CN110540848B - High-strength coke and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of coke, in particular to high-strength coke and a preparation method thereof. The high-strength coke at least comprises the following components in parts by weight: 20-45 parts of coking coal, 10-25 parts of fat coal, 10-20 parts of gas coal, 10-30 parts of anthracite, 2-15 parts of petroleum coke, 3-10 parts of boron compound and 5-15 parts of filler. The anthracite added in the invention can replace a part of coking coal and fat coal, and the market price of the anthracite is far lower than that of the coking coal and the fat coal, so that the production cost of coke is reduced; because the ash content of anthracite and petroleum coke is extremely low, the ash content of coke is obviously reduced. In addition, the coke prepared by the method has the characteristics of high strength, good stability and the like.

Description

High-strength coke and preparation method thereof

Technical Field

The invention relates to the technical field of coking, in particular to high-strength coke and a preparation method thereof.

Background

The coke is a solid fuel formed by a series of complex physicochemical processes such as pyrolysis, polycondensation, solidification, shrinkage and the like of a coking coal material under the action of high-temperature dry distillation. More than 96% carbon and the calorific value is about 29X 103 kJ/kg. The coke is mainly used for blast furnace ironmaking and blast furnace smelting of nonferrous metals such as copper, lead, zinc, titanium, antimony, mercury and the like, and plays roles of a reducing agent, a heating agent and a material column framework.

With the large-scale of the steel blast furnace and the development of the high-pressure blowing technology, the requirements of the coke quality and the coke stability of the large blast furnace are higher and higher. As the coking coal resources are gradually scarce, the price of the coal as fired is kept high for a long time, and the price of the coke is gradually lowered, coking enterprises are required to reduce the cost of the coal as fired and improve the quality of coke products. Therefore, the coking industry requires the optimization of a coal as fired scheme, the coking coal proportion is reduced as much as possible, the coal as fired raw materials is greatly reduced, and the market competitiveness of coke products is improved.

Therefore, coking enterprises need to further improve the coke strength, reduce the ash content of the coke, save the consumption of main coking coal and reduce the production cost.

Disclosure of Invention

In order to solve the above technical problems, a first aspect of the present invention provides a high strength coke, which comprises at least the following components in parts by weight: 20-45 parts of coking coal, 10-25 parts of fat coal, 10-20 parts of gas coal, 10-30 parts of anthracite, 2-15 parts of petroleum coke, 3-10 parts of boron compound and 5-15 parts of filler.

As a preferable technical scheme of the invention, the high-strength coke at least comprises the following components in parts by weight: 30 parts of coking coal, 20 parts of fat coal, 15 parts of gas coal, 25 parts of anthracite, 10 parts of petroleum coke, 8 parts of boron compound and 10 parts of filler.

As a preferred technical solution of the present invention, the boron compound is selected from one or a combination of more of boric acid, boric anhydride, borax, boron oxide, boron carbide, titanium boride, calcium borate, and barium metaborate.

As a preferred embodiment of the present invention, the boron compound is a combination of boric acid and boron carbide.

As a preferable technical solution of the present invention, the mass ratio of the boric acid to the boron carbide is 1: (0.3-1.2).

In a preferred embodiment of the present invention, the filler is a coal-based binder and/or a petroleum-based binder.

In a preferred embodiment of the present invention, the coal-based binder is tar and/or pitch.

In a preferred embodiment of the present invention, the petroleum-based binder is solvent deasphalting and/or heavy residue.

As a preferable technical means of the present invention, the mass ratio of the petroleum-based binder to the coal-based binder is 1: (0.4-1.5).

The second aspect of the present invention provides a method for preparing high strength coke, which at least comprises the following steps:

(1) weighing coking coal, fat coal, gas coal, anthracite, petroleum coke, boron compound and filler according to parts by weight;

(2) firstly, mixing coking coal, fat coal, gas coal, anthracite and petroleum coke, crushing, then adding a boron compound and a filler for tamping, then carrying out carbonization coking at the coking temperature of 950-1150 ℃ for 18-20h to obtain red coke, and cooling after coking.

Has the advantages that: the invention provides a high-strength coke and a preparation method thereof, and the high-strength coke is prepared by coking coal, fat coal, gas coal, anthracite, petroleum coke, boron compounds and fillers. The anthracite added in the invention can replace a part of coking coal and fat coal, and the market price of the anthracite is far lower than that of the coking coal and the fat coal, so the production cost of coke is reduced; because the ash content of anthracite and petroleum coke is extremely low, the ash content of the coke is lower. In addition, the coke prepared by the method has the characteristics of high strength, good stability and the like.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. 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. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

In order to solve the above technical problems, a first aspect of the present invention provides a high strength coke, which comprises at least the following components in parts by weight: 20-45 parts of coking coal, 10-25 parts of fat coal, 10-20 parts of gas coal, 10-30 parts of anthracite, 2-15 parts of petroleum coke, 3-10 parts of boron compound and 5-15 parts of filler.

Preferably, the high-strength coke at least comprises the following components in parts by weight: 30 parts of coking coal, 20 parts of fat coal, 15 parts of gas coal, 25 parts of anthracite, 10 parts of petroleum coke, 8 parts of boron compound and 10 parts of filler.

Coking coal

Coking coal, also known as metallurgical coal, is also known as main coking coal. The bituminous coal is medium caking property and strong caking property with medium and low volatile components, and the coking coal is a name for the bituminous coal with higher coalification degree and good coking property in the national standard of Chinese coal classification. Coking coal is a medium rank bituminous coal. Because of strong caking property, high-quality coke with high strength, large lumpiness, high strength and few cracks can be refined, and the coke is the best raw material for coking. The shrinkage degree of the coking coal is small when the coking coal is used alone for coking, the expansion pressure is large, the coking coal is not easy to be pushed out from the coking furnace, and the coking furnace is easy to be damaged, so that a proper amount of gas coal, fat coal or lean coal and the like must be added into the coking coal during coking to improve the operation condition, improve the coke quality and expand the coal resources for coking.

Gas coal

The gas coal is a soft coal with low coalification degree, and is not caking or slightly caking. There is no coking in the layered coke oven. The flame is short during combustion, and the combustion is durable. The air heating is isolated, and a large amount of coal gas can be generated. Some gas coal can be used for oil refining and chemical raw material extraction. As the gas coal with the largest reserve in the coking coal, most of the gas coal has the characteristics of low ash and low sulfur, the coal blending coking can obviously reduce the harmful components of the coke, such as ash, sulfur and the like, simultaneously reduce the discharge of coking pollutants, relieve the influence of metallurgical production on the atmospheric environment and is the coking coal with the most development potential. In coal blending and coking, the capacity of the fat coal for containing the gas coal is the strongest, and the gas coal blending ratio is controlled by taking the fat coal as a base number. With the increase of the gas coal proportion, various gas hole parameters of the coke are obviously changed, the thermal property of the coke is gradually degraded and has a sharp degradation point, and the influence of the gas coal participating in coke formation on the thermal property of the coke is mainly realized by changing the gas hole structure.

Fat coal

The fat coal is one of bituminous coal, has high coalification degree, is weak caking coal with medium and medium-high volatile contents, and has the volatile content of about 25-35%. The fat coal is also one of coking coals, is mostly used for coking, has good coking property, has higher strength of refined coke but poor wear resistance, is easy to expand and damage a furnace when being used for coking by the fat coal alone, and is often mixed with other bituminous coals for use. The maximum thickness y of the fat coal colloidal layer is more than 25 mm. Fat coals generally have higher sulfur contents than other coal grades.

Anthracite coal

Anthracite, commonly known as white coal or red coal, is the coal with the largest degree of coalification. Anthracite is a hard, dense and high-gloss coal mine variety. Among all coal varieties, anthracite coal, although having a low calorific value, has the highest carbon content and the lowest impurity content. The anthracite has high fixed carbon content, low volatile matter yield, high density, high hardness, high burning point and no smoke during burning. Black, hard and has metallic luster. No pollution by grease friction, shell-like fracture, short flame and less smoke during combustion. No coking is generated. Generally, the carbon content is more than 90%, and the volatile matter is less than 10%. No colloidal layer thickness. The heat value is about 6000 and 6500 kcal/kg. Sometimes, the coal with extremely large volatile matter content is called semi-anthracite; the extra small coal is called high anthracite.

Petroleum coke

The black solid coke is generated by cracking and coking the vacuum residue of petroleum at the temperature of 500-550 ℃ by a coking device. The appearance of the coke oven is a black or dark gray honeycomb structure, and the inner pores of the coke oven are mostly oval and are communicated with each other. It is generally considered to be an amorphous carbon body; or a highly aromatized high-molecular carbide containing a carbon material having a needle-like or granular structure of fine graphite crystals. The carbon-hydrogen ratio is high and is 18-24. The relative density is 0.9-1.1, the ash content is 0.1-1.2%, and the volatile matter content is 3-16%.

In the invention, the anthracite is added to replace part of coking coal and fat coal, and the market price of the anthracite is far lower than that of the coking coal and the fat coal, so that the production cost of the coke is reduced. The ash content of anthracite is lower, and meanwhile, the ash content of petroleum coke is extremely low, so that the ash content of the coke is reduced.

Boron compound

In the invention, the boron compound is selected from one or more of boric acid, boric anhydride, borax, boron oxide, boron carbide, titanium boride, calcium borate and barium metaborate.

Preferably, the boron compound is a combination of boric acid and boron carbide.

More preferably, the mass ratio of the boric acid to the boron carbide is 1: (0.3-1.2).

Most preferably, the mass ratio of the boric acid to the boron carbide is 1: 0.9.

in the invention, the addition of the boron compound obviously improves the strength of the coke. The inventors consider that possible reasons are: 1. the boron carbide has the characteristics of low density, high strength, high-temperature stability and good chemical stability, and can play a role of a protective film when covering the surface of the coke. 2. Boric acid quickly permeates from the surface of the coke to form a boronized film which is filled in pores on the surface of the coke, so that the surface strength of the coke is enhanced. 3. The boric acid is dehydrated twice to obtain B when the temperature of the boric acid is heated to 1100 ℃ along with the coke₂O₃。B₂O₃Is an acidic substance which forms a B-O-B bond after dehydration by heating. B is an electron-deficient body, has electrophilic tendency, and the coke dissolution loss reaction is easy to occur on the defect part on the coke surface. A large number of carbon arc pair electrons exist on the surface defect positions, so that a B-O-B bond is easy to gather to a lone pair electron position, thereby blocking an active position on which a dissolution loss reaction is based, and reducing the effective surface area of an active point, thereby hindering the dissolution loss reaction; meanwhile, boron carbide migrates to the surface defect part of the coke under the high-temperature condition to synergistically hinder the dissolution loss reaction, and the hindering effect is enhanced due to the increase of the number of B-O-B and B-C-B bonds. This not only can modify the pore structure of coke and reduce coke CO₂The area of reaction, and the generated hard-to-oxidize pyrolytic carbon is attached to the inner and outer surfaces of the coke so as to enhance the carbon dissolution reaction resistance of the coke, thereby improving the strength enhancement of the coke.

The addition of the boron compound improves the strength of the coke, but the caking property among the raw material components of the coke is not obviously improved, and the inventor improves the caking property among the raw materials of the coke by compounding the coal-based binding material and the petroleum-based binding material, thereby further enhancing the strength and the stability of the coke.

Filler material

In the invention, the filler is a coal-based binder and/or a petroleum-based binder.

Preferably, the coal-based binder is tar and/or pitch.

Preferably, the petroleum-based binder is solvent deasphalting and/or heavy residue.

More preferably, the mass ratio of the petroleum-based binder to the coal-based binder is 1: (0.4-1.5).

Most preferably, the filler is asphalt and heavy residue, and the mass ratio of the asphalt to the heavy residue is 1: 1.2.

in the present invention, the strength of the coke is further enhanced by the addition of the filler. The inventors consider that possible reasons are: coal such as coking coal, fat coal, gas coal, anthracite and the like in the coal are subjected to mutual bonding with the coal-based bonding material before softening and melting to the initial stage of softening and melting; at this time, there is hardly any interaction between the petroleum-based binder and the coal; but after the coal is softened and melted, the petroleum binder has a binding effect on the coal, which means that the interaction of the petroleum binder and the coal occurs after the softening and melting of the coal is started; the coal-based binder and the petroleum-based binder generate synergistic effect, and strong mutual synergistic effect is formed at the early stage, the middle stage and the later stage of softening and melting of coal, so that the expansion pressure during dry distillation is further inhibited, and the strength of coke is obviously improved.

The second aspect of the present invention provides a method for preparing high strength coke, which at least comprises the following steps:

(1) weighing coking coal, fat coal, gas coal, anthracite, petroleum coke, boron compound and filler according to parts by weight;

(2) firstly, mixing coking coal, fat coal, gas coal, anthracite and petroleum coke, crushing, then adding a boron compound and a filler for tamping, then carrying out carbonization coking at the coking temperature of 950-1150 ℃ for 18-20h to obtain red coke, and cooling after coking.

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

In addition, the starting materials used are all commercially available, unless otherwise specified.

Examples

Example 1

Example 1 provides a high strength coke comprising at least the following components: 30 parts of coking coal, 20 parts of fat coal, 15 parts of gas coal, 25 parts of anthracite, 10 parts of petroleum coke, 8 parts of boron compound and 10 parts of filler;

the boron compound is a combination of boric acid and boron carbide, and the mass ratio of the boron compound to the boron carbide is 1: 0.9;

the filler is a combination of asphalt and heavy residue, and the mass ratio of the filler to the heavy residue is 1: 1.2.

the preparation method of the high-strength coke at least comprises the following steps:

(1) weighing coking coal, fat coal, gas coal, anthracite, petroleum coke, boron compound and filler according to parts by weight;

(2) firstly, mixing coking coal, fat coal, gas coal, anthracite and petroleum coke, crushing, then adding a boron compound and a filler for tamping, then carrying out carbonization coking at 1150 ℃ for 20h to obtain red coke, and cooling after decoking to obtain the red coke.

Example 2

Example 2 provides a high strength coke comprising at least the following components: 20 parts of coking coal, 10 parts of fat coal, 10 parts of gas coal, 10 parts of anthracite, 2 parts of petroleum coke, 3 parts of boron compound and 5 parts of filler;

the boron compound is a combination of boric acid and boron carbide, and the mass ratio of the boron compound to the boron carbide is 1: 0.3;

the filler is a combination of asphalt and heavy residue, and the mass ratio of the filler to the heavy residue is 1: 0.4.

the high strength coke was prepared in the same manner as in example 1.

Example 3

Example 3 provides a high strength coke comprising at least the following components: 45 parts of coking coal, 25 parts of fat coal, 20 parts of gas coal, 30 parts of anthracite, 15 parts of petroleum coke, 10 parts of boron compound and 15 parts of filler;

the boron compound is a combination of boric acid and boron carbide, and the mass ratio of the boron compound to the boron carbide is 1: 1.2;

the filler is a combination of asphalt and heavy residue, and the mass ratio of the filler to the heavy residue is 1: 1.5.

the high strength coke was prepared in the same manner as in example 1.

Example 4

Example 4 differs from example 1 in that the boron compound is boric acid.

Example 5

Example 5 differs from example 1 in that the boron compound is boron carbide.

Example 6

Example 6 differs from example 1 in that the boron compound is boron oxide.

Example 7

Example 7 differs from example 1 in that the boron compound is a combination of boric acid and boron carbide in a mass ratio of 1: 0.1.

example 8

Example 8 differs from example 1 in that the coke feed does not contain boron compounds.

Example 9

Example 9 differs from example 1 in that the filler is a heavy residue.

Example 10

Example 10 differs from example 1 in that the filler is bitumen.

Example 11

Example 11 differs from example 1 in that the filler is a combination of bitumen and heavy residue in a mass ratio of 1: 0.1.

example 12

Example 12 differs from example 1 in that the coke feed does not contain filler.

Example 13

Example 13 differs from example 1 in that the coke feedstock does not contain petroleum coke.

Performance testing

Testing the strength of coke: reference is made to the JISK 2151 test standard. The results of the coke property tests obtained from examples 1-13 are shown in Table 1.

TABLE 1 results of the performance test of the cokes prepared in examples 1 to 13

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.

Claims (3)

1. The high-strength coke is characterized by at least comprising the following components in parts by weight: 20-45 parts of coking coal, 10-25 parts of fat coal, 10-20 parts of gas coal, 10-30 parts of anthracite, 2-15 parts of petroleum coke, 3-10 parts of boron compound and 5-15 parts of filler; the boron compound is a combination of boric acid and boron carbide, and the mass ratio of the boric compound to the boron carbide is 1: 0.9; the filler is a combination of asphalt and heavy residue, and the mass ratio of the filler to the heavy residue is 1: 1.2.

2. the high strength coke of claim 1, comprising at least the following components in parts by weight: 30 parts of coking coal, 20 parts of fat coal, 15 parts of gas coal, 25 parts of anthracite, 10 parts of petroleum coke, 8 parts of boron compound and 10 parts of filler.

3. A method for producing a high strength coke according to any of claims 1 to 2, characterized by comprising at least the steps of:

(1) weighing coking coal, fat coal, gas coal, anthracite, petroleum coke, boron compound and filler according to parts by weight;

(2) firstly, mixing coking coal, fat coal, gas coal, anthracite and petroleum coke, crushing, then adding a boron compound and a filler for tamping, then carrying out carbonization coking at the coking temperature of 950-1150 ℃ for 18-20h to obtain red coke, and cooling after coking.