High-aluminum checker brick for regenerative chamber of coke oven and preparation process of high-aluminum checker brick

Abstract

The invention relates to a high-aluminum lattice brick for a regenerative chamber of a coke oven and a preparation process of the high-aluminum lattice brick. The high-aluminum lattice brick is prepared from the following raw materials in parts by weight: 15-35 parts of clay clinker of which the Al2O3 content is more than or equal to 40%, 20-50 parts of high-aluminum vanadine clinker of which the Al2O3 content is more than or equal to 70%, 5-25 parts of high-aluminum vanadine clinker of which the Al2O3 content is more than or equal to 80%, 0-15 parts of corundum or calcined alpha-type alumina powder, 10-20 parts of binding clay powder and 4-8 parts of liquid binding agent. Compared with the conventional checker brick, the checker brick disclosed by the invention has the advantages of higher Al2O3 content, lower Fe2O3 and Na2O + K2O impurity content, higher load softening starting temperature and higher volume density; the coke oven heat storage chamber has excellent high temperature resistance and ash corrosion resistance, can be used for a long time in the environment with high temperature and coal gas ash at the top of the coke oven heat storage chamber without deformation, and has better heat storage capacity and heat exchange efficiency, so that the heating energy consumption of the coke oven is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of refractory material preparation, and in particular to a high-aluminum checker brick for a coke oven regenerator which is resistant to high temperature, slag corrosion and high heat storage, and a preparation process thereof. Background Art

[0002] The coke oven regenerator is usually filled with checker bricks, which are a kind of shaped refractory products with multiple parallel straight air passages and in a checkerboard shape. The checker bricks are stacked in the coke oven regenerator to absorb and release heat, that is, to absorb the heat from the high-temperature flue gas discharged from the coke oven combustion chamber, and then transfer the absorbed heat to the coke oven heating gas and combustion-supporting air to preheat it.

[0003] The checker bricks used in the coke oven regenerator must meet the working conditions of the coke oven. First of all, the checker bricks installed in the high temperature area of ​​the coke oven regenerator are required to withstand high temperatures above 1350°C and will not deform during long-term use (25 to 50 years). Secondly, if the gas used for heating the coke oven is blast furnace gas, the checker bricks in the upper high temperature area of ​​the regenerator are required to withstand the dissolution and penetration of ash in the gas and will not melt or deform. In addition, since the checker bricks in the coke oven regenerator are used to recover heat from the coke oven flue gas, the checker bricks are required to have good heat storage capacity and heat exchange efficiency, and the flue gas temperature discharged from the regenerator is generally required to be no higher than 250°C.

[0004] At present, the checker bricks used in the coke oven regenerator are generally made of Al 2 O 3 Semi-silica bricks or clay bricks with a content of 30% to 45% (by weight). 2 O 3 The content is generally 2.5% to 3.0%, Na 2 O+K 2 The content of O is generally 0.5% to 1.0%, the load softening starting temperature (heating method) is generally 1350 to 1400°C, and the bulk density is generally 2.15 to 2.25 g / cm 3 .

[0005] In the past decade, with the large-scale coke ovens and the application of multi-stage heating technology in the combustion chamber, the application environment of the checker bricks used in the regenerator of the coke oven has become more severe. If the material of the checker bricks is not properly selected, the checker bricks on the top of the regenerator will soften and deform or be corroded and deformed by the ash in the coal gas or even melt after the coke oven has been in operation for a few years. When this happens, these deformed or melted checker bricks can only be replaced under the hot conditions of the coke oven, which seriously affects the normal operation of the coke oven. If the heat storage capacity and heat exchange efficiency of the selected checker bricks are insufficient, the flue gas temperature of the coke oven will be too high, which will increase the unit energy consumption of the coke oven and directly affect the economic benefits of the enterprise.

[0006] Based on the above situation, for the high temperature area of ​​the coke oven regenerator, there is an urgent need to develop a checker brick that is resistant to high temperature and ash corrosion, and the checker brick is required to have higher heat storage capacity and heat exchange efficiency, so as to reduce the energy consumption of coke oven production. Summary of the invention

[0007] The present invention provides a high-aluminum checker brick for a coke oven regenerator and a preparation process thereof. The prepared high-aluminum checker brick has a higher Al content than conventional checker bricks. 2 O 3 Content, lower Fe 2 O 3 and Na 2 O+K 2 O impurity content, higher load softening starting temperature and higher bulk density; it not only has excellent high temperature resistance and ash corrosion resistance, but can be used for a long time without deformation in the environment of high temperature and gas ash on the top of the coke oven regenerator without deformation, and at the same time has better heat storage capacity and heat exchange efficiency, thereby effectively reducing the heating energy consumption of the coke oven.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A high-aluminum checker brick for a coke oven regenerator, the high-aluminum checker brick is composed of the following raw materials in parts by weight: Al 2 O 3 15-35 parts of clay clinker with a content of ≥40%, Al 2 O 3 20-50 parts of high-alumina vanadium clinker with a content of ≥70%, Al 2 O 3 5-25 parts of high-alumina vanadium clinker with a content of ≥80%, 0-15 parts of corundum or calcined α-alumina powder, 10-20 parts of combined clay powder, and 4-8 parts of liquid binder; in high-alumina checker bricks, Al 2 O 3 The content is 55% to 70%, Fe 2 O 3 Content ≤2.0%, Na 2 O+K 2 O impurity content ≤ 0.8%; load softening start temperature ≥ 1450℃, bulk density ≥ 2.4g / cm 3 .

[0010] The Al 2 O 3 The particle size of clay clinker with a content of ≥40% is 0-3mm; 2 O 3 The particle size of high-alumina vanadium clinker with a content of ≥70% is 0-3mm; 2 O 3The particle size of high-alumina vanadium clinker with a content of ≥80% is 0-0.074mm; the particle size of corundum or calcined α-alumina powder is 0-0.074mm; and the particle size of combined clay powder is 0-0.088mm.

[0011] The bonding clay powder is Al 2 O 3 Content ≥25%, Fe 2 O 3 Soft clay with a content of ≤2.5%, the main mineral component of which is kaolinite.

[0012] The liquid binder is a water-soluble organic binder.

[0013] A preparation process of high-alumina checker bricks for coke oven regenerators comprises the following steps:

[0014] 1) Al 2 O 3 Clay clinker and Al content ≥40% 2 O 3 High-alumina clinker with a content of ≥70% is put into a mixing mill according to the proportion and mixed for 1 to 2 minutes;

[0015] 2) Add the liquid binder into the mixer and continue mixing for 1 to 2 minutes;

[0016] 3) Al 2 O 3 High alumina clinker with a content of ≥80%, corundum or calcined α-alumina powder, and combined clay powder are added to the mixer in order according to the proportion. After each material is added, it is mixed for 1 to 2 minutes before the next material is added. After all the materials are added, they are mixed for 5 to 10 minutes; or these three materials are weighed according to the proportion and pre-mixed first, and then the pre-mixed and uniformly mixed materials are added to the mixer together and mixed for 5 to 10 minutes;

[0017] 4) Take the mixed mud from the mixer and send it to the mud bin of the brick press, where it will be trapped for more than 1 hour;

[0018] 5) Put the trapped clay into the press mold and pressurize it into shape;

[0019] 6) The formed bricks are dried and dehydrated and then sent to the kiln for firing at a temperature of 1400℃~1480℃.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) In the ingredients of the high-alumina checker brick of the present invention, the aggregate part adopts dense clay clinker with low impurity content and high-alumina vanadium clinker with an alumina content of 70% to 80%. The softening temperature of these two aggregates themselves is much higher than the maximum use temperature of the checker brick in the coke oven regenerator; at the same time, these two aggregates also have excellent resistance to ash dissolution in coal gas, and the structure of the checker brick can still be kept stable when used in the high-temperature area with more ash in the coke oven regenerator.

[0022] 2) In the ingredients of the high-alumina checker brick of the present invention, the fine powder part introduces alumina (Al 2 O 3 ) content of more than 80% high-alumina vanadium clinker fine powder and calcined α-alumina fine powder (or corundum fine powder), so that the matrix part of the checker brick Al 2 O 3 The content is kept above 60%, so that the checker brick has a higher load softening temperature and higher resistance to ash dissolution in coal gas.

[0023] 3) In the ingredients of the high-alumina checker brick of the present invention, the fine powder part uses a bonding clay powder with low impurity content and good plasticity, which can give the checker brick mud good plasticity (i.e., forming performance) when the bonding clay ratio is low, thereby maintaining a high alumina content and a low impurity content in the matrix part of the checker brick.

[0024] 4) In the ingredients of the high-alumina checker bricks of the present invention, the liquid binder adopts a water-soluble organic binder, and the liquid binder can be a "dextrin + water" mixture, a "flour + water" mixture, or paper pulp, etc.; the use of a water-soluble organic binder can improve the molding properties of the mud, reduce the proportion of the bonding clay powder, and improve the strength of the brick.

[0025] 5) The present invention increases the alumina content of the checker brick from the conventional 30% to 45% to 55% to 70%, so that the checker brick has a higher volume density, thereby making the checker brick have a higher unit volume heat storage capacity and thermal conductivity, effectively improving the heat storage and heat exchange efficiency of the high-aluminum checker brick, thereby reducing the temperature of the flue gas discharged from the heat storage chamber and reducing the energy consumption of the coke oven.

[0026] 6) The matrix part of the high-aluminum checker brick of the present invention is mainly mullite, and the ash dissolution effect in the coal gas is limited to the surface layer of the checker brick. It will not cause softening and collapse, grid hole blockage and other problems when used for a long time in the high-temperature area of ​​the coke oven regenerator (the area where the upper 3 to 5 layers of checker bricks are located). It is an updated product of the checker bricks for the coke oven regenerator. DETAILED DESCRIPTION

[0027] The high-aluminum checker brick for the coke oven regenerator of the present invention is composed of the following raw materials in parts by weight: Al 2 O3 15-35 parts of clay clinker with a content of ≥40%, Al 2 O 3 20-50 parts of high-alumina vanadium clinker with a content of ≥70%, Al 2 O 3 5-25 parts of high-alumina vanadium clinker with a content of ≥80%, 0-15 parts of corundum or calcined α-alumina powder, 10-20 parts of combined clay powder, and 4-8 parts of liquid binder; in high-alumina checker bricks, Al 2 O 3 The content is 55% to 70%, Fe 2 O 3 Content ≤2.0%, Na 2 O+K 2 O impurity content ≤ 0.8%; load softening start temperature ≥ 1450℃, bulk density ≥ 2.4g / cm 3 .

[0028] The Al 2 O 3 The particle size of clay clinker with a content of ≥40% is 0-3mm; 2 O 3 The particle size of high-alumina vanadium clinker with a content of ≥70% is 0-3mm; 2 O 3 The particle size of high-alumina vanadium clinker with a content of ≥80% is 0-0.074mm; the particle size of corundum or calcined α-alumina powder is 0-0.074mm; and the particle size of combined clay powder is 0-0.088mm.

[0029] The bonding clay powder is Al 2 O 3 Content ≥25%, Fe 2 O 3 Soft clay with a content of ≤2.5%, the main mineral component of which is kaolinite.

[0030] The liquid binder is a water-soluble organic binder.

[0031] The preparation process of a high-alumina checker brick for a coke oven regenerator according to the present invention comprises the following steps:

[0032] 1) Al 2 O 3 Clay clinker and Al content ≥40% 2 O 3 High-alumina clinker with a content of ≥70% is put into a mixing mill according to the proportion and mixed for 1 to 2 minutes;

[0033] 2) Add the liquid binder into the mixer and continue mixing for 1 to 2 minutes;

[0034] 3) Al 2 O 3 High alumina clinker with a content of ≥80%, corundum or calcined α-alumina powder, and combined clay powder are added to the mixer in order according to the proportion. After each material is added, it is mixed for 1 to 2 minutes before the next material is added. After all the materials are added, they are mixed for 5 to 10 minutes; or these three materials are weighed according to the proportion and pre-mixed first, and then the pre-mixed and uniformly mixed materials are added to the mixer together and mixed for 5 to 10 minutes;

[0035] 4) Take the mixed mud from the mixer and send it to the mud bin of the brick press, where it will be trapped for more than 1 hour;

[0036] 5) Put the trapped clay into the press mold and pressurize it into shape;

[0037] 6) The formed bricks are dried and dehydrated and then sent to the kiln for firing at a temperature of 1400℃~1480℃.

[0038] The Al 2 O 3 Clay clinker with a content of ≥40% is preferably coke, Al 2 O 3 High alumina clinker with a content of ≥70% is preferably sintered alumina, Al 2 O 3 The high-alumina clinker with a content of ≥80% is preferably sintered alumina. The liquid binder is a mixture of "dextrin + water", a mixture of "flour + water", or pulp. The main mineral component of the binding clay is kaolinite, which has excellent plasticity.

[0039] In order to more intuitively embody the present invention, the embodiments of the present invention are further described in conjunction with examples. The following examples are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be obviously obtained by a person skilled in the art within the technical scope disclosed in the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0040] [Example]

[0041] The raw material composition of the high alumina checker brick in each embodiment is shown in Table 1, the physical and chemical properties of the high alumina checker brick in each embodiment are shown in Table 2, the preparation process parameters of the high alumina checker brick in each embodiment are shown in Table 3, and the performance of the high alumina checker brick in each embodiment is shown in Table 4.

[0042] Table 1 Raw material composition (parts by weight)

[0043] Example A B C D E F 1 15 48 20 0 17 4 2 20 40 20 5 15 6 3 24 36 6 15 19 8 4 28 32 15 15 10 7 5 33 27 25 10 15 5

[0044] Note: A in Table 1 represents Al2 O 3 Clay clinker with a content of ≥40%, B represents Al 2 O 3 High alumina clinker with content ≥70%, C represents Al 2 O 3 The high-alumina vanadium clinker with a content of ≥80%, D represents corundum or calcined α-alumina powder, E represents bonding clay powder, and F represents a liquid binder. Among them, D in Examples 1-2 is corundum, and D in Examples 3-5 is calcined α-alumina powder; F in Examples 1-2 is a "dextrin + water" mixture, F in Examples 3-4 is a "flour + water" mixture, and F in Example 5 is pulp.

[0045] Table 2 Physical and chemical properties

[0046]

[0047] Table 3 Preparation process parameters

[0048]

[0049] Note: A in Table 3 represents Al 2 O 3 Clay clinker with a content of ≥40%, B represents Al 2 O 3 High alumina clinker with a content of ≥70%, F represents a liquid binder.

[0050] Table 4 Finished product performance

[0051] Apparent porosity, % Compressive strength at room temperature, MPa Permanent line change after firing at 1400℃×3h, % index ≤22 ≥40 -0.2～+0.3 Example 1 17.6 88 0 Example 2 16.8 95 +0.03 Example 3 21.2 68 -0.10 Example 4 17.2 81 +0.04 Example 5 18.7 72 -0.02

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-alumina checker brick for a coke oven regenerator, characterized in that: The high-aluminum checker brick is composed of the following raw materials in parts by weight: 15-35 parts of clay clinker with an Al2O3 content of ≥40%, 20-50 parts of high-aluminum vanadium clinker with an Al2O3 content of ≥70%, 5-25 parts of high-aluminum vanadium clinker with an Al2O3 content of ≥80%, 0-15 parts of corundum or calcined α-alumina powder, 10-20 parts of bonding clay powder, and 4-8 parts of liquid binder; in the high-aluminum checker brick, the Al2O3 content is 55%-70%, the Fe2O3 content is ≤2.0%, and the Na2O+K2O impurity content is ≤0.8% by weight; the load softening starting temperature is ≥1450℃, and the volume density is ≥2.4g / cm 3 .

2. The high-alumina checker brick for coke oven regenerator according to claim 1, characterized in that: The particle size of the clay clinker with an Al2O3 content of ≥40% is 0-3mm; the particle size of the high-alumina vanadium clinker with an Al2O3 content of ≥70% is 0-3mm; the particle size of the high-alumina vanadium clinker with an Al2O3 content of ≥80% is 0-0.074mm; the particle size of the corundum or calcined α-alumina powder is 0-0.074mm; and the particle size of the combined clay powder is 0-0.088mm.

3. The high-alumina checker brick for coke oven regenerator according to claim 1, characterized in that: The combined clay powder is soft clay with Al2O3 content ≥25% and Fe2O3 content ≤2.5%, and the main mineral component is kaolinite.

4. The high-alumina checker brick for coke oven regenerator according to claim 1, characterized in that: The liquid binder is a water-soluble organic binder.

5. A process for preparing high-alumina checker bricks for coke oven regenerators as claimed in any one of claims 1 to 4, characterized in that: The steps include: 1) Put the clay clinker with Al2O3 content ≥40% and the high-alumina clinker with Al2O3 content ≥70% into a mixing mill according to the proportion, and mix for 1 to 2 minutes; 2) Add the liquid binder into the mixer and continue mixing for 1 to 2 minutes; 3) Add high-alumina clinker with Al2O3 content ≥80%, corundum or calcined α-alumina powder, and combined clay powder into a mixer in order according to the proportions. After each material is added, mix it for 1 to 2 minutes before adding the next material. After all the materials are added, mix them for 5 to 10 minutes; or weigh the three materials according to the proportions and pre-mix them first, then put the pre-mixed mixture into the mixer together and mix it for 5 to 10 minutes; 4) Take the mixed mud from the mixer and send it to the mud bin of the brick press, where it will be trapped for more than 1 hour; 5) Put the trapped clay into the press mold and pressurize it into shape; 6) The formed bricks are dried and dehydrated and then sent to the kiln for firing at a temperature of 1400℃~1480℃.

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