Reservoir sediment non-burned brick and preparation method thereof

Abstract

The application discloses a reservoir sediment non-burned brick and a preparation method thereof; the non-burned brick takes reservoir sediment and shells as base materials, and further comprises a main curing agent, an auxiliary curing agent and reed fibers. The preparation method of the non-burned brick is as follows: preparing raw materials, sample pretreatment (crushing and grinding, passing through a 100-mesh standard sieve, planetary ball milling), adding water and stirring to mix uniformly, pressing and forming, and curing of the reservoir sediment non-burned brick; the strength grade of the reservoir sediment non-burned brick prepared by the application reaches the MU10 standard in the national standard "Ordinary Concrete Small-sized Brick" (GB / T 8239-2014). The method does not need to use high-temperature calcination equipment, saves energy and reduces consumption, and can effectively solve the problem of occupying a large amount of land in the process of treating the sediment, realizes the transformation of waste into treasure, and realizes recycling.

Description

Technical Field

[0001] This invention relates to a non-fired brick made from reservoir sediment and its preparation method, belonging to the fields of environmental protection and engineering construction technology. Background Technology

[0002] As a major source of water for daily life, reservoirs require regular cleaning of bottom sediment to ensure water quality and storage capacity. The proper disposal of this sediment has become a pressing issue. Common methods for sediment disposal include sanitary landfill, land application, and resource utilization in building materials. Because reservoir sediment is relatively clean—compared to sludge from urban sewage treatment plants and river silt—it contains extremely low levels of toxic and harmful components, has low natural water content, and no foul odor. Therefore, it can be reused. The aforementioned resource utilization in building materials aligns with the concept of resource recycling, turning waste into treasure and achieving efficient utilization. Summary of the Invention

[0003] Based on the above background technology, the purpose of this invention is to provide a non-fired brick made from reservoir sediment and its preparation method. This invention produces shaped bricks from reservoir sediment with low energy consumption and low pollution, resulting in low brick production cost. At the same time, the shaped bricks produced have a certain compressive strength, realizing the transformation of reservoir sediment from waste to treasure.

[0004] The technical solution of the present invention is described in detail below.

[0005] This invention provides a method for preparing non-fired bricks from reservoir sediment. The formula for non-fired bricks from reservoir sediment is as follows:

[0006] 100 parts base material, 18-22 parts main curing agent, 2-4 parts auxiliary curing agent, 8-20 parts reed fiber, 47-49 parts aggregate, and 3-5 parts water; wherein:

[0007] The base material is composed of reservoir bottom mud and shells, the main curing agent is composed of activated alumina and quartz powder, the auxiliary curing agent is calcium hydroxide, and the aggregate is composed of crushed stone and artificial sand.

[0008] Reservoir sediment-based non-fired bricks are prepared using the following method:

[0009] (1) Crush the reservoir bottom mud and shells separately with a crusher, and then pass them through a 100-mesh standard sieve;

[0010] (2) The sieved reservoir bottom mud and shells are mixed and loaded into a planetary ball mill for ball milling; the activated alumina and quartz powder are mixed and loaded into a planetary ball mill for ball milling.

[0011] (3) Add the ball-milled base material, main curing agent, auxiliary curing agent, reed fiber, aggregate, and water to the mixer and stir evenly to form a mixture.

[0012] (4) Load the mixture into the mold of the fully automatic constant stress press and press it into shape;

[0013] (5) Place the molded sample in a constant temperature and humidity curing chamber to cure it, and obtain reservoir bottom mud non-fired bricks.

[0014] In this invention, the mass ratio of reservoir bottom mud to shells is 1:0.25 to 1:0.55; preferably, the mass ratio is 1:0.4 to 1:0.5.

[0015] In this invention, the mass ratio of quartz powder in the main curing agent is 25% to 49%. Preferably, the mass ratio is 40% to 48%.

[0016] In this invention, in step (2), the planetary ball mill operates at a speed of 400–600 r / min for 1–3 h. Preferably, the speed is 480–512 r / min and the operating time is 2–2.5 h.

[0017] In this invention, in step (3), the particle size of the auxiliary curing agent calcium hydroxide is 0.033-0.053 mm, the mass ratio of crushed stone and artificial sand in the aggregate is 5:7, the particle size of the crushed stone in the aggregate is 9-12 mm, the particle size of the artificial sand is less than 5 mm, and both the crushed stone and the artificial sand are pre-wetted.

[0018] In this invention, in step (3), the reed fiber is dried reed, and the length of the reed fiber is 1-2 cm.

[0019] In this invention, in step (4), when pressing the mixture, the fully automatic constant stress press applies pressure at a speed of 1kN / s, and when the pressure reaches 5-6MPa, it is left to stand for 100-130s.

[0020] In this invention, in step (5), the temperature in the constant temperature and humidity curing chamber is 21℃±1, the humidity is 95%±3, and the curing time is 80~100h.

[0021] The present invention also provides a reservoir bottom sediment non-fired brick, which is prepared by the above-described method for preparing reservoir bottom sediment non-fired brick.

[0022] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows:

[0023] (1) This invention utilizes reservoir bottom mud to prepare bottom mud non-fired bricks. The bottom mud non-fired brick test blocks are pressed by a fully automatic constant stress press and do not require high-temperature firing, resulting in low energy consumption.

[0024] (2) Co-ball milling of main curing agent

[0025] Active Al2O3 can react with Ca(OH)2 to form hydrated calcium aluminate with hydraulic cementitious properties. Furthermore, active Al2O3 can react with alkaline solutions to lower the pH value, preventing the mixture from becoming too alkaline and thus contributing to the stability of the internal environment of the brick.

[0026] Quartz powder is mainly composed of SiO2. After ball milling, the active SiO2 undergoes a pozzolanic reaction under the action of the alkaline activator Ca(OH)2, generating more hydrated calcium silicate with hydraulic cementing properties. The resulting cementitious substance is non-toxic and harmless and has good hydration properties, exhibiting a good curing effect.

[0027] Quartz powder and activated alumina are ball-milled together, revealing more active SiO2 and active Al2O3. The finer particle size promotes more uniform mixing of active ingredients. Under the action of the alkali activator Ca(OH)2, a pozzolanic reaction occurs, and the resulting gelling substance exerts a good curing effect.

[0028] (3) The role of auxiliary curing agent

[0029] Adding Ca(OH)₂ can increase the pH value of the base material, thereby ensuring that the solution in the pores of the base material is saturated with Ca(OH)₂. This allows it to react with active SiO₂ and active Al₂O₃ in a pozzolanic reaction, generating a large amount of cementitious substances such as hydrated calcium silicate and hydrated calcium aluminate. This enhances the early and later strength of the mud-based brick blanks, while also improving the durability of the brick blanks, reducing permeability, and preventing the mud-based brick blanks from peeling off. The Ca₂ in this solution... 2+ It can undergo ion exchange reactions, reacting with the positively charged Na on the surface of the sediment particles. + K + Equivalent adsorption and exchange are carried out to improve the stability of the initial solidification of the reservoir bottom sediment.

[0030] SiO2+Ca(OH)2+nH2O→CaO·SiO2·(n+1)H2O

[0031] Al2O3+Ca(OH)2+nH2O→CaO·Al2O3·(n+1)H2O

[0032] (4) The role of reed fiber

[0033] Inexpensive and abundant natural reed fiber is a new type of environmentally friendly building material. Reed fiber incorporated into brick-making mixtures can reduce the plastic shrinkage of reservoir bottom mud unfired bricks, thus preventing the formation of plastic microcracks in the bricks. At the same time, it absorbs and stores moisture in the brick structure. The later release of this moisture helps the cracks heal, enhancing the toughness, strength, bending resistance, and impact resistance of the bricks.

[0034] (5) Co-milling of shell powder and reservoir sediment:

[0035] Shells, as a natural source of calcium, are primarily composed of CaCO3. Crushed and ground shell powder is then ball-milled with reservoir sediment. The resulting finer-particle-size shell powder exhibits stronger activity and solidification effects, while simultaneously increasing the CaCO3 content. 2+ Na, which has a positive charge on the surface of the sediment particles in the reservoir, + K + Through equivalent adsorption and exchange, the fine clay and powder particles in the reservoir sediment are coated with shell powder to facilitate further stabilization and solidification.

[0036] The main components of reservoir sediment, such as SiO2, Al2O3, Fe2O3, and CaO, are activated under mechanical force, and active SiO2 and active Al2O3 are exposed. Under the action of the alkaline activator Ca(OH)2, a pozzolanic reaction can occur, generating a large amount of cementing products such as hydrated calcium silicate and hydrated calcium aluminate, which enhances the solidification effect.

[0037] (6) The compressive strength of the reservoir bottom mud unfired bricks prepared by the present invention reaches the MU10 standard in the national standard "Ordinary Concrete Small Blocks" (GB / T8239-2014), and can be used in non-load-bearing structures; at the same time, its leaching toxicity is far lower than the leaching toxicity identification standard value in the national standard "Identification Standard for Hazardous Waste Leaching Toxicity Identification" (GB5085.3-2007), and the reservoir bottom mud unfired bricks can be used for the construction of dikes and embankments around reservoirs, mountain trails, etc. Detailed Implementation

[0038] According to the overall concept of the present invention, a method for preparing reservoir sediment-free bricks is provided, comprising a base material mixture, a primary curing agent, and an auxiliary curing agent, with the addition of aggregates and reed fibers. The base material consists of reservoir sediment and seashells. A planetary ball mill is used to mechanically activate the base material and the primary curing agent separately. The brick-making materials are mixed and stirred evenly in a three-dimensional rotary mixer, and the mixture is pressed into shape using a fully automatic constant stress press. The primary curing agent and the auxiliary curing agent are proportioned in the following mass fractions: 20 parts primary curing agent and 2-4 parts auxiliary curing agent. The primary curing agent is active alumina or quartz powder, and the auxiliary curing agent is calcium hydroxide. Further, the mass ratio of quartz powder in the primary curing agent is 20%-49%, the mass ratio of reservoir sediment to seashells in the base material is 1:0.25-0.55, and the reed fiber is 8-20 parts; the above three are preferred.

[0039] The bottom sediment extracted from the reservoir is pre-dehydrated in a pressure dewatering machine and then dried in an oven to obtain the reservoir bottom sediment.

[0040] Determination of heavy metal content in reservoir sediment: 0.1–0.2 g of dry sediment from Jinze Reservoir in Shanghai was subjected to microwave high-pressure digestion. The heavy metal concentrations measured using inductively coupled plasma optical emission spectrometry (ICP-OES) were significantly lower than the pollutant concentration limits specified in the standard "Sludge Disposal for Brick Making from Urban Wastewater Treatment Plants" (GB / T 25031-2010), as shown in Table 1.

[0041] Table 1 Unit: mg / kg

[0042]

[0043] This invention provides a method for preparing non-fired bricks from reservoir sediment, comprising the following steps:

[0044] (1) Prepare the following raw materials according to the mass proportions:

[0045] Base material: 100 parts;

[0046] Water: 3-5 parts;

[0047] As described above, the main curing agent: 18-22 parts;

[0048] As described above, the curing agent: 2-4 parts;

[0049] Reed fiber: 8-20 parts;

[0050] Aggregate: 47-49 parts, with a mass ratio of crushed stone to manufactured sand of 5:7;

[0051] The base material is reservoir bottom mud and shells, and the mass ratio of reservoir bottom mud to shells is 1:0.25 to 0.55;

[0052] (2) The bottom mud pumped from the reservoir is pre-dehydrated in a pressure dewatering machine, then dried in an oven, crushed by a crusher, ground and passed through a 100-mesh standard sieve; the shells collected from the reservoir and surrounding area are crushed by a crusher, ground and passed through a 100-mesh standard sieve.

[0053] (3) The base material is mixed and loaded into a planetary ball mill for ball milling; the two components of the main curing agent are mixed and loaded into a planetary ball mill for ball milling.

[0054] (4) The base material, main curing agent, auxiliary curing agent, reed fiber, aggregate, and water after ball milling are added to a three-dimensional rotary mixer and stirred evenly to form the mixture required for preparing reservoir bottom mud non-fired bricks.

[0055] (5) The mixture is loaded into the mold of a fully automatic constant stress press and pressed into shape;

[0056] (6) Place the unfired bricks made from reservoir bottom mud into a constant temperature and humidity curing chamber and cure for 80-100 hours.

[0057] Preferably, in step (1), the main curing agent, activated alumina, has a particle size of 0.063–0.090 mm and a purity of ≥99%, the quartz powder has a particle size of 0.075–0.106 mm and a purity of ≥99%, and the auxiliary curing agent, calcium hydroxide, has a particle size of 0.033–0.053 mm and a purity of ≥99%.

[0058] Preferably, in step (1), the particle size of the crushed stone is 9-12 mm, the particle size of the artificial sand is less than 5 mm, and both the crushed stone and the artificial sand are pre-wetted; the reeds are dried and the length of the reed fibers is 1-2 cm.

[0059] Preferably, in step (2), the particle size of the crushed shells is less than 0.15 mm;

[0060] Preferably, in step (3), the planetary ball mill operates at a speed of 400-600 r / min and for a time of 1-3 h.

[0061] Preferably, in step (5), when pressing the mixture, the fully automatic constant stress press applies pressure at a constant speed of 1kN / s, and when the pressure reaches 5-6MPa, it is left to stand for 100-130s; the mold and reservoir bottom mud unfired bricks are taken out from the fully automatic constant stress press, and the mold is disassembled after standing for 10-15min.

[0062] To achieve the objectives of this invention and to make the technical solutions and beneficial effects clearer, the invention will be further described below with reference to specific embodiments. The amounts of curing agent, aggregate, and reed fiber added are based on the dry weight of the base material.

[0063] Example 1: Weigh reservoir sediment and seashells as base materials, crush and grind them separately, and pass them through a 100-mesh standard sieve. Taking a dry weight of 720-730g as an example, the mass ratio of reservoir sediment to seashells in the base material is 1:0.45. Place them in a planetary ball mill for ball milling. Based on the dry weight of the base material, weigh 3-5% by weight of water, 15% by weight of reed fiber, 48% by weight of aggregate, and 20% by weight of primary curing agent, wherein the mass ratio of activated alumina and quartz powder in the primary curing agent is 13:12. Place them in a planetary ball mill for ball milling. Weigh 2-4% by weight of secondary curing agent. The mass ratio of balls to material in the planetary ball mill for ball milling activation treatment is 5.5:1. The rotation speed of the three-dimensional rotary mixer is 55-65 r / min, and the mixing time is 8-10 min, so that the mixture is fully and evenly mixed. The fully automatic constant stress press is used to press out the shaped reservoir bottom mud non-fired brick test blocks after the pressure value reaches 5-6 MPa and is left to stand for 100-130 s.

[0064] Comparative Example 1: Same as Example 1, except that the mass ratio of reservoir bottom mud to shells is 1:0, and no main curing agent or reed fiber is added.

[0065] Comparative Example 1': Same as Example 1, except that the main curing agent is not ball-milled.

[0066] Example 2: Same as Example 1, except for the change in the composition of the main curing agent. Based on the dry weight of the base material, the mass ratio of reservoir mud to shells in the base material is 1:0.45. After crushing and grinding, the materials are passed through a 100-mesh standard sieve. 3-5% by weight of water, 15% by weight of reed fiber, 48% by weight of aggregate, and 20% by weight of the main curing agent are weighed. The mass ratio of activated alumina to quartz powder in the main curing agent is 3:2. 2-4% by weight of the auxiliary curing agent is also weighed. The mass ratio of ball material to material in the planetary ball mill activation treatment is 5.5:1. The rotation speed of the three-dimensional rotary mixer is 55-65 r / min, and the mixing time is 8-10 min, ensuring thorough and uniform mixing. The mixture is then pressed into shaped reservoir mud non-fired brick test blocks by a fully automatic constant stress press after the pressure reaches 5-6 MPa and is allowed to stand for 100-130 s.

[0067] Comparative Example 2: Same as Example 2, except that no main curing agent was added.

[0068] Comparative Example 2': Same as Example 2, except that the main curing agent is not ball-milled.

[0069] Example 3: Same as Example 1, except for the change in the content of the two components in the base material. Based on the dry weight of the base material, the mass ratio of reservoir mud to shells in the base material is 1:0.3. After crushing and grinding, the materials are passed through a 100-mesh standard sieve. 3-5% by weight of water, 15% by weight of reed fiber, 48% by weight of aggregate, and 20% by weight of the main curing agent are weighed. The mass ratio of activated alumina to quartz powder in the main curing agent is 13:12. 2-4% by weight of the auxiliary curing agent is also weighed. The mass ratio of ball material to material in the planetary ball mill activation treatment is 5.5:1. The rotation speed of the three-dimensional rotary mixer is 55-65 r / min, and the mixing time is 8-10 min, ensuring thorough and uniform mixing. The mixture is then pressed into shaped reservoir mud non-fired brick test blocks by a fully automatic constant stress press after the pressure reaches 5-6 MPa and is left to stand for 100-130 s.

[0070] Comparative Example 3: Same as Example 3, except that the mass ratio of reservoir bottom mud to shells in the base material is 1:0.

[0071] Comparative Example 3': Same as Example 3, except that the main curing agent is not ball-milled.

[0072] Example 4: Same as Example 1, except for the change in the amount of reed fiber added. Based on the dry weight of the base material, the mass ratio of reservoir mud to seashells in the base material is 1:0.45. After crushing and grinding, the materials are passed through a 100-mesh standard sieve. 3-5% by weight of water, 10% by weight of reed fiber, 48% by weight of aggregate, and 20% by weight of the main curing agent are weighed. The main curing agent contains activated alumina and quartz powder in a mass ratio of 13:12. 2-4% by weight of the auxiliary curing agent is also weighed. The ball-to-material mass ratio for ball milling activation treatment is 5.5:1. The rotation speed of the three-dimensional rotary mixer is 55-65 r / min, and the mixing time is 8-10 min, ensuring thorough and uniform mixing. The mixture is then pressed into shaped reservoir mud non-fired brick test blocks by a fully automatic constant stress press after the pressure reaches 5-6 MPa and is allowed to stand for 100-130 s.

[0073] Comparative Example 4: Same as Example 4, except that reed fiber was not added.

[0074] Comparative Example 4': Same as Example 4, except that the main curing agent is not ball-milled.

[0075] The contents of each component of the main curing agent, the mass ratio of reservoir sediment and shells in the base material, the mass content of the auxiliary curing agent, and the mass content of reed fiber in the examples and comparative examples are shown in Table 2:

[0076] Table 2

[0077]

[0078] The compressive strength of the pre-formed reservoir sediment unfired bricks was tested. The measured data was compared with the strength grade specified in the national standard "Ordinary Concrete Small Blocks" (GB / T 8239-2014). It was found that the compressive strength grade of the reservoir sediment unfired bricks in the above embodiment reached MU10. The specific data are shown in Tables 3, 4 and 5.

[0079] Table 3

[0080]

[0081] Note: The compressive strength of the unfired bricks made from reservoir bottom mud will slowly increase and gradually stabilize in the later stages.

[0082] Table 4

[0083]

[0084] Note: The comparative example is only used as a comparison and verification of various additives in the non-fired bricks made from reservoir sediment. The compressive strength in the comparative example reaches the MU5 standard.

[0085] Table 5

[0086]

[0087] Note: Table 5 shows that the main curing agent was not ball-milled, only the base material was ball-milled. The material dosage in each comparative example is the same as in each embodiment. The compressive strength in the comparative examples only reached the MU7.5 standard, not the MU10 standard. Therefore, the main curing agent needs to be ball-milled before it can be used in brick making.

[0088] The frost resistance of the pre-formed reservoir bottom mud-free bricks was tested. According to the frost resistance requirements in the national standard "Ordinary Concrete Small Blocks" (GB / T 8239-2014), the brick blanks formed by this invention were tested and found to have an average mass loss rate of less than 5%, a maximum mass loss rate of less than 10% for a single brick, an average strength loss rate of less than 20%, and a maximum average strength loss rate of less than 30% for a single brick. The test results meet the frost resistance requirements in the national standard "Ordinary Concrete Small Blocks" (GB / T 8239-2014).

[0089] The leaching toxicity of the formed reservoir bottom mud-free bricks was identified. According to the national standard "Identification Standard for Hazardous Waste: Leaching Toxicity Identification" (GB5085.3-2007), the heavy metal leaching test required treating the brick samples according to the national standards "Specifications and Methods for Water Used in Analytical Laboratories" (GB / T6682-2008) and "Leaching Toxicity of Solid Waste: Sulfuric Acid and Nitric Acid Method" (HJ / T 299-2007). The treated sample solution was then analyzed for heavy metal concentration using inductively coupled plasma optical emission spectrometry (ICP-OES). The measured data are shown in Table 5.

[0090] Table 6 Units: mg / L

[0091]

[0092] The leaching toxicity of the formed reservoir bottom mud unfired bricks is far lower than the leaching toxicity identification standard value in the national standard "Identification Standard for Hazardous Waste - Leaching Toxicity Identification" (GB5085.3-2007). The reservoir bottom mud unfired bricks can be used for the construction of dikes around reservoirs, paving of mountain trails, etc.

[0093] The present invention utilizes reservoir sediment to produce non-fired bricks. Simultaneously, it fully leverages the abundant shells, reeds, and other resources of the reservoir and its surrounding area. A fully automatic constant stress press compacts the brick-making mixture, eliminating the need for high-temperature firing, thus saving energy and reducing consumption, aligning with the concept of sustainable development. Heavy metal testing of the reservoir sediment shows results that meet the national standard "Sludge for Brick Making from Sludge from Urban Wastewater Treatment Plants" (GB / T 25031-2010), indicating that the produced reservoir sediment non-fired bricks can be used in and around the reservoir area. The dimensions of the reservoir sediment non-fired bricks are 190*190*190 (mm). Based on the compressive strength test data, the results meet the MU10 standard in the national standard "Ordinary Concrete Small Blocks" (GB / T8239-2014), indicating that the produced reservoir sediment non-fired bricks can be used in non-load-bearing structures.

[0094] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various changes can be made according to the purpose of the invention.

Claims

1. A method for preparing non-fired bricks from reservoir sediment, characterized in that, The formula for reservoir bottom mud-free bricks is as follows, by weight: 100 parts base material, 18-22 parts main curing agent, 2-4 parts auxiliary curing agent, 8-20 parts reed fiber, 47-49 parts aggregate, and 3-5 parts water; wherein: The base material is composed of reservoir bottom mud and shells, the main curing agent is composed of activated alumina and quartz powder, the auxiliary curing agent is calcium hydroxide, and the aggregate is composed of crushed stone and artificial sand. Reservoir sediment-based non-fired bricks are prepared using the following method: (1) The bottom mud and shells of the reservoir were crushed by a crusher and then passed through a 100-mesh standard screen. (2) The sieved reservoir bottom mud and shells are mixed and loaded into a planetary ball mill for ball milling; the activated alumina and quartz powder are mixed and loaded into a planetary ball mill for ball milling. (3) Add the ball-milled base material, main curing agent, auxiliary curing agent, reed fiber, aggregate, and water to the mixer and stir evenly to form a mixture. (4) Load the mixture into the mold of the fully automatic constant stress press and press it into shape; (5) Place the molded sample in a constant temperature and humidity curing chamber to cure it, and obtain reservoir bottom mud non-fired bricks.

2. The method for preparing reservoir bottom sediment non-fired bricks as described in claim 1, characterized in that: The mass ratio of reservoir bottom sediment to shells is 1:0.25 to 1:0.

55.

3. The method for preparing reservoir sediment-free bricks as described in claim 1, characterized in that: Quartz powder accounts for 25% to 49% of the mass of the main curing agent.

4. The method for preparing reservoir bottom sediment non-fired bricks as described in claim 1, characterized in that: In step (2), the planetary ball mill operates at a speed of 400~600 r / min and for a time of 1~3 h.

5. The method for preparing reservoir bottom sediment non-fired bricks as described in claim 1, characterized in that: In step (3), the particle size of the auxiliary curing agent calcium hydroxide is 0.033~0.053mm, the mass ratio of crushed stone and artificial sand in the aggregate is 5:7, the particle size of the crushed stone is 9~12mm, the particle size of the artificial sand is less than 5mm, and both the crushed stone and artificial sand are pre-wetted.

6. The method for preparing reservoir sediment-free bricks as described in claim 1, characterized in that: In step (3), the reed fiber is dried reed, and the length of the reed fiber is 1~2cm.

7. The method for preparing reservoir bottom sediment non-fired bricks as described in claim 1, characterized in that: In step (4), when pressing the mixture, the fully automatic constant stress press applies pressure at a speed of 1kN / s and is left to stand for 100-130s when the pressure reaches 5-6MPa.

8. A type of non-fired brick made from reservoir bottom mud, characterized in that: The bricks were prepared by the method described in any one of claims 1-7 for preparing non-fired bricks from reservoir sediment.

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