CN113564298B - Refractory lining body for smelting zone of stress release type steel converter and building method thereof - Google Patents

Abstract

The invention relates to a stress release type refractory lining body in a smelting zone of a steelmaking converter, which comprises a furnace lining working layer and a furnace lining permanent layer in a furnace shell, wherein the furnace lining working layer consists of a first arc zone masonry, a parallel zone masonry and a tail arc zone masonry which are sequentially arranged in an annular structure and is positioned between a furnace bottom ring brick layer and a furnace body ring brick layer for smooth arc surface transition connection; the brickwork in each area is formed by high-temperature refractory bricks with completely identical longitudinal sections in a surface-to-surface seamless fit mode, and a stress absorption buffer layer is arranged in the middle layer of the brickwork in the first arc area and the brickwork in the last arc area. The refractory lining body is an innovative structure which realizes the turning of a masonry surface by using a double-arc masonry and realizes the transition between two arcs by using a parallel masonry surface, and the middle layer of the arc masonry is respectively arranged as a stress absorption buffer layer.

Description

Refractory lining body for smelting zone of stress release type steel converter and building method thereof

Technical Field

The invention relates to a stress release type refractory lining body for a smelting zone of a steelmaking converter and a building method thereof, belonging to the technical field of refractory materials for steelmaking converters.

Background

Due to the advantages of high productivity, good smelting quality, low construction cost, labor saving, easy flue gas dust removal, low refractory consumption and the like, converter steelmaking has been developed into the current mainstream steelmaking method. Particularly in China, according to statistics of relevant departments, converter steel accounts for more than 80% of total crude steel yield of the whole country in recent years. Therefore, the development of new refractory material technology for the converter and the improvement of the service life of the furnace lining have important promotion effect on the way of the health development of the steel industry in China, which insists on green, emission reduction and low consumption. At present, in the furnace linings of large and medium-sized converters (the nominal capacity is more than 100 tons) in China, the furnace bottom working lining is generally built by a spherical magnesia carbon brick annular method.

As shown in figure 1, in a smelting area of a traditional converter, a turning brick 13 with a right-angled trapezoid longitudinal section is mostly adopted to connect a spherical bottom ring brick 1 and a molten pool brick layer 14, and the turning brick layer is generally 3-5 layers. The building method is that after the last ring brick 1 at the bottom of the spherical furnace is built, a permanent layer brick 15 is firstly laid along the direction of the furnace shell 6 according to a design drawing; then finding out the bottom turn-over brick masonry surface 131 according to the elevation H, and filling gaps below the masonry surface with a magnesia ramming mass 16, wherein the masonry surface 131 is required to be a horizontal plane; sequentially building the turnover bricks from bottom to top according to the sequence of the turnover bricks, wherein under the condition of ensuring the horizontal building surface, the oblique angle surface of each layer of the turnover bricks is tightly attached to the outer side surface 101 of a bottom end ring brick, and gaps between the outer end of the furnace of the turnover bricks and a permanent layer brick 15 are tamped and filled by adopting a magnesia ramming mass 16; and finally, building the first layer of the melting bath bricks 14 on the surface of the turning brick 132 on the uppermost layer, and building other layers of the melting bath bricks from bottom to top according to a design drawing, thereby completing the building work of the refractory lining of the whole melting zone.

The traditional refractory lining structure of the smelting zone of the converter is widely applied because of the advantages of relatively simple brick-shaped design, convenient manufacture and the like. However, with the increasing demand of people for high-quality steel, converter steelmaking is developing towards large furnace shells, purification of molten steel, low consumption of metallurgical auxiliary materials and rapid development of production rhythm, and a low carbon oxygen deposit smelting technology, a bottom blowing intensified stirring technology, an ultra-low iron consumption smelting technology and the like are gradually popularized and applied, so that higher quality requirements are provided for converter linings. It is against this background that the above-mentioned disadvantages of conventional lining constructions are gradually revealed, and become a major factor which currently limits further improvements in the life of the converter lining. The following points can be summarized:

(1) the bottom turning brick is elevated, positioned and leveled before the bottom turning brick is built, so that certain building difficulty is increased, and in addition, once the leveling operation of the bottom turning brick building reference surface is improper, the building quality of the whole converter lining is directly influenced;

(2) the production cost of the refractory manufacturer is increased. In the traditional smelting zone furnace lining structure, the turning brick built by the last ring brick layer at the top of the spherical furnace bottom usually consists of 3-5 layers, is just positioned in a triangular turning zone between the furnace bottom of the converter and the furnace shell of the lower cone section, and is seen to be gradually lengthened from bottom to top;

(3) because the size error is inevitably generated in the brick type production and building process, under the premise of ensuring the levelness of the building surface, the oblique angle surface of the turnover brick is not tightly attached to the outer side surface of the last ring brick at the bottom of the furnace, thereby not only influencing the sealing property of the building body and having the risks of steel penetration and steel leakage during smelting, but also forming a line-surface connection structure which is easy to concentrate thermal stress between the oblique angle surface and the outer side surface of the last ring brick at the bottom of the furnace, thereby causing the refractory lining body in the smelting area to be damaged too fast and reducing the whole service life of the furnace lining;

(4) the turnover brick is sealed in a triangular area among the bottom brick, the melting bath brick and the furnace shell, the expansion effects generated by all parts in the temperature rising process are asynchronous and mutually contradicted and limited, and thus the problem that the contact part of all parts is easy to form thermal stress concentration is caused.

In a continuously harsh smelting environment, the defects of the traditional masonry structure are increasingly highlighted, and particularly, as illustrated in (3) and (4), the phenomena of 'bottom angle deep pit', 'smelting zone erosion too fast', and the like, which seriously affect the safe production and the whole service life of the converter, are generated in practical application due to the concentrated thermal stress, the 'natural' brick joints, and the like. In order to adapt to the application and development of new converter steelmaking technologies such as low-carbon-oxygen-accumulation smelting, bottom-blowing enhanced stirring, ultra-low iron-consumption smelting and the like, the problems need to be solved urgently.

Disclosure of Invention

The invention provides a stress-release type steel-making converter smelting zone refractory lining body and a building method thereof, wherein the refractory lining body is an innovative structure which realizes the turning of a building surface by a double-arc-shaped building body and the transition between two arcs by a parallel building surface, and the middle layer of the arc-shaped building body is respectively arranged as a stress absorption buffer layer, so that the structure can guide the thermal expansion of the whole converter lining of a converter to a furnace mouth sealing material layer to the maximum extent without dead angles, and the stress release of the converter lining body in a thermal state is realized to the maximum extent.

In order to solve the above problems, the specific technical scheme of the invention is as follows: a stress release type refractory lining body in a smelting zone of a steelmaking converter comprises a furnace lining working layer and a furnace lining permanent layer in a furnace shell, wherein the furnace lining working layer is composed of an annular structure formed by sequentially arranging a first arc zone masonry, a parallel zone masonry and a tail arc zone masonry and is positioned between a furnace bottom ring brick layer and a furnace body ring brick layer for smooth arc surface transition connection; the brickwork in each area is formed by high-temperature refractory bricks with completely identical longitudinal sections in a surface-to-surface seamless fit mode, and a stress absorption buffer layer is arranged in the middle layer of the brickwork in the first arc area and the brickwork in the last arc area.

The primary arc zone brickwork is positioned at the junction of the lower conical section furnace shell and the furnace bottom furnace shell, and the central line of the stress absorption buffer layer of the primary arc zone brickwork passes through the central position of the corner area of the lower conical section furnace shell and the furnace bottom furnace shell; the tail arc area brickwork is positioned at the junction of the furnace body section furnace shell and the lower cone section furnace shell, and the central line of the stress absorption buffer layer of the tail arc area brickwork passes through the central position of the corner area of the furnace body section furnace shell and the lower cone section furnace shell; the parallel area masonry is positioned in the center of the lower cone section furnace shell.

The stress absorption buffer layer is an ultra-high carbon magnesia carbon brick with chemical components of MgO being more than or equal to 40 percent and C being more than or equal to 40 percent.

The permanent lining layer is built by a plurality of layers of high-temperature refractory bricks with horizontal building surfaces; welding a permanent layer supporting platform on the furnace bottom shell, wherein the permanent layer supporting platform is an annular high-strength steel structure with an inverted L-shaped longitudinal section; the vertical surface of the permanent layer supporting platform is positioned right below the first layer of bricks of the primary arc area masonry, and the upper surface of the permanent layer supporting platform is a horizontal plane and is a foundation for building the upper permanent layer of high-temperature refractory bricks.

The permanent layer is divided into three areas, namely a first arc area permanent layer, a parallel area permanent layer and a tail arc area permanent layer, and the furnace inner end surface of the first arc area permanent layer is seamlessly attached to the furnace outer end surface of the first arc area masonry furnace; the furnace inner end surface of the parallel zone permanent layer is seamlessly attached to the furnace outer end surface of the parallel zone masonry; the furnace inner end surface of the permanent layer of the tail arc area is seamlessly attached to the furnace outer end surface of the brickwork of the tail arc area.

The high-temperature refractory bricks in the first arc-area masonry and the tail arc-area masonry are arc-shaped bricks with sector-ring-shaped longitudinal sections and isosceles trapezoid transverse sections; the high-temperature refractory bricks of the first arc zone permanent layer and the tail arc zone permanent layer are in asymmetrical concave arc shapes at the inner end of the furnace with longitudinal sections, the outer end of the furnace is in an oblique angle shape, and the cross section is in an isosceles trapezoid shape; the longitudinal section of the high-temperature refractory brick in the parallel-area masonry is rectangular, and the cross section of the high-temperature refractory brick is isosceles trapezoid; the longitudinal section of the high-temperature refractory brick of the parallel-area permanent layer is a parallelogram, and the cross section of the high-temperature refractory brick is an isosceles trapezoid.

The permanent layer of the first arc area is 4-6 layers; the parallel area permanent layer is 2-6 layers; the permanent layer of the tail arc area is 2 layers.

And a heat insulation layer is arranged between the permanent layer and the furnace shell.

The masonry method of the refractory lining body in the smelting area of the steelmaking converter comprises the following steps:

step 1, welding a permanent layer supporting platform: firstly, according to the requirements of a design drawing, a permanent layer supporting platform is welded on a furnace shell of a furnace bottom in a full welding mode, and the levelness of the supporting platform is ensured to meet the design requirements;

step 2, paving the heat insulation layer: paving thermal insulation layers on the inner surfaces of the lower conical section furnace shell and the furnace body section furnace shell from bottom to top in sequence from the upper surface of the permanent layer supporting platform built in the step 1, wherein the thickness of the thermal insulation layers is 10-30 mm;

step 3, building a permanent layer in a smelting zone: uniformly coating a thin magnesium fire clay layer on the upper surface of the permanent layer supporting platform built in the step 1, wherein the thickness of the fire clay layer is less than or equal to 3 mm; then, sequentially laying a first arc area permanent layer, a parallel area permanent layer and a tail arc area permanent layer according to design requirements, wherein the outer end surface of the permanent layer is tightly propped against the heat insulation layer;

step 4, masonry of a masonry brick layer in the initial arc area:

step 4.1, polishing the outer side surface of the furnace bottom ring brick layer by using an electric angle grinder to ensure the flatness;

step 4.2, masonry of the masonry brick layer of the first arc area of the 1 st layer: finding out the lowest point of the whole furnace bottom ring brick layer by using a laser level meter, and sequentially building along the ring along the clockwise direction and the anticlockwise direction by taking the lowest point as a starting point; during building, the building of each high-temperature refractory brick always takes the principle that adjacent bricks are kept horizontal and flat, the outer end surface of the furnace is required to be tightly and firmly propped against a permanent layer, and the inner end of the furnace is flush with the lower layer of the furnace, so that the platform is not withdrawn or bulges are not generated;

step 4.3, building 2 nd to N-1 st layers, wherein N is the number of middle layers of the masonry in the initial arc area; starting from the second layer, the masonry starting position of each layer is still staggered by 10-15 degrees clockwise or anticlockwise along a ring at the starting position of the lower layer, and the rest methods are the same as the step 4.2;

step 4.4, building the Nth layer: firstly, measuring whether the center line of the Nth layer is positioned at the center position of the corner area of the furnace bottom shell and the lower cone-section shell, if the center line of the Nth layer is deviated, the deviation is required to be controlled within +/-5 mm, and if the center line of the Nth layer is beyond the range, the whole outer side face of the N-1 layer needs to be polished; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 4.3;

step 4.5, building the (N + 1) th to last layers, wherein the building method and the requirements are consistent with those in the step 4.3;

step 5, masonry of brick layers of the parallel area:

step 5.1, carrying out local polishing treatment on the outer side surface of a last ring brick of the masonry in the initial arc area by using an electric angle grinder, so that the flatness of the ring surface within the range of 0-360 degrees meets the design requirement;

step 5.2, building each brick layer of the parallel area layer by layer from bottom to top by taking the outer side surface treated in the step 5.1 as a building surface; the building starting point position of each layer is obtained by staggering 10-15 degrees clockwise or anticlockwise in a ring shape from the starting point position of the lower layer, the outer end surface of the furnace is required to be tightly and firmly propped against the permanent layer, and the inner end of the furnace is flush with the lower layer, so that the platform withdrawing or the bulge cannot occur;

step 6, masonry of a masonry brick layer in a tail arc area:

step 6.1, polishing the outer side surfaces of the masonry end ring bricks in the parallel areas by using an electric angle grinder to ensure the flatness;

6.2, building the 1 st layer to the N-1 st layer, wherein N is the number of middle layers of the masonry in the initial arc area; taking the annular side surface treated in the step 6.1 as a masonry surface, and performing masonry by staggering 10-15 degrees clockwise or anticlockwise on the lower-layer starting point position along the annular direction;

step 6.3, building the Nth layer: firstly, measuring whether the center line of the Nth layer is positioned at the center position of the corner area of the lower cone-section furnace shell and the furnace body section furnace shell, if the center line of the Nth layer is deviated, the deviation is required to be controlled within +/-5 mm, and if the center line of the Nth layer is beyond the range, the whole outer side face of the N-1 layer needs to be polished; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 6.2;

step 6.4, building the (N + 1) th to last layers, wherein the building is carried out on the basis of the outer surfaces of the N layers, and the building method and the requirements are consistent with those in the step 6.2;

step 7, treating the upper surface of the last layer brick of the masonry in the tail arc area: the laser level meter and the level ruler are used for simultaneously detecting and verifying the levelness of the annular surface 501, the levelness in the radial direction of the converter is required to be less than or equal to 2mm/m, and the converter is qualified, otherwise, an electric angle grinder is required to be used for grinding; and removing the end face of the brickwork from the qualified tail arc to serve as a building foundation face of the furnace body brick 2, and marking that the building work of the refractory furnace lining of the whole smelting area is completely finished.

The technical scheme adopted by the application has the following technical effects:

1. whether in a first arc area, a parallel area or a tail arc area, the longitudinal section sizes of each layer of bricks in the same area are consistent, and the influence of the size change of a furnace shell is small, so that the universal degree of the same brick type on different converters is improved, and the production mold cost can be greatly reduced for refractory material manufacturers;

2. from the bottom ring brick to the first arc zone, the parallel zone, the tail arc zone and finally to the furnace body brick layer, no matter how the brick shape manufacturing and building errors change, the contact part between the layers is always in a 'surface-surface' seamless structure, so that the sealing performance and the safety under the high-temperature smelting condition of the converter smelting zone are improved;

3. the two masonry surface turning areas in the smelting area of the converter adopt circular arc structures to realize gradual turning, and the circular arcs are always kept to be fused or tangent with the permanent layer, so that the expansion of the lining body in the masonry direction under the hot state is prevented, the thermal expansion generated by the whole lining is completely guided to the furnace mouth sealing material layer to be absorbed and released, in addition, the middle layers of the head arc area and the tail arc area are respectively provided with a super-high carbon magnesia carbon brick layer, the thermal expansion in different directions of the turning areas can be effectively absorbed, and the problems of desynchrony and incongruity of the thermal expansion in different directions are solved. Therefore, compared with the traditional lining body structure, the invention has good thermal stress conduction and release capacity;

4. because the refractory lining body structure provided by the invention is the same as a furnace bottom brick layer and a molten pool brick layer, the problem of closed space does not exist, special elevation and leveling are not needed, and only the refractory lining body is built by stacking one layer upwards along the original building surface according to the regulation, so that the construction difficulty is low, and the building quality is easy to control;

5. because the invention has adopted the permanent layer of building of asymmetric arc brick in the double-arc turning area, after the building of this arc brick is finished, the furnace inner end presents the arcwall face of laminating perfectly with head arc area or tail arc area, does not need to adopt the magnesium ramming mass to tamp and pack among them, it is seamless and building without material, stop the sinking phenomenon of the masonry completely, further improve the safety of the smelting area of the converter;

6. just because the technical scheme of the invention realizes the beneficial effects that the masonry surface is always kept in surface-surface seamless connection, has good thermal stress release capability and the like, the invention thoroughly solves the problem that a traditional converter smelting area is easy to generate bottom angle deep pits, greatly reduces the repair frequency in the service period of the converter, and effectively reduces the daily maintenance work of the converter and the consumption of per ton steel refractory materials;

7. the furnace hearth of the converter is provided with a smooth transition and gradually opened smelting area, which is very beneficial to the rolling of molten steel flow brought by bottom blowing gas, the molten steel stirring efficiency is increased, the metallurgical reaction is promoted, and the production efficiency of the converter is greatly improved.

Drawings

FIG. 1 is a schematic diagram of a "turning brick" type furnace lining masonry structure of a traditional converter smelting zone in FIG. 1.

FIG. 2 is a schematic structural view of a refractory lining in the smelting zone of a stress-relieving steelmaking converter.

FIG. 3a is a front view of a brick type of a first arc zone masonry and a tail arc zone masonry.

FIG. 3b is a top view of the brick shape of the initial arc zone masonry and the final arc zone masonry.

Fig. 4a is a front view of a parallel block masonry brick.

Fig. 4b is a top view of a parallel block masonry brick.

Fig. 5a is a front view of a first arc permanent layer and a last arc permanent layer in a brick shape.

Fig. 5b is a top view of the first arc permanent layer and the last arc permanent layer in a brick shape.

Fig. 6a is a front view of parallel permanent layers.

FIG. 6b is a top view of parallel permanent layers.

Detailed Description

As shown in fig. 2, the stress release type refractory lining body for the smelting zone of the steelmaking converter comprises a furnace lining working layer and a furnace lining permanent layer in a furnace shell, wherein a heat insulation layer 12 is arranged between the permanent layer and the furnace shell, the furnace lining working layer is composed of annular structures in which a first arc zone masonry 3, a parallel zone masonry 4 and a tail arc zone masonry 5 are sequentially arranged, and the annular structures are positioned between a furnace bottom ring brick layer 1 and a furnace body ring brick layer 2 and are in smooth arc surface transition connection; the masonry of each area is composed of high-temperature refractory bricks with completely identical longitudinal sections in a surface-to-surface seamless joint mode, and the seamless joint improves the sealing property and the safety under the high-temperature smelting condition of a converter smelting area; and a stress absorption buffer layer 10 is arranged in the middle layer of the first arc zone brickwork 3 and the tail arc zone brickwork 5. Because the longitudinal section shape and the size of each layer of bricks in the same area are completely consistent and are slightly influenced by the size change of the furnace shell, the universal degree of the same brick type on different converters is improved, and the production mold cost can be greatly reduced for refractory material manufacturers; in addition, in a masonry surface turning area, the outer end of the working layer furnace is always fused or tangent with the inner end surface of the permanent layer furnace by a smooth arc surface, so that the expansion of the lining body in the masonry direction under a hot state is prevented, and the thermal expansion generated by the whole lining is completely guided to a furnace opening sealing material layer to be absorbed and released.

The primary arc zone brickwork 3 is positioned at the junction of the lower conical section furnace shell 63 and the furnace bottom furnace shell 62, and the central line of the stress absorption buffer layer 10 of the primary arc zone brickwork 3 passes through the central position of the corner area of the lower conical section furnace shell 63 and the furnace bottom furnace shell 62; the tail arc zone brickwork 5 is positioned at the junction of the furnace body section furnace shell 64 and the lower cone section furnace shell 63, and the central line of the stress absorption buffer layer 10 of the tail arc zone brickwork 5 passes through the central positions of corner areas of the furnace body section furnace shell 64 and the lower cone section furnace shell 63; the parallel area masonry 4 is positioned at the central position of the lower cone section furnace shell 63.

The stress absorption buffer layer 10 is an ultra-high carbon magnesia carbon brick with chemical components of MgO which is more than or equal to 40 percent and C which is more than or equal to 40 percent. The preparation technology of the ultra-high carbon magnesia carbon brick is disclosed in the patent of 25.11.2020, the patent number is 202011341444.3 and the invention name is 'an ultra-high carbon magnesia carbon brick with the carbon content more than 40% and the preparation method thereof', the ultra-high carbon magnesia carbon brick has the characteristics of small enough thermal expansion, strong enough temperature conduction capability, thermal stress absorption, conduction and release capability and large enough toughness, and can effectively absorb the thermal expansion in different directions of a steering area, thereby solving the problems of asynchronous and uncoordinated thermal expansion in different directions.

The furnace lining permanent layer is built by adopting a plurality of layers of high-temperature refractory bricks with horizontal building surfaces, a permanent layer supporting platform 61 is welded on the furnace bottom shell 62, and the permanent layer supporting platform 61 is an annular high-strength steel structure with an inverted L-shaped longitudinal section; the vertical surface of the permanent layer supporting platform 61 is positioned right below the first layer of bricks of the first arc zone masonry 3, and the upper surface of the permanent layer supporting platform 61 is a horizontal plane and is a foundation for building the upper permanent layer of high-temperature refractory bricks. The high-strength steel supporting platform structure can provide continuous and stable supporting function for the permanent layer, thereby ensuring that the working layer does not sink or slide in the whole furnace service process, and improving the safety performance of the smelting area of the converter!

The permanent layer is divided into three areas, namely a first arc area permanent layer 7, a parallel area permanent layer 8 and a tail arc area permanent layer 9, and the furnace inner end face of the first arc area permanent layer is seamlessly attached to the furnace outer end face of the first arc area masonry 3; the furnace inner end surface of the parallel area permanent layer 8 is seamlessly attached to the furnace outer end surface of the parallel area masonry 4; the furnace inner end surface of the tail arc zone permanent layer 9 is seamlessly attached to the furnace outer end surface of the tail arc zone brickwork 5. The double-arc steering area adopts an asymmetric arc-shaped brick masonry permanent layer, after the arc-shaped bricks are built, an arc surface perfectly attached to the head arc area or the tail arc area is presented near the inner end of the furnace, magnesium ramming materials are not needed to be used for ramming and filling, the double-arc steering area belongs to seamless material-free building, the sinking phenomenon of the building body is thoroughly avoided, and the safety of a converter smelting area is further improved.

As shown in fig. 3a and 3b, the high temperature refractory bricks in the first arc zone brickwork 3 and the last arc zone brickwork 5 are arc bricks with sector ring-shaped longitudinal section and isosceles trapezoid transverse section; as shown in fig. 5a and 5b, the high-temperature refractory bricks of the first arc zone permanent layer 7 and the tail arc zone permanent layer 9 are shaped like an asymmetric concave arc at the inner end of the furnace with a longitudinal section, and are shaped like an oblique angle at the outer end of the furnace, and the cross section is in the shape of an isosceles trapezoid; as shown in fig. 4a and 4b, the high temperature refractory bricks in the parallel zone brickwork 4 have a rectangular longitudinal section and an isosceles trapezoid cross section; as shown in fig. 6a and 6b, the refractory bricks of the parallel zone permanent layer 8 have a parallelogram shape in longitudinal section and an isosceles trapezoid shape in cross section.

The primary arc area permanent layer 7 is 4-6 layers; the parallel area permanent layer 8 is 2-6 layers; the permanent layer 9 of the tail arc area is 2 layers.

And a heat insulation layer 12 is arranged between the permanent layer and the furnace shell.

The invention relates to an innovative structure of a refractory lining body, which realizes Masonry surface turning by Double-arc Masonry (Double Circular-arc Masonry) and transitions between two arcs by a Parallel Masonry surface (Parallel Masonry).

The masonry method of the refractory lining body in the smelting area of the steelmaking converter comprises the following steps:

step 1, welding a permanent layer supporting platform 61: firstly, according to the requirements of a design drawing, a permanent layer supporting platform 61 is welded on a furnace bottom furnace shell 62 in a full welding mode, and the levelness of the supporting platform 61 is ensured to meet the design requirements;

step 2, paving the heat insulation layer 12: paving a heat insulation layer 12 on the inner surfaces of the lower conical section furnace shell 63 and the furnace body section furnace shell 64 from bottom to top in sequence from the upper surface of the permanent layer supporting platform built in the step 1, wherein the thickness of the heat insulation layer is 10-30 mm;

step 3, building a permanent layer in a smelting zone: uniformly coating a thin magnesium fire clay layer on the upper surface of the permanent layer supporting platform built in the step 1, wherein the thickness of the fire clay layer is less than or equal to 3 mm; then, a first arc zone permanent layer, a parallel zone permanent layer and a tail arc zone permanent layer are sequentially laid according to the design requirements, and the outer end surface of the permanent layer is tightly propped against the heat insulation layer 12;

step 4, masonry of a masonry brick layer in the initial arc area:

step 4.1, polishing the outer side surface of the furnace bottom ring brick layer 1 by using an electric angle grinder to ensure the flatness;

step 4.2, masonry of the masonry brick layer of the first arc area of the 1 st layer: finding out the lowest point of the whole furnace bottom ring brick layer 1 by using a laser level meter, and sequentially building along the ring along the clockwise direction and the anticlockwise direction by taking the lowest point as a starting point; during building, the building of each high-temperature refractory brick always takes the principle that adjacent bricks are kept horizontal and flat, the outer end surface of the furnace is required to be tightly and firmly propped against a permanent layer, and the inner end of the furnace is flush with the lower layer of the furnace, so that the platform is not withdrawn or bulges are not generated;

step 4.3, building 2 nd to N-1 st layers, wherein N is the number of middle layers of the masonry in the initial arc area; starting from the second layer, the masonry starting position of each layer is still staggered by 10-15 degrees clockwise or anticlockwise along a ring at the starting position of the lower layer, and the rest methods are the same as the step 4.2;

step 4.4, building the Nth layer: firstly, measuring whether the central line of the insulating brick of the Nth layer is positioned at the central position of the corner area of the furnace bottom shell 62 and the lower cone-section shell 63, if the central line has deviation, the deviation is required to be controlled within +/-5 mm, and if the central line exceeds the range, the whole outer side surface of the N-1 layer needs to be polished; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 4.3;

step 4.5, building the (N + 1) th to last layers, wherein the building method and the requirements are consistent with those in the step 4.3;

step 5, parallel area masonry brick layer masonry:

step 5.1, carrying out local polishing treatment on the outer side surface of a last ring brick of the masonry in the initial arc area by using an electric angle grinder, so that the flatness of the ring surface within the range of 0-360 degrees meets the design requirement;

step 5.2, building each brick layer of the parallel area layer by layer from bottom to top by taking the outer side surface treated in the step 5.1 as a building surface; the building starting point position of each layer is obtained by staggering 10-15 degrees clockwise or anticlockwise in a ring shape from the starting point position of the lower layer, the outer end surface of the furnace is required to be tightly and firmly propped against the permanent layer, and the inner end of the furnace is flush with the lower layer, so that the platform withdrawing or the bulge cannot occur;

step 6, masonry of a masonry brick layer in a tail arc area:

step 6.1, polishing the outer side surface of a last ring brick of the parallel area masonry 4 by using an electric angle grinder to ensure the flatness;

6.2, building the 1 st layer to the N-1 st layer, wherein N is the number of middle layers of the masonry in the initial arc area; taking the annular side surface treated in the step 6.1 as a masonry surface, and performing masonry by staggering 10-15 degrees clockwise or anticlockwise on the lower-layer starting point position along the annular direction;

step 6.3, building the Nth layer: firstly, measuring whether the center line of the Nth layer is positioned at the center position of the corner area of the lower cone section furnace shell 63 and the furnace body section furnace shell 64, if deviation exists, the deviation is required to be controlled within +/-5 mm, and if the deviation exceeds the range, polishing treatment is required to be carried out on the whole outer side surface of the N-1 layer; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 6.2;

step 6.4, building the (N + 1) th to last layers, wherein the building is carried out on the basis of the outer surfaces of the N layers, and the building method and the requirements are consistent with those in the step 6.2;

step 7, treating the upper surface of the last layer brick of the masonry in the tail arc area: the laser level and the level ruler are used for simultaneously detecting and verifying the levelness of the annular surface 501, the levelness in the radial direction of the converter is required to be less than or equal to 2mm/m, and the converter is qualified, otherwise, an electric angle grinder is required to be used for grinding. And removing the end face of the brickwork from the qualified tail arc to serve as a building foundation face of the furnace body brick 2, and marking that the building work of the refractory furnace lining of the whole smelting area is completely finished.

The following will further illustrate the specific implementation method and the achieved effect of the technical solution of the present invention with reference to specific examples.

Example 1 the present invention was applied to a 210 ton converter of a certain large iron and steel company in China

In order to reduce the content of impurities in steel and improve the product quality, a certain large-scale steel company in China mainly takes SAPH400 series hot-rolled sheets and 40CrH series alloy bars as main products, the company generally adopts a standard far lower than the carbon content of the products to carry out end-point carbon drawing when smelting in a 210 ton converter, and requires the whole-process furnace service to maintain bottom blowing high-strength stirring, and finally creates severe conditions that the end-point temperature is usually higher than 1700 ℃, molten steel is over oxidized, molten steel in a smelting area has large kinetic energy for washing a furnace lining, the oxidizing property of final slag is strong, the slag layer of the furnace lining is thin and the like, which seriously affect the service life of the furnace lining. In view of the smelting conditions, the embodiment of the invention is applied to the construction of the refractory lining of the smelting zone of the converter. In this embodiment, the structural features of the working layer and the permanent layer in the first arc region, the parallel region, and the last arc region, the connection manner of each part, the masonry method, and the like are consistent with the technical solutions described above, and no further description is given here, but in order to better illustrate the beneficial effects of the present invention in this embodiment, the following specific technical information needs to be listed:

the working layer of the furnace bottom is made of MT-14B magnesia carbon bricks, and the length of the bricks is 1000 mm; the first arc zone brickwork 3 has 7 layers, and is built by magnesia carbon bricks with the brick length of 1000mm and the mark number of MT-16A, the first arc zone permanent layer has 5 layers, the actual value of the arc radius at the inner end of the furnace is 1522mm through measurement, the radius of the outer end of the furnace of the first arc zone brickwork is 1520mm, the gap between the working layer and the permanent layer is less than 1mm through the measurement of a feeler gauge, and the arc fitting degree meets the design requirement; the parallel area masonry has 5 layers in total, each layer has the height of 150mm, and the length of the brick is 1000mm and MT-16A magnesia carbon bricks are built, 4 layers of permanent layers in the parallel area are formed, the gap between the working layer and the permanent layer is less than 1mm through the measurement of a feeler gauge, and the fitting degree meets the design requirement; the tail arc zone brickwork 5 lining bodies are 5 layers in total, the brickwork is built by magnesia carbon bricks with the brick length of 1000mm and the mark number of MT-16A, the tail arc zone permanent layer is 2 layers in total, the actual value of the arc radius of the furnace inner end is 1579mm through measurement, the radius of the furnace outer end of the tail arc zone lining body is 1576mm, the gap between the working layer and the permanent layer is less than 1mm through measurement of a feeler gauge, and the arc fitting degree meets the design requirement; the thermal stress absorbing buffer layer between the first arc area and the tail arc area is formed by laying ultra-high carbon magnesia carbon bricks with the length of 1000mm, and the ultra-high carbon magnesia carbon bricks are formed by 53 percent of electric melting black tiles, 43.5 percent of V96 high carbon mixed scaly graphite and 2 percent of (Al + Mg + TiB)₂) The composite antioxidant is produced by a 1300-ton friction brick press by using 1.5 percent of silicon carbide whisker (toughening agent) as a raw material and 3 percent of thermosetting phenolic resin as a bonding agent, and the chemical components of the composite antioxidant are MgO =51.20wt percent and C =42.15wt percent through detection.

Comparative example 1: before the invention is adopted, the smelting zone of the converter adopts the traditional 'turning brick' type furnace lining structure design as shown in figure 1, which is a comparative example 1. In comparative example 1, the length of the working layer in the smelting zone and the material and formulation of the magnesia carbon brick were completely the same as in example 1, namely: the length of the furnace bottom magnesia carbon brick is 1000mm, the mark is MT-14B, the length of the molten pool magnesia carbon brick is 1000mm, and the mark is MT-16A.

The results of example 1 and comparative example 1 are shown in the following table:

it can be seen from the table that after the invention is adopted, the service life of the converter is greatly improved, the amplification is about 46.3%, the consumption of the repairing burden and the unit consumption of the refractory are greatly reduced, and the reduction amplitudes are respectively as high as 24.6% and 36.1%, compared with the comparative example 1, as the lining masonry surface of the smelting zone designed in the embodiment 1 always keeps 'surface-surface' seamless connection and has good thermal stress release capability, the smooth bottom corner appearance of the transition is always maintained in the whole furnace service process, and the problem of 'deep pit' in the comparative example 1 is thoroughly solved.

Example 2 the present invention was applied to a 150 ton converter of a certain iron and steel company in China

The steel company mainly uses Q235 and Q195 series high-quality carbon structural steel and the like as main production steel grades, belongs to low-carbon steel doors, and mainly adopts the common ribbed steel bars and high-speed wires in the market. In order to improve the product quality and the production efficiency, the 150-ton converter smelting of the company also adopts the bottom blowing strength which is far higher than the average level of the industry, so that the molten steel in a smelting zone strongly scours a furnace lining. In addition, because of the smelting requirement of low-carbon steel, the molten steel has higher end point [ O ], strong oxidation of final slag and very rare slag, not only has poor furnace protection effect by gradual slag, but also has abnormal infiltration and erosion capacity to furnace lining bricks. In view of the smelting conditions, the embodiment of the invention is applied to the construction of the refractory lining of the smelting zone of the converter. In this embodiment, the structural features of the working layer and the permanent layer in the first arc region, the parallel region, and the last arc region, the connection manner of each part, the masonry method, and the like are consistent with the technical solutions described above, and no further description is given here, but in order to better illustrate the beneficial effects of the present invention in this embodiment, the following specific technical information needs to be listed:

the working layer of the furnace bottom is made of MT-12B magnesia carbon bricks, and the length of the bricks is 800 mm; the primary arc zone brickwork comprises 7 layers in total, wherein the primary arc zone brickwork comprises 800mm of bricks and MT-14A magnesia carbon bricks, the primary arc zone permanent layer comprises 5 layers in total, the actual value of the arc radius of the furnace inner end is 1485mm through measurement, the radius of the furnace outer end of the primary arc zone brickwork is 1482mm through measurement by a feeler gauge, the gap between the working layer and the permanent layer is smaller than 1mm, and the arc fitting degree meets the design requirement; 4 layers of parallel area masonry are 4, each layer is 150mm high and is built by magnesia carbon bricks with the brick length of 800mm and the mark number of MT-14A, 3 layers of parallel area permanent layers are 3, the gap between the working layer and the permanent layer is less than 1mm through the measurement of a feeler gauge, and the fitting degree meets the design requirement; 5 layers of the masonry in the tail arc area are built by magnesia carbon bricks with the brick length of 800mm and the mark number of MT-14A, 2 layers of the permanent layer in the tail arc area are built, the actual value of the arc radius of the inner end of the furnace is 1565mm through measurement, the radius of the outer end of the lining body furnace in the tail arc area is 1563mm, the gap between the working layer and the permanent layer is less than 1mm through measurement of a feeler gauge, and the arc paste is stuck to the arcThe degree of conformity meets the design requirements; the thermal stress absorbing buffer layer between the first arc area and the tail arc area is formed by building ultra-high carbon magnesia carbon bricks with the length of 800mm, and the ultra-high carbon magnesia carbon bricks are formed by 48 percent of electric melting black tiles, 48 percent of V96 high carbon mixed scaly graphite and 2 percent of (Al + Mg + TiB)₂) The composite antioxidant is produced by a 1300-ton friction brick press by using 2% of silicon carbide whiskers (toughener) as raw materials and 3% of thermosetting phenolic resin as a binder, and the chemical components of the composite antioxidant are MgO =47.15wt% and C =46.53wt% through detection.

Comparative example 2: before the invention is adopted, the smelting zone of the converter also adopts the traditional design of a furnace lining of a turning brick type as shown in the attached figure 1, which is a comparative example 2. In comparative example 2, the length of the working layer in the smelting zone and the material and formulation of the magnesia carbon brick were completely the same as in example 1, namely: the length of the furnace bottom magnesia carbon brick is 800mm, the mark is MT-12B, the length of the molten pool magnesia carbon brick is 800mm, and the mark is MT-14A.

The results of example 2 and comparative example 2 are shown in the following table:

it can be seen from the table that after the invention is adopted, the service life of the converter is greatly improved, the increase is about 29.8%, the consumption of the repairing burden and the unit consumption of the refractory are greatly reduced, the reduction is respectively as high as 14.3% and 22.7%, compared with the comparative example 2, because the masonry surface of the lining body of the smelting area designed in the example 2 always keeps 'surface-surface' seamless connection and has good thermal stress release capability, the smooth bottom corner appearance of the transition is always maintained in the whole furnace service process, and the problem of 'deep pit' in the comparative example 2 is thoroughly solved.

Claims (7)

1. The utility model provides a stress release type steelmaking converter smelting zone refractory lining body, includes the furnace lining working layer and the permanent layer of furnace lining in the stove outer covering, its characterized in that: the furnace lining working layer is composed of an annular structure formed by sequentially arranging a first arc zone masonry (3), a parallel zone masonry (4) and a tail arc zone masonry (5), and is positioned between the furnace bottom ring brick layer (1) and the furnace body ring brick layer (2) to be in smooth arc surface transition connection; the brickwork of each area is composed of high-temperature refractory bricks with completely identical longitudinal sections in a surface-to-surface seamless joint mode, and a stress absorption buffer layer (10) is arranged in the middle layer of the first arc brickwork (3) and the tail arc brickwork (5); the primary arc zone brickwork (3) is positioned at the junction of the lower conical section furnace shell (63) and the furnace bottom furnace shell (62), and the central line of the stress absorption buffer layer (10) of the primary arc zone brickwork (3) passes through the central position of the corner area of the lower conical section furnace shell (63) and the furnace bottom furnace shell (62); the tail arc zone brickwork (5) is positioned at the junction of the furnace body section furnace shell (64) and the lower cone section furnace shell (63), and the central line of a stress absorption buffer layer (10) of the tail arc zone brickwork (5) passes through the central position of the corner area of the furnace body section furnace shell (64) and the lower cone section furnace shell (63); the parallel area masonry (4) is positioned at the central position of the lower cone section furnace shell (63); wherein the stress absorbing buffer layer (10) is an ultra-high carbon magnesia carbon brick with chemical components of MgO which is more than or equal to 40 percent and C which is more than or equal to 40 percent.

2. The stress-relieved steelmaking converter melting zone refractory lining of claim 1, further comprising: the permanent lining layer is built by a plurality of layers of high-temperature refractory bricks with horizontal building surfaces; welding a permanent layer supporting platform (61) on a furnace bottom shell (62), wherein the permanent layer supporting platform (61) is an annular high-strength steel structure with an inverted L-shaped longitudinal section; the vertical surface of the permanent layer supporting platform (61) is positioned right below the first layer of bricks of the primary arc zone masonry (3), and the upper surface of the permanent layer supporting platform (61) is a horizontal plane and is a foundation for building the upper permanent layer of high-temperature refractory bricks.

3. The stress-relieved steelmaking converter melting zone refractory lining of claim 2, wherein: the permanent layer is divided into a first arc zone permanent layer (7), a parallel zone permanent layer (8) and a tail arc zone permanent layer (9), and the furnace inner end surface of the first arc zone permanent layer is seamlessly attached to the furnace outer end surface of the first arc zone brickwork (3); the furnace inner end surface of the parallel zone permanent layer (8) is seamlessly attached to the furnace outer end surface of the parallel zone masonry (4); the furnace inner end surface of the tail arc zone permanent layer (9) is seamlessly attached to the furnace outer end surface of the tail arc zone brickwork (5).

4. The stress-relieved steelmaking converter melting zone refractory lining of claim 3, wherein: the high-temperature refractory bricks in the first arc zone masonry (3) and the tail arc zone masonry (5) are arc-shaped bricks with sector-ring-shaped longitudinal sections and isosceles trapezoid transverse sections; the high-temperature refractory bricks of the first arc zone permanent layer (7) and the tail arc zone permanent layer (9) are in the shape of an asymmetric concave arc at the inner end of the furnace with a longitudinal section, the outer end of the furnace is in an oblique angle shape, and the cross section is in an isosceles trapezoid shape; the longitudinal section of the high-temperature refractory brick in the parallel area masonry (4) is rectangular, and the cross section of the high-temperature refractory brick is isosceles trapezoid; the longitudinal section of the high-temperature refractory brick of the parallel-area permanent layer (8) is parallelogram, and the cross section is isosceles trapezoid.

5. The stress-relieved steelmaking converter melting zone refractory lining of claim 3, wherein: the primary arc area permanent layer (7) is 4-6 layers; the parallel area permanent layer (8) is 2-6 layers; the permanent layer (9) of the tail arc area is 2 layers.

6. The stress-relieved steelmaking converter melting zone refractory lining of claim 1, further comprising: and a heat insulation layer (12) is arranged between the permanent layer and the furnace shell.

7. The method for building the refractory lining of the smelting zone of the steelmaking converter as set forth in claim 3, characterized by comprising the steps of:

step 1, welding a permanent layer supporting platform (61): firstly, according to the requirements of a design drawing, a permanent layer supporting platform (61) is welded on a furnace bottom furnace shell (62) in a full welding mode, and the levelness of the supporting platform (61) is ensured to meet the design requirements;

step 2, paving the heat insulation layer (12): from the upper surface of the permanent layer supporting platform built in the step 1, paving heat insulation layers (12) on the inner surfaces of the lower conical section furnace shell (63) and the furnace body section furnace shell (64) from bottom to top in sequence, wherein the thickness of the heat insulation layers is 10-30 mm;

step 3, building a permanent layer in a smelting zone: uniformly coating a thin magnesium fire clay layer on the upper surface of the permanent layer supporting platform built in the step 1, wherein the thickness of the fire clay layer is less than or equal to 3 mm; then, a first arc zone permanent layer, a parallel zone permanent layer and a tail arc zone permanent layer are sequentially laid according to the design requirements, and the outer end surface of the permanent layer is tightly propped against the heat insulation layer (12);

step 4, masonry of a masonry brick layer in the initial arc area:

step 4.1, polishing the outer side surface of the furnace bottom ring brick layer (1) by using an electric angle grinder to ensure the flatness;

step 4.2, masonry of the masonry brick layer of the first arc area of the 1 st layer: finding out the lowest point of the whole furnace bottom ring brick layer (1) by using a laser level meter, and sequentially building along the ring along the clockwise direction and the anticlockwise direction by taking the lowest point as a starting point; during building, the building of each high-temperature refractory brick always takes the principle that adjacent bricks are kept horizontal and flat, the outer end surface of the furnace is required to be tightly and firmly propped against a permanent layer, and the inner end of the furnace is flush with the lower layer of the furnace, so that the platform is not withdrawn or bulges are not generated;

step 4.3, building 2 nd to N-1 st layers, wherein N is the number of middle layers of the masonry in the initial arc area; starting from the second layer, the masonry starting position of each layer is still staggered by 10-15 degrees clockwise or anticlockwise along a ring at the starting position of the lower layer, and the rest methods are the same as the step 4.2;

step 4.4, building the Nth layer-the stress absorption buffer layer: firstly, measuring whether the center line of the Nth layer is positioned at the center position of a corner area of a furnace bottom furnace shell (62) and a lower cone section furnace shell (63), if deviation exists, the deviation is required to be controlled within +/-5 mm, and if the deviation exceeds the range, the whole outer side surface of the N-1 layer needs to be polished; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 4.3;

step 4.5, building the (N + 1) th to last layers, wherein the building method and the requirements are consistent with those in the step 4.3;

step 5, masonry of brick layers of the parallel area:

step 5.1, carrying out local polishing treatment on the outer side surface of a last ring brick of the masonry in the initial arc area by using an electric angle grinder, so that the flatness of the ring surface within the range of 0-360 degrees meets the design requirement;

step 5.2, building each brick layer of the parallel area layer by layer from bottom to top by taking the outer side surface treated in the step 5.1 as a building surface; the building starting point position of each layer is obtained by staggering 10-15 degrees clockwise or anticlockwise in a ring shape from the starting point position of the lower layer, the outer end surface of the furnace is required to be tightly and firmly propped against the permanent layer, and the inner end of the furnace is flush with the lower layer, so that the platform withdrawing or the bulge cannot occur;

step 6, masonry of a masonry brick layer in a tail arc area:

step 6.1, polishing the outer side surface of a last ring brick of the parallel area masonry (4) by using an electric angle grinder to ensure the flatness;

6.2, building the 1 st layer to the N-1 st layer, wherein N is the number of middle layers of the masonry in the initial arc area; taking the annular side surface treated in the step 6.1 as a masonry surface, and performing masonry by staggering 10-15 degrees clockwise or anticlockwise on the lower-layer starting point position along the annular direction;

step 6.3, building the Nth layer-the stress absorption buffer layer: firstly, measuring whether the center line of the Nth layer is positioned at the center position of a corner area of a lower cone section furnace shell (63) and a furnace body section furnace shell (64), if deviation exists, the deviation is required to be controlled within +/-5 mm, and if the deviation exceeds the range, the whole outer side surface of the N-1 layer needs to be polished; then taking the masonry starting position of the N-1 layer as a base point, clockwise or anticlockwise rotating the ring by 10-15 degrees to serve as the position of a first brick of the middle layer, and sequentially building the bricks along the ring from the clockwise direction and the anticlockwise direction, wherein the building method and the requirements are consistent with the step 6.2;

step 6.4, building the (N + 1) th to last layers, wherein the building is carried out on the basis of the outer surfaces of the N layers, and the building method and the requirements are consistent with those in the step 6.2;

step 7, treating the upper surface of the last layer brick of the masonry in the tail arc area: the laser level meter and the level ruler are used for simultaneously detecting and verifying the levelness of the annular surface 501, the levelness in the radial direction of the converter is required to be less than or equal to 2mm/m, and the converter is qualified, otherwise, an electric angle grinder is required to be used for grinding; and removing the end face of the brickwork from the qualified tail arc to serve as a building foundation face of the furnace body brick 2, and marking that the building work of the refractory furnace lining of the whole smelting area is completely finished.

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