil , my country's Yunnan, Sichuan, Anhui, Henan, Guangxi, Guizhou and other places are also distributed. Black cotton soil is used as an engineering material, such as: roadbed, foundation, dam ladder, and other municipal constructions, which is a disadvantage. The reason is that this type of soil has high hydration expansibility, that is, when this type of soil encounters water, its volume can expand to 1.5 to 3 times, and its strength is also reduced to 10% of its original value. Taking the subgrade as an example, its free expansion rate is between 150% and 300%, and the California bearing ratio is reduced to 10% to 15% of the original soil. Therefore, the soil cannot be directly used as roadbed filler. At present, the most effective treatment method adopted in engineering is to excavate such clay and strengthen the foundation to obtain a high-strength roadbed. Although the foundation excavation method can meet the needs of building construction, the amount of black cotton soil dug out is large. If it is not treated, the storage cost will also increase.

Contents of the invention

The present invention provides a method for preparing unburned bricks to overcome the above problems or partially solve the above problems.

According to one aspect of the present invention, a kind of unfired brick preparation method is provided, comprising:

Crush black cotton soil and volcanic ash;

The pulverized black cotton soil, the pozzolan, cement, and calcium hydroxide are formulated according to the proportioning ratio, and ground evenly;

adding water to the ingredients and stirring evenly to obtain a mixture;

Pressing the mixed material into shape, and aging at room temperature to obtain a preform;

The blank is placed in a steam curing kettle for curing;

The preform is cooled to room temperature to obtain the unburned brick.

Optionally, the particle size of the black cotton soil and the pozzolan is ≤400 mesh.

Optionally, the proportion is: 60-75 parts by mass of the black cotton soil, 10-18 parts by mass of the pozzolan, 5-15 parts by mass of the cement, and 2-10 parts by mass of the calcium hydroxide.

Optionally, the mass of the water is 5%-10% of the mass of the ingredients.

Optionally, the pressure for the compression molding of the mixture is 10MPa˜15MPa, and the holding time is ≥10 seconds.

Optionally, the aging time is not less than 12 hours.

Optionally, the curing time of the green body in the steam curing kettle is 8-24 hours, the curing temperature is 90°C-220°C, and the curing humidity is ≥90%.

According to another aspect of the present invention, an unburned brick is provided, which is prepared according to any one of the above-mentioned unburned brick preparation methods.

According to another aspect of the present invention, there is provided a raw material for non-burning bricks, the ingredients of the raw material for non-burning bricks include: 60-75 parts by mass of black cotton soil, 10-18 parts by mass of pozzolan, 5-15 parts by mass of cement, 2-10 parts by mass of calcium hydroxide.

The invention provides a method for preparing non-burning bricks with black cotton soil as the main material and volcanic ash, cement and calcium hydroxide as auxiliary materials. The non-burning bricks prepared by the method have high strength and low water absorption, which meet the national standard. It is a widely used engineering building material.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the specific embodiments of the present invention are enumerated below.

Those skilled in the art will be more aware of the above and other objects, advantages and features of the present invention according to the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Various other advantages will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for illustrating preferred embodiments and are not to be considered as limiting the invention. Also throughout the drawings, the same reference numerals are used to designate the same components. In the attached picture:

Fig. 1 is a flow chart of a method for preparing unburned bricks according to an embodiment of the invention;

Fig. 2 is a physical schematic diagram of an unburned brick according to an embodiment of the present invention;

Fig. 3 is a SEM image of an unburned brick according to an embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

By analyzing the chemical composition, minerals, and structure of black cotton soil and volcanic ash, the present invention also provides a method for preparing unburned bricks. As shown in Figure 1, the method for preparing unburned bricks provided by the present invention includes:

Step S102, pulverizing black cotton soil and volcanic ash;

Step S104, the pulverized black cotton soil, volcanic ash, cement, and calcium hydroxide are formulated according to the proportion, and ground evenly;

Step S106, adding water to the ingredients and stirring evenly to obtain a mixture;

Step S108, pressing the mixture into shape, and aging at room temperature to obtain a blank;

Step S110, placing the blank in a steam curing kettle for curing;

Step S112, cooling the blank to room temperature to obtain unfired bricks.

The unburned brick provided by the invention has a simple preparation process, and the obtained unburned brick has high strength and low water absorption, meets national standards, and is a widely applicable engineering building material. Through the test, the compressive strength of unburned bricks reaches 15Mpa, the water absorption rate is not more than 20%, and the product performance meets the MU15 requirements of the building materials industry standard of the People's Republic of China (JC 422-91). Moreover, the black cotton soil is widely distributed as the main material of the unfired brick raw material of the present invention, and the material can be obtained locally, which can not only reduce the difficulties caused by raw material transportation, but also reduce the production cost of the product and improve economic benefits.

In a preferred embodiment of the present invention, the above ratio can be: 60-75 parts by mass of black cotton soil, 10-18 parts by mass of pozzolan, 5-15 parts by mass of cement, and 2-10 parts by mass of calcium hydroxide.

The above ratio is the best ratio found by the inventor through experiments. As long as the ratio of black cotton soil, pozzolan cement and calcium hydroxide is adjusted within the optional range, unburned bricks that meet the national standard can be prepared. However, it should be noted that since the number of experiments performed by the inventor is limited, it is not ruled out that there are other feasible ratios that do not belong to the above optional range.

Preferably, the particle size of black cotton soil and volcanic ash after crushing is ≤400 mesh; the quality of water added in the ingredients is 5% to 10% of the weight of the ingredients; The time is ≥10 seconds; the aging time is not less than 12 hours; the curing time of the blank in the steam curing kettle is 8-24 hours, the curing temperature is 90°C-220°C, and the curing humidity is ≥90%.

The above conditions are also the better execution conditions for the steps of crushing, pressing, aging, curing, etc. found by the inventor through experiments, and the above conditions can be flexibly adjusted according to the change of the ratio of raw materials, the state of equipment and other factors. Adjustment.

Corresponding to the above method for preparing unburned bricks, the embodiment of the present invention also provides an unburned brick prepared by the above-mentioned preparation method. In terms of composition, the composition of this unburned brick is: black cotton soil 60-75% by mass 10-18 parts by mass of volcanic ash, 5-15 parts by mass of cement, and 2-10 parts by mass of calcium hydroxide.

Further, the embodiment of the present invention also provides a raw material for non-burning bricks. The ingredients of the raw material for non-burning bricks include: 60-75 parts by mass of black cotton soil, 10-18 parts by mass of pozzolan, 5-15 parts by mass of cement, hydrogen 2 to 10 parts by mass of calcium oxide.

In view of the technical solutions provided in the above embodiments, the inventor selected multiple groups of unburned brick raw materials with different ratios to prepare unburned bricks, and tested the performance of the prepared unburned bricks.

Example 1

The non-burning brick of this embodiment has the composition of each raw material according to parts by mass: 65 parts by mass of black cotton soil; 10 parts by mass of pozzolan; 15 parts by mass of cement; 10 parts by mass of calcium hydroxide. The specific mass of each component is: black cotton soil 390g; volcanic ash 60g; cement 90g; calcium hydroxide 60g. Preferably, the black cotton soil sample used in this embodiment is taken from Nairobi subgrade soil in Kenya, and the sampling depth is 2.0m.

Example 2

The non-burning brick of this embodiment has the composition by mass of each raw material: 65 mass parts of black cotton soil; 15 mass parts of pozzolan; 10 mass parts of cement; 5 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 390g; volcanic ash 90g; cement 60g; calcium hydroxide 30g.

Example 3

The non-burning brick of this embodiment has the composition by mass of each raw material: 65 parts by mass of black cotton soil; 18 parts by mass of pozzolan; 5 parts by mass of cement; 2 parts by mass of calcium hydroxide. The specific mass of each component is: black cotton soil 390g; volcanic ash 108g; cement 30g; calcium hydroxide 12g.

Example 4

The non-burning brick of this embodiment has the composition by mass of each raw material: 70 mass parts of black cotton soil; 10 mass parts of pozzolan; 10 mass parts of cement; 2 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 420g; volcanic ash 60g; cement 60g; calcium hydroxide 12g.

Example 5

The non-burning brick of this embodiment has the composition by mass of each raw material: 70 mass parts of black cotton soil; 15 mass parts of pozzolan; 5 mass parts of cement; 10 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 420g; volcanic ash 90g; cement 30g; calcium hydroxide 60g.

Example 6

The non-burning brick of this embodiment has the composition by mass of each raw material: 70 mass parts of black cotton soil; 18 mass parts of pozzolan; 15 mass parts of cement; 5 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 420g; volcanic ash 108g; cement 90g; calcium hydroxide 30g.

Example 7

The non-burning brick of this embodiment has the composition by mass of each raw material: 75 mass parts of black cotton soil; 10 mass parts of pozzolan; 5 mass parts of cement; 5 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 450g; volcanic ash 60g; cement 30g; calcium hydroxide 30g.

Example 8

The non-burning brick of this embodiment has the composition by mass of each raw material: 75 mass parts of black cotton soil; 15 mass parts of pozzolan; 15 mass parts of cement; 2 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 450g; volcanic ash 90g; cement 90g; calcium hydroxide 12g.

Example 9

The non-burning brick of this embodiment has the composition by mass of each raw material: 75 mass parts of black cotton soil; 18 mass parts of pozzolan; 10 mass parts of cement; 10 mass parts of calcium hydroxide. The specific mass of each component is: black cotton soil 450g; volcanic ash 108g; cement 60g; calcium hydroxide 60g.

Based on above-mentioned embodiment 1, the preparation method of unburned brick provided by the present invention is as follows:

1. Use a disc crusher to crush the black cotton soil and volcanic ash, so that the particle size of the black cotton soil and volcanic ash is ≤400 mesh;

2. Make ingredients of black cotton soil, volcanic ash, cement and calcium hydroxide, and grind them evenly;

3. Add water equal to 5% to 10% of the mass of the above-mentioned ingredients into the ingredients and stir and mix evenly to obtain a mixture;

4. Compress the mixture under a pressure of 10MPa to 15MPa, hold the pressure for no less than 10 seconds, and age at room temperature for 12 hours to obtain a blank;

5. Curing the blank in the steam curing kettle for 8 hours, the curing temperature is 220°C, and the curing humidity is 90%;

6. After cooling to room temperature, the finished black cotton soil unburned brick is obtained. The unburned brick is 12cm long, 6cm wide, and 3cm high. The physical picture is shown in Figure 2, and the SEM (Scanning Electron Microscope) picture is shown in Figure 2. 3.

The method for preparing unburned bricks based on the unburned brick raw materials provided in Examples 2 to 8 is similar to the above-mentioned method for preparing unburned bricks based on Example 1, and will not be repeated here.

The properties of unburned bricks obtained according to Examples 1 to 9 are shown in Table 1, and the properties of JC 422-91 are shown in Table 2.

Table 1

Table 2

By testing the performance of the unburned bricks obtained in the above-mentioned embodiments, and comparing the test results with the performance in JC422-91, it can be found that the unburned brick ingredients of the above embodiments are passed through the unburned bricks provided by the present invention. The compressive strength and water absorption rate of unfired bricks prepared by the method for preparing fired bricks all meet the standards in JC422-91.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, in order to streamline this disclosure and to facilitate an understanding of one or more of the various inventive aspects, various features of the invention are sometimes grouped together in a single embodiment, figure, or its description. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, those skilled in the art will understand that although some embodiments described herein include some features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention. and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (9)

1. A method for preparing an unburned brick, comprising: Crush black cotton soil and volcanic ash; The pulverized black cotton soil, the pozzolan, cement, and calcium hydroxide are formulated according to the proportioning ratio, and ground evenly; adding water to the ingredients and stirring evenly to obtain a mixture; Pressing the mixed material into shape, and aging at room temperature to obtain a preform; The blank is placed in a steam curing kettle for curing; The preform is cooled to room temperature to obtain the unburned brick. 2. The method according to claim 1, wherein the particle size of the pulverized black cotton soil and pozzolan is ≤400 mesh. 3. The method according to claim 1, wherein the proportioning is: 60-75 parts by mass of the black cotton soil, 10-18 parts by mass of the pozzolan, 5-15 parts by mass of the cement, the 2-10 parts by mass of calcium hydroxide. 4. The method according to claim 1, wherein the mass of the water is 5%-10% of the mass of the ingredients. 5 . The method according to claim 1 , wherein, the pressure for pressing the mixed material is 10Mpa˜15Mpa, and the holding time is ≥10 seconds. 6. The method according to claim 1, wherein the aging time is not less than 12 hours. 7. The method according to claim 1, wherein the curing time of the blank in the steam curing kettle is 8-24 hours, the curing temperature is 90°C-220°C, and the curing humidity is ≥90%. 8. An unburned brick, which is prepared by using the unfired brick preparation method according to any one of claims 1-7. 9. A non-burning brick raw material, the ingredients of the non-burning brick raw material include: 60-75 parts by mass of black cotton soil, 10-18 parts by mass of pozzolan, 5-15 parts by mass of cement, and 2-10 parts by mass of calcium hydroxide .