阅读说明：本技术 一种均匀侵蚀型长寿高炉炉缸砌筑方法 (Uniform erosion type long-life blast furnace hearth building method ) 是由 姜喆 谢明辉 郭天永 车玉满 姚硕 刘炳楠 邵思维 费静 李晓春 曾宇 于 2021-07-15 设计创作，主要内容包括：本发明涉及一种均匀侵蚀型长寿高炉炉缸砌筑方法,从上到下在炉缸顶部至铁口部位,炉衬由高导热石墨砖砌筑；从上到下在铁口至炉底部位,炉衬由长度逐渐增大的超微孔炭砖砌筑；在炉缸炉衬内侧砌筑至少一层陶瓷杯；炉底平铺炭砖6～8层,在炉底炭砖上设置至少一层粘土砖；铁口中心线到炉底最上层炭砖的距离为炉缸直径的12％～16％。优点是：不仅可以避免炉缸炉衬应力最大部位固定不变而造成的炉缸局部单一位置侵蚀速度过快和最终导致一代炉役时间变短的状况,还可大幅度的降低高炉的砌筑成本。(The invention relates to a method for building a uniform erosion type long-life blast furnace hearth, wherein a furnace lining is built by high-heat-conductivity graphite bricks from the top of the furnace hearth to an iron notch part from top to bottom; the furnace lining is built by the ultramicropore carbon bricks with gradually increased length from the iron notch to the furnace bottom from top to bottom; building at least one layer of ceramic cup on the inner side of a furnace lining of a furnace hearth; 6-8 layers of carbon bricks are tiled at the bottom of the furnace, and at least one layer of clay brick is arranged on the carbon bricks at the bottom of the furnace; the distance from the center line of the taphole to the carbon brick at the uppermost layer of the furnace bottom is 12 to 16 percent of the diameter of the furnace hearth. The advantages are that: the method can avoid the conditions that the erosion speed of the local single position of the hearth is too high and the service time of the first generation of furnace is shortened finally caused by the fact that the maximum stress position of the hearth lining is fixed, and can also greatly reduce the building cost of the blast furnace.)

1. A method for building a uniform erosion type long-life blast furnace hearth is characterized by comprising the following steps:

1) the furnace lining is built by high heat conduction graphite bricks from the top of the furnace hearth to the taphole part from top to bottom; the heat conductivity coefficient of the high-heat-conductivity graphite brick at 30-1150 ℃ is more than 80 w/mk;

2) the furnace lining is built by the ultramicropore carbon bricks with gradually increased length from the iron notch to the furnace bottom from top to bottom;

the heat conductivity coefficient of the ultramicropore carbon brick is more than 15w/mk at 30-1150 ℃; the average pore diameter of the ultramicropore carbon brick is less than or equal to 1 mu m; the aperture of the ultramicropore carbon brick is less than 1 μm, and the pore volume is more than 80 percent; the compressive strength of the ultramicropore carbon brick is more than 50 MPa;

3) building at least one layer of ceramic cup on the inner side of a furnace lining of a furnace hearth;

the ceramic cup has normal temperature compressive strength of not less than 60MPa, apparent porosity of not more than 11%, and volume density of not less than 3.25g/cm³；

4) 6-8 layers of carbon bricks are tiled at the bottom of the furnace, and at least one layer of clay brick is arranged on the carbon bricks at the bottom of the furnace;

the distance from the center line of the taphole to the carbon brick at the uppermost layer of the furnace bottom is 12 to 16 percent of the diameter of the furnace hearth.

2. The method for constructing the furnace hearth of the uniform-erosion long-life blast furnace according to the claim 1, wherein in the step 2), the ultra-microporous carbon bricks are constructed by adopting staggered joint treatment.

3. The method for constructing a uniformly eroded long-life blast furnace hearth according to claim 1, wherein in 2), the length of the ultra-microporous carbon brick is 800 to 1000 mm.

4. The masonry method of the uniform erosion type long-life blast furnace hearth according to the claim 1, characterized in that, in 3), Al in the ceramic cup₂O₃The content is more than or equal to 80wt percent, Fe₂O₃The content is less than or equal to 0.6wt percent.

5. The masonry method of the uniform erosion type long-life blast furnace hearth according to claim 1, wherein in 4), the carbon brick is a graphite brick, the height of the graphite brick is 400-600 mm, and the thermal conductivity coefficient is 30-1150 ℃: is > 40 w/mk.

Technical Field

The invention belongs to the field of blast furnace masonry, and particularly relates to a method for masonry of a uniform erosion type long-life blast furnace hearth.

Background

The blast furnace is large-scale high-temperature high-pressure reaction equipment for iron making, and is divided into a hearth, a furnace belly, a furnace waist, a furnace body and a furnace throat from bottom to top in sequence. The furnace hearth mainly has the main functions of regularly storing and discharging the iron slag, and the furnace lining of the furnace hearth is thinned due to the fact that the furnace hearth is washed by the high-temperature iron slag for a long time, so that the furnace hearth becomes a limiting part which limits the whole service life of the blast furnace. Once the lining in the hearth is thinned to below 300mm, overhaul is required, and the shutdown overhaul of the blast furnace disturbs the normal production plan of a steel plant and increases huge overhaul cost. Therefore, the structure of the existing hearth needs to be improved and optimized, and the erosion speed of the furnace lining in the hearth is effectively relieved, so that the long service life of the blast furnace is realized.

The high-temperature and high-pressure working environment of the blast furnace hearth determines that the hearth lining is easy to be corroded and damaged, and the corrosion reasons are mainly slag iron flowing scouring, thermal stress impact, harmful element corrosion and the like. The local position within 15 degrees of the circumference direction of the taphole is most seriously impacted by molten iron scouring and stress, which causes the fastest erosion speed at the position, often 1.5m-3m below the center line of the taphole of the furnace hearth. When the residual thickness of the furnace lining at a certain position of the furnace hearth is less than 300mm, the whole furnace hearth and the bottom of the blast furnace need to be built again. If the position which is most seriously impacted by molten iron scouring and stress can be gradually changed along with the production process of the first-generation blast furnace campaign, the lining of the blast furnace hearth can be evenly eroded, thereby achieving the purpose of prolonging the service life of the first-generation blast furnace campaign.

Chinese patent application No. 202020029567.2 discloses an erosion guide type long-life blast furnace bottom hearth, the upper part is a hearth, the bottom is a furnace bottom, it includes furnace shell, cooling wall and iron notch set on the hearth, its innovation point lies in, the inside of the cooling wall is equipped with several layers of hearth ring-built microporous carbon bricks from top to bottom, several layers of hearth ring-built ultramicropore carbon bricks and several layers of furnace bottom flat-built ultramicropore carbon bricks, the several layers of hearth ring-built microporous carbon bricks and several layers of hearth ring-built ultramicropore carbon bricks are equipped with vertical and flat-laid ceramic cups inside; the top layer of the plurality of layers of tiled carbon bricks is a combined masonry form of two carbon bricks, namely, the central inner ring area adopts furnace bottom microporous carbon bricks, and the outer ring adopts furnace bottom ultramicropore carbon bricks. Although the invention can guide the hearth to be corroded in a boiler bottom shape to a certain extent, the microporous carbon bricks and the ultramicropore carbon bricks on the same layer of the boiler bottom can cause the corner parts of the carbon bricks on the contact surface to be crushed due to different expansion coefficients of the two types of bricks, so that the parts of the boiler bottom and the hearth, such as the foot parts, are corroded quickly, and the integral service life of the hearth is not effectively prolonged.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method for building a furnace hearth of a uniform-erosion type long-life blast furnace, which can ensure the stable and smooth running of the blast furnace and prolong the first-generation service life of the blast furnace.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method for building a uniform erosion type long-life blast furnace hearth comprises the following steps:

1) the furnace lining is built by high heat conduction graphite bricks from the top of the furnace hearth to the taphole part from top to bottom; the heat conductivity coefficient of the high-heat-conductivity graphite brick at 30-1150 ℃ is more than 80 w/mk;

2) the furnace lining is built by the ultramicropore carbon bricks with gradually increased length from the iron notch to the furnace bottom from top to bottom;

the heat conductivity coefficient of the ultramicropore carbon brick is more than 15w/mk at 30-1150 ℃; the average pore diameter of the ultramicropore carbon brick is less than or equal to 1 mu m; the aperture of the ultramicropore carbon brick is less than 1 μm, and the pore volume is more than 80 percent; the compressive strength of the ultramicropore carbon brick is more than 50 MPa;

3) building at least one layer of ceramic cup on the inner side of a furnace lining of a furnace hearth;

the ceramic cup has normal temperature compressive strength of not less than 60MPa, apparent porosity of not more than 11%, and volume density of not less than 3.25g/cm³；

4) 6-8 layers of carbon bricks are tiled at the bottom of the furnace, and at least one layer of clay brick is arranged on the carbon bricks at the bottom of the furnace;

the distance from the center line of the taphole to the carbon brick at the uppermost layer of the furnace bottom is 12 to 16 percent of the diameter of the furnace hearth.

The ultramicropore carbon brick is built by adopting staggered joint treatment.

The length of the ultramicropore carbon brick is 800-1000 mm.

Al in the ceramic cup₂O₃The content is more than or equal to 80wt percent, Fe₂O₃The content is less than or equal to 0.6wt percent.

The carbon brick is a graphite brick, the height of the graphite brick is 400-600 mm, and the heat conductivity coefficient is 30-1150 ℃: is > 40 w/mk.

Compared with the prior art, the invention has the beneficial effects that:

the masonry method of the invention not only can avoid the conditions that the erosion speed of the local single position of the hearth is too fast and the service time of the first-generation furnace is shortened finally caused by the fixed maximum stress position of the hearth lining, but also can greatly reduce the masonry cost of the blast furnace, and has the following specific advantages:

(1) because the low-price clay bricks and the high-heat-conductivity graphite bricks are respectively used for replacing the original high-price ceramic pads and the original ultra-microporous carbon bricks at the bottom of the blast furnace, the construction cost of the blast furnace can be greatly reduced;

(2) the carbon part of the hearth ring and the elephant foot part at the junction of the hearth and the furnace bottom are built by adopting a staggered joint processing mode, so that the penetration of molten iron along the brick gap is effectively avoided, the scouring erosion of the refractory material on the side wall of the hearth by the circulation of the molten iron is avoided, and the uniform erosion of the hearth and the furnace bottom is realized.

Drawings

Figure 1 is a first schematic view of a masonry structure of the present invention.

Figure 2 is a second schematic representation of the masonry structure of the present invention.

In the figure: 1-hearth 2-furnace bottom 3-furnace shell 4-cooling wall 5-taphole 6-graphite brick 7-ultramicropore carbon brick 8-ceramic cup 9-clay brick.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings, but it should be noted that the present invention is not limited to the following embodiments.

The structure of the hearth and the bottom of the blast furnace hearth is as follows: the upper part is a hearth 1, the bottom part is a furnace bottom 2, the specific structure of the blast furnace hearth comprises a furnace shell 3, a cooling wall 4 and an iron notch 5 arranged on the hearth 1, and a plurality of layers of hearth-encircling carbon bricks are arranged on the inner side of the cooling wall 4 from top to bottom.

Example 1

Referring to fig. 1, a method for building a uniform erosion type long-life blast furnace hearth comprises the following steps:

1) the furnace lining is built by graphite bricks 6 from top to bottom from the top of the furnace hearth to the taphole part, and the heat conductivity coefficient is 80-90 w/mk at 30-1150 ℃;

2) the furnace lining is built by large blocks of ultramicropore carbon bricks 7 from the iron notch to the furnace bottom from top to bottom; the length of the 1 st to 4 th layers of ultramicropore carbon bricks of the hearth is gradually increased, staggered joints are adopted for treatment, and the thermal conductivity coefficient of the hearth is as follows: 15-18 w/mk, average pore diameter of 0.8 μm, and pore volume of < 1 μm of 86%; the compressive strength is 60 MPa; (the content herein indicates whether the microporous carbon brick 7 is a portion after construction)

3) The length of the first layer of carbon bricks on the side wall of the hearth is 950mm, the length of the second layer of carbon bricks is 900mm, the length of the third layer of carbon bricks is 850mm, and the length of the fourth layer of carbon bricks is 800 mm;

4) a layer of ceramic cup 8 is built on the inner side of the furnace lining of the furnace hearth; ceramic cup Al₂O₃86 wt% of ceramic cup Fe₂O₃The content is 0.6 wt%, and the normal temperature compressive strength is 62 MPa; the apparent porosity is 10 percent, and the volume density is 3.65g/cm³；

5) A layer of clay brick 9 is built on the inner side of the ceramic cup of the hearth, and the performance of the clay brick is not required;

6) the carbon bricks laid on the bottom of the furnace are 6 layers, and 2 layers of clay rollers are arranged on the carbon bricks on the bottom of the furnace; the furnace bottom tiled carbon bricks are all large graphite bricks 10, and the thickness of the large graphite bricks is as follows: 500 mm; the heat conductivity coefficient is 45-50 w/mk at 30-1150 ℃, and the performance of the clay brick is not required;

7) the distance from the center line of the taphole to the carbon bricks on the uppermost layer of the furnace bottom is 1.5m, the diameter of the hearth is 11.5m, and the distance from the center line of the taphole to the carbon bricks on the uppermost layer of the furnace bottom is 13 percent of the diameter of the hearth.

Example 2

Referring to fig. 2, a method for building a uniform erosion type long-life blast furnace hearth comprises the following steps:

1) the furnace lining is built by graphite bricks 6 from top to bottom from the top of the furnace hearth to the taphole part, and the heat conductivity coefficient is 80-90 w/mk at 30-1150 ℃; (whether the size of the graphite brick is limited or not)

2) The furnace lining is built by large blocks of ultramicropore carbon bricks from the iron notch to the furnace bottom from top to bottom; the length of the 1 st to 4 th layers of ultramicropore carbon bricks of the hearth is gradually increased, staggered joints are adopted for treatment, and the thermal conductivity coefficient of the hearth is as follows: 16-19 w/mk, average pore diameter of 0.6 μm, and pore volume of < 1 μm of 85%; the compressive strength is 56 MPa;

3) the length of the first layer of carbon bricks on the side wall of the hearth is 1000mm, the length of the second layer of carbon bricks is 950mm, the length of the third layer of carbon bricks is 900mm, and the length of the fourth layer of carbon bricks is 850 mm;

4) a layer of ceramic cup 7 is built on the inner side of the furnace lining of the furnace hearth; ceramic cup Al₂O₃86 wt% of ceramic cup Fe₂O₃The content is 0.6 wt%, and the normal temperature compressive strength is 62 MPa; the apparent porosity is 10 percent, and the volume density is 3.65g/cm 3;

5) a layer of clay brick 8 is built on the inner side of the ceramic cup of the hearth, and the performance of the clay brick is not required;

6) the carbon bricks laid on the bottom of the furnace are 8 layers, and 2 layers of clay rollers are arranged on the carbon bricks on the bottom of the furnace; the furnace bottom tiled carbon bricks are all large graphite bricks 9, and the thickness of the large graphite bricks is as follows: 400 mm; the heat conductivity coefficient is 45-50 w/mk at 30-1150 ℃, and the performance of the clay brick is not required;

7) the distance from the center line of the taphole to the carbon bricks on the uppermost layer of the furnace bottom is 1.8m, the diameter of the hearth is 12.4m, and the distance from the center line of the taphole to the carbon bricks on the uppermost layer of the furnace bottom is 14.5 percent of the diameter of the hearth.