Protective layer for reducing coke burning loss and preparation method
By using a protective layer composed of a variety of coal materials in the heat recovery coke oven, the problem of burning of coal cakes and coke cakes is solved, the coking rate and coke strength are improved, and the coal consumption and coke ash content are reduced.
Patent Information
- Application Number
- CN202411671271.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-02-14
AI Technical Summary
In the heat recovery coke oven, the burning problem of coal cakes and coke cakes on the surfaces leads to low coke rate, decreased coke strength, increased coal consumption and increased coke ash content.
A protective layer consisting of lignite, long flame coal, coking dust removal ash, orchid powder, coal slime and other materials is used to reduce burning and improve coke maturity by crushing and laying on the coal cake.
It effectively reduces coke burning, improves coking rate, reduces coal consumption, stabilizes coke ash and strength indicators, and reduces the burning of normal coal and coke through consumption protective layers.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of heat recovery coke ovens in the coking industry, and in particular to a protective layer for reducing coke burning loss and a preparation method thereof. Background Art
[0002] The entire coking production process of the heat recovery coke oven is operated under negative pressure, and no pollutants escape; the coal gas and chemical products are all burned in the furnace to generate heat for power generation, which is an environmentally friendly coking process throughout the production process.
[0003] The production process of heat recovery coke oven is roughly as follows: the mixed coal is sent into the coke oven coal tower through a belt conveyor, and a tamping station is set up under the coal tower to tamp the coal into briquettes and send them to the carbonization chamber for coking. Since the carbonization chamber furnace top, side walls and furnace bottom flame channel have a certain amount of heat, part of the coking coal is then heated to precipitate raw coal gas. An adjustable air intake valve is provided on the furnace top to introduce primary air. The air and raw coal gas combustion generates heat to heat the furnace top space, and heat the briquettes through heat conduction and heat radiation. Since the air intake valve introduces insufficient air, the furnace top space is a reducing atmosphere, and the incompletely burned gas enters the machine side and coke side descending flame channels from the descending flame channel openings on the furnace walls on both sides of the carbonization chamber, and then enters the furnace bottom flame channel. The furnace bottom arch flame channel is divided into the machine side flame channel and the coke side flame channel, which are separately adjusted to achieve the purpose of uniform heating. Each furnace bottom flame channel has four sections of channels. Air is added in the channel to make the incompletely burned gas burn twice, generate heat to heat the furnace bottom bricks, and heat the bottom of the briquettes through heat conduction.
[0004] As the air introduced into the top of the carbonization chamber and the precipitated raw gas are burned, it is inevitable that the surface of the coal cake and coke cake will also be burned, which makes the coal consumption per ton of coke higher than that of ordinary coke ovens, the coke yield lower than that of ordinary coke ovens, the ash content of coke increases, and the overall strength decreases. Therefore, it is very important to control the amount of burnt loss on the surface of the coal cake and coke cake in the carbonization chamber. Summary of the invention
[0005] The invention provides a protective layer for reducing coke burning loss and a preparation method thereof, which reduces the burning loss of early coal cakes and later coke, improves the coking rate, reduces coal consumption, and stabilizes the ash content and strength index of the coke.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A protective layer for reducing coke burning loss, characterized in that the protective layer is composed of at least two materials selected from lignite, long flame coal, coking dust ash, blue carbon powder, and coal slime; the materials in the protective layer are proportioned by weight as follows: 0 to 58 parts of lignite, 23 to 60 parts of long flame coal, 0 to 22 parts of coking dust ash, 0 to 26 parts of blue carbon powder, and 0 to 17 parts of coal slime.
[0008] The moisture content of the lignite M t ≤18%, ash content Ad ≤20%, Volatile matter V daf Greater than 37%.
[0009] The moisture content of the long flame coal M t ≤18%, ash content A d ≤7%, volatile matter V daf Greater than 33%.
[0010] The moisture content of the coking dust is M t ≤1%, ash content A d ≤15%, volatile matter V daf Less than 3%.
[0011] The moisture content of the blue carbon powder is M t ≤11%, ash content A d ≤6%, Volatile matter V daf Less than 7%.
[0012] The moisture content of the coal slime M t ≤20%, ash content A d ≤55%, Volatile matter V daf Greater than 33%.
[0013] The quality index of the protective layer is: 10.5% ≤ moisture M t ≤13.0%, ash content A d ≤10%, Volatile matter V daf Requirements: 29% to 33%.
[0014] A method for preparing a protective layer for reducing coke burning loss comprises the following steps:
[0015] 1) Mix the materials according to weight proportions and crush them until the proportion of particles with a diameter less than 3 mm reaches more than 90wt%;
[0016] 2) Spread a layer of the mixed material obtained in step 1) on the upper layer of the coal cakes, and then compact it with a tamping machine to form a protective layer.
[0017] The thickness of the compacted protective layer on the coal cake is 20 to 30 mm.
[0018] After a certain coking time, the coal cake with a protective layer is mature, requiring that there is no obvious burning on the surface of the coke cake, the coking rate (characterizing the coke burning rate index) is above 74%, and the coke volatile matter V daf (Indicator representing the maturity of coke) is between 0.9% and 1.3%, which meets the requirements.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] The protective layer for reducing coke burning loss of the present invention has a volatile matter Vdaf Compared with the normal coal entering the furnace, it can produce a large amount of raw coal gas, which burns well with the introduced air, generates heat to heat the furnace top space, and heats the coal cakes through heat conduction and heat radiation, which can ensure the good maturity of coke and the strength of the whole furnace coke. At the same time, by consuming this protective layer, the burning loss of normal coal and coke is reduced by about 1.0% to 1.5%. According to the price difference of 700 yuan / ton between the protective layer and the mixed coal, about 7 to 10 yuan per ton of coal is saved.
[0021] In addition, this protective layer is composed of a mixture of lignite, long flame coal, coking dust, blue carbon powder, and coal slime. In particular, coking dust, blue carbon powder, and coal slime are powders or waste materials in the coking production, blue carbon production, and coal washing processes, and their prices are very low, hundreds of yuan lower than long flame coal. This protective layer makes full use of the characteristics of each material, makes reasonable combinations, and controls the moisture content M t 、Ash content d , Volatile matter V daf The three main indicators ensure the effect of reducing burning losses of coal cakes. At the same time, they greatly reduce the cost of the protective layer, maximize the value of these scraps or waste materials, and make the economic benefits more obvious. DETAILED DESCRIPTION
[0022] The specific implementation modes of the present invention are further described below in conjunction with examples. The following examples are used to specifically illustrate the contents of the present invention. These examples are only general descriptions of the contents of the present invention and do not limit the contents of the present invention.
[0023] A protective layer for reducing coke burning loss and a preparation method thereof: the protective layer is composed of at least two materials selected from lignite, long flame coal, coking dust ash, blue carbon powder and coal slime; the materials in the protective layer are proportioned by weight as follows: 0 to 58 parts of lignite, 36 to 60 parts of long flame coal, 0 to 22 parts of coking dust ash, 0 to 26 parts of blue carbon powder and 0 to 17 parts of coal slime.
[0024] Preparation method: Mix the materials according to the weight ratio and crush them until the proportion of particles with a diameter less than 3 mm reaches more than 90wt%; after the mixed coal is tamped into coal cakes, a mixed protective layer is spread on the coal cakes, and then compacted with a tamping machine. The thickness of the protective layer is 20mm. In the early stage of coking, the protective layer is burned with the introduced air to prevent the combustion of the mixed coal and form a protective layer.
[0025] The present invention will be further described in detail below with reference to specific embodiments.
[0026] Specific indicators and prices of various materials selected for the protective layer of the embodiment are shown in Table 1.
[0027] Table 1 Index and price of each material
[0028]
[0029] Embodiment 1:
[0030] The materials and their weight proportions of the protective layer are shown in Table 2: 55 parts of lignite, 23 parts of long flame coal, 5 parts of coking dust removal ash, and 17 parts of blue carbon powder. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 12.6%, ash content A d 9.95%, volatile matter V daf 30.6%, sulfur content S t It is 0.50% and the price is 741.3 yuan / ton, which is 232.9 yuan / ton cheaper than the long flame coal laid entirely.
[0031] Table 2 Corresponding protective layer material composition ratios (parts by weight) of different embodiments
[0032] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 lignite 55 30 45 40 15 0 Long flame coal 23 46 37 36 53 60 Coking dust removal 5 10 5 15 15 0 Blue carbon powder 17 9 10 9 9 23 Slime 0 5 3 0 8 17
[0033] Table 3 Corresponding protective layer indicators and prices of different embodiments
[0034]
[0035] After a certain coking time, the coal cake with a protective layer is mature and there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.2% and the volatile matter V daf At 1.1%, the requirement is met.
[0036] Embodiment 2:
[0037] The materials and their weight proportions of the protective layer are shown in Table 2: 30 parts of lignite, 46 parts of long flame coal, 10 parts of coking dust, 9 parts of blue carbon powder, and 5 parts of coal slime. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 12.2%, ash content A d 9.70%, volatile matter V daf 30.9%, sulfur content S t The price is 0.50%, and the price is 839.1 yuan / ton, which is 260.9 yuan / ton cheaper than the long flame coal. After a certain coking time, the briquettes with protective layer are mature, and there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.5%, and the volatile matter V daf At 1.0%, the requirement is met.
[0038] Embodiment 3:
[0039] The materials and their weight proportions of the protective layer are shown in Table 2: 45 parts of lignite, 37 parts of long flame coal, 5 parts of coking dust, 10 parts of blue carbon powder, and 3 parts of coal slime. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 11.5%, ash content A d9.54%, volatile matter V daf 29.1%, sulfur content S t The coal cake with protective layer has a coking time of 0.49% and a price of 820.1 yuan / ton, which is 279.9 yuan / ton cheaper than the long flame coal. After a certain coking time, the coke is mature and there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.7% and the volatile matter V daf At 1.2%, the requirement is met.
[0040] Embodiment 4:
[0041] The materials and their weight proportions of the protective layer are shown in Table 2: 40 parts of lignite, 36 parts of long flame coal, 15 parts of coking dust removal ash, and 9 parts of blue carbon powder. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 12.9%, ash content A d 9.98%, volatile matter V daf The sulfur content is 32.7%, the sulfur content St is 0.48%, and the price is 778.4 yuan / ton, which is 321.6 yuan / ton cheaper than the long flame coal laid all over. After a certain coking time, the coal cake with a protective layer is mature, and it is found that there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.7%, and the volatile matter V daf At 1.2%, the requirement is met.
[0042] Embodiment 5:
[0043] The materials and their weight proportions of the protective layer are shown in Table 2: lignite 15 parts, long flame coal 53 parts, coking dust 15 parts, blue carbon powder 9 parts, coal slime 8 parts. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 11.5%, ash content A d 9.73%, volatile matter V daf The sulfur content is 29.2%, the sulfur content St is 0.53%, and the price is 888.5 yuan / ton, which is 211.5 yuan / ton cheaper than the long flame coal. After a certain coking time, the coal cake with a protective layer is mature. It is found that there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.8%, and the volatile matter V daf At 1.1%, the requirement is met.
[0044] Embodiment 6:
[0045] The materials and their weight proportions of the protective layer are shown in Table 2: 60 parts of long flame coal, 23 parts of blue carbon powder, and 17 parts of coal slime. The indicators and prices of the protective layer are shown in Table 3: Moisture M t 12.3%, ash content A d 9.80%, volatile matter V daf 30.5%, sulfur content S tThe price is 901.3 yuan / ton, which is 198.5 yuan / ton cheaper than the long flame coal. After a certain coking time, the briquettes with protective layer are mature. It is found that there is no obvious burning damage on the surface of the coke cake. The coking rate is 74.5%, and the volatile matter V daf At 1.1%, the requirement is met.
[0046] Comparative Example 1:
[0047] The specific indexes and prices of the materials selected for the protective layer are shown in Table 1. The material composition ratios of the protective layers of comparative examples 1-4 are shown in Table 4, and the indexes and prices of the protective layers of comparative examples 1-4 are shown in Table 5.
[0048] Table 4: Proportions of protective layer materials corresponding to different comparative examples (parts by weight)
[0049] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 lignite 0 35 59 24 Long flame coal 60 42 26 50 Coking dust removal 0 23 0 0 Blue carbon powder 22 0 15 26 Slime 18 0 0 0
[0050] Table 5 Corresponding protective layer indicators and prices for different comparative proportions
[0051]
[0052] Comparative Example 1 is 207.8 yuan / ton cheaper than all long flame coal. t Ash A d The main reason for exceeding the set target is that the coal slime ratio exceeds the technical requirements of the present invention. t Ash A d Higher than normal blended coal will result in poor coke maturity and excessive ash content. The protective layer is placed on the upper layer of the coal cake with a height of 20mm. After a certain coking time, the coke maturity is poor, the coking rate is 74.2%, and the coke volatile matter V daf At 1.32%, it is a little raw and does not meet the requirements.
[0053] Comparative Example 2 is 256 yuan / ton cheaper than laying all long flame coal. daf The ratio of coking dust is 28.8%, which is lower than the set target and does not meet the requirements. The main reason is that the ratio of coking dust exceeds the technical requirements of the present invention. The protective layer is placed on the upper layer of the coal cake with a height of 20mm. After a certain coking time, the coke is poorly matured, the coking rate is 74.4%, and the coke volatile matter V daf At 1.34%, it is a bit raw and does not meet the requirements.
[0054] Comparative Example 3 is 370.5 yuan / ton cheaper than all long flame coal. t and volatile matter V dafThe main reason for exceeding the set target is that the lignite ratio exceeds the technical requirements of the present invention, which will cause poor coke maturity and increased burnout rate. The protective layer is placed on the upper layer of the coal cake with a height of 20mm. After a certain coking time, the coke maturity is poor, and the coke volatile matter V daf At 1.34%, it is slightly raw; the coking rate is 73.8%, and the burn-loss rate does not meet the requirements.
[0055] Comparative Example 4 is 172.6 yuan / ton cheaper than all long flame coal. daf The main reason is that the ratio of blue coal powder exceeds the technical requirements of the present invention, which will cause poor coke maturity. The protective layer is placed on the upper layer of the coal cake with a height of 20mm. After a certain coking time, the coke maturity is poor, and the coke volatile matter V daf At 1.33%, it is a little raw and does not meet the requirements.
Claims
1. A protective layer for reducing coke burning loss, characterized in that: The protective layer is composed of at least two materials selected from lignite, long flame coal, coking dust ash, semi-coke powder and coal slime; the weight proportions of the materials in the protective layer are as follows: 0 to 58 parts of lignite, 23 to 60 parts of long flame coal, 0 to 22 parts of coking dust ash, 0 to 26 parts of semi-coke powder and 0 to 17 parts of coal slime.
2. A protective layer for reducing coke burning loss according to claim 1, characterized in that: The moisture content of the lignite M t ≤18%, ash content A d ≤20%, Volatile matter V daf Greater than 37%.
3. The protective layer for reducing coke burning loss according to claim 1, characterized in that: The moisture content of the long flame coal M t ≤18%, ash content A d ≤7%, volatile matter V daf Greater than 33%.
4. The protective layer for reducing coke burning loss according to claim 1, characterized in that: The moisture content of the coking dust is M t ≤1%, ash content A d ≤15%, volatile matter V daf Less than 3%.
5. The protective layer for reducing coke burning loss according to claim 1, characterized in that: The moisture content of the blue carbon powder is M t ≤11%, ash content A d ≤6%, Volatile matter V daf Less than 7%.
6. The protective layer for reducing coke burning loss according to claim 1, characterized in that: The moisture content of the coal slime M t ≤20%, ash content A d ≤55%, Volatile matter V daf Greater than 33%.
7. The protective layer for reducing coke burning loss according to claim 1, characterized in that: The quality index of the protective layer is: 10.5% ≤ moisture M t ≤13.0%, ash content A d ≤10%, Volatile matter V daf Requirements: 29% to 33%.
8. A method for preparing a protective layer for reducing coke burning loss according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: 1) Mix the materials according to weight proportions and crush them until the proportion of particles with a diameter less than 3 mm reaches more than 90wt%; 2) Spread a layer of the mixed material obtained in step 1) on the upper layer of the coal cakes, and then compact it with a tamping machine to form a protective layer.
9. The method for preparing a protective layer for reducing coke burning loss according to claim 8, characterized in that: The thickness of the compacted protective layer on the coal cake is 20 to 30 mm.