Black mud shale brick as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of waste recycling, and particularly relates to a black mud shale brick as well as a preparation method and application thereof. The black mud shale brick provided by the invention is prepared from the following raw materials in percentage by mass: 40 to 70 percent of shale particles, 10 to 30 percent of papermaking black mud, 5 to 20 percent of probiotic stock solution and 10 to 30 percent of water, the mass concentration of the probiotic stock solution is 10-30%; the probiotic stock solution is prepared from bacillus and / or cytophage and water. The black mud shale brick provided by the invention has the advantages of environment-friendly raw materials, excellent thermal insulation performance, low heat transfer coefficient, low cost and considerable market application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of waste recycling, and in particular relates to a black mud shale brick and a preparation method and application thereof. Background Art

[0002] my country's papermaking industry produces a large amount of papermaking black mud every year. There are many problems in the treatment process. The stacking or landfill of papermaking black mud causes a lot of land waste and groundwater pollution. In addition, during the stacking or landfill process, the papermaking black mud ferments to produce harmful gases, polluting the surrounding environment and air. Some companies incinerate papermaking black mud, which emits toxic substances such as dioxins during the combustion process, causing serious environmental pollution. The new treatment technology turns black mud into fertilizer, but the cost is high and the efficiency is low, so it cannot be promoted and applied on a large scale.

[0003] Papermaking black mud is the slurry left after papermaking, which contains a large amount of cellulose, lignin and hemicellulose, as well as nitrogen, phosphorus, potassium and inorganic substances. Using papermaking black mud to manufacture building products, turning waste into treasure, has good economic and social benefits. At present, black mud can be used in the construction industry to make blocks and composite boards, which saves cement materials and shale materials for building materials and solves the problem of black mud accumulation. Therefore, introducing papermaking black mud into the building materials industry can solve the above-mentioned problems.

[0004] The Chinese patent with publication number CN101941808A discloses a method for producing shale sintered bricks using black mud discharged from a paper mill. The patent uses black mud, shale and coal gangue as raw materials to sinter bricks, reduces the amount of coal gangue, reduces the cost of sintered bricks, and realizes the recycling of solid waste. However, the sintered bricks produced by the patent have poor thermal insulation, sound absorption and sound insulation performance. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a black mud shale brick and a preparation method and application thereof. The black mud shale brick provided by the present invention has environmentally friendly raw materials, low heat transfer coefficient, and excellent thermal insulation performance.

[0006] The present invention provides a black mud shale brick, comprising the following raw materials in percentage by mass:

[0007] 40-70% shale particles, 10-30% papermaking black mud, 5-20% probiotic stock solution, and 10-30% water;

[0008] The mass concentration of the probiotic stock solution is 10-30%;

[0009] The probiotic stock solution comprises bacillus and / or cellulophagus and water.

[0010] Preferably, the particle size of the shale particles is less than 0.063 mm.

[0011] Preferably, the particle size of the papermaking black mud is <0.125 mm; the moisture content of the papermaking black mud is 25-35%.

[0012] Preferably, the method for preparing the probiotic stock solution comprises the following steps:

[0013] The probiotics, brown sugar and water are mixed and cultured to obtain a probiotic stock solution;

[0014] The probiotics include Bacillus and / or Cellulophagus;

[0015] The water is deionized water or pure water;

[0016] The culture is carried out in a sealed state and under standard atmospheric pressure; the temperature of the culture is 25±0.5° C., and the time is 12 to 24 hours.

[0017] The present invention also provides a method for preparing the black mud shale bricks described in the above technical solution, comprising the following preparation steps:

[0018] The shale particles, papermaking black mud, probiotic stock solution and water are mixed to obtain a prefabricated slurry;

[0019] Aging the prefabricated slurry to obtain an aged material;

[0020] shaping the aged material to obtain a brick;

[0021] The brick blank is fired to obtain the black mud shale brick.

[0022] Preferably, the aging temperature is room temperature, and the aging time is 12 to 60 hours.

[0023] Preferably, the forming comprises preparing a brick and shaping the brick in sequence; the temperature of the brick shaping is 20-25° C., the air humidity is 15-25%, and the time is 1-3 days.

[0024] Preferably, before the firing, the bricks are shade-dried at a temperature of 20-25° C., an air humidity of 25-35%, and a time of 2-10 days.

[0025] Preferably, the calcination includes a drying stage, a preheating stage, a calcination stage and a cooling stage in sequence; the temperature of the drying stage is 100°C to 300°C, and the heating rate from room temperature to the temperature of the drying stage is 1 to 2°C / min; the temperature of the preheating stage is 300°C to 550°C, and the heating rate from the temperature of the drying stage to the temperature of the preheating stage is 1 to 2°C / min; the temperature of the calcination stage is 500°C to 1050°C, and the heating rate from the temperature of the preheating stage to the temperature of the calcination stage is 1 to 2°C / min, and the time is 3 to 10 hours; the cooling stage is a natural cooling to room temperature.

[0026] The present invention also provides the application of the black mud shale bricks described in the above technical solution or the black mud shale bricks prepared by the preparation method in the field of building materials.

[0027] The present invention provides a black mud shale brick, comprising the following raw materials in mass percentage: 40-70% shale particles, 10-30% papermaking black mud, 5-20% probiotic stock solution, and 10-30% water; the mass concentration of the probiotic stock solution is 10-30%; the probiotic stock solution comprises bacillus and / or cellulophagus and water.

[0028] The present invention adds probiotic stock solution, and the Bacillus and cellulophagic bacteria in the probiotic stock solution can effectively decompose the organic matter (such as cellulose, lignin and hemicellulose) remaining in the papermaking black mud, and avoid these organic matters from generating pollutants such as dioxins during roasting; The Bacillus in the probiotic stock solution can also adsorb heavy metals, reducing the heavy metal pollution in the papermaking black mud. Moreover, the papermaking black mud is fermented by the probiotic stock solution, and the papermaking black mud is mixed with shale particles more evenly and closely, and the gas generated by the fermentation can form fine holes in the aging material, so that the brick blank prepared by the aging material also has abundant holes, so that the black mud shale brick obtained after roasting has more excellent heat preservation and heat insulation performance, and its deadweight is lighter. In addition, the probiotics remaining in the brick blank can be used as organic fuel, and during roasting, dispersed internal combustion nodes are formed inside the brick blank, and the strength and hardness of the black mud shale brick of the present invention are higher than those of ordinary brick blanks. Therefore, the black mud shale brick provided by the present invention has excellent heat preservation and heat insulation performance.

[0029] The results of the embodiment show that the heat transfer coefficient of the black mud shale brick provided by the present invention is as low as 1.1, the compressive strength can reach MU20, the flexural strength is ≥4.6MPa, the water absorption rate is ≤7.9%, and the volume density is ≤984.6kg / m 3 It meets the requirements of the national standard GB / T5101-2017 "Sintered Ordinary Bricks" and can be widely used in actual engineering construction.

[0030] The present invention provides a method for preparing the black mud shale brick, comprising the following preparation steps: mixing shale particles, papermaking black mud, probiotic stock solution and water to obtain a prefabricated slurry; aging the prefabricated slurry to obtain an aged material; shaping the aged material to obtain a brick blank; and calcining the brick blank to obtain the black mud shale brick.

[0031] In the present invention, during the aging process, a part of cellulose, lignin and hemicellulose, soluble salts in papermaking black mud will float with water or dissolve in water, and another part of cellulose, lignin and hemicellulose and probiotics in papermaking black mud will be precipitated to the bottom layer;Bacillus and cellulophagy in probiotic stock solution gradually ferment and decompose organic matter such as cellulose, lignin and hemicellulose deposited in the papermaking black mud at the bottom layer under suitable temperature conditions, and generate glucose and other materials that can be used for combustion support;The gas produced by fermentation will entrain some light impurities and float with water, and the water layer and impurities of the upper layer will be discharged, and the aged material precipitated from the bottom layer will be separated. In addition, the gas produced by fermentation will form a bubbling stirring effect, so that the bottom papermaking black mud and shale particles are mixed more evenly and closely;Moreover, the gas produced by fermentation will form fine holes in the aged material at the bottom layer, so that the baked black mud shale brick has abundant holes, avoids cracking caused by internal stress, and has better thermal insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of the method for preparing black mud shale bricks provided by the present invention;

[0033] Figure 2 This is the SEM image of the black mud shale brick prepared in Example 1;

[0034] Figure 3 This is a finished product picture of the black mud shale brick prepared in Example 1;

[0035] Figure 4 This is a diagram showing the thermal insulation effect of the black mud shale bricks prepared in Example 1. DETAILED DESCRIPTION

[0036] The present invention provides a black mud shale brick, comprising the following raw materials in percentage by mass:

[0037] 40-70% shale particles, 10-30% papermaking black mud, 5-20% probiotic stock solution, and 10-30% water;

[0038] The mass concentration of the probiotic stock solution is 10-30%;

[0039] The probiotic stock solution comprises bacillus and / or cellulophagus and water.

[0040] In the present invention, unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0041] The raw materials for preparing the black mud shale brick provided by the present invention include 40-70% by mass of shale particles, preferably 50-70%. In the present invention, the particle size of the shale particles is preferably <0.063mm, more preferably <0.05mm. In the present invention, the shale particles have the function of supporting the strength of the brick body and ensuring the strength of the brick body.

[0042] The raw materials for preparing the black mud shale bricks provided by the present invention include 10-30% by mass of papermaking black mud, preferably 15-25%. In the present invention, the particle size of the papermaking black mud is preferably <0.125mm, more preferably <0.1mm. In the present invention, the moisture content of the papermaking black mud is preferably 25-35%, more preferably 25-30%. In the present invention, the papermaking black mud is a waste resource recycling of paper mills, with a wide source, low cost, thermal insulation, and can also save fuel required for roasting.

[0043] The raw materials for preparing the black mud shale bricks provided by the present invention include a probiotic stock solution with a mass percentage of 5 to 20%, preferably 10 to 20%. In the present invention, the probiotic stock solution preferably includes Bacillus and / or cellulophagus and water. In the present invention, the mass concentration of the probiotic stock solution is 10 to 30%, preferably 20 to 30%.

[0044] In the present invention, the method for preparing the probiotic stock solution preferably comprises the following steps: mixing probiotics, brown sugar and water, and culturing to obtain the probiotic stock solution;

[0045] The probiotics include Bacillus and / or Cellulophagus;

[0046] The water is deionized water or pure water;

[0047] The culture is carried out in a sealed state and under standard atmospheric pressure; the temperature of the culture is 25±0.5° C., and the time is 12 to 24 hours.

[0048] In the present invention, the mass ratio of probiotics, brown sugar and water in the probiotic stock solution is preferably 0-0.5:1:45-55, and is not 0, more preferably 0.2-0.4:1:50. In the present invention, the probiotics preferably include Bacillus and / or cellulophagus. In the present invention, the mass ratio of Bacillus and cellulophagus in the probiotics is preferably 0-1:0-1, more preferably 1:1. In the present invention, the water is preferably deionized water or pure water. In the present invention, the culture is preferably carried out in a sealed state and under standard atmospheric pressure. In the present invention, the temperature of the culture is preferably 25±0.5°C, and the time is preferably 12-24h, more preferably 24h.

[0049] In the present invention, the Bacillus and Cellulophage in the probiotic stock solution have the functions of eliminating heavy metals in papermaking black mud, reducing radiation, and decomposing cellulose mixed in papermaking black mud into combustible organic matter.

[0050] The raw materials for preparing the black mud shale bricks provided by the present invention include 10-30% by mass of water, preferably 10-15%. In the present invention, the water is preferably deionized water and / or pure water.

[0051] The present invention also provides a method for preparing the black mud shale bricks described in the above technical solution, comprising the following preparation steps:

[0052] The shale particles, papermaking black mud, probiotic stock solution and water are mixed to obtain a prefabricated slurry;

[0053] Aging the prefabricated slurry to obtain an aged material;

[0054] shaping the aged material to obtain a brick;

[0055] The brick blank is fired to obtain the black mud shale brick.

[0056] The invention mixes shale particles, papermaking black mud, probiotic stock solution and water to obtain prefabricated slurry.

[0057] In the present invention, the shale particles and papermaking black mud are preferably used in the form of a mixed powder of shale particles and papermaking black mud. In the present invention, the preparation method of the mixed powder of shale particles and papermaking black mud preferably includes the following steps: adding shale and papermaking black mud to a jaw crusher for crushing to obtain a mixture of papermaking black mud and shale particles; adding the mixture of papermaking black mud and shale particles to a drum screen for screening to obtain a coarse powder of a mixture of papermaking black mud and shale particles, the particle size of the coarse powder of the mixture of papermaking black mud and shale particles is 1 to 1.5 mm; sending the coarse powder of the mixture of papermaking black mud and shale particles to a wheel mill for refining to obtain the mixed powder of shale particles and papermaking black mud. In the present invention, the particle size of the mixed powder of shale particles and papermaking black mud is preferably 0.05 to 0.11 mm. In the present invention, the crushing time is preferably 20 to 120 min. In the present invention, the refining time is preferably 60 to 100 min.

[0058] In the present invention, the mixing of shale particles, papermaking black mud, probiotic stock solution and water is preferably carried out in a mixer. In the present invention, the mixing time of shale particles, papermaking black mud, probiotic stock solution and water is preferably 15 to 50 minutes.

[0059] After obtaining the prefabricated slurry, the present invention ages the prefabricated slurry to obtain an aged material.

[0060] In the present invention, the aging is preferably carried out in an aging chamber. In the present invention, the aging temperature is preferably room temperature. In the present invention, the aging time is preferably 12 to 60 hours, more preferably 36 to 48 hours.

[0061] In the present invention, after the aging is completed, it is preferred to further include discharging the upper water layer and impurities and separating them from the aged material precipitated at the bottom.

[0062] The present invention ages the prefabricated pulp, and the aging can fully ferment the raw materials of papermaking black mud, probiotic stock solution and water, so that the raw materials are mixed more evenly, the raw materials are fully combined, and some impurities are filtered out.

[0063] After obtaining the aged material, the present invention shapes the aged material to obtain a brick.

[0064] In the present invention, the molding preferably includes preparing the brick blank and shaping the brick blank in sequence. In the present invention, the preparation of the brick blank is preferably carried out in a two-stage vacuum brick extruder, an automatic strip cutter and an automatic blank cutter in sequence. In the present invention, the preparation of the brick blank specifically preferably includes: feeding the aged material into a two-stage vacuum brick extruder, extruding and molding to obtain mud strips; feeding the mud strips into a grinder, and after surface treatment, feeding them into an automatic strip cutter and an automatic blank cutter in sequence to cut them into bricks of the desired size; feeding the bricks into a mold to shape the brick blank. In the present invention, after the brick blank is shaped, the shape and size are fixed, and the mold can be removed to obtain the brick blank.

[0065] In the present invention, the brick shaping is preferably carried out in a constant temperature and humidity environment. In the present invention, the temperature of the brick shaping is preferably 20-25°C, the air humidity is preferably 15-25%, more preferably 25%, and the time is preferably 2-5 days, more preferably 3 days.

[0066] Before firing, the present invention preferably also includes drying the bricks in the shade. In the present invention, the shade drying is preferably carried out in a constant temperature and humidity environment. In the present invention, the time for the shade drying is preferably 2 to 10 days, and more preferably 7 days. In the present invention, the temperature for the shade drying is preferably 20 to 25°C, and more preferably 22 to 25°C. In the present invention, the air humidity for the shade drying is preferably 25 to 35%, and more preferably 30%. In the present invention, the shade drying can allow the free moisture on the surface of the bricks to fully evaporate and dry, and the moisture inside the bricks gradually penetrates into the surface, which is more conducive to moisture drying and reduces the cracking and deformation problems of the bricks during the firing process.

[0067] After obtaining the air-dried bricks, the present invention bakes the bricks to obtain the black mud shale bricks.

[0068] In the present invention, the roasting preferably includes a drying stage, a preheating stage, a roasting stage and a cooling stage in sequence.

[0069] In the present invention, the temperature of the drying stage (T1) is preferably 100 to 300°C, and the heating rate from room temperature to the temperature of the drying stage is preferably 1 to 2°C / min.

[0070] In the present invention, the temperature of the preheating stage (T2) is preferably 300-550°C, and the heating rate from the temperature of the drying stage to the temperature of the preheating stage is preferably 1-2°C / min.

[0071] In the present invention, the temperature of the roasting stage (T3) is preferably 500-1050°C, more preferably 550-1050°C, the heating rate from the temperature of the preheating stage to the temperature of the roasting stage is preferably 1-2°C / min, more preferably 1°C / min, and the holding time after heating to the temperature of the roasting stage is preferably 3-10h, more preferably 6-8h.

[0072] In the present invention, the cooling stage (T4) is preferably a natural cooling to room temperature.

[0073] In the present invention, the calcination is preferably carried out in a silicon-molybdenum resistance furnace.

[0074] The present invention can fully dry the green bricks by setting a gradient temperature rise baking program, thereby avoiding the problems of cracking and deformation during the baking process caused by uneven drying of the green bricks and residual moisture.

[0075] The present invention also provides the application of the black mud shale bricks described in the above technical solution in the field of building materials.

[0076] The present invention does not specifically limit the application method, and the application can be performed using operations well known to those skilled in the art.

[0077] The technical solution of the present invention is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0078] Example 1

[0079] 200 g of Bacillus, 200 g of Cellulophagus and 1 kg of brown sugar were added into 30 kg of pure water, mixed evenly, and then cultured at 25° C., sealed and under standard atmospheric pressure for 24 hours to obtain a probiotic stock solution.

[0080] 30 kg of papermaking black mud and 70 kg of shale are added to a jaw crusher and crushed for 30 minutes to obtain a mixture of papermaking black mud and shale particles; the mixture of papermaking black mud and shale particles is added to a drum screen for screening to obtain a coarse powder of the mixture of papermaking black mud and shale particles with a particle size of 1 to 1.5 mm; the coarse powder of the mixture of papermaking black mud and shale particles is sent to a wheel mill for refining to obtain shale particles and papermaking black mud mixed powder with a particle size of 0.05 to 0.11 mm that can be used to prepare black mud shale bricks.

[0081] 100 kg of the obtained shale particles and papermaking black mud mixed powder were added to a mixer, and 10 kg of water and the obtained probiotic stock solution were added, and stirred for 20 minutes to obtain a prefabricated slurry. The prefabricated slurry was placed in an aging warehouse and aged at room temperature for 12 hours to obtain an aged material.

[0082] The aged material is fed into a double-stage vacuum brick extruder to extrude mud strips of 2400mm*1150mm*53mm, and the mud strips are fed into a grinder for surface treatment, and then fed into an automatic strip cutter and an automatic blank cutter in sequence to obtain bricks of 240mm*115mm*53mm.

[0083] The obtained bricks were put into a mold for brick blank shaping, and the shape and size were fixed for 3 days under the conditions of air humidity of 25% and temperature of 25°C. After removing the mold, the brick blank was obtained. Under the conditions of air humidity of 30% and temperature of 25°C, the brick blank was further dried in the shade for 7 days to prevent the brick blank from cracking.

[0084] The air-dried bricks were sent to a silicon-molybdenum resistance furnace for calcination, which included a drying stage (T1), where the temperature was raised to 300°C at a heating rate of 1°C / min; a preheating stage (T2), where the temperature was raised from 300°C to 550°C at a heating rate of 1°C / min; a calcination stage (T3), where the temperature was raised from 550°C to 1050°C at a heating rate of 1°C / min, and the heat preservation time of the calcination stage was 8h; a cooling stage (T4), where the temperature was naturally lowered to room temperature after the calcination stage to obtain black mud shale bricks (see Figure 3 ).

[0085] Figure 2 This is the SEM image of the black mud shale brick prepared in Example 1. Figure 2 It can be seen that there are many pores on the surface of the brick, which is conducive to thermal insulation.

[0086] Figure 4The thermal insulation effect diagram of the black mud shale bricks prepared in Example 1 is as follows: the test is carried out in a workshop, and the black mud shale bricks prepared in Example 1 are stacked into a test wall of 3 bricks long and 5 bricks high, with a thickness of 1 brick wide. A heater is used to heat one side of the test wall. The heater is 30 to 80 cm away from the wall. The temperature of the heater is maintained at 30 ± 2 ° C. After the temperature stabilizes, the temperature on both sides of the sample wall is measured every 3 to 6 hours. The measurement is continued for 6 days. The temperature on the side with the heater is recorded as the inner wall surface temperature, and the temperature on the side without the heater is recorded as the outer wall surface temperature. The difference between the inner wall surface temperature and the outer wall surface temperature is recorded as the inner and outer wall surface temperatures. The test results are shown in FIG. Figure 4 ,from Figure 4 It can be seen that: at the beginning, the temperature of the inner wall rose slightly, the highest was 35°C, and after stabilization in the later period, the surface temperature of the inner wall stabilized at 31-32.5°C. The heat was transferred to the outer wall along the black mud shale bricks prepared by the present invention. The temperature of the outer wall did not change much, basically fluctuating between 24 and 26°C, and the fluctuation range was within 2°C. The fluctuation of the surface temperature of the inner and outer walls was within 5-7°C, which fully proved that the black mud shale bricks prepared by the present invention had good thermal insulation effect and low heat transfer coefficient, and could effectively isolate the external cold air or high temperature environment and keep the internal temperature constant.

[0087] According to the standard GB / T 5101-2017 "Sintered Ordinary Bricks", the water absorption and volume density of the black mud shale bricks were tested. According to the protective box method in the standard GB / T 13475-2008, the heat transfer coefficient K of the black mud shale bricks was tested. According to the standard GB / T 5101-2017, the compressive strength and flexural strength of the black mud shale bricks were tested.

[0088] The test results are: water absorption rate 5.0%, heat transfer coefficient K is 1.1, compressive strength is 23.8MPa, strength reaches MU20, flexural strength is 5.0MPa, volume density is 845.3kg / m 3 .

[0089] Example 2

[0090] The only difference from Example 1 is: 20 kg of papermaking black mud and 80 kg of shale.

[0091] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 6.2%, heat transfer coefficient K 1.4, compressive strength 24.1MPa, strength reached MU20, flexural strength 5.2MPa, volume density 912.8kg / m 3 .

[0092] Example 3

[0093] The only difference from Example 1 is: 10 kg of papermaking black mud and 90 kg of shale.

[0094] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 7.9%, heat transfer coefficient K 1.5, compressive strength 24.5MPa, strength reached MU20, flexural strength 5.3MPa, volume density 984.6kg / m 3 .

[0095] Example 4

[0096] The only difference from Example 1 is that the calcination temperature is 1000°C.

[0097] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 5.6%, heat transfer coefficient K 1.1, compressive strength 19.5MPa, strength reached MU15, flexural strength 4.8MPa, volume density 873.2kg / m 3 .

[0098] Example 5

[0099] The only difference from Example 1 is that the calcination temperature is 950°C.

[0100] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 5.9%, heat transfer coefficient K 1.1, compressive strength 18.4MPa, strength reached MU15, flexural strength 4.6MPa, volume density 897.2kg / m 3 .

[0101] Example 6

[0102] The only difference from Example 1 is that the holding time in the roasting stage is 7 h.

[0103] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 5.1%, heat transfer coefficient K 1.1, compressive strength 22.9MPa, strength reached MU20, flexural strength 4.8MPa, volume density 854.7kg / m 3 .

[0104] Example 7

[0105] The only difference from Example 1 is that the holding time in the roasting stage is 6 hours.

[0106] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 5.1%, heat transfer coefficient K 1.1, compressive strength 21.8MPa, strength reached MU20, flexural strength 4.6MPa, volume density 867.1kg / m 3 .

[0107] Example 8

[0108] The only difference from Example 1 is that the heating rate in the calcination stage is 2°C / min.

[0109] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 4.6%, heat transfer coefficient K 1.1, compressive strength 19.7MPa, strength reached MU20, flexural strength 4.7MPa, volume density 824.7kg / m 3 .

[0110] Comparative Example 1

[0111] The only difference from Example 1 is that papermaking black mud is not used and the amount of shale added is 100 kg.

[0112] The obtained shale bricks were tested, and the test results were: water absorption rate 7.2%, heat transfer coefficient K 1.4, compressive strength 19.4MPa, flexural strength 3.4MPa, volume density 1147.3kg / m 3 .

[0113] Comparative Example 2

[0114] The only difference from Example 1 is that no probiotic stock solution was used.

[0115] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 4.5%, heat transfer coefficient K 1.3, compressive strength 13.4MPa, flexural strength 4.2MPa, volume density 901.3kg / m 3 .

[0116] Comparative Example 3

[0117] The only difference from Example 1 is that the prefabricated slurry is not aged.

[0118] The obtained black mud shale bricks were tested, and the test results were: water absorption rate 6.7%, heat transfer coefficient K 1.3, compressive strength 14.2MPa, flexural strength 4.7MPa, volume density 912.5kg / m 3 .

[0119] By comparing the test data of Examples 1 to 8, it can be seen that: when the amount of papermaking black mud added is less, the water absorption rate, heat transfer coefficient K, compressive strength, flexural strength and bulk density are higher;

[0120] The lower the roasting temperature, the higher the water absorption rate, the heat transfer coefficient K value remains basically unchanged, the lower the compressive strength, the lower the flexural strength, and the higher the volume density;

[0121] When the holding time in the roasting stage is within the range of 6 to 8 hours, the water absorption rate and heat transfer coefficient K remain basically unchanged, the compressive strength and flexural strength decrease slightly, and the bulk density increases slightly, but the changes are not large.

[0122] By comparing the data of Example 1 and Comparative Examples 1 to 3, it can be seen that the water absorption rate, heat transfer coefficient K, and bulk density of the shale brick obtained in Comparative Example 1 without adding papermaking black mud are greatly increased, and the compressive strength and flexural strength are reduced;

[0123] In Comparative Example 2, the water absorption rate, compressive strength and flexural strength of the black mud shale brick obtained without adding the probiotic stock solution were all reduced, while the heat transfer coefficient K and volume density were significantly increased;

[0124] In Comparative Example 3, the water absorption rate, heat transfer coefficient K and volume density of the black mud shale bricks obtained by papermaking black mud without aging increased, while the compressive strength and flexural strength decreased.

[0125] Table 1 Performance test results of black mud shale bricks obtained in Examples 1 to 8 and Comparative Examples 1 to 3

[0126]

[0127] The preparation method provided by the present invention is stable and reliable, and the performance of the black mud shale bricks obtained fully meets the requirements of national standards and has high feasibility. It provides a new development and reuse approach to effectively reduce the pollution of papermaking black mud to the environment. The present invention rationally screens and designs the raw material combination, and through the verification and optimization of orthogonal experiments, verifies the influence of aging, roasting, raw material ratio, temperature, time and other steps and factors on the performance of the new black mud shale bricks, and obtains the process parameters for preparing the black mud shale bricks with the best performance: aging time 12h, roasting temperature 1050℃, insulation time in the roasting stage 6~8h, heating rate 1~2℃ / min. The preparation method provided by the present invention has considerable prospects for industrial application.

[0128] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A black mud shale brick, characterized in that: The preparation comprises the following raw materials in mass percentage: 40-70% shale particles, 10-30% papermaking black mud, 5-20% probiotic stock solution, and 10-30% water; The mass concentration of the probiotic stock solution is 10-30%; The probiotic stock solution comprises bacillus and / or cellulophagus and water.

2. The black mud shale brick according to claim 1, characterized in that: The particle size of the shale particles is less than 0.063 mm.

3. The black mud shale brick according to claim 1, characterized in that: The particle size of the papermaking black mud is less than 0.125 mm; the moisture content of the papermaking black mud is 25-35%.

4. The black mud shale brick according to claim 1, characterized in that: The preparation method of the probiotic stock solution comprises the following steps: The probiotics, brown sugar and water are mixed and cultured to obtain a probiotic stock solution; The probiotics include Bacillus and / or Cellulophagus; The water is deionized water or pure water; The culture is carried out in a sealed state and under standard atmospheric pressure; the temperature of the culture is 25±0.5° C., and the time is 12 to 24 hours.

5. The method for preparing the black mud shale brick according to any one of claims 1 to 4, characterized in that: The method comprises the following preparation steps: The shale particles, papermaking black mud, probiotic stock solution and water are mixed to obtain a prefabricated slurry; Aging the prefabricated slurry to obtain an aged material; shaping the aged material to obtain a brick; The brick blank is fired to obtain the black mud shale brick.

6. The preparation method according to claim 5, characterized in that: The aging temperature is room temperature, and the aging time is 12 to 60 hours.

7. The preparation method according to claim 5, characterized in that: The molding comprises preparing a brick and shaping the brick in sequence; the temperature of the brick shaping is 20-25° C., the air humidity is 15-25%, and the time is 1-3 days.

8. The preparation method according to claim 5, characterized in that: Before the firing, the bricks are also dried in the shade at a temperature of 20-25° C., an air humidity of 25-35%, and a time of 2-10 days.

9. The preparation method according to claim 5, characterized in that: The calcination includes a drying stage, a preheating stage, a calcination stage and a cooling stage in sequence; the temperature of the drying stage is 100°C to 300°C, and the heating rate from room temperature to the temperature of the drying stage is 1 to 2°C / min; the temperature of the preheating stage is 300°C to 550°C, and the heating rate from the temperature of the drying stage to the temperature of the preheating stage is 1 to 2°C / min; the temperature of the calcination stage is 500°C to 1050°C, and the heating rate from the temperature of the preheating stage to the temperature of the calcination stage is 1 to 2°C / min, and the time is 3 to 10 hours; the cooling stage is a natural cooling to room temperature.

10. Use of the black mud shale bricks according to any one of claims 1 to 4 or the black mud shale bricks prepared by the preparation method according to any one of claims 5 to 9 in the field of building materials.

Images