CN114507076B

CN114507076B - Vertical kiln panel castable and use method thereof

Info

Publication number: CN114507076B
Application number: CN202011274570.1A
Authority: CN
Inventors: 江书文; 王绪国
Original assignee: Nanjing Baodi Meishan Industrial City Development Co ltd; Shanghai Meishan Iron and Steel Co Ltd
Current assignee: Nanjing Baodi Meishan Industrial City Development Co ltd; Shanghai Meishan Iron and Steel Co Ltd
Priority date: 2020-11-15
Filing date: 2020-11-15
Publication date: 2022-11-15
Anticipated expiration: 2040-11-15
Also published as: CN114507076A

Abstract

The invention relates to a vertical kiln panel castable which is prepared from the following raw materials in percentage by mass:

Description

Vertical kiln panel castable and use method thereof

Technical Field

The invention relates to a castable, in particular to a castable for a vertical kiln panel, and belongs to the technical field of metallurgical industrial kilns.

Background

The active lime shaft kiln is divided into a coke shaft kiln, a sleeve kiln, a Frakas and the like, and the annular sleeve kiln is a kiln type which is generally used for producing active lime at home and abroad at present, and has the advantages of environmental protection, safety, energy conservation, good product quality, high equipment operation rate and the like. After the overhaul of the plum steel 3# kiln, due to the reasons that the high-temperature strength of the clay heat-insulating brick NF2 brick is insufficient, shrinkage and sintering phenomena occur in the high-temperature state of a combustion chamber, the damage is fast, and high-temperature air flow is rapidly conducted to a burner panel, so that the burner panel turns red and is damaged. The panel begins to change color after 20 months, the temperature rises, the panel becomes black after 24 months, the temperature gradually rises to more than 400 ℃, and the situation of burning-through of the steel plate occurs in severe places. The existing furnace kiln has long service life, tight production task and can not be stopped. After the refractory material of the burner nozzle panel is damaged, outside air directly enters the combustion chamber, the combustion effect is poor, the heat consumption of gas combustion is increased, the process requirement of normal production cannot be met, and the lime yield and quality are greatly influenced. The common treatment method is kiln shutdown maintenance treatment, and burner bricks and burner panel refractory bricks are replaced, but the kiln shutdown time is at least one week, the production time of the lime kiln is wasted, the temporary solution is simply replaced, the permanent solution is not treated, and the service life of later-stage refractory materials is not long. The problems of the lime kilns at home and abroad are mostly solved. So, in order to reduce the influence of burner panel refractory material damage to lime production and quality to minimum, need a neotype shaft kiln panel pouring material, can repair the burner panel on line fast, reduce because the burner panel damages the influence to production, improve the output of lime, reduction in production cost. A preparation and use method of a vertical kiln panel castable mainly solves the problems of fast online pouring of the vertical kiln nozzle panel castable, prolongs the service life of the panel and improves the yield of a lime kiln; the main raw materials of the casting material of the invention, namely, the steel slag powder, the limestone sieve powder, the kiln dust removal powder and the like, are wastes generated in steel mill production, and cause pollution to the environment, so the casting material has the advantages of environmental protection, production cost reduction and the like.

And (4) searching for new things and comparing:

the invention discloses a wear-resistant castable for a lime kiln (CN 200810021194.8) and an anti-skinning wear-resistant castable for the lime kiln (CN 201710410657.9) through searching for new patents. A wear-resistant castable (CN 200810021194.8) for a lime kiln mainly solves the technical problem that the existing castable falls off in the using process, and is mainly used for working linings on the outer sides of an upper sleeve and a lower sleeve in a sleeve lime kiln. A skinning-resistant and wear-resistant castable for a lime kiln (CN 201710410657.9) is disclosed, which maintains the overall performance of the castable, not only enhances the erosion resistance and the scour resistance, but also can effectively prevent skinning, overcome blockage and ensure smooth ventilation of a kiln system, and is different from the problems solved by the scheme.

Disclosure of Invention

The invention provides a vertical kiln panel castable aiming at the problems in the prior art, and the technical scheme mainly solves the problems of quick online pouring of the vertical kiln nozzle panel castable, prolongs the service life of the panel, improves the yield of a lime kiln and reduces the production cost.

In order to achieve the purpose, the technical scheme of the invention is as follows, the castable for the vertical kiln panel is prepared from the following raw materials in percentage by mass:

as an improvement of the invention, the steel slag particles are regular solid waste materials with certain shapes after steel slag of steel mills is treated; the floating bead is a fly ash hollow sphere which can float on the water surface, is offwhite, has a thin and hollow wall, a volume weight of 0.4-0.5g/cm & lt 3 & gt, small thermal conductivity, granular shape and a particle size of about 0.1mm.

As an improvement of the invention, the limestone sieve powder is limestone sieve powder generated by sieving limestone raw materials before entering a kiln, caCO ₃ The content is 85-90%, and limestone powder with particle size of 0.05-0.1mm is selected.

As an improvement of the invention, the kiln dust removal powder is dust removal powder ash (waste material influencing the environment) generated by hot airflow circulation in a kiln caused by a fan in the production process of a sleeve kiln, the main contents of the dust removal powder ash are CaO and CaCO3, the CaO content is 40-50%, the CaCO3 content is 35-45%, and the particle size is 0.05-0.1mm.

As an improvement of the invention, the castable is prepared from the following raw materials in percentage by weight:

the granularity requirement of the steel slag particles is as follows: the height of the regular triangular cone body is 4-5mm, the side length of the bottom is 2-3mm, and the granularity of the steel slag powder is required to be as follows: the mass percentage of the particle size less than or equal to 85um is more than or equal to 90 percent.

the granularity requirement of the steel slag particles is as follows: spherical shape with the diameter of 2-3mm,

the granularity requirement of the steel slag powder is as follows: the mass percentage of the granularity less than or equal to 80um is more than or equal to 90 percent.

A preparation and use method of a vertical kiln panel castable comprises the following steps:

step 1: preparing raw materials, namely steel slag particles, floating beads, limestone sieve powder, kiln dust removal powder, steel slag powder and perlite according to a ratio, and carrying out pre-drying treatment to remove water in the steel slag particles;

and 2, step: adding the mixture prepared in the step 1 into a dry mixer according to the mass percentage, and mixing and stirring to obtain a mixture;

and 3, step 3: and (3) bagging the mixture obtained in the step (2) by 25kg (the inner layer is a waterproof plastic film), and sealing.

The use method of the castable comprises the following steps:

tap water or waste water subjected to precipitation treatment in a steel mill is adopted, and the castable and the water are fully stirred according to the mass ratio of 0.07-0.1kg of water to 1kg of castable; in winter, water in a normal temperature state is adopted, and a heat preservation device is not needed; the stirred castable is used up within 30 minutes.

Compared with the prior art, the invention has the advantages that the manufacturing method is simple, the use is convenient, and the service life of the sleeve kiln panel is prolonged by the method; the concrete effects are as follows:

1) The raw materials adopted by the invention are mostly wastes generated in steel-making production, and the pollution to the environment is reduced: a large amount of steel slag, steel slag powder, limestone sieve powder and kiln dust removal powder are used in the self-produced castable, which belongs to waste materials generated in steelmaking production and pollutes the environment.

2) Greatly reduces the use cost of the casting material: the price of the externally purchased castable in a company is about 4500 yuan/ton, a large amount of steel slag, steel slag powder, limestone screen powder and kiln dust removal powder are used in the self-produced castable, the price of the steel slag and the steel slag powder in plum steel is about 5 yuan/ton, the price of the limestone screen powder and the kiln dust removal in plum steel is about 8 yuan/ton, and the comprehensive price of the self-produced castable is about 420 yuan/ton.

3) When the castable is used in winter, hot water and heat preservation equipment are not needed any more, and because CaO is added with water to react, a large amount of heat can be generated, so that the castable can be directly constructed in low-temperature weather without heating.

4) The use quality is greatly improved, and in the experimental stage,

(1) after using novel shaft kiln panel castable, improved the resistant material life-span of nozzle panel: the average service life of the burner is improved from 17 months to 61 months, which is shown in table 1;

table 1 statistical table of refractory life of burner face plate before and after using novel castable

(2) After the novel vertical kiln panel castable is used, the panel heat preservation effect is greatly improved, and the temperature of the burner panel is reduced from 180 ℃ to 110 ℃, which is shown in Table 2;

TABLE 2 statistical table for comparing temperatures of front and rear burner face plates by using novel castable

(3) The key physicochemical indexes of the self-produced castable, such as compressive strength, permanent line change rate, thermal conductivity and the like, are greatly improved.

The recycling of solid waste is increased in the self-produced castable, the use of cement in outsourcing castable is reduced, the pollution to the environment is reduced, the service life of the panel is greatly prolonged, the labor intensity is reduced, and the self-produced castable has good social benefits.

Drawings

FIG. 1 shows that the shape of the steel slag particles is a regular triangle cone, wherein H is the height of the cone, and S is the side length of the bottom of the cone;

FIG. 2 shows that the shape of the steel slag particles is a regular four-corner cone, wherein H is the height of the cone, and S is the side length of the bottom of the cone;

FIG. 3 shows the shape of the steel slag particles as a regular hexagonal pyramid, wherein H is the height of the pyramid, and S is the side length of the bottom of the pyramid;

FIG. 4 the shape of the steel slag particles is spherical, wherein D is the diameter of the sphere;

FIG. 5 is a graph of sample temperature rise;

FIG. 6 burner face plate temperature ramp.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1:

a vertical kiln panel castable is prepared from the following raw materials in percentage by weight:

the granularity requirement of the steel slag particles is as follows: a regular triangular pyramid, wherein the height of the pyramid is 4-5mm, and the side length of the bottom is 2-3mm, as shown in figure 1;

the granularity requirement of the steel slag powder is as follows: the mass percentage of the particle size less than or equal to 85um is more than or equal to 90 percent.

Example 2:

the granularity requirement of the steel slag particles is as follows: the height of the regular quadrangle vertebral body is 2-3mm, and the side length of the bottom is 2-3mm, as shown in figure 2;

the granularity requirement of the steel slag powder is as follows: the mass percentage of the granularity of less than or equal to 70um is more than or equal to 85 percent.

Example 3:

the granularity requirement of the steel slag particles is as follows: a right hexagonal pyramid, the height of the pyramid is 3-4mm, the bottom side length is 2-3mm, see figure 3;

the granularity requirement of the steel slag powder is as follows: the mass percentage of the granularity less than or equal to 75um is more than or equal to 90 percent.

Example 4:

the granularity requirement of the steel slag particles is as follows: spherical shape with a diameter of 2-3mm, as shown in figure 4.

The preparation method of the castable for the shaft kiln panels in the embodiments 1 to 4 comprises the following steps:

the raw materials are prepared according to the weight percentage requirements in the embodiment, and are added into a V-shaped stirrer to uniformly mix steel slag particles, floating beads, limestone sieve powder, kiln dust removal powder, steel slag powder and closed-cell perlite to obtain a mixture;

and (3) bagging the mixture according to a standard of 25 kg/bag (the inner layer is a waterproof plastic film), and hermetically packaging to obtain the vertical kiln panel castable.

The physical and chemical properties of the prepared shaft kiln panel castable are detected as follows:

taking 25kg of prepared vertical kiln panel castable in a packaging bag, then adding 2.25kg of tap water or steel mill wastewater subjected to precipitation treatment, and fully stirring and uniformly mixing to obtain mixed slurry; and respectively pouring the obtained mixed slurry into small experimental molds at one time, paying attention to uniformly vibrating the slurry in the molds after charging, troweling the slurry by using a scraper, and simultaneously scraping the redundant slurry at the die orifice. Maintaining for 24 hours, and then removing the mold; after the mold is removed, the sample is put into an oven to be heated according to the following heating curve chart (see figure 5), the temperature is kept at 1100 ℃ for 3 hours, then the compressive strength and the heating permanent line change rate of the castable at 1100 ℃ are detected, and particularly, referring to figure 5,

the performance tests (according to the current industry standard) were carried out on the shaft kiln face plate castable prepared in examples 1-4, and the test results are shown in table 3.

TABLE 3 castable Performance testing and comparing Table

The detection result shows that: the castable for the vertical kiln panel prepared by the invention has lower thermal conductivity, the permanent line change rate and the compressive strength index are improved, and the castable is preferably used in the four embodiments according to the embodiment 2 and the embodiment 3. And wastes such as limestone sieve powder, kiln dust removal, steel slag and the like are recycled, so that the difficult problem of utilizing a large amount of wastes is solved, and the novel vertical kiln panel castable is required to be widely popularized and used.

The application example is as follows: experimental stage

When 6 burner nozzle panels of a combustion chamber under a steel mill and a 2# kiln are damaged and repaired, the castable for the vertical kiln panels prepared in the embodiment 2 is selected, and the proportion of the castable to common tap water is 1: adding the mixture into a stirrer according to the mass ratio of 0.08, and fully stirring; the repair time of the refractory material of each panel is 20-30 minutes. In order to ensure that the stirred castable is used up in 30 minutes, the mixing amount of the castable at each time must be determined according to the damage degree of each burner, the mixed castable can only be used for 1 burner panel at each time, and the waste caused by the influence on the use effect due to the fact that the mixed castable at one time is too large and cannot be used up in 30 minutes is prevented.

The amount of the vertical kiln face plate castable consumed by repairing the burner face plates of the lower combustion chambers 1-6 is 1.8 tons, 2.1 tons, 2.2 tons, 1.75 tons, 1.98 tons and 2.15 tons respectively, the total amount of the vertical kiln face plate castable consumed is 11.98 tons, and the temperature is raised according to a burner face plate temperature rise curve chart (see fig. 6) after the repairing is finished. And (3) formally reaching the yield of the 2# kiln after the temperature rise is finished at noon in 12 months and 20 days, wherein the yield is 470 tons/day. Referring to fig. 6, the temperature rise curve of the burner panel shows that the service life of the improved burner panel is obviously prolonged from 17 months to 61 months from the viewpoint of use effect, as shown in table 4; the heat preservation effect is greatly improved, the temperature of the panel is reduced from 180 ℃ to 110 ℃, see table 5, the gas consumption is reduced, and the energy-saving effect is very obvious.

TABLE 4 statistical table of refractory life of burner face plates before and after changing castable

TABLE 5 comparison statistical table for temperatures of burner face plates before and after changing castable

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.

Claims

1. The castable for the vertical kiln face plate is characterized by being prepared from the following raw materials in percentage by mass:

18 to 28 percent of steel slag particles

3 to 4 percent of floating bead

16-20% of limestone sieve powder

32 to 40 percent of kiln dust removal powder

6 to 15 percent of steel slag powder

9-12% of closed cell perlite;

selecting regular solid waste with a certain shape after steel slag treatment in a steel mill from the steel slag granules; the floating bead is a fly ash hollow sphere capable of floating on water surface, is offwhite, has thin and hollow wall and volume weight of 0.4-0.5g/cm ³ The thermal conductivity is small, the particle size is about 0.1mm;

the limestone sieve powder is limestone sieve powder, caCO, generated by sieving limestone before kiln entry ₃ The content is 85-90%, limestone powder with the particle size range of 0.05-0.1mm is selected;

the kiln dust removal powder is dust removal powder ash generated by hot airflow circulation in a kiln caused by a fan in the production process of the sleeve kiln, and the main contents of the dust removal powder ash are CaO and CaCO ₃ CaO content of 40-50%, caCO ₃ The content is 35-45%, and the particle diameter is 0.05-0.1mm.

2. The shaft kiln panel castable according to claim 1, characterized in that the castable is prepared from the following raw materials in percentage by weight:

23 percent of steel slag particles

3 percent of floating bead

Limestone screen powder 16%

38 percent of kiln dust removal powder

10 percent of steel slag powder

10 percent of closed cell perlite;

the granularity requirement of the steel slag particles is as follows: the height of the regular triangular cone body is 4-5mm, the side length of the bottom is 2-3mm, and the granularity of the steel slag powder is required to be as follows: the mass percentage of the particle size less than or equal to 85 mu m is more than or equal to 90 percent.

3. The shaft kiln faceplate castable of claim 1, wherein the castable is prepared from the following raw materials by weight percent:

26 percent of steel slag particles

4 percent of floating bead

Limestone screen powder 18%

32% of kiln dust removal powder

9 percent of steel slag powder

11 percent of closed cell perlite

the granularity requirement of the steel slag powder is as follows: the mass percentage of the particle size less than or equal to 80 mu m is more than or equal to 90 percent.

4. A method for preparing a castable material for a shaft kiln faceplate according to any one of claims 1-3, wherein the method comprises the steps of:

step 1: preparing raw materials, namely steel slag particles, floating beads, limestone sieve powder, kiln dust removal powder, steel slag powder and closed-cell perlite according to a ratio, and performing pre-drying treatment to remove water in the steel slag particles;

step 2: adding the mixture prepared in the step 1 into a dry mixer according to the mass percentage, and mixing and stirring to obtain a mixture;

and step 3: and (3) bagging the mixture obtained in the step (2) by 25 kilograms, and sealing the bags to finish the process.

5. The method for using the castable for the shaft kiln panel according to any one of claims 1 to 3, wherein the method for using the castable is as follows: tap water or waste water subjected to precipitation treatment in a steel mill is adopted, and the castable and the water are fully stirred according to the mass ratio of 0.07-0.1kg of water to 1kg of castable; in winter, water in a normal temperature state is adopted, and a heat preservation device is not needed; the stirred castable is used up within 30 minutes.