CN112036628B - Method for establishing model for representing coal blending cost variation - Google Patents

Abstract

The invention discloses a method for establishing a model for representing coal blending cost variation. The method comprises the following steps: 1) selecting a coal blending scheme with stable coke quality as a reference coal blending scheme, and adjusting the coal blending scheme on the basis; 2) selecting a quality control index of the blended coal, and controlling the adjusted quality index of the blended coal within a certain range to stabilize the quality of coke; 3) calculating the change of the coal cost after the coal blending scheme is adjusted; 4) calculating the change of the yield generated by the increase of the coke yield; 5) the yield change due to the change of the gas yield; 6) and calculating the comprehensive variation of the coal blending cost after the coal blending scheme is adjusted. By utilizing the calculation model of the comprehensive variation of the coal blending cost, which is established by the invention, a coal blending scheme can be reasonably formulated, the coal blending structure is optimized, the coal blending cost is reduced, the coke yield is improved, the purchased quantity of outsourcing coke is reduced, and the cost reduction and the efficiency improvement are maximized.

Description

Method for establishing model for representing coal blending cost variation

Technical Field

The invention belongs to the technical field of coking and coal blending, and particularly relates to a method for establishing a model for representing coal blending cost variation.

Background

Reducing the raw material cost of enterprises is an important way for reducing cost, improving efficiency and promoting survival development of iron and steel enterprises. In recent years, because of environmental emission index control, the coke ovens in coke plants of large steel enterprises have limited production and reduced capacity, and the produced coke cannot maintain the blast furnace demand, so the steel enterprises have to purchase coke with a soaring price. The purchased coke generally has poor quality stability and high price, and not only has great influence on the raw material cost of enterprises, but also has great influence on the stable yield and smooth operation of blast furnaces.

Therefore, under the condition that the coke yield of iron and steel enterprises cannot be self-sufficient, a high-cost-performance coal blending method needs to be developed urgently, the coal blending cost is low, the coke yield is high, outsourcing coke purchase is less, the discount is reduced, the gas income is reduced, and the comprehensive benefit is high on the premise of stable coke quality.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for establishing a model for representing the change of coal blending cost, which can reduce the purchase of outsourcing coke and achieve the maximization of cost reduction and effect by reasonably blending coal, integrating the coke quality, the coke yield, the coal blending cost and the coal gas generation amount under the condition of insufficient coke productivity.

In order to solve the technical problems, the invention designs the following technical scheme:

1) selecting a coal blending scheme with stable coke quality as a reference coal blending scheme, and adjusting the coal blending scheme on the basis;

2) selecting a quality control index of the blended coal, and controlling the adjusted quality index of the blended coal within a certain range to stabilize the quality of coke; the quality control indexes of the blended coal include ash content, sulfur content, volatile matter, G value, Y value, coking coarse grain inlaying, fiber structure, sheet structure, isotropic structure and key coal fluidity. The ash content is less than 9.6%, the sulfur content is less than 0.9%, the volatile content is less than 28%, G: 79-82, Y: 15-17 mm, the embedding of coking coarse particles is more than 35%, the fiber structure + sheet structure + isotropic structure is less than 10%, and the flow logarithmic value of key coal species is weighted and summed: 1.3-1.8, wherein the key coal types are gas fat coal, fat coal and 1/3 coking coal;

3) after the coal blending scheme is calculated and adjusted, the change of the coal cost is as follows:

the coal cost after the coal blending scheme is adjusted to be P_{In fact}The coal cost of the reference coal blending scheme is P_{Base of}The coal cost before and after the adjustment is changed to delta P_{Cost of coal}And then:

ΔP_{cost of coal}＝P_{Practice of}-P_{Base of}

4) Calculating the change in yield Δ P resulting from increased coke production_Coke：

Comparing the change conditions of the coke rate and the standard coal blending scheme before and after the coal blending scheme is adjusted, calculating the coke yield increased by one ton of coal, namely the reduced outsourcing coke quantity, combining the dry coal quantity to obtain the coke yield increased by the same dry coal quantity after the adjustment scheme is obtained, and combining the coke price in the market to obtain the saved outsourcing coke cost, namely the revenue change delta P generated by the increase of the coke yield_CokeEconomic cost of outsourcing or yield change Δ P due to increased coke production_CokeSee formula (1).

ΔP_CokeDry coal quantity × [ (V)_{dm rear-dm radical})+(A_{After dm}-A_{dm radical})]/(1-A_{d jiao}-V_{d jiao})×K_{Smelting process}×P_{Coke (coke)} (1)；

Wherein:

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

A_{dm radical}: blending coal dry-based ash in a reference coal blending scheme;

V_{after dm}: blending the dry-based volatile components of the coal after adjusting the coal blending scheme;

A_{after dm}: blending coal dry basis ash content after adjusting the coal blending scheme;

V_{d. coke (coke)}: coke dry-based volatiles;

A_{d. coke (coke)}: dry basis ash of coke;

K_{smelting process}: the metallurgical coke rate;

P_{coke (coke)}: the price of the purchased coke.

5) Yield change Δ P due to gas yield change_mq：

The gas yield can be correspondingly increased or decreased by the increase or decrease of the volatile components of the blended coal; let Delta K_mqDelta P as a change in coal gas yield per ton_mqThe revenue generated for the change in gas yield changes and order:

ΔK_mq＝Kmq((V_{after dm}-V_{dm radical}) (2)；

ΔP_mq＝P_mq×ΔK_mqX amount of dry coal (3);

in the above formulas (2) and (3):

kmq: gas yield coefficient;

V_{after dm}: blending the dry-based volatile components of the coal after adjusting the coal blending scheme;

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

P_mq: the price of the gas;

6) after the coal blending scheme is calculated and adjusted, the comprehensive variation P of the coal blending cost_{Synthesis of}：

P_{Synthesis of}＝ΔP_{Cost of coal}+ΔP_{Coke +}ΔP_mq (4)。

When the coke capacity is insufficient and outsourced coke needs to be purchased, the coal blending scheme can be reasonably formulated by utilizing the calculation model of the comprehensive variation of the coal blending cost established by the invention, the coal blending structure is optimized, the coal blending cost is reduced, the coke yield is improved, the outsourced coke purchase amount is reduced, and the cost reduction and the efficiency improvement are maximized.

Detailed Description

The method for establishing the model for representing the change of the coal blending cost comprises the following steps:

1) selecting a coal blending scheme with stable coke quality as a reference coal blending scheme, and adjusting the coal blending scheme on the basis;

2) selecting a quality control index of the blended coal, and controlling the adjusted quality index of the blended coal within a certain range to stabilize the quality of coke; the quality control indexes of the blended coal comprise ash content, sulfur content, volatile matter, G value, Y value, coking coarse grain inlaying, fiber structure, sheet structure, isotropic structure and key coal fluidity; the ash content is less than 9.6%, the sulfur content is less than 0.9%, the volatile content is less than 28%, G: 79-82, Y: 15-17, the embedding of the coke-forming coarse particles is more than 35%, the combination of the fiber structure, the sheet structure and the isotropic structure is less than 10%, and the flow logarithmic value of the key coal is weighted and summed: 1.3-1.8, wherein the key coal types are gas fat coal, fat coal and 1/3 coking coal;

3) after the coal blending scheme is calculated and adjusted, the change of the coal cost is as follows:

the coal cost after the coal blending scheme is adjusted to be P_{In fact}The coal cost of the benchmark coal blending scheme is P_{Base of}The coal cost before and after the adjustment is changed to delta P_{Cost of coal}And then:

ΔP_{cost of coal}＝P_{Practice of}-P_{Base (C)}；

4) Calculating the change in yield Δ P resulting from increased coke production_Coke：

Comparing the change conditions of the coke rate and the standard coal blending scheme before and after the coal blending scheme is adjusted, calculating the coke yield increased by one ton of coal, namely the reduced outsourcing coke quantity, combining the dry coal quantity to obtain the coke yield increased by the same dry coal quantity after the adjustment scheme is obtained, and combining the coke price in the market to obtain the saved outsourcing coke cost, namely the revenue change delta P generated by the increase of the coke yield_CokeEconomic cost of outsourcing or yield change Δ P due to increased coke production_CokeSee formula (1).

ΔP_CokeDry coal quantity × [ (V)_{After dm}-V_{dm radical})+(A_{After dm}-A_{dm radical})]/(1-A_{d jiao}-V_{d jiao})×K_{Smelting process}×P_{Coke (coke)}(1)；

Wherein:

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

A_{dm radical}: blending coal dry-based ash in a reference coal blending scheme;

V_{after dm}: blending the dry-based volatile components of the coal after adjusting the coal blending scheme;

A_{after dm}: blending coal dry basis ash content after adjusting the coal blending scheme;

V_{d jiao}: coke dry-based volatiles;

A_{d jiao}: dry basis ash of coke;

K_{smelting process}: the metallurgical coke rate;

P_coke: the price of the purchased coke;

5) change in yield Δ P resulting from change in gas yield_mq：

The gas yield can be correspondingly increased or reduced by the increase or decrease of the volatile components of the blended coal; let Delta K_mqDelta P as a change in coal gas yield per ton_mqThe revenue generated for the change in gas yield changes and order:

ΔK_mq＝Kmq((V_{after dm}-V_{dm radical}) (2)；

ΔP_mq＝P_mq×ΔK_mqX amount of dry coal (3);

in the above formulas (2) and (3):

kmq: gas yield coefficient;

V_{after dm}: blending the dry-based volatile components of the coal after adjusting the coal blending scheme;

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

P_mq: the price of the gas;

6) after the coal blending scheme is calculated and adjusted, the comprehensive variation P of the coal blending cost_{Synthesis of}：

P_{Synthesis of}＝ΔP_{Cost of coal}+ΔP_Coke+ΔP_mq(4)。

Example (b):

according to the current coal blending scheme, the coke of a coking plant consumes 500 million tons of dry coal annually and lacks 2-5 million tons of coke annually, the coal blending scheme needs to be adjusted, and the coke yield is increasedCan simultaneously control the coal blending cost and require the coke quality CSR>67％，M₄₀>86％，M₁₀＜6.2％。

The coal types used in the coke-oven plant: the method comprises the following steps of gas-fat coal, 1/3 coking coal 1#, 1/3 coking coal 2#, fat coal, coking coal 1#, coking coal 2#, and lean coal.

TABLE 1 Single coal quality

Coal sample	Vdaf/％	Ad/％	S/％	G	Y/mm	lgMF
							Gas fat coal	40.23	7.41	1.61	98	26	4.7
1/3 coking coal 1#	31.45	9.93	0.52	88	17	3.3
							1/3 coking coal 2#	35.26	7.52	0.61	87	17	3.1
Fat coal 1#	30.65	9.12	1.46	95	26	4.1
							Fat coal 2#	34.68	7.81	0.45	98	27	4.3
1# coking coal	24.56	9.72	0.45	84	17	2.5
							Coke coal 2#	23.56	9.51	1.51	81	16	2
Lean coal	16.55	9.81	0.42	25	4	1.2

TABLE 2 char-forming microstructure of single coal

Coal sample	Coarse grain/%)	Grains/%)	Fiber/%)	Tablet/%	Inertia/%)	Isotropy/%)
							Gas fat coal	0	70	0	0	25	5
1/3 coking coal 1#	40	32	0	0	28	0
							1/3 coking coal 2#	8	65	0	0	27	0
Fat coal 1#	40	38	0	0	22	0
							Fat coal 2#	15	62	0	0	23	0
1# coking coal	62	8	0	2	28	0
							Coke coal 2#	50	2	7	2	29	0
Lean coal	10	0	30	20	40	0

TABLE 3 base blending protocol wt/%)

1) Coke quality stability control

Matching coal quality control indexes: ash content, sulfur content, volatile matter, G value, Y value, coke-forming coarse grain mosaic, fiber structure, sheet structure, isotropic structure and key coal fluidity.

The quality requirement of the blended coal is as follows: ad/% < 9.6%, sulfur < 0.9%, volatile < 28%, G: 79-82, Y: 15-17; coarse char formation control > 35%, fiber structure + flake structure + isotropic structure < 10%, 1/3 weighted fluidity of coking coal + fat coal + gas fat coal: 1.3 to 1.8.

TABLE 4 coal blending protocol wt/%)

TABLE 5 coal blending quality

2) Coal cost variation of coal blending

TABLE 6 cost per ton of individual coal

Gas fat coal	1/3 coking coal 1	1/3 coking coal 2	Fat coal 1	Fat coal 2	Coking coal 1	Coking coal 2	Lean coal
								1200	1250	1190	1100	1300	1400	1200	1000

From tables 4 and 6, the change in coal cost after adjusting the blending schedule is calculated, see table 7.

TABLE 7 coal cost Change after adjusting coal blending schedule

3) Calculating the change in yield Δ P resulting from increased coke production_Coke：

TABLE 8 Coke yield Change and Effect

Note: the metallurgical coke rate K in the table is 85 percent; the price of the purchased coke is 2000 yuan/ton;

4) yield change Δ P due to gas yield change_mq

TABLE 9 coal gas generation amount variation

Note: the gas change rate K in the table is 6.25; gas price of 1000 yuan/km³；

6) After the coal blending scheme is calculated and adjusted, the comprehensive variation P of the coal blending cost_{Synthesis of}：

TABLE 10 comprehensive Performance analysis

Therefore, according to the above comprehensive success analysis, it is known that although the coal blending cost is reduced in the scheme 1, the coke yield is hardly increased, while the coke yield is increased in the scheme 2, the coal blending cost is obviously increased, and the comprehensive success is low, not only is the coal blending cost low in the scheme 3, but also the coke yield is high, and the comprehensive coal blending cost performance is highest, and although the coal blending cost is increased in the scheme four, the coke yield increase success is higher, and the priority is given to the coke yield increase. Therefore, the cost performance ranking of the four schemes is as follows:

scheme 3> scheme 4> scheme 1> scheme 2.

After the coal blending scheme of the plant is adjusted and implemented, the volatile component of the blended coal is reduced, the coke yield is improved, the coal blending cost is controlled, the volatile component of the blended coal is reduced from 27.23 percent to 26.53 percent, the coke yield is increased by nearly 3 ten thousand tons every year, the gas amount is deducted, and the annual comprehensive effect reaches more than 7500 ten thousand yuan.

Claims (1)

1. A method for establishing a model for representing coal blending cost variation is characterized by comprising the following steps: the method comprises the following steps:

1) selecting a coal blending scheme with stable coke quality as a reference coal blending scheme, and adjusting the coal blending scheme on the basis;

2) selecting a quality control index of the blended coal, and controlling the adjusted quality index of the blended coal within a certain range to stabilize the quality of coke; the quality control indexes of the blended coal include ash content, sulfur content, volatile matter, G value, Y value, coking coarse grain inlaying, fiber structure, sheet structure, isotropic structure and key coal fluidity; the ash content is less than 9.6%, the sulfur content is less than 0.9%, the volatile content is less than 28%, G: 79-82, Y: 15-17, the coking coarse grain mosaic is more than 35%, the fiber structure + sheet structure + isotropic structure is less than 10%, the fluidity logarithmic value of key coal species is weighted and summed: 1.3-1.8, wherein the key coal types are gas fat coal, fat coal and 1/3 coking coal;

3) after the coal blending scheme is calculated and adjusted, the change of the coal cost is as follows:

the coal cost after the coal blending scheme is adjusted to be P_{In fact}The coal cost of the reference coal blending scheme is P_{Base (C)}The coal cost before and after the adjustment is changed to delta P_{Cost of coal}And then:

ΔP_{cost of coal}＝P_{Practice of}-P_{Base of}；

4) Calculating the change in yield Δ P resulting from increased coke production_Coke：

Comparing the change conditions of the coke rate and the standard coal blending scheme before and after the coal blending scheme is adjusted, calculating the coke yield increased by one ton of coal, namely the reduced outsourcing coke quantity, combining the dry coal quantity to obtain the coke yield increased by the same dry coal quantity after the adjustment scheme is obtained, and combining the coke price in the market to obtain the saved outsourcing coke cost, namely the revenue change delta P generated by the increase of the coke yield_CokeEconomic cost of outsourcing or yield change Δ P due to increased coke production_CokeSee formula (1):

ΔP_cokeDry coal quantity x [ (V)_{After dm}-V_{dm radical})+(A_{After dm}-A_{dm radical})]/(1-A_{d jiao}-V_{d jiao})×K_{Smelting process}×P_{Coke (coke)} (1)；

Wherein:

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

A_{dm radical}: blending coal dry-based ash in a reference coal blending scheme;

V_{after dm}: blending the dry-based volatile components of the coal after adjusting the coal blending scheme;

A_{after dm}: blending coal dry basis ash content after adjusting the coal blending scheme;

V_{d jiao}: coke dry-based volatiles;

A_{d jiao}: dry basis ash of coke;

K_{smelting process}: the metallurgical coke rate;

P_{coke (coke)}: the price of the purchased coke;

5) gas productionRate change resulting in a change in yield Δ P_mq：

The gas yield can be correspondingly increased or reduced by the increase or decrease of the volatile components of the blended coal; let Delta K_mqDelta P as a change in coal gas yield per ton_mqThe revenue generated for the change in gas yield changes and order:

ΔK_mq＝Kmq((V_{after dm}-V_{dm radical}) (2)；

ΔP_mq＝P_mq×ΔK_mqX amount of dry coal (3);

in the above formulas (2) and (3):

kmq: gas yield coefficient;

V_{after dm}: adjusting the coal blending scheme and then blending the coal dry-based volatile components;

V_{dm radical}: blending coal dry-based volatile components in the reference coal blending scheme;

P_mq: the price of the gas;

6) after the coal blending scheme is calculated and adjusted, the comprehensive variation P of the coal blending cost_{Synthesis of}：

P_{Synthesis of}＝ΔP_{Cost of coal}+ΔP_Coke+ΔP_mq (4)。