Coking method matched with ultra-clean coal and coke produced by method

Abstract

The invention provides a coking method matched with ultra-clean coal and coke produced by the method. The coking method using the ultra-clean coal comprises the following steps: S1, preparation of blended coal: based on the total weight of the blended coal as 100%, preparing the blended coal for coking by adopting the following coal blending ratios in percentage by mass: 15%-35% of gas coal, 8%-20% of 1 / 3 coking coal, 2%-20% of fat coal, 5%-15% of coking coal, 15%-20% of lean coal, 15%-20% of meager lean coal and 5%-15% of ultra-clean coal; and S2, tamping and coking: blending and uniformly mixing the mixed coal, crushing and tamping the mixed coal, coking by using a tamping coke oven, and carrying out dry quenching to obtain dry quenched coke. According to the invention, the super-clean coal is added into the mixed coal, so that the use amount of the high-quality fertilizer coking coal can be effectively reduced, high-valued application of low-rank coal resources is realized, domestic high-quality coking coal resources are saved, and the coke quality is improved.

Description

Technical Field

[0001] The invention belongs to the field of coal blending and coking, and in particular relates to a coking method using ultra-cleaned coal and coke produced by the method. Background Art

[0002] Usually, hypercoal (HPC) is a high-quality coal with low ash, low sulfur, high volatility, high calorific value, high reactivity, good thermoplasticity, etc. obtained by organic solvent extraction from low-rank coal with abundant resources such as lignite and weakly sticky coal. It can be used as a good binder for coking with coal blending. In recent years, the thermal extraction of low-metamorphic coal with recyclable organic solvents has become a research hotspot for the comprehensive utilization of inferior coal, in order to obtain coke with high reactivity and high post-reaction strength, and provide raw material support for improving smelting efficiency and maintaining stable forward operation at low fuel ratio of blast furnace. Japan is making every effort to develop hypercoal for coking with coal blending, so as to produce high-strength coke.

[0003] China is a country rich in coal but short of oil and gas. It is one of the few countries in the world that uses coal as its main energy source. Lignite and non-coking coal resources are relatively abundant, but high-quality coking coal resources are scarce. Low-rank coal such as lignite has high ash, high water content, poor adhesion, and low calorific value, making it difficult to be directly used in coking and coal liquefaction and gasification, resulting in serious waste of resources. With the rapid development of the national economy, my country's steel industry has developed rapidly, but the supply of high-quality coking coal and coke required for steel production is tense. In order to expand coking coal resources, save high-quality coking coal, and produce high-quality coke, it is still necessary to develop a coal blending coking method that improves the quality of coke, saves high-quality coking coal resources, and increases the amount of high-ash, high-sulfur, and low-adhesive coal. Summary of the invention

[0004] In view of the above description, the traditional coal blending coking technology is highly dependent on high-quality fat coking coal resources and cannot use low-quality coal resources such as lignite and weakly sticky coal with abundant reserves. The present invention proposes a technology for adding ultra-fine coal extracted from low-quality coal resources for coal blending coking, thereby ensuring the quality of coke and reducing the cost of coal blending.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a coking method using ultra-clean coal to replace part of fat coking coal, the method comprising the following steps:

[0007] S1: Preparation of blended coal:

[0008] Taking the total weight of the blended coal as 100%, the following blending ratios by mass percentage are used to prepare the blended coal for coking: gas coal 15% to 35%, 1 / 3 coking coal 8% to 20%, fat coal 2% to 20%, coking coal 5% to 15%, lean coal 15% to 20%, lean coal 15% to 20%, super clean coal 5% to 15%, and

[0009] S2: Ramming coking: After the blended coal is mixed and evenly blended, it is crushed and rammed, and coking is performed in a ramming coke oven, and dry quenching is performed to obtain dry quenched coke.

[0010] Wherein, the ash content of the super clean coal is d <0.5%、sulfur content S t <0.35%、Adhesion index G>95、V daf In the range of 50% to 60%, the particle size is 1mm to 3mm, and

[0011] The blended coal meets the following quality indicators: V daf At 26% to 31%, ash content A d <9.8%, sulfur content S t ≤0.80%, bonding index G≥60, gelatin layer index Y≥13mm.

[0012] In a specific implementation, in S1, taking the total weight of the blended coal as 100%, the blended coal for coking is prepared by using the following blending ratios in terms of mass percentage:

[0013] Gas coal 32%, 1 / 3 coking coal 8%, fat coal 5%, coking coal 10%, lean coal 20%, lean coal 20%, super clean coal 5%; or

[0014] Gas coal 32%, 1 / 3 coking coal 8%, fat coal 10%, coking coal 5%, lean coal 20%, lean coal 20%, super clean coal 5%; or

[0015] Gas coal 28%, 1 / 3 coking coal 16%, fat coal 2%, coking coal 12%, lean coal 15%, lean coal 17%, and super clean coal 10%.

[0016] In a specific embodiment, the gas coal meets the following index requirements: ash content 8.5% to 11.0%, volatile matter 35% to 40%, sulfur content 0.50% to 0.60%, G value ≥ 65, Y value ≥ 11, CSR of 40kg small coke oven coking coke of single coal is 35% to 40%, active-inert ratio is 0.95 to 1.4, and MCI value is < 6;

[0017] The 1 / 3 coking coal meets the following index requirements: ash content 8.0% to 11.0%, volatile matter 30% to 38%, sulfur content 0.3% to 1.5%, G value ≥ 80, Y value ≥ 18, CSR of 40kg small coke oven coking coke of single coal is 40% to 55%, active-inert ratio is 0.9 to 1.5, and MCI value is <5;

[0018] The fat coal meets the following index requirements: ash content 7.0% to 12.0%, volatile matter 27% to 38%, sulfur content 0.4% to 4.0%, G value ≥ 90, Y value ≥ 25, CSR of 40kg small coke oven coking coke of single coal is 35% to 70%, active-inert ratio is 1 to 4, and MCI value is < 6;

[0019] The coking coal meets the following index requirements: ash content 10.0% to 11.0%, volatile matter 20% to 28%, sulfur content 0.4% to 0.8%, G value ≥ 75, Y value ≥ 19, CSR of 40kg small coke oven coking coke of single coal is 50% to 70%, active-inert ratio is 2.5 to 4, and MCI value is < 6;

[0020] The lean coal meets the following index requirements: ash content 10% to 11%, volatile matter 16% to 20%, sulfur content 0.6% to 0.8%, G value ≥ 50, Y value ≥ 8, CSR of 40kg small coke oven coking coke of single coal is 40% to 60%, active-inert ratio is 0.8 to 1.0, and MCI value is < 6;

[0021] The lean coal meets the following index requirements: ash content 9.5% to 11%, volatile matter 10% to 15%, sulfur content 0.3% to 1.2%, G value <15, Y value ≥0, active-inert ratio 0.4 to 1, and MCI value <6.

[0022] In a specific embodiment, in S2, the particle size of the crushed blended coal is less than 3 mm, accounting for 85% to 90%.

[0023] In a specific embodiment, in S2, the bulk density of the briquettes fed into the rammed coke oven is controlled at 1.0-1.1 t / m 3 .

[0024] In a specific implementation, in S2, the coking standard temperature is controlled within the range of 1250°C to 1350°C, and the coking time is 20 to 30 hours.

[0025] On the other hand, the present invention provides a blended coal for producing coke, wherein the weight percentages of various coking coals are as follows based on 100 weight percent of the blended coal:

[0026] Gas coal 15%~35%, 1 / 3 coking coal 8%~20%, fat coal 2%~20%, coking coal 5%~15%, lean coal 15%~20%, poor lean coal 15%~20%, super clean coal 5%~15%.

[0027] In a specific embodiment, based on 100% by weight of the blended coal, the weight percentages of various coking coals are as follows:

[0028] Gas coal 32%, 1 / 3 coking coal 8%, fat coal 5%, coking coal 10%, lean coal 20%, lean coal 20%, super clean coal 5%; or

[0029] Gas coal 32%, 1 / 3 coking coal 8%, fat coal 10%, coking coal 5%, lean coal 20%, lean coal 20%, super clean coal 5%; or

[0030] Gas coal 28%, 1 / 3 coking coal 16%, fat coal 2%, coking coal 12%, lean coal 15%, lean coal 17%, and super clean coal 10%.

[0031] In another aspect, the present invention provides a coke produced by the method described in the first aspect above, wherein the coke meets the following quality indicators: A d (%)≤13.0,S t,d (%)≤0.7, CSR(%)≥60.

[0032] Beneficial Effects

[0033] The present invention adds a certain proportion of ultra-clean coal to the blended coal of the ramming coke oven, and only needs to add the ultra-clean coal on the main coal blending belt to mix evenly, which has the advantages of low equipment requirements, no need for additional equipment, low investment, simple operation, etc. It solves the problem that the conventional method of increasing the amount of high-quality coking coal such as fat coking coal or changing the coking process can improve the quality of coke, and has positive significance in terms of economy and environmental protection.

[0034] The present invention can effectively reduce the amount of high-quality fat coking coal by adding ultra-cleaned coal prepared from low-rank coal to the blended coal, realize the high-value application of low-rank coal resources, save domestic high-quality coking coal resources, and improve the quality of coke, becoming one of the effective ways to solve the problem of coking coal resource shortage. Using non-coking coal for coal blending and coking has very important significance and economic value.

[0035] Adding ultra-fine coal to the blended coal can reduce the use of high-priced fat coking coal and increase the use of low-priced coal such as high ash, high sulfur and low caking coal, so as to reduce the overall coal blending cost. Compared with the same quality of coke, the blending coal price is reduced by 50 to 150 yuan / ton. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is clearly and completely described below. Obviously, the embodiments described in the present invention are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. In addition, in order to better illustrate the present invention, numerous specific details are given in the specific embodiments below. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details. In some embodiments, the raw materials, original parts, methods, means, etc. of the numerical values ​​of those skilled in the art are not described in detail, so as to highlight the main purpose of the present invention.

[0037] The present invention relates to a coking method for adding ultra-clean coal to blended coal to replace part of fat coking coal, which is as follows: (1) various coking coals and ultra-clean coals are dropped onto a belt according to a certain proportion; (2) the blended coal is crushed in a pulverizer to obtain new blended coal; (3) the blended coal is tamped into coal cakes on a tamping vehicle and pushed into a carbonization chamber for dry distillation into coke; (4) product coke is obtained through quenching and coke screening. In step (2), the pulverization makes the particle size of the blended coal less than 3 mm account for 85% to 90%; in step (3), the coking standard temperature is controlled within the range of 1250°C to 1350°C, and the coking time is 20 to 30 hours.

[0038] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it more clearly and easily according to the contents of the specification, the specific implementation methods of the present invention are listed below.

[0039] It should be noted that the following examples are provided for illustrative purposes only and do not constitute a limitation on the scope of the present invention. Unless otherwise specified, the raw materials, reagents, methods, etc. used in the examples are all conventional raw materials, reagents, methods in the art.

[0040] The coal index determination method is as follows:

[0041] Ash and volatile matter: Determined according to the rapid ashing method A and volatile matter determination method in GB / T 212-2008 “Industrial analysis methods for coal”.

[0042] Sulfur content: Determined by the coulometric method in accordance with GB / T214-2007 “Determination of total sulfur in coal”.

[0043] Adhesion index (G value): Determined in accordance with GB / T 50047-2014 "Determination method for adhesion index of bituminous coal".

[0044] Y value: Determined in accordance with GB / T 479-2016 “Determination method for bituminous coal colloid index”.

[0045] The active-inert ratio is calculated by following formula 1:

[0046]

[0047] Among them, the active-inert ratio (A / I) represents the ratio of active components to inert components in a single coal or a blended coal, vitrinite (V), %, exinite (E), %, inertinite (I), %, minerals, %.

[0048] First, prepare the pulverized coal optical film according to GBT 16773-2008 "Method for Preparation of Coal and Rock Analysis Samples", and then determine the active and inert microscopic components according to GB / T8899-2013 "Microscopic Component Grouping and Mineral Determination Methods of Coal".

[0049] The alkali metal catalytic index MCI value is calculated according to the following formula 2:

[0050]

[0051] Among them, MCI is the mineral catalytic index, Fe2O3, Na2O, K2O, CaO, MgO, SiO2, Al2O3, and TiO2 are the mass fractions of each metal element in the ash component, respectively; Ad and Vd are the mass fractions of dry ash and volatile matter in the coal, respectively.

[0052] Determination of the content of each metal element in the ash component: Determined in accordance with GBT 37673-2019 "Determination of silicon, aluminum, iron, calcium, magnesium, potassium, phosphorus, titanium, manganese, barium and strontium in coal ash by X-ray fluorescence spectrometry".

[0053] The coke index determination method is as follows:

[0054] Coke sample collection and preparation: Sample preparation shall be carried out in accordance with GB / T 1997-2008 “Coke sample collection and preparation”.

[0055] Coke ash content: Determined according to arbitration method A in GB / T 2001-2013 "Analysis and determination methods for coke industry".

[0056] Coke sulfur content: Determined by the coulometric method in accordance with GB / T 2286-2017 “Determination of total sulfur content in coke”.

[0057] Determination method of coke mechanical strength M40, M25, M10: in accordance with GB / T 2006-2008 "Determination method of coke mechanical strength".

[0058] Coke reactivity (CRI) and post-reaction strength (CSR): Determined in accordance with GB / T 4000-2017 "Test method for coke reactivity and post-reaction strength".

[0059] Table 1 below shows the quality indicators of various coking coals used in the following examples and comparative examples.

[0060] Table 1 Quality indicators of coking coal used

[0061] Coal Type <![CDATA[A d (%)]]> <![CDATA[V daf (%)]]> <![CDATA[S t (%)]]> G-Value Y value(mm) CSR (%) Active-inactive ratio MCI value Gas coal 1 8.7 37.5 0.56 67 11 35 1.394 2.63 Gas Coal 2 10.3 37 0.5 73 12 35 1.247 4.11 1 / 3 coking coal 10.8 32.5 1.3 82 17 55 0.902 1.30 Fat coal 9 38 3.05 92 28 40 2.075 1.62 Coking coal 10.3 24 0.55 86 20 63 2.962 3.30 lean coal 10.4 20 0.7 55 8 55 0.889 2.80 Lean coal 10.5 13.5 0.35 0 0 0 0.843 2.84 Super clean coal 0.4 55 0.3 105 / / / /

[0062] Embodiment and comparative example:

[0063] The single coals were blended according to the proportions in Table 2 below to obtain blended coals of various embodiments and comparative examples, wherein the ultra-cleaned coal was crushed to a particle size of less than 3 mm before blending, and the proportion of blended coal less than 3 mm after crushing was 88%. The crushed blended coal was rammed, and the coal cake obtained by ramming had a bulk density of 1.04 t / m 3 ; Production tests were carried out in a 5.5m ramming coke oven, with the standard coking temperature being 1345℃ / 1340℃, the coking time being 26h, and the quenching method being dry quenching.

[0064] The indices of blended coal and coke were tested according to the above index determination methods, and the results are shown in Tables 3 and 4 below respectively.

[0065] Table 2 Proportion of each type of coal

[0066]

[0067]

[0068] Table 3 Quality indexes of blended coal

[0069] <![CDATA[A d (%)]]> <![CDATA[V daf (%)]]> <![CDATA[S t (%)]]> G-Value Y value(mm) Comparative Example 1 9.99 27.45 0.79 61.25 13.26 Example 1 9.51 28.58 0.77 62.94 14.57 Example 2 9.53 28.27 0.72 62.45 14.41 Comparative Example 2 9.6 29.31 0.793 62.28 13.16 Example 3 9.03 30.21 0.74 65.63 14.02

[0070] Table 4 Quality indexes of coke

[0071] <![CDATA[A d (%)]]> <![CDATA[S t,d (%)]]> CRI(%) CSR (%) Comparative Example 1 12.76 0.68 21.5 62.3 Example 1 12.14 0.66 20.1 64.5 Example 2 12.16 0.62 19.1 65.2 Comparative Example 2 12.26 0.68 22.3 61.9 Example 3 11.53 0.64 20.0 67.3

[0072] As shown in Tables 2-4 above, when Comparative Example 1 is compared with Example 1, after replacing 5% fat coal with super clean coal, since the ash content in super clean coal is only 0.4%, the ash content of the blended coal is reduced by 0.48%, the sulfur content is reduced by 0.02%, the bonding index is increased by 1.69, and the colloidal layer index Y value is increased by 1.31 mm. Therefore, it can be seen from the blended coal indicators that the various indicators of the blended coal are improved after replacing fat coal with high ash and sulfur relative to super clean coal. At the same time, the reaction strength of the coke obtained by replacing part of the fat coal with super clean coal for coking is increased by 2.2%, the reactivity is reduced by 1.4%, and the strength of the coke is improved.

[0073] Comparing Comparative Example 1 with Example 2, after 5% of coking coal was replaced with super clean coal, the ash content of the blended coal decreased by 0.46%, the sulfur content decreased by 0.07%, the volatile matter increased by 0.82%, the bonding index increased by 1.2, and the gelatin layer index Y increased by 1.15 mm. Therefore, it can be seen from the various indicators of the blended coal that after 5% of coking coal was replaced with super clean coal, the various indicators of the blended coal were improved. At the same time, the reactivity of the coke obtained by replacing part of the coking coal with super clean coal for coking was reduced by 2.4%, the strength after reaction was increased by 2.9%, and the quality of the coke was improved.

[0074] Comparing Comparative Example 2 with Example 3, since the ash and sulfur content of ultra-cleaned coal are lower, after replacing 10% fat coal with ultra-cleaned coal, the ash content of the blended coal is reduced by 0.57%, the sulfur content is reduced by 0.053%, and the gelatinous layer index is increased by 0.86mm, and the bonding index is increased by 3.35, and the quality of the blended coal is improved. The ash content of the coke is reduced by 0.73%, the sulfur content is reduced by 0.04%, and the CSR of the coke is increased by 5.4%.

[0075] For those skilled in the art, other different forms of changes or modifications can be made based on the above description, and it is not necessary and impossible to list all implementation methods here. However, the obvious changes or modifications derived from this are still within the protection scope of the invention.

Claims

1. A coking method using ultra-clean coal to replace part of fat coking coal, the method comprising the following steps: S1: Preparation of blended coal: Taking the total weight of the blended coal as 100%, the following blending ratios by mass percentage are used to prepare the blended coal for coking: gas coal 15% to 35%, 1 / 3 coking coal 8% to 20%, fat coal 2% to 20%, coking coal 5% to 15%, lean coal 15% to 20%, lean coal 15% to 20%, and super clean coal 5% to 15%; and S2: Ramming coking: After the blended coal is mixed and evenly blended, it is crushed and rammed, and coking is performed in a ramming coke oven, and dry quenching is performed to obtain dry quenched coke. Wherein, the ash content of the super clean coal is d <0.5%、sulfur content S t <0.35%、Adhesion index G>95、V daf In the range of 50% to 60%, the particle size is 1mm to 3mm, and The blended coal meets the following quality indicators: V daf At 26% to 31%, ash content A d <9.8%, sulfur content S t ≤0.80%, bonding index G≥60, gelatin layer index Y≥13mm.

2. The method according to claim 1, wherein: In S1, taking the total weight of the blended coal as 100%, the blended coal for coking is prepared by using the following blending ratios in terms of mass percentage: Gas coal 32%, 1 / 3 coking coal 8%, fat coal 5%, coking coal 10%, lean coal 20%, lean coal 20%, super clean coal 5%; or Gas coal 32%, 1 / 3 coking coal 8%, fat coal 10%, coking coal 5%, lean coal 20%, lean coal 20%, super clean coal 5%; or Gas coal 28%, 1 / 3 coking coal 16%, fat coal 2%, coking coal 12%, lean coal 15%, lean coal 17%, and super clean coal 10%.

3. The method according to claim 1, wherein: The gas coal meets the following index requirements: ash content 8.5% to 11.0%, volatile matter 35% to 40%, sulfur content 0.50% to 0.60%, G value ≥ 65, Y value ≥ 11, CSR of 40kg small coke oven coking coke of single coal is 35% to 40%, active-inert ratio is 0.95 to 1.4, and MCI value is < 6; The 1 / 3 coking coal meets the following index requirements: ash content 8.0% to 11.0%, volatile matter 30% to 38%, sulfur content 0.3% to 1.5%, G value ≥ 80, Y value ≥ 18, CSR of 40kg small coke oven coking coke of single coal is 40% to 55%, active-inert ratio is 0.9 to 1.5, and MCI value is <5; The fat coal meets the following index requirements: ash content 7.0% to 12.0%, volatile matter 27% to 38%, sulfur content 0.4% to 4.0%, G value ≥ 90, Y value ≥ 25, CSR of 40kg small coke oven coking coke of single coal is 35% to 70%, active-inert ratio is 1 to 4, and MCI value is < 6; The coking coal meets the following index requirements: ash content 10.0% to 11.0%, volatile matter 20% to 28%, sulfur content 0.4% to 0.8%, G value ≥ 75, Y value ≥ 19, CSR of 40kg small coke oven coking coke of single coal is 50% to 70%, active-inert ratio is 2.5 to 4, and MCI value is < 6; The lean coal meets the following index requirements: ash content 10% to 11%, volatile matter 16% to 20%, sulfur content 0.6% to 0.8%, G value ≥ 50, Y value ≥ 8, CSR of 40kg small coke oven coking coke of single coal is 40% to 60%, active-inert ratio is 0.8 to 1.0, and MCI value is less than 6; and The lean coal meets the following index requirements: ash content 9.5% to 11%, volatile matter 10% to 15%, sulfur content 0.3% to 1.2%, G value <15, Y value ≥0, active-inert ratio 0.4 to 1, and MCI value <6.

4. The method according to claim 1, wherein: In S2, the particle size of the crushed blended coal is less than 3 mm, accounting for 85% to 90%.

5. The method according to claim 1, wherein: In S2, the bulk density of the briquettes fed into the rammed coke oven is controlled at 1.0-1.1 t / m 3 .

6. The method according to claim 1, wherein: In S2, the standard coking temperature is controlled within the range of 1250°C to 1350°C, and the coking time is 20 to 30 hours.

7. A blended coal for producing coke, wherein the weight percentages of various coking coals are as follows based on 100 weight percent of the blended coal: Gas coal 15%~35%, 1 / 3 coking coal 8%~20%, fat coal 2%~20%, coking coal 5%~15%, lean coal 15%~20%, poor lean coal 15%~20%, super clean coal 5%~15%.

8. The blended coal for coke production according to claim 7, wherein: Based on 100% by weight of the blended coal, the weight percentages of various coking coals are as follows: Gas coal 32%, 1 / 3 coking coal 8%, fat coal 5%, coking coal 10%, lean coal 20%, lean coal 20%, super clean coal 5%; or Gas coal 32%, 1 / 3 coking coal 8%, fat coal 10%, coking coal 5%, lean coal 20%, lean coal 20%, super clean coal 5%; or Gas coal 28%, 1 / 3 coking coal 16%, fat coal 2%, coking coal 12%, lean coal 15%, lean coal 17%, and super clean coal 10%.

9. A coke produced by the method according to any one of claims 1 to 6, wherein the coke meets the following quality indicators: A d (%)≤13.0,S td (%)≤0.7, CSR(%)≥60.

Images