CN114561223A - Preparation method of coke - Google Patents

Abstract

The invention particularly relates to a preparation method of coke, belonging to the technical field of carbon materials. Which comprises the following steps: obtaining ash-removed coal; mixing the ash-removed coal with a binder to obtain a mixture; and carrying out heat treatment on the mixture to obtain the coke. The method comprises the steps of mixing the ash-removed coal with the binder, binding the ash-removed coal by using the binder so as to meet the condition that the particle size of the ash-removed coal is smaller, then carrying out heat treatment, and preparing the bound mixture into coke, wherein the ash content of the coke prepared by the method is less than 1.5%, and the coke can meet the requirements of low-ash carbon products such as carbon for aluminum, graphite electrodes and the like on the ash content and the particle size of raw materials.

Description

Preparation method of coke

Technical Field

The invention belongs to the technical field of carbon materials, and particularly relates to a preparation method of coke.

Background

Petroleum coke is an important production raw material of carbon materials, and the annual consumption is huge. However, in recent years, with the overall reduction of crude oil quality, the sulfur content and harmful metal elements in petroleum coke are higher and higher, and the petroleum coke meeting the production requirements of carbon materials such as carbon for aluminum, graphite electrodes and the like is less and less. Meanwhile, the petroleum coke is a low-value byproduct in the petrochemical industry, the positivity of the petroleum coke produced in the petrochemical industry is not high, and along with the progress of the oil refining process, processes such as flexible coking and the like which basically do not produce the petroleum coke appear. In the long run, the petroleum resources are relatively deficient, and the long-term large demand of the carbon industry on petroleum coke is difficult to guarantee. Therefore, a coke raw material capable of replacing petroleum coke must be found to ensure the demand of the carbon industry for low ash coke raw materials. The ash content of the pitch coke is low, so that the pitch coke can be used for producing carbon products, but the yield is low, and the industrial requirement of carbon cannot be met; the quality of biomass charcoal such as charcoal is poor, and the requirement of carbon industry is difficult to meet; coal reserves are huge, but ash content is high, and the direct use of the coal reserves in carbon product production is difficult.

Coal ash removal technology is becoming more mature, and methods for preparing low-ash ultra-pure coal include physical methods, such as a coal separator multiple concentration method, a selective flocculation technology and the like, chemical methods, such as a hydrofluoric acid method, an acid-base method, a molten base leaching method and the like, and physical-chemical ash removal methods, such as an Otisca-T process, an oil mass-flotation method and the like, and physical-chemical ash removal methods, such as physical-chemical ash removal methods, can prepare coal with ash content less than 1%. However, the low-ash coal obtained by the ash removal methods is all fine particles or powder, and cannot meet the requirement of the carbon industry on large-particle coke raw materials.

At present, researches and processes for producing coke by mixing coal, coal pitch, tar and the like exist, when the coke is produced by using the coal, indexes such as granularity, strength and the like of coke products are improved by adding a small amount of coal pitch or tar and the like, but the coal used is coal with higher ash content, the finally prepared coke has high ash content, the particle strength is difficult to guarantee, and the coke cannot be used for producing low-ash carbon products. The research of using the coal coke powder and the like to mix with binders such as asphalt and the like and then carbonize to prepare large-particle coke has the advantages that the ash content of the coal coke powder is high, and the obtained large-particle coke cannot be used for producing low-ash carbon products. The research on the aspects of preparing foundry coke by coal and asphalt and the like shows that the obtained product has high ash content and can not be used for producing low-ash carbon products.

CN107828437A, a method for producing civil clean coke by using coal tar pitch, using common coal with higher ash content as main raw material, adding coal tar pitch and multifunctional compound additive, preparing coke after heat treatment, wherein the ash content of the obtained coke is required to be less than or equal to 23%, the lowest ash content of the coke in the embodiment is 17.2%, and the coke is difficult to be used as raw material of low ash carbon product.

"CN 1268717C, a preparation method of foundry coke", uses anthracite, coal pitch, coal tar as raw material, and carbonizes in a ring furnace after molding, does not set specific requirements for ash content of the product, the ash content of the product is also high, the lowest ash content of the coke mentioned in the examples is 4.61%, and it is difficult to use the coke as raw material of low ash carbon product.

CN104194813B, a method for preparing coke, uses main coke powder, anthracite powder, petroleum coke powder, asphalt powder and other raw materials to mix, then die-casts them into moulded coal, then carbonizes them, the ash content of the obtained coke does not provide clear requirements, the ash content of the product in the examples is 8-10%, it is difficult to use it as raw material of low ash carbon product.

CN1872950A, a coking additive and a coking method, anthracite, lean coal and the coking additive are added in a certain proportion during coking and blending coal. The coking additive consists of a coking agent and a coking promoter, and the coking agent comprises coal tar, tar pitch, petroleum pitch, residue oil and the like. The patent does not describe the ash content of the coke product, but the technology is to relieve the problem of shortage of coke coal supply in a coke-oven plant, the technical scheme is not provided for reducing the ash content of the coke, and the ash content of the coke product is higher in view of the fact that the coal in the raw material is common coal and accounts for more than 80%.

CN1557910A, a method for cold press molding of foundry coke by automatic temperature control and regulation, which utilizes a waste material of coke powder, anthracite powder, weathered coal and non-bonded coal, adds coal tar pitch adhesive, cold presses the mixture into a formed coke blank, and carbonizes the formed coke, wherein the ash content of the prepared foundry coke is less than 8 percent, and the ash content requirement is not strict.

CN104194816A, a method for preparing coke, utilizes main coking coal, lean coal, anthracite, coke powder, asphalt and petroleum coke, mixes and carries out die casting to prepare molded coal, and prepares coke after carbonization, and does not make a clear requirement on the ash content of coke products, and the minimum ash content of the coke products in the examples is 8.1 percent, which is difficult to be used as a raw material of low-ash carbon products.

The patent does not explain the ash content of coke products, but the technology aims to reduce the reactivity of the coke products and improve the strength of the coke after reaction, still belongs to the field of coal blending and coking, and the provided technical scheme does not aim to reduce the ash content of the coke. Since the coal in the raw material is ordinary coal and accounts for more than 95%, the ash content of the coke product is relatively high.

CN1710024A, a technology for producing coke by directly blending coal with bulk asphalt, when the coal blending variety contains weak caking coal or non-caking coal, the bulk asphalt with the weight less than or equal to 15 percent is blended, the patent does not provide the requirement on the ash content of coke products, the coal in the raw materials is common coal, the ash content of the coke products is high, the ash content of the mentioned coke products is 13.23 at least, and the coke products are difficult to be used as the raw materials of low-ash carbon products.

"CN 101429462A, a low-cost high-quality coking coal", uses gas coal, fat coal, coking coal, lean coal, tar pitch, non-sticky coal and/or weakly sticky coal as coking coal, and the ash content of the obtained coke is 12.30% in the patent, which is difficult to be used as a raw material of low-ash carbon products.

CN1587349A, a method for coking with low volatile weak caking or non-caking coal, which is characterized in that the low volatile weak caking or non-caking coal is used, 0.5-20% (based on the raw material coal) of emulsified asphalt is added, mixed, extruded and then coked to prepare coke. This patent does not claim the ash content of coke products, 11.6% ash, which is difficult to use as a feedstock for low ash carbon products.

The above-mentioned techniques do not solve the problem of preparing low ash coke by using coal as raw material.

Disclosure of Invention

The application aims to provide a preparation method of coke, which solves the technical problem that the prior art cannot solve the problem of preparing low-ash coke by using coal as a raw material.

The embodiment of the invention also provides a preparation method of the coke, which comprises the following steps:

obtaining ash-removed coal;

mixing the ash-removed coal with a binder to obtain a mixture;

and carrying out heat treatment on the mixture to obtain the coke.

Optionally, the dry-basis ash content of the ash-removing coal is less than or equal to 1.5%.

Optionally, the mass percentage of the part of the ash removing coal which is smaller than 1mm is more than or equal to 50%.

Optionally, the mixture comprises 10-90% of the ash removal coal by mass percentage.

Optionally, the binder comprises any one or more of coal tar, coal pitch, petroleum residual oil and petroleum pitch.

Optionally, in the mixture, the product of the mass percentage of the binder and the coking value of the binder is more than or equal to 0.03.

Optionally, the heat treatment includes the following steps:

heating the mixture from room temperature to a preset temperature;

preserving the heat for a preset time under the condition of a preset temperature to obtain coke;

wherein:

the preset temperature is 450-1400 ℃.

Optionally, the preset time is 20min-24 h.

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

the preparation method of the coke provided by the embodiment of the invention comprises the following steps: obtaining ash-removed coal; mixing the ash-removed coal with a binder to obtain a mixture; and carrying out heat treatment on the mixture to obtain the coke. According to the invention, through the steps, the ash-removed coal and the binder are mixed, the ash-removed coal is bound by the binder so as to meet the condition that the particle size of the ash-removed coal is smaller, then the ash-removed coal is subjected to heat treatment, and the bound mixture is prepared into the coke, and the ash content of the coke prepared by the method is less than 1.5%, so that the requirements of low-ash carbon products such as carbon for aluminum, graphite electrodes and the like on the ash content and the particle size of the raw materials can be met.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a flow chart of a method provided by an embodiment of the invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. For example, the room temperature may be a temperature within a range of 10 to 35 ℃.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

In order to solve the technical problems, the general idea of the embodiment of the application is as follows:

According to an exemplary embodiment of the present invention, there is provided a method for preparing coke, including the steps of:

and S1, obtaining the deashing coal.

Specifically, the method comprises the following steps: the ash-removed coal can be prepared by any one of the existing processes, and can also be purchased from any one of the existing sources.

And S2, mixing the deashing coal with a binder to obtain a mixture.

S3, carrying out heat treatment on the mixture to obtain the coke.

The invention achieves the purpose of preparing low-ash coke by coal through the steps, and concretely relates to the method, the ash-removing coal and the binder are mixed through the step S2, the powder or granular ash-removing coal is bound into a whole through the binder, so as to deal with the situation that the particle size of the ash-removing coal is small and the coke product can not meet the requirement, the mixture is subjected to heat treatment through the step S3, the bound mixture is prepared into the coke, and the coke prepared through the method has the ash content of less than 1.5 percent and can meet the requirements of low-ash carbon products such as carbon for aluminum, graphite electrodes and the like on the ash content and the particle size of raw materials.

In some embodiments, the ash-removed coal has a dry basis ash content of 1.5% or less.

In some embodiments, the mixture comprises 10-90% of the ash-removed coal by mass percent.

The reason for controlling the dry basis ash content of the ash removing coal to be less than or equal to 1.5 percent is as follows: the technical aim is that the prepared coke can be used as a raw material or a part of raw material of low-ash carbon products such as carbon for aluminum or graphite electrodes, and therefore, ash removing coal for preparing the coke needs to limit the ash range. It is feasible to add a portion of coke having an ash content of < 1.5% to certain low ash carbon products, such as aluminum carbon anodes. In the mixture of the ash-removed coal and the binder according to the present technology, the lower limit of the product of the mass percentage of the binder and the coking value of the binder is 0.03, the maximum mass percentage of the ash-removed coal is 90%, and if the ash content of the ash-removed coal exceeds 1.5%, the ash content of the finally prepared coke is likely to exceed 1.5% considering that the volatilization of the volatile matter (which causes the further increase of the ash content in the obtained coke) is accompanied in the heat treatment process of the mixture, the ash-removed coal is difficult to be used as the raw material of the low-ash carbonaceous product.

In some embodiments, the mass percentage of the < 1mm portion of the ash-removed coal is greater than or equal to 50%.

The purpose of controlling the above parameter ranges is to: in the ash removal process of coal such as a physical method, a chemical method, a physical-chemical ash removal method and the like, only if the coal is crushed to be relatively fine, the ash can be fully separated from a coal matrix or consumed through reaction by the method. Coal outside the above particle size range (i.e., coal with coarser particle size) will have ash removal effect that will hardly meet the ash removal requirement of the present technology.

In some embodiments, the binder comprises any one or combination of coal tar, coal pitch, petroleum residuum, and petroleum pitch.

The reason for choosing the above substances as binders is that: the adhesive has low ash content, wide source and low price.

In some embodiments, the mixture has a product of the mass percent of the binder and the coking value of the binder of 0.03 or more.

The significance of controlling the above parameter ranges is: under the condition of controlling the range of the product, the binder has a certain coking amount after heat treatment, and ash-removing coal particles or powder can be combined to ensure the strength of the final coke.

In some embodiments, the heat treatment comprises the steps of:

s3.1, heating the mixture from room temperature to a preset temperature;

s3.2, preserving the heat for a preset time under the condition of a preset temperature to obtain coke;

wherein:

the preset temperature is 450-1400 ℃.

The reason for controlling the range of the preset temperature is: when the preset temperature is lower than 450 ℃, the mixture is difficult to be converted into coke (or needs to be kept warm for too long); when the preset temperature is higher than 1400 ℃, the requirement on the heat treatment equipment is too high, and energy is wasted. Therefore, the preset temperature is controlled to be 450-1400 ℃ in the scheme.

In some embodiments, the predetermined time is 20min-24 h.

The reason for controlling the preset time is that: when the preset time is too short, the mixture cannot be completely converted into coke; when the preset time is too long, energy is wasted, and the production efficiency is low. Therefore, the control time in the scheme is 20min-24 h. It is known that the higher the holding temperature, the shorter the time required for the mixture of the deashed coal and the binder to be converted into coke.

The protocol of the present application will be described in detail below with reference to examples, comparative examples, and experimental data.

Example 1

The embodiment provides a preparation method of coke, which comprises the following steps:

and S1, obtaining the deashing coal.

Wherein: the ash removal coal had a dry ash content of 0.78%, and the mass percentage of the part < 1mm in the ash removal coal was 99.18%.

And S2, mixing the deashing coal with a binder to obtain a mixture.

Wherein: the mixture comprises 70% of deashed coal and 30% of binder, the binder is coal tar, the coking value of the coal tar is 24.06%, and the product of the mass percent of the binder and the coking value of the binder is 0.072.

S3, carrying out heat treatment on the mixture to obtain the coke.

S3.1, heating the mixture from room temperature to 450 ℃;

S3.2, preserving the heat for 8 hours at the temperature of 450 ℃ to obtain the coke.

Example 2

The embodiment provides a preparation method of coke, which comprises the following steps:

and S1, obtaining the deashing coal.

Wherein: the ash removal coal had a dry ash content of 1.48%, and the mass percentage of the part < 1mm in the ash removal coal was 50.64%.

And S2, mixing the deashing coal with a binder to obtain a mixture.

Wherein: the mixture comprises 50% of deashed coal and 50% of binder, the binder is a mixture of coal tar and petroleum pitch, the coking value of the mixture is 26.71%, and the product of the mass percent of the binder and the coking value of the binder is 0.134.

S3, carrying out heat treatment on the mixture to obtain the coke.

S3.1, heating the mixture to 680 ℃ from room temperature;

s3.2, preserving the heat for 23.5 hours at the temperature of 650 ℃ to obtain the coke.

Example 3

The embodiment provides a preparation method of coke, which comprises the following steps:

and S1, obtaining the deashing coal.

Wherein: the ash removal coal had a dry ash content of 1.12%, and the mass percentage of the part of the ash removal coal smaller than 1mm was 87.15%.

And S2, mixing the deashing coal with a binder to obtain a mixture.

Wherein: the mixture comprises 89% of deashed coal and 11% of binder, the binder is a mixture of coal tar, coal pitch, petroleum residual oil and petroleum pitch, the coking value of the mixture is 31.28%, and the product of the mass percent of the binder and the coking value of the binder is 0.034.

S3, carrying out heat treatment on the mixture to obtain the coke.

S3.1, heating the mixture to 1400 ℃ from room temperature;

s3.2, preserving the heat for 20min at 1400 ℃ to obtain the coke.

Example 4

The embodiment provides a preparation method of coke, which comprises the following steps:

and S1, obtaining the ash removing coal.

Wherein: the ash removal coal has a dry ash content of 0.94%, and the ash removal coal has a mass percentage of less than 1mm of 100%.

And S2, mixing the deashing coal with a binder to obtain a mixture.

Wherein: the mixture comprises 10% of deashed coal and 90% of binder, the binder is a mixture of coal tar pitch and petroleum residue, the coking value of the mixture is 50.68%, and the product of the mass percent of the binder and the coking value of the binder is 0.456.

S3, carrying out heat treatment on the mixture to obtain the coke.

S3.1, heating the mixture from room temperature to 1050 ℃;

s3.2, preserving the heat for 6 hours at 1050 ℃ to obtain the coke.

Example 5

The embodiment provides a preparation method of coke, which comprises the following steps:

and S1, obtaining the deashing coal.

Wherein: the ash removal coal has a dry ash content of 0.86%, and the ash removal coal has a mass percentage of less than 1mm of 100%.

And S2, mixing the deashing coal with a binder to obtain a mixture.

Wherein: the mixture comprises 60% of deashed coal and 40% of binder, the binder is selected from petroleum asphalt, the coking value of the petroleum asphalt is 29.65%, and the product of the mass percent of the binder and the coking value of the binder is 0.119.

S3, carrying out heat treatment on the mixture to obtain the coke.

S3.1, heating the mixture from room temperature to 1300 ℃;

s3.2, preserving the heat for 1h at 1280 ℃ to obtain the coke.

Examples of the experiments

The coke produced in examples 1-5 were tested for particle stability to reflect their strength. The results of the measurements are shown in Table 1 below.

The detection method comprises the following steps: after preparing coke, if the preset temperature in the coke heat treatment process is lower than 1250 ℃, putting the coke into a crucible with a cover, heating to 1250 ℃ at the heating rate of 3 ℃ per minute, preserving the heat for 2 hours at 1250 ℃, and measuring the particle stability after cooling; if the preset temperature of the coke heat treatment process is not lower than 1250 ℃, directly sampling the coke to measure the particle stability.

TABLE 1 Coke test results

	Ash content of coke%	Volatile content%	Calcination temperature C	Stability of the granules%
					Example 1	0.66	14.10	1250	79.13
Example 2	1.29	4.69	1250	86.91
					Example 3	1.08	0.20		74.03
Example 4	0.43	0.90	1250	91.23
					Example 5	0.83	0.27		82.37
Petroleum coke				70-90％

From the above table, according to the comparison between examples 1 to 5 and petroleum coke, the particle stability of the coke prepared by the method provided by the embodiment of the present invention can meet the requirements of low ash carbon products such as carbon for aluminum and graphite electrode on the ash content and particle size of the raw material, and the ash content is less than or equal to 1.5%.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (8)

1. A method for preparing coke is characterized by comprising the following steps:

obtaining ash-removed coal;

Mixing the deashing coal with a binder to obtain a mixture;

and carrying out heat treatment on the mixture to obtain the coke.

2. The method of producing coke according to claim 1, wherein the ash-removed coal has a dry ash content of 1.5% or less.

3. The method for producing coke according to claim 1, wherein the mass percentage of the portion of the ash-removed coal smaller than 1mm is not less than 50%.

4. The method for producing coke according to claim 1, wherein the mixture comprises 10 to 90% by mass of the ash-removed coal.

5. The method of preparing coke according to claim 1, wherein the binder comprises any one or more of coal tar, coal pitch, petroleum residuum and petroleum pitch.

6. The method for producing coke according to claim 1, wherein the product of the mass percentage of the binder and the coking value of the binder in the mixture is not less than 0.03.

7. The method for producing coke according to claim 1, wherein the heat treatment comprises the steps of:

heating the mixture from room temperature to a preset temperature;

preserving the heat for a preset time under the condition of a preset temperature to obtain coke;

Wherein:

the preset temperature is 450-1400 ℃.

8. The method for preparing coke according to claim 7, wherein the predetermined time is 20min to 24 hours.

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