阅读说明：本技术 一种用于协同处置水泥窑预分解带的复合高铝碳化硅砖 (Composite high-alumina silicon carbide brick for cooperatively treating cement kiln predecomposition zone ) 是由 俞益君 王才军 徐志坚 俞清耀 朱秀芬 于 2020-06-29 设计创作，主要内容包括：本发明提出一种用于协同处置水泥窑预分解带的复合高铝碳化硅砖,在砖本体的冷态面嵌有隔热部,隔热部面积占砖冷态面面积的55％～65％,砖本体以高铝矾土熟料、高岭土为骨料,以碳化硅粉、红柱石粉、莫来石为基质,加入适量外加剂制成。本发明具有不炸裂、强度高、低导热、热震稳定性高、耐冲刷、抗侵蚀、不掉砖的特性,质量稳定,使用周期长,减少窑的检修次数,解决了残砖厚度变薄后易红窑的问题。(The invention provides a composite high-alumina silicon carbide brick for cooperatively treating a predecomposition zone of a cement kiln, wherein a heat insulation part is embedded in a cold-state surface of a brick body, the area of the heat insulation part accounts for 55-65% of the area of the cold-state surface of the brick, and the brick body is prepared by taking high-alumina bauxite chamotte and kaolin as aggregates, taking silicon carbide powder, andalusite powder and mullite as matrixes and adding a proper amount of additives. The invention has the characteristics of no cracking, high strength, low heat conduction, high thermal shock stability, scouring resistance, erosion resistance, no brick falling, stable quality, long service cycle, reduced maintenance frequency of the kiln and solves the problem that the kiln is easy to be red after the thickness of the residual brick is thinned.)

1. The composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln is characterized by comprising a brick body, wherein a heat insulation part is embedded in a cold surface of the brick body, and the area of the heat insulation part accounts for 55-65% of that of the cold surface of the brick; the brick body is prepared by taking bauxite chamotte and kaolin as aggregates, taking silicon carbide powder, andalusite powder and mullite as substrates and adding a proper amount of additives.

2. The composite high-alumina silicon carbide brick for the co-disposal cement kiln predissociation zone as claimed in claim 1, wherein the brick body comprises the following components in parts by weight:

adding:

sodium carboxymethylcellulose

Ultrafine powder

Water (W)

The components are mixed and made into pug in a mixing roll, and the pug is pressed into adobes, dried and sintered into products.

3. The composite high-alumina silicon carbide brick for the co-disposal cement kiln predissociation zone according to claim 1 or 2, wherein the brick body comprises the following components in parts by weight:

adding:

sodium carboxymethylcellulose

Ultrafine powder

Water (W)

The components are mixed and made into pug in a mixing roll, and the pug is pressed into adobes, dried and sintered into products.

4. The composite high-alumina silicon carbide brick for the co-processing cement kiln predecomposition zone as claimed in claim 2, wherein the particle composition of the high-alumina bauxite chamotte comprises 2-4 mm coarse powder, 0.088-2 mm medium powder and 0-0.088 mm fine powder, and the proportion is as follows: coarse powder, medium powder and fine powder, 4:2: 4.

5. The composite high-alumina silicon carbide brick for the co-disposal cement kiln predecomposition zone as claimed in claim 2, wherein the proportion of the silicon carbide powder with the particle size of 0-0.088 mm is less than or equal to 50%.

6. The composite high alumina silicon carbide brick for co-disposal cement kiln predecomposition strip according to claim 2, characterized in that the drying temperature is 110 ℃ and the drying time is 24 h.

7. The composite high alumina silicon carbide brick for the co-disposal cement kiln predecomposition zone as claimed in claim 2, wherein the sintering temperature is 1550 ℃ and the sintering time is 3 h.

8. The composite high alumina silicon carbide brick for co-disposal cement kiln predissociation zones according to claim 1, wherein the insulation area is 60% of the brick cold face area.

9. The composite high alumina silicon carbide brick for co-disposal cement kiln predecomposition strip according to claim 1 or 8, wherein the thermal insulation portion is filled with thermal insulation material having a thermal conductivity of 0.1W/m-k at 500 ℃.

10. A method for preparing a composite high alumina silicon carbide brick for use in a pre-disintegration zone of a co-disposal cement kiln according to any of claims 1 to 9, comprising the steps of:

step 1: crushing and screening bauxite chamotte, and then feeding the bauxite chamotte into a storage bin;

step 2: weighing raw materials such as bauxite chamotte, kaolin, silicon carbide powder, andalusite powder, mullite and the like, and then performing a mixing and grinding process;

and step 3: adding coarse and medium granules, mixing uniformly, adding a binder sodium carboxymethylcellulose, adding fine powder, mixed powder and additives after the binder is uniformly bonded on the surfaces of the granules, controlling the mixing time after all raw materials are added to uniformly wrap the granules by the fine powder, and conveying the mixed and ground materials to a storage bin for pugging for 1 hour for later use;

and 4, step 4: positioning the position and the area of a heat insulation part, injecting mixed and ground materials, molding by adopting a 2500-ton brick press, placing the green bricks on a platform for detection after the green bricks are pressed, detecting the internal compactness and the like by using a small hammer beating method according to the detected items including appearance, size and single weight, and returning the unqualified green bricks;

and 5: putting the green brick on a brick frame of a drying vehicle, and pushing the green brick into a drying kiln for drying;

step 6: after drying, firing the raw materials by a 102-meter self-control natural gas tunnel kiln, preheating the raw materials to about 400 ℃, firing the raw materials for 2 hours at a high temperature of 1200 ℃, keeping the constant temperature for 1 hour, and then heating the raw materials to about 1550 ℃ for continuously firing the raw materials for 2 hours;

and 7: and after cooling, sorting and polishing, and packaging for delivery.

Technical Field

The invention belongs to the technical field of refractory materials, and particularly relates to a composite high-alumina silicon carbide brick for cooperatively treating a cement kiln predecomposition zone.

Background

The international development trend of the refractory materials for the cement kiln is as follows: on the premise of meeting the requirements of cement production process, the method realizes chromium-free and long service life and is beneficial to reducing production energy consumption.

Along with the improvement of domestic environmental protection consciousness and the large-scale production of cement, more severe technical requirements are put forward on refractory materials. The chromium-free basic refractory material for the burning zone of the rotary cement kiln is successfully developed through scientific and technological challenges and has commercial production capacity and good application effect.

The rotary kiln pre-decomposition zone is divided into a decomposition zone, an upper transition zone and a burning zone. The stress born by the lining materials in each zone is approximately as follows according to the raw fuel entering the kiln and the burning condition in the kiln, the materials in the upper transition zone gradually rise to about 1300Y, then enter the burning zone to generate clinker, the clinker is cooled in the lower transition zone, and the clinker is discharged from the kiln mouth of the rotary kiln to a basketry type cooler. The thermal conductivity of the kiln skin is about 1.2W/(m.Y), which can often maintain the thickness of the kiln skin as high as about 150M, and the inner upper transition zone, the lower transition zone and the burning zone are the parts of the predecomposition kiln with more serious heat, mechanical stress and chemical erosion, and are also the parts built by alkaline refractory materials. The seriously damaged part of the alkaline lining is the kiln mouth part of the lower transition belt, which accounts for 42 percent of the total stress, and the lining below the upper transition belt wheel belt is 22 percent, the mechanical stress generated by the ovality deformation of the cylinder body of the part is up to 14 percent, the lining of the burning zone is protected by kiln skin, the stress of the central burning zone is only 19 percent, and the upper alkane zone is about 15 percent. The temperature of the materials in the decomposition belt of the rotary kiln is lower than 900Y, no kiln shell exists in the decomposition belt during normal production, and the lining in the decomposition belt is subjected to strong alkali, chlorine and sulfur corrosion, thermal shock, oxidation reduction load and mechanical load generated by the ellipse of a cylinder. The stress percentage of the lining material reflects the damage condition of the lining material, and the material must be selected according to the stress action condition of the lining material, so that the long service life can be obtained in the production.

Disclosure of Invention

The technical problem solved by the invention is to provide a composite high-alumina silicon carbide brick for cooperatively treating a predecomposition zone of a cement kiln, wherein a heat insulation part is embedded in a cold surface of a brick body, the brick body is prepared by taking high-alumina bauxite chamotte and kaolin as aggregates, taking silicon carbide powder, andalusite powder and mullite as matrixes and adding a proper amount of additives, and the prepared brick has the characteristics of no explosion, high thermal shock resistance, scouring resistance, erosion resistance and no brick falling, has stable quality and long service cycle, and reduces the maintenance frequency of the kiln.

The technical solution for realizing the purpose of the invention is as follows:

a composite high-alumina silicon carbide brick for cooperatively treating a cement kiln predecomposition zone comprises a brick body, wherein a heat insulation part is embedded in a cold surface of the brick body, and the area of the heat insulation part accounts for 55% -65% of that of the cold surface of the brick; the brick body is prepared by taking bauxite chamotte and kaolin as aggregates, taking silicon carbide powder, andalusite powder and mullite as substrates and adding a proper amount of additives.

Further, the composite high-alumina silicon carbide brick for the cooperative treatment of the cement kiln predissociation zone comprises the following components in parts by weight:

adding:

sodium carboxymethylcellulose

Ultrafine powder

Water (W)

The components are mixed and made into pug in a mixing roll, and the pug is pressed into adobes, dried and sintered into products.

Further, the composite high-alumina silicon carbide brick for the cooperative treatment of the cement kiln predecomposition zone is characterized by comprising the following components in parts by weight:

adding:

sodium carboxymethylcellulose

Ultrafine powder

Water (W)

The components are mixed and made into pug in a mixing roll, and the pug is pressed into adobes, dried and sintered into products.

Further, the composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln comprises the following particles of 2-4 mm coarse powder, 0.088-2 mm medium powder and 0-0.088 mm fine powder in proportion: coarse powder, medium powder and fine powder, 4:2: 4.

Further, the composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln has the silicon carbide powder with the granularity of 0-0.088 mm, and the proportion of the silicon carbide powder is less than or equal to 50%.

Further, the composite high-alumina silicon carbide brick for cooperatively treating the cement kiln predecomposition zone has the drying temperature of 110 ℃ and the drying time of 24 hours.

Furthermore, the composite high-alumina silicon carbide brick for cooperatively treating the pre-decomposition zone of the cement kiln has the sintering temperature of 1550 ℃ and the sintering time of 3 h.

Further, the composite high-alumina silicon carbide brick for the co-disposal of the pre-decomposition belt of the cement kiln has the area of the heat insulation part accounting for 60 percent of the area of the cold surface of the brick.

Further, the composite high-alumina silicon carbide brick for the co-disposal of the predissociation zone of the cement kiln is characterized in that the heat insulation part is filled with a heat insulation material, and the heat conductivity of the heat insulation material at 500 ℃ is 0.1W/m.k.

A method of making any of the above composite high alumina silicon carbide bricks for use in a co-disposal cement kiln predecomposition zone, comprising the steps of:

step 1: crushing and screening bauxite chamotte, and then feeding the bauxite chamotte into a storage bin;

step 2: weighing raw materials such as bauxite chamotte, kaolin, silicon carbide powder, andalusite powder, mullite and the like, and then performing a mixing and grinding process;

and step 3: adding coarse and medium granules, mixing uniformly, adding a binder sodium carboxymethylcellulose, adding fine powder, mixed powder and additives after the binder is uniformly bonded on the surfaces of the granules, controlling the mixing time after all raw materials are added to uniformly wrap the granules by the fine powder, and conveying the mixed and ground materials to a storage bin for pugging for 1 hour for later use;

and 4, step 4: positioning the position and the area of a heat insulation part, injecting mixed and ground materials, molding by adopting a 2500-ton brick press, placing the green bricks on a platform for detection after the green bricks are pressed, detecting the internal compactness and the like by using a small hammer beating method according to the detected items including appearance, size and single weight, and returning the unqualified green bricks;

and 5: putting the green brick on a brick frame of a drying vehicle, and pushing the green brick into a drying kiln for drying;

step 6: after drying, firing the raw materials by a 102-meter self-control natural gas tunnel kiln, preheating the raw materials to about 400 ℃, firing the raw materials for 2 hours at a high temperature of 1200 ℃, keeping the constant temperature for 1 hour, and then heating the raw materials to about 1550 ℃ for continuously firing the raw materials for 2 hours;

and 7: and after cooling, sorting and polishing, and packaging for delivery.

Compared with the prior art, the invention adopting the technical scheme has the following technical effects:

1. the composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln has the characteristics of no cracking, high thermal shock, scouring resistance, erosion resistance and no brick falling, has stable quality and long service cycle, and reduces the maintenance frequency of the kiln.

2. The composite high-alumina silicon carbide brick for cooperatively treating the cement kiln predecomposition zone can reduce the temperature of a kiln cylinder body by 60-100 ℃, protect thermal equipment from running safely and normally and reduce the red kiln phenomenon; the deformation of the kiln cylinder body due to high temperature is reduced, the service life of the kiln cylinder body is prolonged, and the abnormal damage of the mechanical stress of the whole material due to the deformation of the kiln cylinder body is reduced.

3. The composite high-alumina silicon carbide brick for the synergistic treatment of the cement kiln predissociation zone has good overall performance, the effective use part is improved by more than 30 percent compared with a composite product, and the product has long service life.

4. The composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln can reduce waste heat and CO₂And S and other harmful gases are discharged, the heat utilization efficiency of the kiln is improved, the energy consumption is saved by more than 10%, the enterprise benefit is improved, and the requirement of energy-saving and environment-friendly industrial development is met.

Drawings

FIG. 1 is a flow chart of the process for producing composite high alumina silicon carbide bricks for use in the co-disposal of cement kiln predecomposition zones in accordance with the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

The composite high-alumina silicon carbide brick for cooperatively treating the predecomposition zone of the cement kiln comprises a brick body, wherein a heat insulation part is embedded in a cold surface of the brick body, and the area of the heat insulation part accounts for 55-65% of the area of the cold surface of the brick; the brick body is prepared by taking bauxite chamotte and kaolin as aggregates, taking silicon carbide powder, andalusite powder and mullite as matrixes and adding a proper amount of additives, and the technical indexes are as follows:

the volume density is 2.63g/cm3, the refractoriness under load (T0.6) is not less than 1650 ℃, the thermal conductivity coefficient is 1.5W/M.K, the compressive strength is not less than 90MPa, the thermal shock stability (water cooling at 1100 ℃) is not less than 20 times, and the service life is not less than that of the original spinel brick under normal use conditions.