CN114956783B - Garbage sintered brick and preparation method thereof - Google Patents

Abstract

The application belongs to the field of sintered bricks, and particularly relates to a garbage sintered brick and a preparation method thereof: preparing 65-80% of alum, 10-30% of calcium chloride and 5-10% of lithium carbonate into a composite auxiliary agent at the high temperature of 500-550 ℃; then 80 to 100 parts of engineering slag soil, 25 to 35 parts of municipal sludge, 10 to 20 parts of biogas residue, 0.2 to 0.4 part of composite auxiliary agent and biogas sewage are made into green bricks, and the green bricks are baked and preheated at 800 to 950 ℃ to be made into garbage baked bricks; the composite auxiliary agent can reduce the firing temperature of the garbage brick by about 150 ℃, save a large amount of fuel and reduce the production cost. The utilization rate of the waste is nearly 100%, the waste discharge amount and the environmental pollution are reduced, the energy consumption is reduced, and the method is an effective technical means for reducing emission and utilizing waste; the prepared garbage sintered brick has stable quality and good heat insulation performance.

Description

Garbage baked brick and preparation method thereof

Technical Field

The invention belongs to the technical field of sintered bricks, and particularly relates to a garbage sintered brick and a preparation method thereof.

Background

The engineering residual soil is one of construction wastes, and refers to waste soil, waste materials and other wastes generated in the process of building, rebuilding, expanding and dismantling various buildings, structures, pipe networks and the like by construction units and house decoration and finishing by residents according to the construction wastes called in urban construction waste management regulations.

Kitchen waste, commonly known as swill, also known as swill and hogwash, is a domestic waste formed in the process of domestic consumption by residents, is extremely easy to rot and deteriorate, emits foul smell, and spreads bacteria and viruses. Along with the rapid development of urbanization in China, the production amount of engineering muck, kitchen waste and domestic excrement is increasing day by day, and the problems of incomplete engineering muck treatment facilities, low resource utilization rate and serious stacking exist; the kitchen waste treatment excessively depends on landfill treatment; the domestic excrement is discharged after fermentation treatment, and the utilization rate is low. After the kitchen waste and the domestic excrement are fermented by the methane tank to generate methane, a large amount of methane residues and methane sewage are generated, and the harmless treatment needs to increase the capital investment and the resource investment.

According to the invention, the engineering waste soil, the municipal sludge, the biogas residues and the biogas sewage are used for preparing the garbage baked bricks, so that harmless and resource utilization of various wastes is realized, and the subsequent treatment cost of the wastes is reduced; the compound additive is researched and developed, so that the firing temperature of the garbage baked brick can be reduced, the energy is saved, and the production cost is reduced.

Disclosure of Invention

In order to reduce natural resources and energy consumption, fully and harmlessly utilize construction waste, municipal sludge and household garbage, reduce waste storage and reduce treatment cost, the invention provides a garbage baked brick and a preparation method thereof.

A garbage baked brick is prepared from the following materials: based on the weight of dry materials, 80 to 100 parts of engineering residue soil, 25 to 35 parts of municipal sludge, 10 to 20 parts of biogas residue and 0.2 to 0.4 part of composite auxiliary agent; the materials are mixed by using biogas sewage, and the ratio of the total mixing water to the dry base materials is 0.19-0.22.

The compound additive is prepared by treating a mixture of 65-80% of alum, 10-30% of calcium chloride and 5-10% of lithium carbonate at the high temperature of 500-550 ℃ for 30-60 min, cooling, crushing and grinding.

The preparation method of the garbage baked brick comprises the following steps:

firstly, treating a mixture of 65-80% of alum, 10-30% of calcium chloride and 5-10% of lithium carbonate at the high temperature of 500-550 ℃ for 30-60 min, cooling, crushing and grinding to prepare a powdery compound additive;

step two, dissolving 0.2-0.4 part of composite additive in the biogas sewage to prepare a mixed solution for later use;

respectively crushing and screening the engineering muck and the biogas residues, and then preparing a mixture of 80-100 parts of the engineering muck, 25-35 parts of municipal sludge and 10-20 parts of the biogas residues according to dry materials;

step four, adding about 2/3 of the mixed solution into the mixture, and uniformly stirring and aging for 18-30 h; then adding the rest mixing liquid, stirring uniformly, and preparing a green brick by vacuum extrusion and cutting; wherein the ratio of the total amount of the mixing water to the dry base material is 0.19-0.22;

and step five, after the green bricks are dried step by step for three times, preheating the green bricks for 1 to 2 hours in a kiln at the temperature of between 300 and 400 ℃, then heating the green bricks to between 800 and 950 ℃, roasting the green bricks for 3 to 5 hours, and cooling the green bricks to obtain the sintered bricks.

Preferably, the particle size of the material screened in the third step is less than or equal to 3mm. Compared with the material with the grain diameter of 0.5 mm-2 mm, the continuous graded material with the grain diameter of less than 3mm can meet the production quality requirement after aging and secondary stirring; the soil or mud particles with the particle size of 2 mm-3 mm in the material can be dispersed and uniformly mixed with the fine material after primary water adding, soaking, stirring, aging and secondary water adding and stirring; the remaining small amount of hard particles (such as sand grains and the like) with the particle size of 2 mm-3 mm has little negative strength to the brick. On one hand, the production efficiency of material crushing and screening can be improved by 10-15%, and the production energy consumption and the production cost are reduced; on the other hand, the crushing fine powder (powder with the particle size of less than 0.5 mm) and the dedusting fine powder can be used in the mixture, so that the crushing fine powder and the dedusting fine powder are reasonably and effectively utilized, and the subsequent disposal links are reduced; and in the third aspect, the fine powder can improve the plasticity and cohesiveness of the mixture, extrusion forming is easier, the brick blank is not easy to lack edges and fall corners, and the appearance quality of the product is improved.

Preferably, the green bricks in the step five are subjected to three step-by-step drying processes. The first drying temperature is 50-70 ℃, and the drying time is 2-3 h; the second drying temperature is 100-120 ℃, and the drying time is 1-2 h; the third drying temperature is 160-180 ℃, and the drying time is 1-2 h. The heat of the first drying comes from the residual heat of a cooling system of the roasting kiln, and the heat of the second drying and the third drying comes from smoke heat and residual heat of the roasting kiln. The green bricks are dehydrated more completely through three-time step-by-step drying, the drying effect is better, the green bricks are not easy to crack, and the appearance quality and the overall performance of the sintered bricks are improved. The invention utilizes the roasting waste heat for drying, can fully utilize the heat energy of the roasting kiln, reduces the energy waste and saves the drying cost.

The invention has the following positive beneficial effects: according to the invention, the alum, the calcium chloride and the lithium carbonate are prepared into the composite auxiliary agent, so that the firing temperature of the garbage brick can be reduced by about 150 ℃, the fuel can be saved by about 20%, the production cost can be reduced, and the energy can be saved; the continuous graded material with the grain size of less than 3mm is used, after aging and secondary stirring, the soil or clay grains with the grain size of 2-3 mm in the material can be dispersed and uniformly mixed with the fine material, the production efficiency of crushing and screening the material can be improved by 10-15%, the crushing and screening cost and energy consumption of the material are reduced, the powder is reasonably and effectively utilized, and the production efficiency of green bricks is improved; the green bricks are dried step by step for three times by using the roasting waste heat, so that the cracking rate and the drying energy consumption of the green bricks can be reduced, and the yield is improved.

According to the invention, the waste baked bricks are produced by utilizing the engineering dregs, the municipal sludge, the biogas residues and the biogas sewage, the utilization rate of the waste is close to 100%, the waste discharge amount is reduced, the environmental protection treatment cost and the environmental pollution are reduced, the energy consumption is reduced, and the method is an effective technical means for reducing emission and utilizing waste; the obtained garbage sintered brick has stable quality and good heat insulation performance.

Detailed Description

The present invention will be described in further detail with reference to examples. In the embodiment, the engineering muck is dried, crushed and sieved until the particle size is less than or equal to 3mm; the municipal sludge comes from a sewage treatment plant and has the water content of 28 percent; the biogas residues and biogas sewage come from a biogas plant, and the biogas residues are dried, crushed and sieved until the particle size is less than or equal to 3mm; the screen allowance of the 0.08mm square-hole screen of the composite additive is less than or equal to 7, and the experimental actual measurement is 3.4%. The compression strength and the heat transfer coefficient of the sintered bricks of the examples and the comparative examples are tested according to the sintered insulating bricks and the insulating blocks (GB 26538-2011).

Example 1

Step one, treating a mixture of 65% of alum, 30% of calcium chloride and 5% of lithium carbonate at 520 ℃ for 40min, cooling, crushing and grinding to prepare a powdery composite auxiliary agent;

step two, dissolving 0.3 part of composite additive in the biogas sewage to prepare a mixed solution for later use;

step three, after the engineering muck and the biogas residues are respectively crushed and screened, 80 parts of the engineering muck, 35 parts of municipal sludge and 15 parts of the biogas residues are prepared into a mixture according to the weight ratio of dry materials;

step four, adding 8 parts of the mixed solution into the mixture, and uniformly stirring and aging for 22 hours; then adding the rest 4 parts of the mixing solution, uniformly stirring, and preparing a green brick by vacuum extrusion and cutting;

and step five, drying the green brick for 3 hours at 50 ℃, 1 hour at 110 ℃ and 1.5 hours at 170 ℃ for three times, preheating the green brick for 1 hour at 350 ℃ in a kiln, heating the green brick to 800 ℃, roasting the green brick for 5 hours, and cooling the green brick to obtain the sintered brick.

Example 2

Step one, treating a mixture of 75% of alum, 18% of calcium chloride and 7% of lithium carbonate at 540 ℃ for 30min, cooling, crushing and grinding to prepare a powdery compound auxiliary agent;

step two, dissolving 0.2 part of composite auxiliary agent in the biogas sewage to prepare a mixed liquid for later use;

step three, after the engineering muck and the biogas residues are respectively crushed and screened, 85 parts of the engineering muck, 30 parts of municipal sludge and 10 parts of the biogas residues are prepared into a mixture according to the weight ratio of dry base materials;

step four, adding 9 parts of the mixed solution into the mixture, and uniformly stirring and aging for 18 hours; then adding the rest 4 parts of the mixing solution, uniformly stirring, and performing vacuum extrusion and cutting to prepare a green brick;

and step five, drying the green brick for 2.5h at 65 ℃, 1h at 120 ℃ and 2h at 165 ℃ for three times, preheating the green brick for 1.5h at 400 ℃ in a kiln, heating the green brick to 900 ℃, roasting the green brick for 4.5h, and cooling the green brick to obtain the sintered brick.

Example 3

Step one, treating a mixture of 80% of alum, 10% of calcium chloride and 10% of lithium carbonate at 550 ℃ for 60min, cooling, crushing and grinding to prepare a powdery composite auxiliary agent;

step two, dissolving 0.3 part of composite auxiliary agent in the biogas sewage to prepare a mixed liquid for later use;

step three, after respectively crushing and screening the engineering muck and the biogas residues, preparing 90 parts of the engineering muck, 25 parts of municipal sludge and 20 parts of the biogas residues into a mixture according to the weight ratio of dry base materials;

step four, adding 11 parts of the mixed solution into the mixture, and uniformly stirring and aging for 26 hours; then adding the rest 6 parts of the mixing solution, uniformly stirring, and preparing a green brick by vacuum extrusion and cutting;

and step five, drying the green bricks for 2 hours at 70 ℃, 2 hours at 100 ℃ and 1 hour at 180 ℃ for three times, preheating the green bricks for 2 hours at 300 ℃ in a kiln, heating the green bricks to 950 ℃, roasting the green bricks for 3 hours, and cooling the green bricks to obtain the sintered bricks.

Example 4

Step one, treating a mixture of 70% of alum, 22% of calcium chloride and 8% of lithium carbonate at a high temperature of 500 ℃ for 50min, cooling, crushing and grinding to prepare a powdery compound auxiliary agent;

step two, dissolving 0.4 part of composite auxiliary agent in the biogas sewage to prepare a mixed liquid for later use;

step three, after the engineering muck and the biogas residues are respectively crushed and screened, preparing 100 parts of the engineering muck, 30 parts of municipal sludge and 18 parts of the biogas residues into a mixture according to the weight ratio of dry materials;

step four, adding 12 parts of the mixed solution into the mixture, and uniformly stirring and aging for 30 hours; then adding the rest 6 parts of the mixing solution, uniformly stirring, and performing vacuum extrusion and cutting to prepare a green brick;

and step five, drying the green brick for 3 hours at 60 ℃, 1.5 hours at 110 ℃ and 2 hours at 160 ℃ for three times, preheating the green brick for 2 hours at 350 ℃ in a kiln, heating the green brick to 850 ℃, roasting the green brick for 4 hours, and cooling the green brick to obtain the sintered brick.

Comparative examples A1 to A4, except that the compound additive is not added, other test conditions are the same as those of the experimental groups of the comparative examples 1 to 4; comparative example A1 was compared to example 1, comparative example A2 was compared to example 2, and so on.

In comparative examples B1 to B4, the test conditions were the same as those in the test groups of examples 1 to 4 except that the composite assistant was not added and the calcination temperature was 1100 ℃; comparative example B1 is compared to example 1, comparative example B2 is compared to example 2, and so on.

TABLE 1 comparative experimental results of the baked bricks of examples and comparative examples

	Composite assistant	Temperature of roasting	Time of calcination	Compressive strength	Coefficient of heat transfer
								℃	h	MPa	W/(㎡·K)
Example 1	0.3	800	5	17.5	0.165
						Example 2	0.2	900	4.5	18.3	0.168
Example 3	0.3	950	3	19.2	0.162
						Example 4	0.4	850	4	19.6	0.163
Comparative example A1	—	800	5	5.4	0.157
						Comparative example A2	—	900	4.5	7.3	0.163
Comparative example A3	—	950	3	8.4	0.164
						Comparative exampleA4	—	850	4	6.3	0.159
Comparative example B1	—	1100	5	19.5	0.166
						Comparative example B2	—	1100	4.5	19.4	0.167
Comparative example B3	—	1100	3	18.3	0.159
						Comparative example B4	—	1100	4	19.1	0.163

When the composite additive is not added, the strength of the sintered bricks of the comparative examples A1 to A4 is only 5MPa to 8MPa, which is much lower than that of the examples 1 to 4 and that of the comparative examples B1 to B4, and the heat transfer coefficient is close to that of the examples. Comparative examples B1 to B4 were prepared without adding a composite auxiliary, and the strength of the sintered bricks after sintering at 1100 ℃ was similar to that of examples 1 to 4. This indicates that: the composite additive can obviously reduce the sintering temperature of the sintered brick, save energy and reduce production cost.

Claims (4)

1. A garbage baked brick is characterized in that: the material is prepared from the following materials: the dry-based materials comprise 80 to 100 parts of engineering residue soil, 25 to 35 parts of municipal sludge, 10 to 20 parts of biogas residue and 0.2 to 0.4 part of composite auxiliary agent by weight, and the materials are mixed by biogas sewage; the composite additive is prepared by treating 65-80% of alum, 10-30% of calcium chloride and 5-10% of lithium carbonate at 500-550 ℃ for 30-60 min, cooling, crushing and grinding.

2. A waste baked brick as claimed in claim 1, wherein: the particle size of the engineering residue soil and the screened biogas residue is less than or equal to 3mm.

3. A process for producing a waste clinker brick according to claim 1 or 2, wherein:

firstly, treating a mixture of 65-80% of alum, 10-30% of calcium chloride and 5-10% of lithium carbonate at the high temperature of 500-550 ℃ for 30-60 min, cooling, crushing and grinding to prepare a powdery compound additive;

step two, dissolving 0.2-0.4 part of composite additive in the biogas sewage to prepare a mixed solution for later use;

step three, after the engineering muck and the biogas residues are respectively crushed and screened, 80 to 100 parts of the engineering muck, 25 to 35 parts of the municipal sludge and 10 to 20 parts of the biogas residues are prepared into a mixture according to dry materials;

step four, adding 2/3 of the mixed solution into the mixture, and uniformly stirring and aging for 18-30 h; then adding the rest mixing liquid, stirring uniformly, and preparing a green brick by vacuum extrusion and cutting; wherein the ratio of the total amount of the mixing water to the dry base material is 0.19-0.22;

and step five, after the green bricks are dried step by step for three times, preheating the green bricks for 1 to 2 hours in a kiln at the temperature of between 300 and 400 ℃, then heating the green bricks to between 800 and 950 ℃, roasting the green bricks for 3 to 5 hours, and cooling the green bricks to obtain the sintered bricks.

4. The method for preparing a waste baked brick according to claim 3, wherein the method comprises the following steps: the third step of drying in the fifth step is drying step by step

The first drying temperature is 50-70 ℃, and the drying time is 2-3 h;

the second drying temperature is 100-120 ℃, and the drying time is 1-2 h;

the third drying temperature is 160-180 ℃, and the drying time is 1-2 h.