CN108383473A - A method of water-permeable brick is prepared based on gangue - Google Patents

Abstract

The invention discloses a kind of methods preparing water-permeable brick based on gangue, belong to water-permeable brick field.Gangue with adhesive property is carried out high-temperature fusion by the present invention in carbon dioxide atmosphere, under high temperature action, the sodium metaaluminate of formation generates sodium bicarbonate with carbon dioxide reaction, heated further decompose of sodium bicarbonate generates sodium carbonate, and pore-creating is carried out, increase porosity, the lignin of absorption simultaneously, the pyrolysis such as cellulose are fallen, protect hole, then it is that adding particle and ice crystal powder carries out mixed calcining, the fusing point of mixture is reduced by ice crystal powder, serpentine is destructurized in calcination process simultaneously, form class forsterite, increase porosity, increase intensity, and the silica in calcined material is reacted with sodium carbonate, generate sodium metasilicate, increase the combination dynamics between each substance, improve resistance to compression and flexural strength.The present invention solves the problems, such as that current water-permeable brick production cost is high, compression strength is low.

Description

A method for preparing permeable bricks based on coal gangue

technical field

The invention belongs to the field of permeable bricks, in particular to a method for preparing permeable bricks based on coal gangue.

Background technique

With the rapid development of the economy and the acceleration of urbanization, the urban surface is covered by more and more impermeable materials such as cement pavement and asphalt pavement, which brings convenience to traffic, but also causes many negative effects. A large number of studies have shown that, compared with impermeable pavement, permeable brick pavement has the functions of alleviating surface runoff, recharging underground, purifying pavement rainwater, improving urban thermal environment, absorbing urban noise, and improving the ecological environment of urban surface soil. Our country is now at the peak of urbanization, the urban area is getting bigger and bigger, the original farmland, ponds and wetlands are gone, and the "hardening" of the surface has replaced the "green space", which also leads to the impossibility of natural water seepage on the ground , a sudden multiplication of rainwater entering the city's drainage system with nowhere to go. Compared with other rainwater recovery technologies, roads paved with permeable bricks have excellent properties such as high water permeability, low cost, and environmental protection. So far, the most mature technology is the permeable pavement paved with concrete pavement bricks, which is known for its low cost.

Permeable bricks originated in the Netherlands. During the process of building the city from the sea, the Dutch found that the ground after the sea water was drained would cause continuous land subsidence due to long-term lack of contact with water. Once the dykes on the coastline are washed away, the seawater will quickly rush to cities much lower than sea level and submerge the entire coastal city. In order to prevent the ground from sinking, the Dutch made a small pavement brick with a length of 200 mm, a width of 100 mm, and a height of 50 or 60 mm, which was laid on the street surface, and a gap of 2 mm was reserved between the bricks. In this way, when it rains, the rainwater will seep into the ground from the gaps between the bricks. This is the famous Dutch brick later. Afterwards, the Shubroko Company of the United States invented a pavement brick whose body itself has a strong water absorption function. When the brick body is full of water, the water will drain to the ground, but the drainage speed of this kind of brick is very slow. In the rainy weather, this kind of brick can hardly help. This kind of brick is also called Shubuluo Branch pavers. Shubuluoke bricks appeared in China in the 1990s. According to the principle of Shubuluoke bricks, the technicians of the Beijing municipal department invented a kind of pavement brick with permeable holes and good water permeability. Rainwater will flow into the ground through the tiny holes in the brick body. After another period of time, in order to strengthen the compressive and flexural strength of the brick body, technicians used crushed stone as raw material and added cement and colloidal admixture to make the water permeability and strength meet the needs of urban pavement. The price is relatively cheaper than ceramic permeable bricks fired with ceramics, and it is suitable for projects in most areas.

Coal gangue is solid waste discharged during the coal mining process and coal washing process. It is a black-gray rock with low carbon content and harder than coal that is associated with coal seams during the coal formation process. Including the excavation gangue during the roadway excavation, the gangue extracted from the roof, floor and interlayer during the mining process, and the gangue picked out during the coal washing process. Its main components are Al ₂ O ₃ and SiO ₂ , and it also contains varying amounts of Fe ₂ O ₃ , CaO, MgO, Na ₂ O, K ₂ O, P ₂ O ₅ , SO ₃ and trace rare elements (gallium, vanadium, titanium, cobalt). At present, coal gangue has been used for power generation and building materials in my country, but a large amount of coal gangue has not been effectively utilized, resulting in a large amount of waste.

The permeable bricks on the existing market can be roughly divided into three basic types: ceramic permeable bricks, cement-based permeable bricks and resin-bonded permeable bricks. In recent years, sand-based permeable bricks have become a hot spot of attention. This kind of sand-based permeable bricks is made of desert sand. It has good water permeability and non-slip performance, but has low compressive strength and poor wear resistance. Therefore, it is of great significance to rationally utilize coal gangue to prepare a permeable brick with high compressive strength.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing permeable bricks based on coal gangue in view of the current problems of high production cost and low compressive strength of permeable bricks.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A method for preparing permeable bricks based on gangue, the method comprising the steps of:

(1) Take coal gangue and put it into a ball mill for ball milling, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, let stand, remove impurities floating on the surface, and filter , collecting the filter residue, drying the filter residue, crushing, sieving, and collecting the sieved particles;

(2) Put the sieved particles and papermaking black liquor into a ball mill for ball milling at a mass ratio of 7:1~3, use carbon dioxide for protection during the ball milling process, collect the ball mills, put the ball mills into an electric melting furnace, and use Carbon dioxide discharges the gas in the electric melting furnace, sets the temperature at 700~720°C, and melts for 40~60 minutes;

(3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles evenly according to the mass ratio of 6~9:0.3~0.6:2~4, and put them into the calciner, set the temperature Calcination at 1100~1300°C;

(4) After the calcination is completed, the calcined product is collected, and the calcined product, accelerator and water are mixed evenly according to the mass ratio of 10~16:1~3:5~7, put into the mold, and carry out under the condition of 4~10MPa Pressing, then drying, demoulding, and collecting the demoulding;

(5) Curing the demoulding object in water vapor for 3~5 times, each curing time is 1~2h. After the curing is completed, dry the cured demoulding object naturally for 20~30min to obtain water permeability brick.

Preferably, the papermaking black liquor in the step (2) is alkaline papermaking black liquor.

Preferably, adding particles in the step (3) is to put serpentine and boehmite in a pulverizer at a mass ratio of 3:2 for crushing, pass through a 200-mesh sieve, and collect the sieved particles to obtain the added particles.

Preferably, the accelerator in the step (3) is formed by mixing tourmaline powder and montmorillonite at a mass ratio of 1:2.

Optionally, the temperature of the water vapor in the step (5) is 100-105°C.

Compared with other methods, the present invention has beneficial technical effects as follows:

(1) The present invention uses coal gangue as the base material, first removes impurities through sodium chloride solution, removes impurities therein, and then mixes it with papermaking black liquor. Fill lignin, cellulose, etc. to prevent the sodium metaaluminate formed by the reaction between the alkali in the papermaking black liquor and the alumina in the gangue from blocking the pores, and the formed sodium metaaluminate makes the gangue have bonding properties. increase activity;

(2) In the present invention, coal gangue with cohesive properties is melted at high temperature in a carbon dioxide atmosphere, and under the action of high temperature, the formed sodium metaaluminate reacts with carbon dioxide to produce sodium bicarbonate, which is further decomposed by heating to produce sodium carbonate, In addition, pore-making was carried out to increase the porosity, and at the same time, the adsorbed lignin and cellulose were pyrolyzed to protect the pores, and then the particles and cryolite powder were added for mixed calcination, and the melting point of the mixture was lowered by the cryolite powder, and at the same time During the calcination process, the serpentine structure is destroyed to form forsterite, which increases the porosity and strength, and the silica is exposed, and the silica in the calcined product reacts with sodium carbonate to form sodium silicate , increasing the bonding strength between the various substances, improving the compressive and flexural strength, followed by curing, forming a gel through the action of water vapor and boehmite to further increase the bonding degree, and further improve the compressive strength and mechanical properties , through the formation of gel, the water permeability coefficient is increased, and the pores can be effectively cleaned through the store tourmaline powder and montmorillonite, achieving a certain self-cleaning ability and increasing the mechanical properties.

Detailed ways

The papermaking black liquor is the alkaline papermaking black liquor, which uses sodium hydroxide to treat the waste liquor produced in the process of vegetation and plants, and the alkali content is 1.3~18g/L.

Preparation of added granules: Put serpentine and boehmite in a pulverizer at a mass ratio of 3:2 for crushing, pass through a 200-mesh sieve, and collect sieved particles to obtain added granules.

Accelerator preparation: Mix tourmaline powder and montmorillonite at a mass ratio of 1:2.

A method for preparing permeable bricks based on gangue, the method comprising the steps of:

(1) Take coal gangue and put it into a ball mill for 2 hours at 800r/min, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, and let it stand for 1~3h , remove impurities floating on the surface, filter, collect the filter residue, dry the filter residue, pulverize, pass through a 100-mesh sieve, and collect the sieved particles;

(2) Put the sieved particles and papermaking black liquor into a ball mill at a mass ratio of 7:1~3 for 50 minutes at 500r/min, use carbon dioxide for protection during the ball milling process, collect the ball mills, and put the ball mills into the electric In the melting furnace, use carbon dioxide to discharge the gas in the electric melting furnace, set the temperature at 700~720°C, and melt for 40~60 minutes;

(3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles at a mass ratio of 6~9:0.3~0.6:2~4 at 700r/min for 30min, and put them into a calciner , set the temperature at 1100~1300°C, and calcine for 35~45min;

(4) After the calcination is completed, the calcined product is collected, and the calcined product, accelerator and water are mixed evenly according to the mass ratio of 10~16:1~3:5~7, put into the mold, and carry out under the condition of 4~10MPa Press for 10 minutes, then dry at 30-35°C, demould, and collect the demoulded material;

(5) Curing the demoulding object in water vapor, the temperature of water vapor is 100~105°C, curing 3~5 times, each curing time is 1~2h, and each interval is 10~15min, after the curing is completed, Dry the cured demoulding objects naturally for 20-30 minutes to obtain permeable bricks.

The papermaking black liquor is the alkaline papermaking black liquor, and the alkaline papermaking black liquor chooses to use sodium hydroxide to treat the waste liquor produced in the process of vegetation and plants, and the alkali content is 1.3g/L.

Preparation of added granules: Put serpentine and boehmite in a pulverizer at a mass ratio of 3:2 for crushing, pass through a 200-mesh sieve, and collect sieved particles to obtain added granules.

Accelerator preparation: Mix tourmaline powder and montmorillonite at a mass ratio of 1:2.

A method for preparing permeable bricks based on gangue, the method comprising the steps of:

(1) Take coal gangue and put it into a ball mill for 2 hours at 800r/min, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, let stand for 1 hour, remove Floating impurities on the surface, filter, collect the filter residue, dry the filter residue, pulverize, pass through a 100-mesh sieve, and collect the sieved particles;

(2) Put the sieved particles and papermaking black liquor in a mass ratio of 7:1, put them into a ball mill for 50 minutes at 500r/min, use carbon dioxide for protection during the ball milling process, collect the ball mills, and put the ball mills into an electric melting furnace , use carbon dioxide to discharge the gas in the electric melting furnace, set the temperature at 700°C, and melt for 40 minutes;

(3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles at a mass ratio of 6:0.3:2 at 700r/min for 30min, and put it into a calciner with a set temperature of 1100 ℃, calcined for 35min;

(4) After the calcination, collect the calcined product, stir and mix the calcined product, accelerator and water according to the mass ratio of 10:1:5, put it into the mold, and press it at 4MPa for 10min, and then carry out at 30℃ Drying, demoulding, collecting demoulding;

(5) Curing the demoulding object in water vapor, the temperature of the water vapor is 100°C, curing 3 times, each curing time is 1h, and the interval is 10min. After the curing is completed, the cured demoulding object is Naturally dry for 20 minutes to obtain permeable bricks.

The papermaking black liquor is the alkaline papermaking black liquor, which uses sodium hydroxide to treat the waste liquor produced in the process of vegetation and plants, and the alkali content is 18g/L.

Preparation of added granules: Put serpentine and boehmite in a pulverizer at a mass ratio of 3:2 for crushing, pass through a 200-mesh sieve, and collect sieved particles to obtain added granules.

Accelerator preparation: Mix tourmaline powder and montmorillonite at a mass ratio of 1:2.

A method for preparing permeable bricks based on gangue, the method comprising the steps of:

(1) Take coal gangue and put it into a ball mill for 2 hours at 800r/min, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, let stand for 3 hours, remove Floating impurities on the surface, filter, collect the filter residue, dry the filter residue, pulverize, pass through a 100-mesh sieve, and collect the sieved particles;

(2) The sieved particles and papermaking black liquor are put into a ball mill at a mass ratio of 7:3, and ball milled at 500r/min for 50 minutes. Carbon dioxide is used for protection during the ball milling process, and the ball milled matter is collected, and the ball milled matter is put into an electric melting furnace , use carbon dioxide to discharge the gas in the electric melting furnace, set the temperature at 720°C, and melt for 60 minutes;

(3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles at a mass ratio of 9:0.6:4 at 700r/min for 30min, and put it into a calciner with a set temperature of 1300 ℃, calcined for 45min;

(4) After the calcination is completed, collect the calcined product, stir and mix the calcined product, accelerator and water according to the mass ratio of 16:3:7, put it into the mold, and press it at 10MPa for 10min, and then carry out at 35℃ Drying, demoulding, collecting demoulding;

(5) Curing the demoulding object in water vapor, the temperature of the water vapor is 105°C, curing 5 times, each curing time is 2 hours, and the interval of each time is 15 minutes. After the curing is completed, the cured demoulding object is Naturally dry for 30 minutes to obtain permeable bricks.

The papermaking black liquor is the alkaline papermaking black liquor, and the alkaline papermaking black liquor chooses to use sodium hydroxide to treat the waste liquor produced in the process of vegetation and plants, and the alkali content is 9.5g/L.

Preparation of added granules: Put serpentine and boehmite in a pulverizer at a mass ratio of 3:2 for crushing, pass through a 200-mesh sieve, and collect sieved particles to obtain added granules.

Accelerator preparation: Mix tourmaline powder and montmorillonite at a mass ratio of 1:2.

A method for preparing permeable bricks based on gangue, the method comprising the steps of:

(1) Take coal gangue and put it into a ball mill for 2 hours at 800r/min, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, let stand for 2 hours, remove Floating impurities on the surface, filter, collect the filter residue, dry the filter residue, pulverize, pass through a 100-mesh sieve, and collect the sieved particles;

(2) Put the sieved particles and papermaking black liquor in a mass ratio of 7:2, put them into a ball mill for 50 minutes at 500r/min, use carbon dioxide for protection during the ball milling process, collect the ball mills, and put the ball mills into an electric melting furnace , use carbon dioxide to discharge the gas in the electric melting furnace, set the temperature at 710°C, and melt for 50 minutes;

(3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles at a mass ratio of 7.5:0.45:3 at 700r/min for 30min, and put it into a calciner with a set temperature of 1200 ℃, calcined for 40min;

(4) After the calcination, collect the calcined product, stir and mix the calcined product, accelerator and water according to the mass ratio of 13:2:6, put it into the mold, and press it at 7MPa for 10min, and then carry out at 33℃ Drying, demoulding, collecting demoulding;

(5) Curing the demoulding object in steam, the temperature of the steam is 103°C, curing 4 times, each curing time is 1.5h, and the interval of each time is 12.5min. The objects were dried naturally for 25 minutes to obtain permeable bricks.

Comparative example: permeable brick produced by a company in Hefei.

The permeable bricks of the examples and comparative examples were tested, referring to "GB/T25993-2010 Permeable Pavement Bricks and Permeable Pavement Panels", the test results are shown in Table 1.

Table 1

Based on the above, the present invention rationally utilizes the permeable brick prepared from coal gangue, and its performance is superior to that of the commercially available permeable brick, which is worthy of popularization and use.

Claims (5)

1. A method for preparing permeable brick based on coal gangue, is characterized in that, the method may further comprise the steps: (1) Take coal gangue and put it into a ball mill for ball milling, collect ball mill A, mix ball mill A with 0.3mol/L sodium chloride solution at a mass ratio of 1:3, let stand, remove impurities floating on the surface, and filter , collecting the filter residue, drying the filter residue, crushing, sieving, and collecting the sieved particles; (2) The sieved particles and papermaking black liquor are put into a ball mill for ball milling at a mass ratio of 7:1 to 3, and carbon dioxide is used for protection during the ball milling process. Carbon dioxide discharges the gas in the electric melting furnace, sets the temperature at 700-720°C, and melts for 40-60 minutes; (3) After the melting is completed, collect the molten material, grind the molten material, cryolite powder and added particles evenly according to the mass ratio of 6~9:0.3~0.6:2~4, and put them into the calciner, set the temperature Calcination at 1100-1300°C; (4) After the calcination is completed, collect the calcined product, stir and mix the calcined product, accelerator and water according to the mass ratio of 10-16:1-3:5-7, put it into the mold, and carry out the process at 4-10MPa Pressing, then drying, demoulding, and collecting the demoulding; (5) Curing the demoulding object in water vapor for 3 to 5 times, each curing time is 1 to 2 hours. After the curing is completed, dry the cured demoulding object naturally for 20 to 30 minutes to obtain water permeability brick. 2. The method for preparing permeable bricks based on coal gangue according to claim 1, characterized in that the papermaking black liquor in the step (2) is alkaline papermaking black liquor. 3. The method for preparing permeable bricks based on coal gangue according to claim 1, characterized in that the addition of particles in the step (3) is to put serpentine and boehmite into the pulverizer at a mass ratio of 3:2 Pulverize, pass through a 200-mesh sieve, and collect the sieved particles to obtain the added particles. 4. The method for preparing permeable bricks based on coal gangue according to claim 1, characterized in that the accelerator in the step (3) is formed by mixing tourmaline powder and montmorillonite at a mass ratio of 1:2. 5. The method for preparing permeable bricks based on coal gangue according to claim 1, characterized in that the temperature of the water vapor in the step (5) is 100-105°C.