JP2013001790A - Method of determining carbonization condition of charcoal material fuel for sintering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the carbonization condition of a coal carbonized object enabling the reduction of NOx generated in the manufacturing process of a sintered ore for a blast furnace material.SOLUTION: This method of determining the optimal carbonization condition of the fuel charcoal material for sintering manufactured by carbonization of coal includes the processes (a) to (c). In the process (a), each of m and n is assumed to be a positive integer of 30 or less (except m=n=1) regarding the temperature condition of the carbonization, (a1) m carbonization finish temperatures are selected in the range of 600-1,000°C, (a2) n carbonization temperature increasing rates are selected in the range of 6-30°C/min, and (a3) the coal is carbonized in the condition of m×n combinations of the carbonization finish temperature and carbonization temperature increasing rate, and m×n kinds of coal carbonized objects are produced. In the process (b), the m×n kinds of coal carbonized objects are actually burned and the amount of the generated NOx is measured. In the process (c), the coal carbonized object for which the amount of the generated NOx per unit mass of the coal is smallest is specified from the m×n kinds of coal carbonized objects, and the carbonization condition where the amount of the generated NOx is smallest is determined.

Description

  The present invention realizes the dry distillation conditions of coal dry distillate that can reduce NOx generated in the process of producing sintered ore for blast furnace raw material using coal dry distillate as fuel, using a general dry distillation apparatus. The present invention relates to a method for determining optimum conditions within a possible range.

  Iron ore, the raw material for blast furnace, is mainly made of fine ore as raw material pretreatment, auxiliary materials such as limestone and silica sand, and heat source fuel are mixed in a certain ratio, and water as binder is added and rotated. After granulating into pseudo particles having a particle size of a certain size or more in advance with a drum, etc., laying on the sintering machine, and making it a sintered ore that has been baked and solidified by ignition by a burner and continuous combustion by lower air suction, before the raw material A treatment method is generally performed (hereinafter, this raw material pretreatment method is referred to as “sintered ore production”).

  The most important performance required for sintered ore obtained by the production of sintered ore is not only the increase in particle size by agglomeration, but also the strength that does not cause pulverization during transportation to a blast furnace and when dropped. In order to increase the strength, it is generally known that the production of sintered ore performed at a higher temperature is effective (see Non-Patent Document 1). For this reason, the fuel most frequently used for sinter production is usually a coal distillate with low volatile content and high calorific value.

  On the other hand, the amount of nitrogen oxides (hereinafter referred to as “NOx”) generated along with fuel combustion during the production of sintered ore occupies half of the total amount of NOx generated in the integrated steelworks (see Non-Patent Document 2). NOx emissions are regulated by various laws and regulations, and suppression is required from the viewpoint of reducing environmental impact.

  There are two types of generation origin of NOx during combustion, and NOx generated based on nitrogen in the atmosphere in a higher temperature combustion process exceeding 1500 ° C. (hereinafter referred to as “Thermal NOx”). It is broadly classified into NOx originating from nitrogen in fuel (hereinafter referred to as “Fuel NOx”), which accounts for most of NOx generated during combustion at 1400 ° C. or lower (see Non-Patent Document 3).

  In the sintered ore manufacturing process, which is a problem in the steel industry, solid fuel with a high calorific value is used. However, since most of the generated heat is used for heating the sintering raw material, the overall process is 1200. Even the same combustion process as ˜1400 ° C. is a low-temperature process, and Fuel NOx is attributed to the generation of NOx (see Non-Patent Document 4).

  Combustion improvement is also effective in reducing Fuel NOx generated during the production of sintered ore (see Non-Patent Document 1), but the fuel itself is generally diverted from blast furnace coke. On the other hand, as a fuel for sintering, the strength required for blast furnace coke is not an essential condition, and is required to be combustible, exothermic, and low NOx.

  Therefore, by selecting a coal type different from blast furnace coke and dry distillation conditions, there is a possibility that a fuel suitable for sintering production can be obtained even with cheaper coal. In particular, the fuel carbon material for sintering capable of reducing the amount of generated NOx can achieve a reduction in the amount of generated NOx by reducing the amount of nitrogen contained or reducing the NOx conversion rate. In either case, there has been no method for obtaining the optimum conditions for dry distillation.

  In recent years, a method for producing a fuel carbon material for sintering has been proposed, but optimization of dry distillation conditions is difficult. In the production of special coke containing alkaline earth metal or transition metal, a method for suppressing the generation of NOx during combustion has been proposed by catalytic action (see Patent Document 1). This is a proposal for a production method using a coke oven, but the heat history of dry distillation is not known, and the dry distillation conditions cannot be optimized.

  In addition, a special gas that uses rapid heating and partial oxidation, and a method to reduce the nitrogen content by pyrolyzing nitrogen in the fuel charcoal with a strong heat of 1200 ° C or higher in a charification facility (coal dry distillation facility) (See Patent Document 2). Although this technique is a technique for reducing the concentration of nitrogen contained, it uses a multi-stage pyrolysis furnace and is not suitable for optimizing the thermal history of coal.

  As described above, the fact is that there is no knowledge about a method for optimizing the dry distillation conditions of the fuel carbon material for sintering that suppresses the generation of NOx during combustion.

JP 2004-285098 A JP 2009-298909 A

Book by Tadahiro Inakaku, Series “Steel Technology Flow Series 2”, Volume 1 Sinter (2000) Steel Handbook 4th edition, Japan Iron and Steel Association Supervision by Norio Arai, edited by Takatoshi Miura, Generation of combustion products and suppression technology (1997) Masahiro Hida, Iron and Steel, Volume 68 (1982) p400

  The present invention can realize the dry distillation conditions of coal dry distillation products that enable the reduction of NOx generated during sintering combustion with a general dry distillation apparatus for coal dry distillation fuels used for sinter production. An object is to provide a method for optimizing the range.

  The inventors of the present invention have conducted various studies on a method for producing a low NOx carbon material used for producing sintered ore. As a result, reducing the amount of NOx generated when used for sinter production by selecting coal that is effective for reducing NOx as the coal used for fuel production or by optimizing the coal dry distillation conditions Found that is possible.

  This invention was made | formed based on the said knowledge, and the summary is as the following (1)-(4).

(1) A method for determining optimum carbonization conditions of a fuel carbon material for sintering produced by carbonizing coal,
(A) Regarding the temperature conditions of carbonization, m and n are positive integers of 30 or less (however, m = n = 1 is excluded), and (a1) m is selected as the carbonization end temperature in the range of 600 to 1000 ° C. (A2) n types of dry distillation heating rates are selected in the range of 6-30 ° C./min, and (a3) coal is carbonized under the conditions of a combination of m × n dry distillation end temperatures and dry distillation heating rates. A process of producing m × n types of coal dry distillate,
(B) a step of actually burning the m × n types of coal dry distillate and measuring the amount of NOx generated; and
(C) identifying the coal dry matter having the smallest amount of NOx generated per unit mass of coal from the m × n kinds of coal dry matter, and determining the carbonization conditions with the smallest amount of NOx generated;
A method for determining dry distillation conditions of a fuel carbon material for sintering, comprising:

(2) A method of determining optimum carbonization conditions for a fuel carbon material for sintering produced by carbonizing coal,
(A) About the temperature conditions of dry distillation, m and n are set to positive integers of 2 or more, (a1) m dry distillation end temperatures are selected in a range of 600 to 1000 ° C., and (a2) dry distillation heating rate is 6 to N types are selected in the range of 30 ° C./min, and (a3) m × n types of coal dry distillation products are produced by dry distillation of coal under conditions of a combination of m × n types of dry distillation end temperature and dry distillation heating rate. Process,
(B) A step of performing elemental analysis of the m × n types of coal dry product and measuring a nitrogen concentration of the m × n types of coal dry product,
(C) a step of actually burning the m × n types of coal distillate and measuring the amount of NOx generated;
(D) a step of calculating the NOx conversion rate by dividing the generated NOx amount by the nitrogen content with respect to the m × n types of coal dry distillation products; and
(E) determining the dry distillation conditions having the lowest NOx conversion rate by identifying the lowest dry NOx conversion rate from the NOx conversion rate of the m × n coal dry distillation products,
A method for determining dry distillation conditions of a fuel carbon material for sintering, comprising:

  (3) The method for determining dry distillation conditions of a fuel carbon material for sintering as described in (1) or (2) above, wherein m or n is 1.

  (4) In the step of producing the m × n types of coal dry product, the mass of the coal used for the production of the coal dry product is 0.01 to 1 g, wherein (1) to (3) The carbonization conditions determination method of the fuel carbon material for sintering in any one.

  According to the present invention, it is possible to realize the dry distillation conditions of coal dry distillation products that enable reduction of NOx generated during sintering combustion with a general dry distillation apparatus for coal dry distillation fuels used for sinter production. It can be optimized to the extent possible.

  Below, the procedure of the carbonization conditions determination method of the carbon material fuel for sintering of this invention is demonstrated. In addition, about the dry distillation method and conditions of coal of this invention, other experiment, and an analysis method, if the same result is obtained, it will not restrict | limit to the method described below.

  First, in order to optimize coal carbonization conditions, a coal carbonized product (hereinafter referred to as “char”) is produced. Although the kind of coal used as object is not limited, it is desirable that it is cheaper and easy to procure, and more preferable is one having a low nitrogen content. Moreover, the kind and form of the furnace used for manufacture of char are not specifically limited.

  In order to optimize the carbonization conditions, the present inventors performed carbonization using a test furnace in which an electric furnace capable of grasping and controlling the thermal history and a quartz core tube were combined. In the experiment using this test furnace, after placing coal in a ventilable furnace core tube, an inert gas is vented to purge the internal atmosphere, and then inserted into an electric furnace and heated.

  Although heating by an electric furnace can be manually controlled, it is desirable to automatically control the temperature history. Moreover, although it is desirable that the number of implementations for determining the dry distillation conditions is large, the maximum number that can actually be completed is 30 or less.

  Secondly, when the optimization based on the NOx conversion rate is performed, the nitrogen concentration in the char obtained by the above method is analyzed. General elemental analysis (JISM8813 C, H, N) is performed to obtain the nitrogen concentration of char under each dry distillation condition. As a condition of the low NOx carbon material, it is desirable that the nitrogen content is lower, and more specifically, it is lower than 1.1% which is the nitrogen content concentration of blast furnace coke as a general sintered fuel. desirable.

  More desirably, since the NOx conversion rate during sintering of blast furnace coke was about 40%, the char concentration of 0.5% or less contained was not affected by the change in NOx conversion rate during sintering combustion. If so, it is not always necessary to examine the following items.

  Thirdly, a combustion experiment of a plurality of chars manufactured and analyzed by the above method is performed, and data relating to the amount of generated NOx is acquired.

  Here, although the method of the combustion experiment is not limited, a simulation experiment that reproduces the actual combustion field is performed as much as possible. Here, in the simulation experiment, it is indispensable that at least the combustion temperature is equivalent. As a sinter ore production simulation experiment, a sinter pot test using a sample of kilogram order is common, but if a sinter combustion phenomenon by downward suction is simulated, an experiment with a smaller amount of sample or gram Custom laboratory experiments are also effective.

  Further, in order to estimate that the sintering reaction is proceeding from the combustion temperature, it is desirable to measure the temperature in the sample with a thermometer. In addition, it is effective to simulate coexisting substances and oxygen concentration during combustion. Furthermore, it is desirable to use actual machine test results if possible.

Subsequently, it is necessary to quantify the amount of generated NOx from the results of the combustion experiment, but the most effective method is to quantify the total amount of NOx generated with respect to the amount of solid fuel input. The determination method does not matter, but the present inventors are NO, NO ₂ , N ₂ O, which are typical NOx generated during combustion by gas continuous measurement by general infrared spectroscopy. It is possible to measure and is confirmed to be effective.

  For quantitative determination, the intensity and position of the peak corresponding to NOx is confirmed by infrared spectroscopy of a NOx sample gas with a known concentration, and then the gas generated during the actual combustion experiment is continuously introduced into the infrared spectrometer. While measuring. After the experiment is completed, the total generation amount can be measured by specifying the generation concentration from the peak intensity and multiplying by the generation time. At this time, the measurement accuracy is further improved by simultaneously measuring the amount of gas flowing through the infrared spectroscopic device and its pressure fluctuation.

  In addition, the present inventors have confirmed that measurement by a general gas chromatography method is also effective in terms of sensitivity, although the measurement continuity is inferior.

  On the other hand, in large-scale experiments and actual machine tests, it is often difficult to determine the total amount generated by the above method, so measurement is performed with a commercially available NOx gas concentration analyzer that can continuously measure the generated concentration, and the average It is also possible to determine the NOx emission level and use it as the amount of generated NOx.

  Finally, as a result of the above experiment, the carbonization conditions are optimized based on the possibility of sintering reaction and the selection of a sintering fuel that can reduce the amount of generated NOx most. In the optimization of the carbonization conditions of the fuel carbon material for sintering, the carbonization conditions where the generated NOx is reduced are found. At this time, the NOx conversion rate obtained by dividing the generated NOx amount by the nitrogen content is obtained, Use in the optimization of carbonization conditions is effective in clarifying the optimum conditions that differ depending on the coal type.

  Whether the sintering reaction is possible or not is judged from the maximum temperature during combustion, and those that cannot generate heat up to 1200 ° C. are considered unsuitable for sintered fuel carbon materials. According to the study by the present inventors, char having a carbonization end temperature of less than 600 ° C. has a large amount of residual volatile matter in any coal and cannot generate heat up to 1200 ° C. during combustion. Optimization with is effective.

  Further, even when the rate of temperature rise exceeds 30 ° C./min, it is difficult to uniformly heat the inside of the coal, it is difficult to control the heat history, and the amount of remaining volatile matter is increased. As a result, since it was not possible to generate heat up to 1200 ° C. during combustion and the fuel carbon material for sintering was not obtained, it was difficult to optimize the dry distillation conditions.

  Furthermore, in the dry distillation atmosphere at a dry distillation end temperature of 1000 ° C. or higher, it was confirmed that the decrease in the nitrogen content of the fuel carbon material stopped, the NOx conversion rate deteriorated during combustion, and the generated NOx amount increased uniformly. And optimization was not possible. On the other hand, when the carbonization rate was less than 6 ° C./min, it was confirmed that the concentration of nitrogen contained decreased, the NOx conversion rate of volatile matter deteriorated, and the amount of generated NOx increased, and optimization was not possible.

  If the production of this char is 1 g or less, the temperature history of the entire sample can be easily fixed, which is desirable for the purpose of optimizing the dry distillation temperature conditions. Large-scale experimental furnaces, industrial furnaces, coke ovens, and other real machines can be used, but the 10 kg test furnace, which is relatively large, is optimized due to the problem of electric heating of coal and the effect of variations in the temperature reached. It was not always effective.

  In addition, if the production amount is less than 0.01 g, the amount of char obtained is very small, so it is difficult to quantify the amount of NOx generated by combustion, and it is highly possible that optimization of dry distillation conditions cannot be performed.

  Next, examples of the present invention will be described. The conditions in the examples are one example of conditions used for confirming the feasibility and effects of the present invention, and the present invention is based on this one example of conditions. It is not limited. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
For a single brand of coal K, the dry distillation conditions with the least amount of NOx generated were verified by changing the dry distillation end temperature at a constant heating rate. 200 mg of coal K is heated at a rate of 6 ° C./min, which simulates a coke oven, and the dry distillation end temperatures are 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., 1000 ° C., 1100 ° C., and 1150 ° C. As a result, fuels for sintering under the respective dry distillation conditions were produced. Table 1 shows the amount of NOx generated during simulated sintering combustion with 100 mg of each sintered fuel.

  In the simulating combustion experiment of blast furnace coke (containing nitrogen concentration of 1.1%) under the same conditions, the amount of NOx generated was about 440 μg. As a result of verification, when a sintering fuel having a carbonization end temperature of 900 ° C. was used, the amount of generated NOx was low. Therefore, the optimum dry distillation end temperature of coal K at the time of dry distillation heating at 6 ° C./min is 900 ° C.

(Example 2)
For a single brand of coal L, the dry distillation conditions with the least amount of NOx generated were verified by changing the dry distillation end temperature at a constant heating rate. 200 mg of coal L was heated at a heating rate of 6 ° C./min simulated by a coke oven, and the end temperature of dry distillation was 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., 1000 ° C., 1100 ° C., and 1150 ° C. As a result, fuels for sintering under the respective dry distillation conditions were produced. Table 2 shows the concentration of each nitrogen, the NOx conversion rate and the amount of generated NOx during the simulated sintering combustion with 100 mg of sintered fuel.

  In the simulating combustion experiment of blast furnace coke (containing nitrogen concentration of 1.1%) under the same conditions, the amount of NOx generated was about 440 μg. As a result of verification, when the fuel for sintering having a carbonization end temperature of 1000 ° C. was followed, the concentration of nitrogen contained was the lowest, and the amount of generated NOx was lower than that of coke for blast furnace. In the case of a sintering fuel having a carbonization end temperature of 900 ° C, the concentration of nitrogen contained is slightly higher than in the case of a sintering fuel having a temperature of 1000 ° C, but the NOx conversion rate during combustion is low, and the amount of NOx generated finally Was lower.

  There were also sintering fuels with a lower NOx conversion rate under other dry distillation end temperature conditions, but the concentration of nitrogen contained was high and the amount of generated NOx increased rather. Therefore, the optimum dry distillation end temperature of coal L at the time of dry distillation heating at 6 ° C./min is 900 ° C.

(Example 3)
For a single brand of coal M, the dry distillation conditions with the least amount of NOx generated were verified by changing the dry distillation end temperature at a constant heating rate. 200 mg of coal K was heated at a heating rate of 6 ° C./min simulated by a coke oven, and the dry distillation end temperatures were 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., 1000 ° C., 1100 ° C., and 1150 ° C. The fuels for sintering under the respective dry distillation conditions were produced. Table 3 shows the concentration of each nitrogen, the NOx conversion rate and the amount of generated NOx during the simulated sintering combustion with 100 mg of sintered fuel.

  In the simulating combustion experiment of blast furnace coke (containing nitrogen concentration of 1.1%) under the same conditions, the amount of NOx generated was about 440 μg. As a result of the verification, in any char, the NOx generation amount was lower than the coke generation amount, but in the case of 900 ° C. sintering fuel, the NOx generation amount finally generated was lower. Therefore, the optimum end temperature of coal M at the time of dry distillation heating at 6 ° C./min is 900 ° C.

Example 4
For a single brand of coal N, the dry distillation conditions with the least amount of NOx generated were verified by changing the dry distillation end temperature at a constant heating rate. The temperature rising rate is 6 ° C./min which simulates a coke oven, and the end temperature of dry distillation is 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., 1000 ° C., 1100 ° C. and 1150 ° C. Table 4 shows the nitrogen concentration, the NOx conversion rate and the amount of generated NOx during the simulated sintering combustion with 100 mg of sintered fuel.

  In the simulating combustion experiment of blast furnace coke (containing nitrogen concentration of 1.1%) under the same conditions, the amount of NOx generated was about 440 μg. As a result of the verification, in the case of a sintering fuel having a dry distillation end temperature of 1000 ° C., the concentration of nitrogen contained was the lowest and the amount of generated NOx was the lowest.

  On the other hand, in the other sintering fuels, the concentration of nitrogen contained is higher than that in the case of sintering fuel having a dry distillation end temperature of 1000 ° C., and the NOx finally generated despite the low NOx conversion rate during combustion. The amount was higher. Accordingly, the optimum end temperature of coal N at the time of dry distillation heating at 6 ° C./min is 1000 ° C.

(Example 5)
For coal M of a single brand, the carbonization conditions with the least amount of NOx generated were verified by changing the temperature increase rate while keeping the temperature of carbonization end constant. Manufactures sintering fuels with dry distillation conditions of 1000 ° C., temperature increase rate of 2 ° C./min, 4 ° C./min, 6 ° C./min, 15 ° C./min, 30 ° C./min, and 40 ° C./min. did. Table 5 shows the concentration of each nitrogen, the NOx conversion rate and the amount of generated NOx during the simulated sintering combustion with 100 mg of sintered fuel.

  In the simulating combustion experiment of blast furnace coke (containing nitrogen concentration of 1.1%) under the same conditions, the amount of NOx generated was about 440 μg. As a result of the verification, the sintering fuel produced at a temperature increase of 30 ° C./min had both the low nitrogen concentration and the low NOx conversion rate, and the lowest generated NOx amount. On the other hand, in the other sintering fuels, the NOx conversion rate was high, and the amount of NOx generated was higher. Therefore, 30 ° C./min is optimal for the rate of temperature increase at the coal distillation end temperature 1000 ° C.

(Example 6)
For the coal types used in the examples, the combustion temperature was verified by changing the dry distillation end temperature at a constant rate of temperature increase. For each 200 mg of coal, the rate of temperature rise was 6 ° C./min simulated by a coke oven, and the dry distillation end temperatures were 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., 1000 ° C., 1100 ° C., and 1150 ° C. As a result, fuels for sintering under the respective dry distillation conditions were produced.

  The combustion temperature at the time of the simulated sintering combustion with each sintered fuel 100 mg was measured with a thermocouple inserted in the sample. Table 7 shows the measurement results.

  In all types of coal, combustion was performed using char produced at a carbonization end temperature of 500 ° C. or less. However, the residual volatile matter was high, and a combustion temperature of 1200 ° C. or higher required for sinter production was obtained during combustion. I couldn't. Eventually, char produced at a carbonization end temperature of 500 ° C. or lower cannot be used as a burning combustion carbonaceous material.

(Example 7)
For the coal types used in the examples, the combustion temperature was verified by changing the dry distillation end temperature at a constant rate of temperature increase. About 200 mg of each coal, the temperature increase rate was set to 6 ° C./min simulated in a coke oven, and the dry distillation end temperatures were set to 1000 ° C., 1100 ° C., and 1150 ° C., and the fuels for sintering under the respective dry distillation conditions were produced. . Table 7 shows the concentration of each nitrogen, the NOx conversion rate and the amount of NOx generated during simulated combustion with 100 mg of sintered fuel.

  In any coal type, at the end of dry distillation of 1100 ° C or higher, the concentration of nitrogen contained hardly changes compared to up to 1000 ° C, only the NOx conversion rate during combustion deteriorates, and the amount of generated NOx increases. Optimization like the example could not be done.

(Example 8)
For the coal types used in the examples, the combustion temperature was verified by changing the dry distillation heating rate at a constant dry distillation end temperature. For each 200 mg of coal, the fuel for sintering under the respective carbonization conditions at a carbonization end temperature of 1000 ° C. and a heating rate of 6 ° C./min, 15 ° C./min, 30 ° C./min, and 40 ° C./min. Manufactured.

  The combustion temperature at the time of the simulated sintering combustion with each sintered fuel 100 mg was measured with a thermocouple inserted in the sample. Table 8 shows the measurement results.

  In all types of coal, combustion was performed using char produced at a dry distillation temperature increase rate of 40 ° C./min or more. However, the residual volatile matter was large, and at the time of combustion, 1200 ° C. or more required for sinter production. The combustion temperature could not be obtained. Eventually, none of the types of charcoal can be used as a combustion charcoal for sintering.

Example 9
For the coal types used in the examples, the combustion temperature was verified by changing the dry distillation temperature increase rate at a constant dry distillation end temperature. About 200 mg of each coal, the fuel for sintering under the respective carbonization conditions was produced at a dry distillation end temperature of 1000 ° C. and a heating rate of 2 ° C./min, 4 ° C./min, and 6 ° C./min. Table 9 shows the NOx conversion rate and the amount of NOx generated at the time of simulated sintering combustion with 100 mg of each sintered fuel.

  In any coal type, when burned with char produced at a dry distillation heating rate of less than 6 ° C./min, the NOx conversion rate during combustion deteriorated, and the generated NOx amount unilaterally deteriorated under any conditions. Therefore, the optimization as in the example could not be performed.

(Comparative Example 1)
Using a 10 kg test furnace for a single brand of coal M, dry distillation conditions with the least amount of NOx generated were verified by changing the end temperature of the dry distillation at a constant rate of temperature increase. When the rate of temperature increase was set to 6 ° C / min, which simulates a coke oven, and a sintering simulated combustion experiment was performed using chars with dry distillation end temperatures of 800 ° C, 900 ° C, and 1000 ° C, a char with a dry distillation end temperature of 800 ° C was used. On the other hand, the decrease in the amount of generated NOx was confirmed for the 900 ° C. and 1000 ° C. chars, but there was no difference between the 900 ° C. and 1000 ° C. chars, and it was difficult to optimize the end temperature of the dry distillation.

  As described above, according to the present invention, a coal dry distillation condition that enables reduction of NOx generated at the time of sintering combustion is used for a coal dry distillation fuel that is used for sinter ore production. Can be optimized to the extent possible. Therefore, the present invention has high applicability in the steel industry.

Claims (4)

A method for determining optimum carbonization conditions for a fuel carbon material for sintering produced by carbonizing carbon,
(A) Regarding the temperature conditions of carbonization, m and n are positive integers of 30 or less (however, m = n = 1 is excluded), and (a1) m is selected as the carbonization end temperature in the range of 600 to 1000 ° C. (A2) n types of dry distillation heating rates are selected in the range of 6-30 ° C./min, and (a3) coal is carbonized under the conditions of a combination of m × n dry distillation end temperatures and dry distillation heating rates. A process of producing m × n types of coal dry distillate,
(B) a step of actually burning the m × n types of coal dry distillate and measuring the amount of NOx generated; and
(C) identifying the coal dry matter having the smallest amount of NOx generated per unit mass of coal from the m × n kinds of coal dry matter, and determining the carbonization conditions with the smallest amount of NOx generated;
A method for determining dry distillation conditions of a fuel carbon material for sintering, comprising: A method for determining optimum carbonization conditions for a fuel carbon material for sintering produced by carbonizing carbon,
(A) About the temperature conditions of dry distillation, m and n are set to positive integers of 2 or more, (a1) m dry distillation end temperatures are selected in a range of 600 to 1000 ° C., and (a2) dry distillation heating rate is 6 to N types are selected in the range of 30 ° C./min, and (a3) m × n types of coal dry distillation products are produced by dry distillation of coal under conditions of a combination of m × n types of dry distillation end temperature and dry distillation heating rate. Process,
(B) A step of performing elemental analysis of the m × n types of coal dry product and measuring a nitrogen concentration of the m × n types of coal dry product,
(C) a step of actually burning the m × n types of coal distillate and measuring the amount of NOx generated;
(D) a step of calculating the NOx conversion rate by dividing the generated NOx amount by the nitrogen content with respect to the m × n types of coal dry distillation products; and
(E) determining the dry distillation conditions having the lowest NOx conversion rate by identifying the lowest dry NOx conversion rate from the NOx conversion rate of the m × n coal dry distillation products,
A method for determining dry distillation conditions of a fuel carbon material for sintering, comprising:   3. The method for determining dry distillation conditions of a fuel carbon material for sintering according to claim 1 or 2, wherein m or n is 1.   The mass of coal used for manufacture of a coal dry distillation thing is 0.01-1g in the process of manufacturing said mxn kinds of coal dry distillation thing, The any one of Claims 1-3 characterized by the above-mentioned. Of carbonization conditions for fuel carbon materials for sintering.