CN108675799B - Red mud permeable brick and preparation method thereof - Google Patents

Abstract

The embodiments of the present invention relate to a red mud permeable brick and a preparation method thereof, relate to the technical field of red mud permeable bricks, and mainly aim to improve the durability of the red mud permeable brick. The main technical scheme adopted is: a method for preparing red mud permeable bricks, including: using red mud powder to granulate to prepare red mud particles; forming glass powder on the outer surface of the red mud particles to form a red mud glass core; The red mud glass core and the pore-forming agent are used to form and fire the red mud permeable brick. In the red mud permeable brick provided by the embodiment of the present invention, the permeable brick body is formed by a red mud glass core, and the red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles, and the glass layer effectively wraps the red mud particles, It is not easy to return to alkali; in addition, because the strength of the glass layer is much higher than that of the red mud particles, it can improve the overall high pressure resistance of the red mud permeable brick. After testing, its compressive strength can reach 42MPa, which is higher than the existing technology. its durability.

Description

Red mud permeable brick and preparation method thereof

technical field

The embodiments of the present invention relate to the technical field of red mud permeable bricks, in particular to a red mud permeable brick and a preparation method thereof.

Background technique

my country is a big producer of alumina, and the current comprehensive utilization rate of red mud in my country is only 4%. With the annual increase of alumina production in my country and the gradual decrease of bauxite grade, the stockpile of red mud will continue to increase. At present, the comprehensive utilization of red mud is still a worldwide problem. The alkali content in red mud is very high, so this disposal method will bring unpredictable harm to the surrounding animals and plants, groundwater and so on. In recent years, the comprehensive utilization of red mud in my country has been highly valued by various parties, and research work on comprehensive utilization of interdisciplinary and multi-field has been carried out.

As a new type of product with red mud as raw material, red mud permeable brick can be used in the laying of roads and squares. The interior of red mud permeable brick has a porous structure, which can allow part of the precipitation to penetrate into the ground. Red mud permeable bricks are mainly divided into three categories according to the preparation process: non-burning type, low temperature calcining type (350℃) and high temperature sintering type (1100℃～1200℃), red mud permeable bricks have durability problems such as low strength .

SUMMARY OF THE INVENTION

In view of this, embodiments of the present invention provide a red mud permeable brick and a preparation method thereof, the main purpose of which is to improve the durability of the red mud permeable brick.

To achieve the above purpose, the embodiments of the present invention mainly provide the following technical solutions:

On the one hand, an embodiment of the present invention provides a preparation method of red mud permeable brick, comprising:

Red mud granules are prepared by granulating red mud powder;

forming the glass powder on the outer surface of the red mud particles to form a red mud glass core;

The red mud permeable brick is formed and fired by using the red mud glass core and the pore-forming agent.

The purpose of the embodiments of the present invention and the solution to the technical problems thereof can be further achieved by adopting the following technical measures.

Optionally, the preparation method of the aforementioned red mud permeable brick, wherein the red mud glass core and the pore-forming agent are used to shape and fire the red mud permeable brick, comprising:

The pore-forming agents of M grades of particle size are respectively formed on the outer surface of the red mud glass core to form M grades of mixture corresponding to the pore-formers of M grades of particle size, wherein the M grades of particles are The size of the diameter increases sequentially, and M is a positive integer greater than or equal to 2;

The M grades of mixtures are layered in sequence in the permeable brick mold, and the M layers of mixture in the permeable brick mold are extruded to form M layers of permeable brick blanks;

The red mud permeable bricks are fired to the M layer permeable brick blanks.

Optionally, the preparation method of the aforementioned red mud permeable brick, wherein the red mud permeable brick is fired to the M layer permeable brick blank, including:

In the temperature range of 50 ℃～150 ℃, drying the M-layer permeable brick blank for not less than 12 hours;

For the dried M-layer permeable brick blanks, the furnace temperature is raised to 1000°C to 1250°C in stages at a heating rate of 30°C/h to 180°C/h, kept for 2h to 6h, and then heated to 120°C/h to 300°C. /h down to room temperature to prepare red mud permeable bricks.

Optionally, the preparation method of the aforementioned red mud permeable brick, wherein the glass powder is formed on the outer surface of the red mud particles to form a red mud glass core, including:

The glass powder is sprayed on the outer surfaces of the red mud particles to form red mud glass cores.

Optionally, the preparation method of the aforementioned red mud permeable brick, wherein using red mud powder granulation to prepare red mud particles, comprising:

The red mud particles to be screened are prepared by the centrifugal spray granulation process using red mud powder with a particle size of 10 μm to 30 μm;

The red mud particles to be screened are sieved to obtain red mud particles with a particle size of 50 μm to 100 μm.

Optionally, in the aforementioned preparation method of red mud permeable brick, the particle size of the glass powder is 1 μm˜10 μm.

On the other hand, an embodiment of the present invention provides a red mud permeable brick, comprising:

A water-permeable brick body with water-permeable pores is formed by a red mud glass core, wherein the red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles.

The purpose of the embodiments of the present invention and the solution to the technical problems thereof can be further achieved by adopting the following technical measures.

Optionally, in the aforementioned red mud permeable brick, the permeable brick body includes M layers of permeable brick layers stacked in sequence; the diameters of the permeable holes of the M layers of permeable brick layers increase sequentially.

Optionally, the aforementioned red mud permeable brick, wherein the M layer of permeable brick layers sequentially includes a first layer of permeable brick layers, a second layer of permeable brick layers, and a third layer of permeable brick layers,

The pore size of the permeable pores of the first permeable brick layer is 0.1 μm to 1 μm;

The pore size of the permeable pores of the second permeable brick layer is 2 μm to 10 μm;

The diameter of the permeable pores of the third layer of permeable bricks is 11 μm to 100 μm.

Optionally, in the aforementioned red mud permeable brick, the red mud particles account for 60%-90% of the weight of the permeable brick body.

By the above-mentioned technical scheme, the red mud permeable brick and the preparation method thereof provided by the technical scheme of the present invention have at least the following advantages:

In the red mud permeable brick provided by the embodiment of the present invention, the permeable brick body is formed by a red mud glass core, and the red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles, and the glass layer effectively wraps the red mud particles, It is not easy to return to alkali; in addition, because the strength of the glass layer is much higher than that of the red mud particles, it can improve the overall high pressure resistance of the red mud permeable brick. After testing, its compressive strength can reach 42MPa, which is higher than the existing technology. its durability.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the embodiments of the present invention more clearly, and to implement them according to the contents of the description, the preferred embodiments of the present invention and the accompanying drawings are described in detail below. .

Description of drawings

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

1 is a schematic structural diagram of a red mud permeable brick provided by an embodiment of the present invention.

Detailed ways

In order to further illustrate the technical means and effects adopted by the present invention to achieve the purpose of the predetermined embodiments of the invention, the following in conjunction with the accompanying drawings and preferred embodiments, the specific implementation of the red mud permeable brick and its preparation method proposed according to the embodiment of the present invention The method, structure, characteristics and efficacy thereof are described in detail as follows. In the following description, different "an embodiment" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

The preparation method of the red mud permeable brick proposed by an embodiment of the present invention comprises:

Red mud granules are prepared by granulating red mud powder;

For example, the red mud particles can be prepared by a wet or dry ball milling process, and the particle size of the red mud particles can be between 10 μm and 30 μm. Red mud powder can be the polluting waste slag discharged from the aluminum industry during the extraction of alumina.

forming the glass powder on the outer surface of the red mud particles to form a red mud glass core;

For example, glass powder is sprayed (atomized spraying or direct spraying) on the outer surface of the red mud particles; in some embodiments, the glass powder is borosilicate glass, and the proportion of the mass of each substance to the total weight is: SiO ₂ is 50% to 60%; B ₂ O ₃ is 5 to 10%; Al ₂ O ₃ is 10% to 20%; CaO is 10% to 20%; and alkali metals. In addition, other substances may be contained in an amount of 1% to 5%.

The red mud permeable brick is formed and fired by using the red mud glass core and the pore-forming agent.

For example, using the red mud glass core and pore-forming agent to form and fire red mud permeable bricks, including:

A pore-forming agent is used to form on the outer surface of the red mud glass core to form a mixture;

Wherein, the pore-forming agent can be carbon powder, sawdust, starch, walnut shell, polyvinyl alcohol, methyl methacrylate, polyvinyl chloride or polystyrene.

Lay the mixture in the permeable brick mould, and extrude the mixture in the permeable brick mould to form the permeable brick blank;

Red mud permeable bricks fired from permeable brick blanks may include:

drying the permeable brick blanks for not less than 12 hours within the temperature range of 50°C to 150°C;

For the dried permeable brick blanks, the furnace temperature is raised to 1000°C to 1250°C in stages at a heating rate of 30°C/h to 180°C/h, kept for 2h to 6h, and then heated to 120°C/h to 300°C/h. The rate is reduced to room temperature to prepare red mud permeable bricks.

The percentage by weight of the pore-forming agent in the total weight of the pore-forming agent and the red mud glass core can be in the range of 15% to 35%. The particle size of the pore-forming agent is controlled within the range of 1 μm to 1000 μm.

The red mud permeable brick preparation method provided in the embodiment of the present invention can prepare the red mud permeable brick, the permeable brick body is formed by the red mud glass core, and the red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles. The layer wraps the red mud particles efficiently, making it difficult to return to alkali; in addition, because the strength of the glass layer is much higher than that of the red mud particles, it can improve the overall high pressure resistance of the red mud permeable brick. After testing, its compressive strength can reach 42MPa , which improves its durability relative to the prior art. In the embodiment of the present invention, centrifugal spray granulation can be used to prepare red mud particles, and then centrifugal granulation, atomization and spraying can be used to form red mud particles. When the weight percentage of glass powder is 10%, the red mud particles can still be effectively and uniformly packed Covering, and the relevant characteristics of the final product can meet the industry standard requirements of permeable bricks.

In concrete implementation, adopt red mud powder granulation to prepare red mud particles; including:

The red mud particles to be screened are prepared by the centrifugal spray granulation process using red mud powder with a particle size of 10 μm to 30 μm;

The red mud particles to be screened are sieved to obtain red mud particles with a particle size of 50 μm to 100 μm.

Correspondingly, the particle size of the glass powder may be 1 μm˜10 μm.

Through the above method, red mud permeable bricks can be prepared, and the internal pore size is relatively uniform. In other embodiments provided by the present invention, red mud permeable bricks with different pore diameters in layers can also be prepared, using the red mud glass Formed and fired red mud permeable bricks with cores and pore formers, including:

The pore-forming agents of M grades of particle size are respectively formed on the outer surface of the red mud glass core to form M grades of mixture corresponding to the pore-formers of M grades of particle size, wherein the M grades of particles are The size of the diameter increases sequentially, and M is a positive integer greater than or equal to 2;

The M grades of mixture are layered and laid in the permeable brick mold in sequence, and the M layers of mixture in the permeable brick mold are extruded to form M layers of permeable brick blanks; the extrusion pressure can be 50MPa-200MPa.

The red mud permeable bricks are fired to the M layer permeable brick blanks.

The thickness of the M layer of permeable brick blanks can be gradually reduced. Specifically, firing red mud permeable bricks for M layer permeable brick blanks, including:

In the temperature range of 50 ℃～150 ℃, drying the M-layer permeable brick blank for not less than 12 hours;

For the dried M-layer permeable brick blanks, the furnace temperature is raised to 1000°C to 1250°C in stages at a heating rate of 30°C/h to 180°C/h, kept for 2h to 6h, and then heated to 120°C/h to 300°C. /h down to room temperature to prepare red mud permeable bricks.

The value of M depends on the demand. Taking M equal to 4 as an example, the pore-forming agents of M grades of particle size include the first-grade pore-forming agent, the second-grade pore-forming agent, the third-grade pore-forming agent, and the fourth-grade pore-forming agent. Pore former. The particle size of the first-grade pore-forming agent is controlled at 1 μm to 10 μm, the particle size of the second-grade pore-forming agent is controlled at 11 μm-100 μm, the particle size of the third-grade pore-forming agent is controlled at 101 μm-500 μm, and the particle size of the fourth-grade pore-forming agent is controlled at 101 μm to 500 μm. Controlled at 501μm ~ 1000μm. The thickness ratio of 4 layers of permeable brick blanks is 4:3:2:1.

Fig. 1 is an embodiment of the red mud permeable brick provided by the present invention. Please refer to Fig. 1. The red mud permeable brick proposed by an embodiment of the present invention includes: a permeable brick body with water permeable holes formed by a red mud glass core, The red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles.

In the red mud permeable brick provided by the embodiment of the present invention, the permeable brick body is formed by a red mud glass core, and the red mud glass core includes red mud particles and a glass layer wrapped on the outer surface of the red mud particles, and the glass layer effectively wraps the red mud particles, It is not easy to return to alkali; in addition, because the strength of the glass layer is much higher than that of the red mud particles, it can improve the overall high pressure resistance of the red mud permeable brick. After testing, its compressive strength can reach 42MPa, which is higher than the existing technology. its durability.

The permeable brick body includes M layers of permeable brick layers stacked in sequence; the apertures of the permeable holes of the M layers of permeable brick layers increase sequentially. For example, as shown in FIG. 1 , the M layer of permeable bricks sequentially includes a first layer of permeable bricks 10 , a second layer of permeable bricks 20 , and a third layer of permeable bricks 30 . The pore size of the permeable pores of the second permeable brick layer 20 is 2 μm to 10 μm; the aperture of the permeable pores of the third permeable brick layer 30 is 11 μm to 100 μm.

The red mud particles account for 60%-90% of the weight of the permeable brick body.

The technical solutions of the embodiments of the present invention have at least the following advantages:

1. The red mud permeable brick is not easy to return to alkali, has high strength and good freezing resistance. Through the design of the red mud glass core structure, and then fired at high temperature, the efficient coating of the red mud particles by glass powder is realized, which solves the problem of red mud base. The permeable brick is easy to return to alkali; because the intrinsic strength of the selected glass powder is much higher than that of red mud, the red mud glass core structure design can effectively ensure the realization of high compressive strength. The compressive strength of the mud permeable brick can reach up to 42MPa; through the ion granulation and atomization spraying process, the high uniform mixing of red mud particles/glass powder/pore-forming agent can be realized, which ensures the uniformity and the final pore structure of the red mud permeable brick. Therefore, in the frost resistance test, the internal stress is relatively uniform, and under the high-strength support of the permeable brick, the frost resistance of the product is effectively improved.

2. Red mud permeable bricks are not easy to block pores. Through structural design, a layered gradient pore structure with 0.1μm-1μm micropores, 2μm-10μm fine pores and 11μm-100μm coarse pores is formed, and the pore size distribution of the surface microporous layer is controlled at 0.1 Within the range of μm to 1 μm, the entry of conventional sundries and dust can be better avoided; while the pore size distribution of the fine pore layer and the coarse pore layer are respectively controlled within the range of 2 μm to 10 μm and 11 μm to 100 μm, which can effectively ensure the height of the permeable brick. Water permeability.

3. The comprehensive utilization rate of red mud is high. Through the core-shell structure design of red mud particles/glass powder/pore-forming agent, combined with the secondary granulation process (centrifugal spray granulation to prepare red mud core, and then centrifugal granulation, atomization spraying , forming a core-shell structure), when the weight percentage of glass powder is 10%, the red mud can still be effectively and uniformly coated, and the relevant characteristics of the final product can meet the requirements of the permeable brick industry standard.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

It is to be understood that the relevant features in the above-mentioned apparatus may refer to each other. In addition, "first", "second", etc. in the above-mentioned embodiments are used to distinguish each embodiment, and do not represent the advantages and disadvantages of each embodiment.

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

Similarly, it is to be understood that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or its description. However, this disclosed apparatus should not be construed as reflecting the intention that the invention as claimed 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.

Those skilled in the art will appreciate that the components of the apparatus in an embodiment may be adaptively changed and arranged in one or more apparatuses different from the embodiment. Components of the embodiments may be combined into one component, and furthermore they may be divided into subcomponents. All features disclosed in this specification (including accompanying claims, abstract and drawings) and all parts of any apparatus so disclosed may be combined in any combination, unless at least some of such features are mutually exclusive. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the invention within and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination. The various component embodiments of the present invention may be implemented in hardware, or in a combination thereof.

It should be noted that the above-described embodiments illustrate rather than limit the invention, and that alternative embodiments may be devised by those skilled in the art 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 components not listed in a claim. The word "a" or "an" preceding a component or component does not preclude the presence of a plurality of such components or components. The present invention can be implemented by means of an apparatus comprising several different components. In the claims enumerating several means, several of these means may be embodied by one and the same item of means. The use of the words first, second, and third, etc. do not denote any order. These words can be interpreted as names.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to the present invention. within the scope of the technical solution of the invention.

Claims (7)

1. The preparation method of the red mud permeable brick is characterized by comprising the following steps:

preparing red mud particles by granulating red mud powder; the preparation of the red mud particles by adopting the red mud powder granulation comprises the following steps: preparing red mud particles to be screened by adopting red mud powder with the particle size of 10-30 microns and adopting a centrifugal spray granulation process, and screening the red mud particles to be screened to obtain red mud particles with the particle size of 50-100 microns;

forming glass powder on the outer surface of the red mud particles to form red mud glass cores; the forming of the glass powder on the outer surface of the red mud particles to form the red mud glass core comprises the following steps: spraying glass powder on the outer surface of the red mud particles to form red mud glass cores, wherein the particle size of the glass powder is 1-10 mu m;

and forming and firing the red mud permeable brick by using the red mud glass core and the pore-forming agent.

2. The production method according to claim 1,

the red mud permeable brick is formed and fired by the red mud glass core and the pore-forming agent, and comprises the following components:

forming pore-forming agents with M grades of particle sizes on the outer surface of the red mud glass core respectively to form M grades of mixture corresponding to the pore-forming agents with M grades of particle sizes one by one, wherein the sizes of the M grades of particle sizes are increased in sequence, and M is a positive integer greater than or equal to 2;

sequentially stacking the M grades of mixed materials in a permeable brick die, and carrying out extrusion forming on M layers of mixed materials in the permeable brick die to form M layers of permeable brick blanks;

and firing the red mud permeable brick from the M layers of permeable brick blanks.

3. The production method according to claim 2,

firing the red mud water permeable brick for the M layers of water permeable brick blanks comprises the following steps:

drying the M layers of permeable brick blanks for not less than 12 hours at the temperature of between 50 and 150 ℃;

and (3) raising the furnace temperature to 1000-1250 ℃ in stages at a temperature raising rate of 30-180 ℃/h for the dried M-layer water permeable brick blank, preserving the temperature for 2-6 h, and then lowering the temperature to room temperature at a rate of 120-300 ℃/h to prepare the red mud water permeable brick.

4. The red mud permeable brick prepared by the red mud permeable brick preparation method according to any one of claims 1 to 3, which is characterized by comprising the following steps:

the red mud glass core comprises red mud particles and a glass layer wrapping the outer surfaces of the red mud particles.

5. The red mud permeable brick according to claim 4,

the water permeable brick body comprises M water permeable brick layers which are sequentially stacked; the diameter of the permeable holes of the M permeable brick layers is increased in sequence.

6. The red mud permeable brick according to claim 5,

the M permeable brick layers sequentially comprise a first permeable brick layer, a second permeable brick layer and a third permeable brick layer,

the diameter of the water permeable holes of the first water permeable brick layer is 0.1-1 mu m;

the diameter of the water permeable holes of the second water permeable brick layer is 2-10 mu m;

the diameter of the water permeable holes of the third water permeable brick layer is 11-100 mu m.

7. The red mud permeable brick according to claim 4,

the red mud particles account for 60-90% of the weight of the water permeable brick body.

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