CN101717235B - Baked brick prepared from desulphurization gypsum, waste mud, construction waste and other solid wastes as raw materials - Google Patents

Abstract

The invention uses crushed construction waste, mud cake after squeezing waste mud, desulfurized gypsum and tannery cinder as aggregate, adds a certain proportion of admixture for sintering, and obtains a new type of solid waste sintered brick. Compared with ordinary clay sintered bricks, while meeting the requirements of compressive strength, the production cost is reduced. All raw materials of this solid waste brick formula come from construction and industrial waste, which solves the problem of construction waste mud and construction waste, solves the problem of environmental pollution caused by solid waste such as desulfurized gypsum, protects cultivated land resources, and realizes Recycling of solid waste.

Description

Sintered bricks made of desulfurized gypsum, waste mud, construction waste and other solid waste as raw materials

technical field

The invention relates to a method for making solid waste sintered bricks, in particular to a formula suitable for making sintered bricks from desulfurized gypsum, mud cake after pressing waste mud, construction waste and leather factory cinder, and belongs to the technical field of civil engineering and building materials.

Background technique

In general coal-fired power plant production enterprises, a large amount of SO ₂ is discharged into the atmosphere through the flue gas flue every day, causing serious environmental pollution. It brings a series of waste gas treatment problems to enterprises, and the so-called desulfurization gypsum is obtained by desulfurizing the discharged flue gas. At present, there is no report of sintering bricks by desulfurization gypsum. Although there are reports of phosphogypsum sintering bricks, clay is still used as the main raw material in the sintering process adopted. Using clay to sinter bricks requires digging and destroying fields, consuming precious land resources and seriously destroying the ecological balance. Over the years, relevant state ministries and commissions have repeatedly issued orders to prohibit the production and use of solid clay bricks in some cities across the country. Therefore, it is of great significance to find alternative brick-making materials of clay.

A large amount of waste mud produced in geotechnical engineering construction is mainly composed of clay, sewage, drilling cuttings and mud treatment agents. In the past, the random discharge of waste mud caused the pollution of a large number of urban rivers, and the rivers were silted up. In recent years, through the strict management of local government departments, this situation has been alleviated and the development of mud pressing technology has also been promoted. However, due to the impact of transportation costs, the cost of mud treatment has remained high, causing a huge economic burden on construction companies. At present, the main disposal methods of the mud cake formed after mud pressing are as follows: one is to fertilize the nearby fields; the other is to transport and backfill low-lying fields; the third is to make bricks. From the perspective of the industrial chain, using the mud cake after mud pressing to make bricks can not only solve the environmental pollution caused by the mud, reduce transportation costs, but also solve the contradiction between the production of brick-making enterprises and the protection of cultivated land. effective measures.

On the other hand, with the rapid development of China's economy, the number of urban and rural infrastructure projects is increasing, leaving a large amount of construction waste in the construction of these projects. Landfilling of construction waste takes up a lot of land and money. Therefore, carrying out comprehensive utilization of construction waste resources has significant economic and social benefits.

The use of desulfurized gypsum sintered bricks generally requires the use of internal fuel. The effect in production is to reduce fuel consumption and shorten the roasting time. The disadvantage is that if the amount of internal fuel is too large, it will lead to more air holes in the bricks, large voids, and high resistance. The compressive strength is reduced. The optimal amount of internal fuel is related to the composition of fired bricks and the type of internal fuel, and needs to be optimized.

The invention uses desulfurized gypsum, crushed construction waste, mud cake after mud pressing and fly ash as aggregates, adds a certain proportion of additives for sintering, and obtains a new type of solid waste sintered brick. Compared with ordinary clay sintered bricks, while meeting the requirements of compressive strength, the production cost is reduced. All raw materials of this solid waste brick formula come from construction and industrial waste, which solves the problem of construction waste mud and construction waste, solves the problem of environmental pollution caused by solid waste such as desulfurized gypsum, protects cultivated land resources, and realizes Recycling of solid waste.

Contents of the invention

The purpose of the present invention is to provide a high-performance, low-cost solid waste sintered brick formula that can be applied to actual production. This kind of sintered brick formula uses desulfurized gypsum, waste mud, construction waste, fly ash and other solid waste as raw materials to solve the problem of environmental pollution caused by solid waste, protect cultivated land resources, and realize the recycling of solid waste.

According to the sintered brick formula of the present invention, the mass ratio of construction waste is 14.15%, the mass ratio of mud cake is 56.60%, the mass ratio of desulfurized gypsum is 14.15%, the mass ratio of fly ash is 9.43%, and the mass ratio of reinforcing agent is 5.66%.

In the sintered brick formula of the present invention, the mud cake used mainly comes from the waste mud produced by the construction of bored piles, and is mainly composed of clay, sand, stone and other components, wherein the clay component accounts for more than 70% of the solid component.

According to the sintered brick formula of the present invention, the mud cake used mainly comes from the mud produced in the construction of bored piles, wherein the mud is formed by flocculation combined with mechanical pressing. Before pressing, large particles such as sand and stones are removed. The water content of the final mud cake is controlled at 35%.

According to the sintered brick formula of the present invention, the construction waste used is mainly composed of waste concrete, broken brick slag and mortar, wherein the content of broken brick slag accounts for 20% of the construction waste.

According to the sintered brick formula of the present invention, the construction waste used is a powder with a diameter of less than 2 mm after being ground by a ball mill.

In the fired brick formula of the present invention, the main component of the desulfurized gypsum is calcium sulfate dihydrate, with a content of more than 75%.

The sintered brick formula of the present invention is characterized in that: the fly ash used is the dry fly ash of the power plant, and the mass fractions of SiO ₂ and CaO are 65.2 and 4.0% respectively

In the fired brick formula of the present invention, the admixture used is a reinforcing agent, and the main component is Fe ₂ O ₃ .

Beneficial effects of the present invention: the solid waste sintered brick is easy to manufacture, and only needs to mix the desulfurized gypsum, mud cake after mud pressing, construction waste powder, fly ash and reinforcing agent in proportion in advance. The strength of sintered bricks can be achieved by adjusting the amount of fly ash and reinforcing agent and the sintering temperature. The sintered brick formula uses solid waste commonly found in construction and industry as raw materials, and compared with ordinary clay sintered bricks, it not only meets the compressive strength, but also reduces the production cost. It solves the problem of desulfurization gypsum, construction waste mud, construction waste and fly ash, solves the problem of environmental pollution caused by solid waste, protects cultivated land resources, and realizes the recycling of solid waste.

Detailed ways

Example 1

After the designed and measured desulfurized gypsum, mud cake, construction waste powder, fly ash and reinforcing agent are evenly stirred, they are aged for 48 hours and set aside. The aged material is made into adobe, and the dimensions of the wet adobe are: length 250mm, width 120mm, height 92mm. After drying (using the heat released from the flue of the roasting kiln), the overall dimensions of the dry adobe brick are: length 242mm, width 118mm, height 91mm, moisture content less than 7%. Sent to the wheel kiln for roasting, the roasting temperature is controlled at 800°C to 1100°C, and it can be made into solid waste sintered bricks.

The finished bricks were tested for compressive strength, and the test results are shown in Tables 1-4.

Table 1 The weight ratio of each component in the trial mixing process of solid waste sintered bricks (admixture 2kg)

Table 2 The weight ratio of each component in the trial mixing process of solid waste sintered bricks (admixture 4kg)

Table 3 The weight ratio of each component in the trial mixing process of solid waste sintered bricks (admixture 6kg)

Table 4 The weight ratio of each component in the trial mixing process of solid waste sintered bricks (admixture 8kg)

Table 5 Permissible deviation of component measurement of light-weight thermal insulation fired bricks

mud cake construction rubbish Desulfurization gypsum Hardener ±2% ±2% ±1% ±0.2%

It can be seen from the above examples that with the increase of the amount of waste coal slag added, the strength of the fired brick first increases and then decreases. With the increase of the admixture, the strength of the fired brick increases gradually.

It can be seen from the above test results that mud cake: 60kg, construction waste: 15kg, desulfurized gypsum: 15kg, waste coal residue: 10kg, reinforcing agent: 6kg; and sludge: 60kg, construction waste: 15kg, desulfurization gypsum: 15kg, waste coal residue: 8kg, reinforcing agent: 8kg; the strength of the sintered brick body is 10.39Mpa and 10.25Mpa respectively, both of which reach the Mu10 strength of ordinary sintered clay bricks. Considering the requirements of economy and solid waste utilization rate, the final choice of mud cake: 60kg, Construction waste: 15kg, desulfurized gypsum: 15kg, waste coal residue: 10kg, reinforcing agent: 6kg as the optimal design formula. Compared with common clay bricks, the cost of the above-mentioned fired bricks is reduced by more than 20%.

Claims (1)

1. the preparation method of a solid waste baked brick; It is characterized in that by the mud cake after the squeezing of desulfurated plaster, mud, building waste powder, flyash, toughener with weight ratio 15: 60: 15: sintering formed in 10: 6; Wherein the sulfate dihydrate calcium contents is greater than 75% in the desulfurated plaster, and mud cake is mainly derived from the waste mud that bored pile construction produces, and mainly is made up of clay, sand, stone; Its medium clay soil composition accounts for more than 70% of solid composition; Wherein mud adopts the moulding of flocculation combine milling process, removes shakeout, stone macrobead composition before the squeezing earlier, and the mud cake water cut after the squeezing is controlled at 35%; Building waste is the diameter of milling through the ball mill powder less than 2mm, and the toughener staple is Fe ₂O ₃Desulfurated plaster, mud cake, building waste powder, flyash and the toughener that will pass through design metering after forcing to stir, ageing 48 hours, subsequent use; Material after the ageing is processed adobe, wet adobe physical dimension: long 250mm, and wide 120mm, high 92mm, after the heat drying of utilizing the release of roasting kiln flue, dry body brick physical dimension: long 242mm, wide 118mm, high 91mm, water cut is less than 7%; Send into wheel kiln baking, 800 ℃～1100 ℃ of control maturing temperatures are processed solid waste baked brick.