Method for evaluating quality cost of sintered solid fuel

Abstract

The invention relates to a sintered solid fuel quality cost evaluation method, which is characterized in that a granularity (LD-0.5) index is taken into evaluation, fuel coal is evaluated by combining actual production and taking an average value of high and low heating values (Qgrd and Qnet), the situation that only the high heating value or only the low heating value is considered in a one-sided manner is avoided, and main indexes such as Ad, Vdaf, Std, Qgrd, Qnet, N, LD + 4 and LD-0.5 of the fuel coal are covered; the method avoids the problem that the existing technical scheme does not consider the influence of heat value, granularity and other indexes, but also avoids repeated evaluation. Compared with the prior art, the evaluation indexes are comprehensive, mutual evaluation can be carried out on different types of fuel coal (sintered coal and coke powder), the defect that mutual evaluation cannot be carried out among cross-material types in an existing scheme is overcome, a scientific and reasonable method for evaluating the quality difference cost is provided, and fuel coal purchasing can be effectively guided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal smelting, more particularly, it relates to a sintered solid fuel quality cost evaluation method. BACKGROUND

[0002] The sintering process is an indispensable process in the long process of blast furnace steelmaking enterprises, and the domestic sintering process is generally a belt type induced draft sintering process. After the ore powder is mixed, a certain amount of flux and solid fuel is added, and the sintered ore is sintered into a block shape, and then the particle size is adjusted (broken and sieved) into finished sintered ore, which is used as the main iron ore raw material (clinker) for blast furnace. The solid fuel used for sintering generally includes sintering anthracite (referred to as sintering coal) and coke powder, which provides heat source for the sintering process.

[0003] The properties and quality of solid fuel are different, and the effects in the sintering process are also different, which will directly affect the quality and cost of sintered ore. The main indicators of solid fuel include ash content, volatile matter, sulfur, fixed carbon, moisture content, nitrogen, calorific value, and particle size indicators such as LD-0.5 (proportion of particle size less than 0.5 mm), LD+4 (proportion of particle size greater than 4 mm). Generally speaking, sintering coal is required to reach a certain particle size ratio, such as LD-0.5 and LD+4 ratio, the lower the better; in addition, the change trend of other indicators has different effects on production, for example, the higher the fixed carbon and calorific value, the better, the lower the ash content, volatile matter and sulfur, and the moisture content needs to be moderate, too low moisture content is easy to cause dust, and too high moisture content is not conducive to production.

[0004] The most important role of solid fuel is to provide heat, so intuitively, the calorific value should be the most important quality indicator, but other indicators such as ash content, volatile matter, sulfur, nitrogen, and particle size will also affect the effective heat of the fuel in the sintering process. Therefore, under the condition of induced draft sintering, how to evaluate the quality difference and the cost of the quality difference of different types and qualities of fuel materials is worth discussing. However, in the existing scheme, the evaluation of solid fuel is simple and rough, such as directly evaluating several main indicators such as fixed carbon or calorific value, ignoring the influence of other indicators; or complicated, based on fixed carbon, calorific value and other indicators, the influence of ash content and moisture content is superimposed, which may cause repeated evaluation. In addition, if it involves cross-material types such as sintering coal and coke powder, the existing evaluation scheme will be distorted. It can be seen that the existing technology is not conducive to objectively reflecting the actual quality difference and the cost of the quality difference of the material, and cannot effectively guide the procurement of fuel materials. SUMMARY

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for evaluating the quality cost of sintered solid fuel, which covers the main indicators of fuel coal such as Ad, Vdaf, Std, Qgrd, Qnet, N, LD+4, and LD-0.5; avoids the influence of the existing technical solutions that do not consider indicators such as calorific value and particle size, but also avoids repeated evaluation.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: A method for evaluating the quality cost of sintered solid fuel is as follows: Assume that the base material is A and the comparison material is B. The normal solid-fuel ratio of sintering is K=52 kg / t. The cost of A is P A Yuan / ton; Calculate the impact of the indicators that directly affect the solid fuel ratio on the final solid fuel ratio ∆K: The indicators that directly affect the solid fuel ratio include ash content, volatile matter, calorific value and LD-0.5; According to the ash content of material B Ad Compare the ash content of material A Ad Difference, impact on solid fuel ratio K Ad :K Ad =(B Ad -A Ad ) × K 2 / 1000; The difference in solid fuel ratio K between the two materials due to the difference in Vdaf Vdaf : K Vdaf =(B Vdaf -A Vdaf )×K / (1-B Vdaf ); The influence of the difference in high calorific value of two materials on the solid fuel ratio K Qgrd : K Qgrd =K×A Qgrd / B Qgrd -K=K×(A Qgrd / B Qgrd -1); The influence of the difference in low calorific value of two materials on the solid fuel ratio K Qnet : K Qnet =K Qnet =K×A Qnet / B Qnet -K=K×(A Qnet / B Qnet -1); The influence of comprehensive calorific value on solid fuel ratio K Q : K Q=[(K×A Qgrd / B Qgrd -K) + (K × A Qnet / B Qnet -K)] / 2 =[K×(A Qgrd / B Qgrd -1)+K×(A Qnet / B Qnet -1)] / 2; Effect of LD-0.5 difference between two materials on solid fuel ratio K LD-0.5 : K LD-0.5 =(B LD-0.5 -A LD-0.5 ) / 10%×0.55; Directly affecting the impact of the solid fuel ratio index on the final solid fuel ratio ∆K: ∆K=K Ad +K Vdaf +K Q +K LD-0.5 ; Calculate the material cost ∆P based on the solid-fuel ratio difference ∆K: ∆P=∆K×P A / 1000 / (K / 1000)=∆K×P A / K; The quality difference cost ∆T caused by material quality difference: ∆T=∆P; The price of base material A is P A , the price of material B is P B , the quality difference cost ∆T caused by the quality difference between material B and material A is ∆P, so the actual value of material B is P B :P B =P A +∆T; Establish an electronic model to measure the quality cost difference of one material relative to another, so as to automatically calculate the quality difference cost caused by the quality difference of one material relative to another, as well as the expected value cost of the material relative to another material.

[0007] In one embodiment, the effect of an indicator influencing processing cost on the final solid-fuel ratio ∆M is calculated: Indicators that affect processing costs include sulfur content; A deduction of RMB 4 / ton will be added to the material price for every 0.1% of Std; M Std =(B Std -A Std ) / 0.1%×4; Impact on the final solid fuel ratio ∆M: ∆M=MStd ; The quality difference cost AT caused by the material quality difference: AT = AP + AM.

[0008] In one of the embodiments, the index affecting the processing cost further includes nitrogen content; The plus and minus is calculated according to the value of 4 yuan / ton per 0.1% of N content; M N = (B N -A N ) / 0.1% * 4; The influence on the final solid fuel ratio AM: AM = M Std + M N ; The quality difference cost AT caused by the material quality difference: AT = AP + AM.

[0009] In one of the embodiments, the index affecting the processing cost further includes LD+4; The plus and minus is calculated according to the value of 1 yuan / ton per 1% of LD+4 content; ML D+4 = (B LD+4 -A LD+4 ) / 1% * 1; The influence on the final solid fuel ratio AM: AM = M Std + M N + M LD+4 ; The quality difference cost AT caused by the material quality difference: AT = AP + AM.

[0010] In summary, the present application has the following beneficial effects: The present application includes the granularity (LD-0.5) index in the evaluation, combines the actual production, takes the average value of the high and low calorific values (Qgrd, Qnet) to evaluate the fuel coal, avoids the situation of only considering the high calorific value or only considering the low calorific value, covers the main indexes of the fuel coal such as Ad, Vdaf, Std, Qgrd, Qnet, N, LD+4, LD-0.5, avoids the influence of the indexes such as the calorific value and granularity not considered in the prior art scheme, but also avoids the repeated evaluation.

[0011] The indexes included in the evaluation of the present application are relatively comprehensive, can evaluate the different types of fuel coal (sintering coal and coke powder), avoids the defect that the prior art scheme cannot evaluate the different types of fuel coal, gives a more scientific and reasonable method for evaluating the quality difference cost, and can effectively guide the fuel coal procurement. DETAILED DESCRIPTION

[0012] The present application will be described in detail below with reference to the embodiments.

[0013] The present application proposes a sinter solid fuel quality cost evaluation method, which is comprehensive of various quality indicators to evaluate the quality difference and quality difference cost of solid fuel, but avoids duplication, such as fixed carbon and calorific value. Generally speaking, the higher the fixed carbon, the higher the calorific value. If the calorific value is used as an evaluation index, the fixed carbon cannot be used as an evaluation index. The present application selects a fuel material A as a reference, and evaluates another material B relative to the reference material A. The specific schemes of the present application are described below.

[0014] Ash content (Ad): Generally speaking, the higher the Ad, the lower the calorific value. If the calorific value is included in the evaluation index, it is not appropriate to consider Ad from the aspect of calorific value; but the higher the Ad, the additional SiO2 and Al2O3 of sinter, which temporarily does not affect the quality of sinter, will also consume additional heat, thereby reducing the effective heat of the fuel. The present application evaluates from the aspect of reducing the effective heat of the fuel.

[0015] Volatile matter (Vdaf): It is generally believed that in the process of downdraft sintering, combustion is carried out from top to bottom. The volatile matter of solid fuel is volatilized by heating, and is not combusted, but is removed by downdraft, so it does not provide effective heat; in addition, volatile matter is easily recondensed in the lower sinter layer of the wet layer during the process of being removed by downdraft, which destroys the air permeability of the sinter layer; in addition, volatile matter condenses on the electric dust removal equipment, which easily damages the dust removal effect and the equipment itself. Therefore, the present application requires that the lower the Vdaf of solid fuel, the better.

[0016] Sulfur (Std): Organic sulfur in solid fuel can provide heat in the sintering process, but considering environmental protection, SO2 generated in the flue gas cannot be directly discharged into the atmosphere, and needs to be removed by desulfurization, which requires cost. Therefore, the present application requires that the lower the Std content in solid fuel, the better.

[0017] Fixed carbon (Fcad): Generally speaking, after removing Ad, Vdaf, Std and other substances, the remaining component is fixed carbon. The calorific value of fuel is mainly derived from fixed carbon, therefore, the higher the fixed carbon in fuel, the better. The present application considers that if the calorific value has been used as an evaluation index, it is not appropriate to use fixed carbon as an evaluation index, otherwise it will cause repeated evaluation.

[0018] Nitrogen (N): The higher the N content in fuel, the higher the content of nitrogen oxides in flue gas after combustion, which cannot be directly discharged into the atmosphere and needs to be removed by denitrification, which requires cost. Therefore, the present application requires that the lower the N content in fuel, the better.

[0019] Moisture (Mt): The solid fuel must have a moderate Mt content. A low Mt content can easily cause dust generation, while a high Mt content can reduce the effective heat (lower calorific value) and cause blockage during production. While ensuring dust generation, this invention requires the Mt content to be as low as possible.

[0020] Higher Specific Calorific Value (Qgrd): Qgrd reflects the higher specific calorific value of the fuel, including the heat released by condensing water vapor. For solid fuels, the higher the Qgrd, the better. However, generally speaking, during the actual sintering process, water vapor is exhausted with the flue gases and does not condense in the sintering material to release heat and provide heat.

[0021] Lower Calorific Value (Qnet): Qnet reflects the lower calorific value of the fuel, excluding the heat released by condensation of water vapor. For solid fuels, the higher the Qnet, the better. Qnet is affected by the moisture content (Mt) of the material; the higher the Mt, the lower the Qnet.

[0022] >4mm particle size (LD+4): Coarse fuel particles (higher LD+4 ratios) are more likely to cause segregation during sintering and distribution, negatively impacting sinter quality and fuel consumption. Therefore, this invention requires the LD+4 to be as low as possible. If the LD+4 ratio is too high, re-crushing is required before sintering, increasing processing costs.

[0023] <0.5mm particle size (LD-0.5): Fuel particles are too fine (the higher the LD-0.5 ratio), making them easily lost during the loading process by dust extraction and extraction, as well as during the sintering process, thereby increasing solid fuel consumption. Furthermore, the fine particles burn too quickly during sintering, which is detrimental to sinter quality and reduces fuel consumption. Therefore, this invention requires that the lower the LD-0.5 ratio, the better.

[0024] Let the base material be A and the comparison material be B. The normal solid-fuel ratio of sintering is K=52 kg / t. The cost of A is P A Yuan / ton.

[0025] The indicators Ad, Vdaf, Qgrd, Qnet, and LD-0.5 that directly affect the solid fuel ratio have the following effects on solid fuel: According to the ash content of material B (B Ad ) compared with the ash content of material A (A Ad ) difference (B Ad -A Ad ), the impact on the solid fuel ratio K Ad :K Ad =(B Ad -A Ad ) × K 2 / 1000.

[0026] The difference in solid fuel ratio K between the two materials due to the difference in VdafVdaf : K Vdaf =(B Vdaf -A Vdaf )×K / (1-B Vdaf )。

[0027] The heat value is divided into high heat value (Qgrd) and low heat value (Qnet). The average value of the high and low heat value fixed combustion ratio is taken as the average value of the comprehensive heat value K Q .

[0028] The difference between the high heat values of the two materials affects the fixed combustion ratio K Qgrd : K Qgrd =K×A Qgrd / B Qgrd -K=K×(A Qgrd / B Qgrd -1)。

[0029] The difference between the low heat values of the two materials affects the fixed combustion ratio K Qnet : K Qnet =K Qnet =K×A Qnet / B Qnet -K=K×(A Qnet / B Qnet -1)。

[0030] The comprehensive heat value affects the fixed combustion ratio K Q : K Q =[(K×A Qgrd / B Qgrd -K)+(K×A Qnet / B Qnet -K)] / 2 =[K×(A Qgrd / B Qgrd -1)+K×(A Qnet / B Qnet -1)] / 2。

[0031] According to the test data, LD-0.5 changes by 10%, and the fixed combustion ratio is affected by 0.55 kg / t. The difference between the LD-0.5 of the two materials affects the fixed combustion ratio K LD-0.5 : K LD-0.5 =(B LD-0.5 -A LD-0.5 ) / 10%×0.55。

[0032] In summary, the four indicators directly affecting the fixed combustion ratio affect the final fixed combustion ratio ∆K: ∆K=KAd +K Vdaf +K Q +K LD-0.5 =(B Ad -A Ad )×K 2 / 1000+(B Vdaf -A Vdaf )×K / (1-B Vdaf )+[K×(A Qgrd / B Qgrd -1)+K×(A Qnet / B Qnet -1)] / 2+(B LD-0.5 -A LD-0.5 ) / 10%×0.55。

[0033] Solid fuel ratio difference ΔK corresponds to the cost (value) of the material ΔP: ΔP=ΔK×P A / 1000 / (K / 1000)=ΔK×P A / K.

[0034] Further, the indicators Std, N, LD+4 affect the processing cost M. These indicators do not directly affect the sintering process and the solid fuel ratio, but affect the links outside the sintering process, causing the processing cost to change.

[0035] The higher the Std, the higher the desulfurization cost M Std . According to the value of 4 yuan / ton per 0.1% of Std, add or deduct the material price (value).

[0036] M Std =(B Std -A Std ) / 0.1%×4.

[0037] The higher the N, the higher the desulfurization cost M N . According to the value of 4 yuan / ton per 0.1% of N content, add or deduct.

[0038] M N =(B N -A N ) / 0.1%×4.

[0039] The higher the LD+4 ratio, the higher the crushing processing cost M LD+4 . According to the value of 1 yuan / ton per 1% of LD+4 content, add or deduct.

[0040] ML D+4 =(B LD+4 -A LD+4 ) / 1%×1.

[0041] In summary, the three indicators affecting the processing cost, the influence of the final solid fuel ratio is ΔM: ΔM=M Std +M N +M LD+4 =(B Std -A Std ) / 0.1%×4+(B N -A N ) / 0.1%×4+(B LD+4 -A LD+4 ) / 1%×1.

[0042] The indicators not included in the evaluation are fixed carbon (Fcad) and moisture (Mt). Since the low calorific value has been included in the evaluation, the fixed carbon and moisture are not included in the evaluation, so as to avoid repeated evaluation.

[0043] In summary, the quality difference cost ΔT caused by the material quality difference: ΔT=ΔP+ΔM.

[0044] That is, the price (value) of the reference material A is P A , the price (value) of the material B is P B , the quality difference cost ΔT=ΔP+ΔM caused by the quality difference between the material B and the material A, so the actual value P B of the material B is: P B =P A +ΔT=P A +ΔP+ΔM.

[0045] According to the above function to establish an electronic model, the main technical quality and economic indicators of the related materials are input, and the quality cost difference of one material relative to another material is calculated according to the above evaluation rules and related functions, so as to automatically calculate the quality difference cost caused by the quality difference of one material relative to another material, and the should-value cost of one material relative to another material.

[0046] The present application successfully includes the particle size (LD-0.5) index in the evaluation, and obtains the influence data on the solid fuel ratio through experiments, covering the main indexes of fuel coal such as Ad, Vdaf, Std, Qgrd, Qnet, N, LD+4, LD-0.5; avoiding the influence of the existing technical scheme without considering the calorific value and particle size; but also avoiding repeated evaluation.

[0047] The present application combines the actual production, takes the average value of high and low calorific value (Qgrd, Qnet) to evaluate the fuel coal, and avoids the situation of only considering the high calorific value or only considering the low calorific value.

[0048] Since the indexes included in the application are comprehensive, different types of fuel coal (sintered coal and coke powder) can be evaluated, avoiding the defects that the prior art cannot evaluate each other across material types, and ultimately a more scientific and reasonable method for evaluating the quality difference cost is given. According to the method, the fuel coal procurement can be effectively guided.

[0049] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. A method for evaluating the quality cost of sintered solid fuel, characterized in that: as follows: Assume that the base material is A and the comparison material is B. The normal solid-fuel ratio of sintering is K=52 kg / t. The cost of A is P A Yuan / ton; Calculate the impact of the indicators that directly affect the solid fuel ratio on the final solid fuel ratio ∆K: The indicators that directly affect the solid fuel ratio include ash content, volatile matter, calorific value and LD-0.5; According to the ash content of material B Ad Compare the ash content of material A Ad Difference, impact on solid fuel ratio K Ad :K Ad =(B Ad -A Ad ) × K 2 / 1000; The difference in solid fuel ratio K between the two materials due to the difference in Vdaf Vdaf : K Vdaf =(B Vdaf -A Vdaf )×K / (1-B Vdaf ); The influence of the difference in high calorific value of two materials on the solid fuel ratio K Qgrd : K Qgrd =K×A Qgrd / B Qgrd -K=K×(A Qgrd / B Qgrd -1); The influence of the difference in low calorific value of two materials on the solid fuel ratio K Qnet : K Qnet =K Qnet =K×A Qnet / B Qnet -K=K×(A Qnet / B Qnet -1); The influence of comprehensive calorific value on solid fuel ratio K Q : K Q =[(K×A Qgrd / B Qgrd -K)+(K×A Qnet / B Qnet -K)] / 2 =[K×(A Qgrd / B Qgrd -1)+K×(A Qnet / B Qnet -1)] / 2; Effect of LD-0.5 difference between two materials on solid fuel ratio K LD-0.5 : K LD-0.5 =(B LD-0.5 -A LD-0.5 ) / 10%×0.55; Directly affecting the impact of the solid fuel ratio index on the final solid fuel ratio ∆K: ∆K=K Ad +K Vdaf +K Q +K LD-0.5 ; Calculate the material cost ∆P based on the solid-fuel ratio difference ∆K: ∆P=∆K×P A / 1000 / (K / 1000)=∆K×P A / K; The quality difference cost ∆T caused by material quality difference: ∆T=∆P; The price of base material A is P A , the price of material B is P B , the quality difference cost ∆T=∆P caused by the quality difference between material B and material A, then the actual value of material B is P B :P B =P A +∆T; Establish an electronic model to measure the quality cost difference of one material relative to another, so as to automatically calculate the quality difference cost caused by the quality difference of one material relative to another, as well as the expected value cost of the material relative to another material.

2. The sintered solid fuel quality cost evaluation method according to claim 1, characterized in that: Calculate the impact of the indicators that affect processing costs on the final solid-fuel ratio ∆M: Indicators that affect processing costs include sulfur content; A deduction of RMB 4 / ton will be added to the material price for every 0.1% of Std; M Std =(B Std -A Std ) / 0.1%×4; Impact on the final solid fuel ratio ∆M: ∆M=M Std ; Quality difference cost ∆T caused by material quality difference: ∆T=∆P+∆M.

3. The sintered solid fuel quality cost evaluation method according to claim 2, characterized in that: Indicators that affect processing costs also include nitrogen content; A deduction will be made based on the value of 4 yuan / ton for every 0.1% of N content; M N =(B N -A N ) / 0.1%×4; Impact on the final solid fuel ratio ∆M: ∆M=M Std +M N ; Quality difference cost ∆T caused by material quality difference: ∆T=∆P+∆M.

4. The method for evaluating the quality cost of sintered solid fuel according to claim 3, wherein: Indicators that affect processing costs also include LD+4; A deduction will be made based on the value of 1 yuan / ton for every 1% of LD+4 content; ML D+4 =(B LD+4 -A LD+4 ) / 1%×1; Impact on the final solid fuel ratio ∆M: ∆M=M Std +M N +M LD+4 ; Quality difference cost ∆T caused by material quality difference: ∆T=∆P+∆M.