Carbonaceous charge for the hearth of a blast furnace and method for its production

Abstract

This invention discloses a carbon filler for blast furnace bottoms and its preparation method. The carbon filler comprises component A and component B; wherein: component A, by mass percentage, includes: 17-25% electrode graphite particles, 50-55% flake graphite, 20-26% electrode graphite powder, 3-5% flexible graphite, and 0.3-1% accelerator; component B includes thermoplastic phenolic resin and ethanol in a mass ratio of (4-6):(1-2); the amount of component B added is 19-22% of the weight of component A. The carbon filler is prepared by pre-mixing flake graphite and flexible graphite evenly, then mixing and stirring with a portion of component B, then adding electrode graphite particles, electrode graphite powder, and accelerator and mixing evenly, and finally adding the remaining component B and mixing evenly. The carbon filler obtained by this invention has good workability, thermal conductivity, and surface quality, increases the bonding performance between the material and the filling area, and effectively protects the furnace lining.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon fillers, and particularly relates to a carbon filler for a blast furnace bottom and a preparation method thereof. BACKGROUND

[0002] At present, domestic blast furnaces gradually develop towards large-scale and modernization, which also brings great progress in ironmaking technology, the utilization coefficient of the blast furnace is greatly improved, and the output also grows rapidly. The blast furnace bottom and hearth part is the key part of the blast furnace, and its service life directly determines the length of the blast furnace campaign, so the quality of the refractory lining of the blast furnace bottom and hearth part is particularly important. Modern blast furnace bottoms mostly adopt ceramic cup + carbon brick structure, and the blast furnace bottom and hearth ramming material adopts carbon ramming material, but the carbon ramming material has certain problems, that is, the thermal conductivity coefficient is low, and if the ramming quality is poor, an air thermal resistance layer will be formed, which reduces the efficiency of the blast furnace heat transfer system, the heat in the furnace cannot be timely conducted to the blast furnace cooling system, the temperature in the ceramic cup increases, the high temperature, high pressure, slag iron, alkali metal erosion and penetration erosion are intensified, which leads to accelerated damage of the ceramic cup, if cracks are formed, high temperature and high pressure gas in the furnace passes through the gap to the blast furnace bottom area, which leads to an increase in the temperature of the blast furnace bottom, affecting the normal use of the carbon brick, and thus affecting the service life of the blast furnace bottom, so the quality of the carbon ramming material in the blast furnace bottom and hearth area is crucial.

[0003] The ramming material generally adopts coarse, medium and fine particle gradation to form a compacted pile, which can form a compact whole during machine ramming, and will not appear to run out of the mold. However, if large particles are added to the material, after the ramming material is constructed, concave pitted surface will appear on the surface, which will form a thermal resistance layer and reduce the heat transfer efficiency. However, if only small particles are added to the ramming material, it will appear like wet mud and rubber clay, and cannot be rammed into a compact whole during machine ramming. In order to improve the construction performance, a large amount of adhesion components need to be added, and the addition of a large amount of adhesion components will have adverse effects on the thermal conductivity performance.

[0004] Therefore, how to improve the surface quality of the material while improving the thermal conductivity performance of the material is an urgent matter. SUMMARY

[0005] The application aims to provide a carbon filler for a blast furnace bottom and a preparation method thereof, which has good construction performance, thermal conductivity performance and construction surface quality, increases the bonding performance of the carbon filler and the filled part, and enables the carbon filler to better fill the blast furnace bottom part, so as to timely conduct the heat to the cooling system and effectively protect the furnace lining.

[0006] In order to achieve the above-mentioned purpose, the technical scheme is as follows:

[0007] The application provides a carbon filler for a blast furnace bottom, which comprises A component and B component; wherein:

[0008] In the A component, by mass percentage, includes: electrode graphite particles 17-25%, flake graphite 50-55%, electrode graphite powder 20-26%, flexible graphite 3-5%, accelerator 0.3-1%; wherein the electrode graphite particle size is 0-0.5mm; the electrode graphite powder particle size is 0-0.088mm; the accelerator is epoxy functionalized oligomeric siloxane;

[0009] In the B component, includes thermoplastic phenolic resin and ethanol, mass ratio is (4-6):(1-2);

[0010] The addition amount of the B component is 19-22% of the weight of the A component.

[0011] According to the above scheme, the flake graphite and the flexible graphite are mixed uniformly in advance.

[0012] According to the above scheme, the electrode graphite particle material meets the following requirements: C≥99wt%, ash≤0.4wt%.

[0013] According to the above scheme, the flake graphite C≥95wt%.

[0014] According to the above scheme, the flake graphite particle size is 0.1-0.2mm.

[0015] According to the above scheme, the electrode graphite powder meets the following requirements: C≥99wt%, ash≤0.4wt%.

[0016] According to the above scheme, the flexible graphite C≥97wt%, the bulk density is 0.002-0.01g / cm 3 .

[0017] According to the above scheme, the epoxy functionalized oligomeric siloxane has epoxy functional groups, colorless viscous liquid, active ingredient 47%-53%, relative density is 0.9-1.1g / cm 3 .

[0018] According to the above scheme, the thermoplastic phenolic resin is in liquid state, the fixed carbon content is≥74%, the carbon residue rate is≥46%, and the free phenol is≤8%.

[0019] A preparation method of the above-mentioned carbon filler for the blast furnace bottom is provided, which comprises the following steps:

[0020] 1) Mix the flake graphite and the flexible graphite in the A component and uniformly stir;

[0021] 2) Add part of the B component to the mixture obtained in step 1) and open the milling stirring;

[0022] 3) Then the remaining electrode graphite particles, electrode graphite powder and the accelerator in A component are added into the mixture obtained in step 2) and stirred uniformly;

[0023] 4) Finally the remaining B component is added into the mixture obtained in step 3) and stirred uniformly, thus obtaining the carbon filler for the blast furnace bottom.

[0024] According to the above scheme, in step 1), the stirring time is 5-7 min.

[0025] According to the above scheme, in step 2), the mixing and stirring time is 5-7 min.

[0026] According to the above scheme, in step 2), 55-60% of the B component is added.

[0027] According to the above scheme, in step 3), the stirring time is 3-5 min.

[0028] According to the above scheme, in step 4), the stirring time is 5-10 min.

[0029] The present application provides a carbon filler for the blast furnace bottom, which uses small-particle-size electrode graphite particles, electrode graphite powder and flake graphite as the main heat-conducting carbon raw materials, and cooperates with flexible graphite as the framework material, so as to improve the construction surface quality and effectively improve the construction performance when using small-particle-size carbon materials; the flexible graphite has very low volume density, large surface area and surface energy, and has strong plasticity and self-adhesion; the flexible graphite is porous and curved, forms the framework of the material, and has strong adhesion with the flake graphite. By mixing the flexible graphite and the flake graphite first, the flake graphite can be better dispersed and embedded in the flexible graphite framework structure, and then other graphite is filled in the pores formed by the flexible graphite, and by using the self-tightly-embedded characteristics of the flexible graphite, when subjected to the ramming forming pressure, the flexible graphites are embedded with each other, which prevents the sliding between the particles, so that the material is rammed to form a compact whole. Therefore, the material of the present application does not need to add other components which increase the plasticity but affect the thermal conductivity coefficient, and still has excellent construction performance, and effectively improves the thermal conductivity coefficient of the material. In addition, the introduction of a small amount of accelerator in the carbon filler of the present application can effectively increase the adhesion between the rammed material and the steel sealing plate and flat steel of the furnace bottom, and cooperate with the good self-adhesion of the flexible graphite, so that the material is tightly filled between the sealing plate and the flat steel, forms good adhesion, and improves the integrity of the material and the metal.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] 1. The present application provides a carbon filler for blast furnace bottom, which is prepared from small particle size electrode graphite particles, electrode graphite powder and flake graphite as main heat-conducting carbon raw materials, in combination with flexible graphite as a skeleton material and a small amount of accelerant, together with thermoplastic phenolic resin and ethanol.

[0032] 2. The present application provides a preparation method of the carbon filler for blast furnace bottom, which comprises mixing flexible graphite and flake graphite first, embedding the flake graphite in the skeleton structure of the flexible graphite, and then filling other graphite in the pores formed by the flexible graphite. DETAILED DESCRIPTION

[0033] The following examples further illustrate the technical solutions of the present application, but do not limit the scope of protection of the present application.

[0034] The raw materials used in the examples of the present application have the following indexes:

[0035] The electrode graphite particles meet the following requirements: C≥99wt%, ash≤0.4wt%, and particle size of 0-0.5mm.

[0036] The flake graphite has C≥95wt% and particle size of 0.1-0.2mm.

[0037] The electrode graphite powder meets the following requirements: C≥99wt%, ash≤0.4wt%, and particle size of 0-0.088mm.

[0038] The flexible graphite has C≥97wt% and bulk density of 0.002-0.01g / cm 3 .

[0039] The accelerant is an epoxy-functionalized oligomeric siloxane with epoxy functional groups, colorless viscous liquid, active ingredient 47-53%, and relative density of 0.9-1.1g / cm 3 , which is DA-226H produced by Guangzhou Wanjun Chemical Industry.

[0040] The thermoplastic phenolic resin is liquid, produced by Shandong Shengquan Company, with fixed carbon content ≥ 74%, residual carbon rate ≥ 46%, and free phenol ≤ 8%.

[0041] The preparation method of the carbon filler for the blast furnace bottom in the embodiment of the application is as follows: the flake graphite and the flexible graphite in part A are mixed and uniformly stirred for 6 min; 60% of part B is added and stirred for 6 min; then the remaining electrode graphite and the accelerator in part A are added into the mixture and stirred for 4 min; finally, the remaining 40% of part B is added and fully stirred for 8 min, to obtain the carbon filler for the blast furnace bottom.

[0042] Example 1

[0043] The application provides a carbon filler for a blast furnace bottom, which comprises an A component and a B component.

[0044] In the A component, the electrode graphite particles, the flake graphite, the electrode graphite powder, the flexible graphite and the accelerator are included in a mass percentage of 19%, 52.5%, 23%, 5% and 0.5% respectively.

[0045] In the B component, the thermoplastic phenolic resin and the ethanol are included in a mass ratio of 4:1.

[0046] The adding amount of the B component is 21.3% of the weight of the A component.

[0047] According to the above formula, the materials are mixed and stirred into ramming material with good forming performance according to the preparation method, and then the finished product is obtained by packaging in a sealed packaging bag.

[0048] After the material is dried at 110 DEG C, the thermal conductivity can reach 27.62 W / (m·K), which fully meets the heat conduction requirement of the blast furnace bottom heat transfer system and matches the heat conduction of the carbon brick. No mold running phenomenon occurs in the ramming process, and the construction performance is good.

[0049] Example 2

[0050] The application provides a carbon filler for a blast furnace bottom, which comprises an A component and a B component.

[0051] In the A component, the electrode graphite particles, the flake graphite, the electrode graphite powder, the flexible graphite and the accelerator are included in a mass percentage of 19%, 52.5%, 23%, 5% and 0.5% respectively.

[0052] In the B component, the thermoplastic phenolic resin and the ethanol are included in a mass ratio of 4:1.

[0053] The adding amount of the B component is 21.3% of the weight of the A component.

[0054] According to the above formula, the materials are mixed and stirred into ramming material with good forming performance according to the preparation method, and then the finished product is obtained by packaging in a sealed packaging bag.

[0055] The thermal conductivity of the material can reach 28.55 W / (m·K) after drying at 110 DEG C, which fully meets the thermal conductivity requirement of the blast furnace bottom heat transfer system and matches the thermal conductivity of the carbon brick. No mold running phenomenon occurs during the tamping process, and the construction performance is good.

[0056] Example 3

[0057] The application provides a carbon filler for a blast furnace bottom, which comprises A component and B component.

[0058] The A component comprises, in percentage by mass, 25% of electrode graphite particles, 51% of flake graphite, 20% of electrode graphite powder, 3.4% of flexible graphite and 0.6% of a promoter.

[0059] The B component comprises thermoplastic phenolic resin and ethanol at a mass ratio of 4:1.

[0060] The B component is added in an amount of 19.5% of the weight of the A component.

[0061] According to the above formula, the materials are mixed, milled and stirred into tamping material with good forming performance according to the preparation method, and then the finished product is obtained by packaging in a sealed packaging bag.

[0062] The thermal conductivity of the material can reach 29.84 W / (m·K) after drying at 110 DEG C, which fully meets the thermal conductivity requirement of the blast furnace bottom heat transfer system and matches the thermal conductivity of the carbon brick. No mold running phenomenon occurs during the tamping process, and the construction performance is good.

[0063] Example 4

[0064] The application provides a carbon filler for a blast furnace bottom, which comprises A component and B component.

[0065] The A component comprises, in percentage by mass, 18% of electrode graphite particles, 51.3% of flake graphite, 26% of electrode graphite powder, 4% of flexible graphite and 0.7% of a promoter.

[0066] The B component comprises thermoplastic phenolic resin and ethanol at a mass ratio of 4:1.

[0067] The B component is added in an amount of 21.6% of the weight of the A component.

[0068] According to the above formula, the materials are mixed, milled and stirred into tamping material with good forming performance according to the preparation method, and then the finished product is obtained by packaging in a sealed packaging bag.

[0069] The thermal conductivity of the material can reach 27.97 W / (m·K) after drying at 110 DEG C, which fully meets the heat conduction requirement of the blast furnace bottom heat transfer system and matches the carbon brick heat conduction. No running mold phenomenon occurs during the material ramming process, and the construction performance is good.

[0070] Embodiment 5

[0071] The application provides a carbon filler for a blast furnace bottom, which comprises A component and B component.

[0072] The A component comprises, in mass percentage, 23.6% of electrode graphite particles, 50% of flake graphite, 21% of electrode graphite powder, 5% of flexible graphite and 0.4% of a promoter.

[0073] The B component comprises thermoplastic phenolic resin and ethanol, and the mass ratio is 4:1.

[0074] The adding amount of the B component is 20.2% of the weight of the A component.

[0075] According to the above formula, the material is mixed, rolled and stirred into ramming material with good forming performance according to the preparation method, and then is packaged with a sealed packaging bag to obtain the finished product.

[0076] The thermal conductivity of the material can reach 28.67 W / (m·K) after drying at 110 DEG C, which fully meets the heat conduction requirement of the blast furnace bottom heat transfer system and matches the carbon brick heat conduction. No running mold phenomenon occurs during the material ramming process, and the construction performance is good.

[0077] Obviously, the above embodiments are merely examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and all the embodiments do not need to be exhausted, and thus the obvious changes or variations still fall within the protection scope of the application.

Claims

1. A carbonaceous packing for a blast furnace hearth, characterized in that, It comprises A component and B component; wherein: In the A component, by mass percentage, it comprises: electrode graphite particles 17~25%, flake graphite 50~55%, electrode graphite powder 20~26%, flexible graphite 3~5%, and promoter 0.3~1%; the electrode graphite particle size is 0~0.5mm; the electrode graphite powder size is 0~0.088mm; the promoter is epoxy-functionalized oligomeric siloxane; the flake graphite and the flexible graphite are mixed uniformly in advance; In the B component, it comprises thermoplastic phenolic resin and ethanol, and the mass ratio is (4~6):(1~2); The adding amount of the B component is 19~22% of the weight of the A component.

2. The carbonaceous filler according to claim 1, characterized in that, The electrode graphite particle material meets the following requirements: C ≥ 99wt%, ash ≤ 0.4wt%; the electrode graphite powder meets the following requirements: C ≥ 99wt%, ash ≤ 0.4wt%.

3. The carbonaceous filler of claim 1, wherein, The flake graphite C ≥ 95wt%.

4. The carbonaceous filler of claim 1, wherein The flake graphite size is 0.1~0.2mm.

5. The carbonaceous filler of claim 1, wherein The flexible graphite has a C content of 97 wt% or greater and a bulk density of 0.002 to 0.01 g / cm 3 .

6. The carbonaceous filler of claim 1, wherein The epoxy-functionalized oligomeric siloxane has epoxy functional groups, is a colorless viscous liquid, active ingredient 47-53%, and relative density 0.9-1.1 g / cm 3 The thermoplastic phenolic resin is in liquid state, fixed carbon content ≥ 74%, residual carbon content ≥ 46%, and free phenol ≤ 8%.

7. A method for the production of carbonaceous fillers for the hearth of a blast furnace according to any one of claims 1 to 6, characterized in that, It comprises the following steps: 1) Mix the flake graphite and the flexible graphite in the A component and stir uniformly; 2) Add part of the B component to the mixture obtained in step 1) and open the mixing and stirring; 3) Then add the electrode graphite particles, the electrode graphite powder and the promoter in the A component to the mixture obtained in step 2) and stir uniformly; 4) Finally, add the remaining B component to the mixture obtained in step 3) and stir uniformly, thereby obtaining the carbon filler for the blast furnace bottom.

8. The preparation method according to claim 7, characterized in that, In the step 1), the stirring time is 5~7min; In the step 2), the mixing and stirring time is 5~7min; In the step 3), the stirring time is 3~5min; In the step 4), the stirring time is 5~10min.

9. The preparation method according to claim 7, characterized in that, In the step 2), 55~60% of the B component is added.