JP2010209212A - Method for producing fuel charcoal material for sintering - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fuel charcoal material to be a coal char as a solid fuel for sintering an iron ore which does not generate a volatile component of the solid fuel which does not contribute to combustion in a sintering step of iron ore sintering ore and is capable of starting reaction at low temperature in the sintering step and promoting crack of sintered ore. <P>SOLUTION: A gas composition in an exhaust gas is measured when coal, as a raw material, is decarbonized by using a rotary kiln or a batch type carbonization furnace and when the exhaust gas is a hydrogen gas, exhaust of the hydrogen gas is maintained to adjust decarbonization processing temperature in the range of 650 to 850°C, and thus the char as the fuel coal material for sintering is produced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a fuel carbon material for sintering as a solid fuel used as a heat source when iron ore sintered ore is produced by a sintering machine.

  In a steelmaking process using a blast furnace, methods for producing char as an intermediate of metallurgical coke from coal have been proposed (Patent Documents 1 and 2).

  The char production method disclosed in Patent Document 1 is a multi-stage heating in a rotary kiln using high volatile content non-coking coal (high volatile content non-coking coal, lignite, high volatile content coking coal) as a raw material. Coal raw material char for metallurgical metal is manufactured. High volatile content non-fine coking coal (high volatile content non-coking coal, lignite, high volatile content coking coal) from 250 ° C up to 450-600 ° C The volatile matter remains by slow-drying in the temperature range.

  The method for producing char disclosed in Patent Document 2 is a method of slow dry distillation and volatilization using high volatile content non-, slightly caking coal (high volatile content non-caking coal, lignite, high volatile content caking coal) or bituminous coal as raw materials. In the chamber furnace (externally heated batch shaft furnace, which is a normal coke oven), the heating gas temperature is adjusted, and the vicinity of the inner wall of the chamber furnace and the center are heated at the same heating rate. In this way, a metallurgical coke raw material char is manufactured. The raw material coal is preheated to a constant temperature in a temperature range of 100 to 300 ° C. and then charged into the chamber furnace. At that time, the temperature of the heating gas outside the heat transfer wall of the chamber furnace is appropriately controlled from about 250 ° C. in the initial stage to a temperature of 450 to 600 ° C. in the end according to a predetermined pattern with time. The raw coal near the heat transfer wall and in the center are heated at the same rate of temperature increase.

JP-A-56-136880 Japanese Patent Laid-Open No. 56-136881

  The char production methods disclosed in Patent Documents 1 and 2 all relate to a char production method as an intermediate for producing metallurgical coke.

  For this reason, char as an intermediate of metallurgical coke produced by such a method is used for sintering as a raw material of solid fuel for sintering when producing sintered ore used in a blast furnace with a sintering machine. The following problems occur when used for fuel carbon materials.

  As shown in FIG. 3, in the char having a low carbonization temperature, a large amount of volatile matter (VM) remains in the char. Therefore, when the char is used in a sintering machine, the volatile matter (VM) generated in a low temperature region. A part of the dust may be sucked into the dust collector and blower without contributing to the combustion, resulting in a dust collector trouble or the like.

  On the other hand, a char having a volatile content (VM) of 1.0% or more has a characteristic that the chemical structure is easily cut and the reaction starts at a low temperature. For this reason, when using char as a carbon material for sintering of a solid fuel for sintering, it is desired to use a char with a certain amount of VM.

  The present invention has been made in view of such a viewpoint, and does not generate a volatile component that does not contribute to combustion in the sintering process of iron ore sintered ore, and can initiate a combustion reaction at a low temperature in the sintering process. An object of the present invention is to provide a method for producing a fuel carbon material used for fuel.

  The present invention solves the above technical problem, and the gist of the invention is as follows.

  (1) Coal is used as a raw material, and when this is carbonized by a rotary kiln or a batch type carbonization furnace, the gas composition in the exhaust gas is measured, and the specific gas emission is maintained and at least the carbonization temperature is 650 among the carbonization conditions. A method for producing a fuel carbon material for sintering, characterized in that it is adjusted within a range of ˜850 ° C. to produce char as a fuel carbon material for sintering.

  (2) The specific gas is hydrogen, the dry distillation treatment temperature is increased when the hydrogen concentration tends to increase, and the dry distillation treatment temperature is lowered when the hydrogen concentration tends to decrease. (1) The method for producing a fuel carbon material for sintering.

  (3) The dry distillation treatment conditions other than the dry distillation treatment temperature are residence time, raw material supply amount, raw material change in the rotary kiln, and one or more of these other dry distillation treatment conditions are combined, and the specific gas concentration If there is a tendency to increase the residence time, decrease the feed rate of the raw material, change the raw material with a specific gas composition low, and if the concentration of the specific gas tends to decrease, the residence time The method for producing a fuel carbon material for sintering according to the above (1) or (2), characterized in that the raw material is changed by shortening, increasing the amount of the raw material supplied, and changing the composition of a specific gas.

  (4) The adjustment of the carbonization temperature is performed by increasing / decreasing the amount of fuel supplied to combustion and the amount of heat generated from the fuel, and the fuel carbon material for sintering according to any one of (1) to (3) above Method.

  (5) The method for producing a fuel carbon material for sintering according to any one of (1) to (4), wherein the raw material is low-grade coal such as lignite or subbituminous coal.

  According to the present invention, char as a fuel carbon material for sintering, which is a manufactured product, is used as fuel. For example, hydrogen gas remains as volatile matter (VM), but tar and hydrocarbon gas are included. Therefore, when sintering ore is sintered by a sintering machine, the combustion reaction can be started at a low temperature, so that the production efficiency of the sintered ore can be improved and the low temperature region of the sintering process. Because there is no generation of tar or hydrocarbon gas, it is possible to prevent the occurrence of troubles in the dust collector that forms the sintered ore production facility.

  In addition, since low-grade coal such as lignite or sub-bituminous coal can be used as a raw material for the fuel carbon material for sintering, sintered ore can be produced at low cost.

Schematic which shows 1st Embodiment of this invention. Schematic which shows 2nd Embodiment of this invention. The graph which shows the relationship between the carbonization process temperature and volatile matter (VM) of coal. The figure which shows the relationship between VM and H / C.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment FIG. 1 is a schematic view of a production apparatus for carrying out a method for producing a fuel carbon material for sintering according to the present invention.

  In the method for producing a fuel carbon material for sintering according to the present embodiment, coal as a raw material is continuously supplied into a rotary kiln 1 having a closed structure, which is a carbonization device, the rotary kiln 1 is heated by a burner 2, Charging is performed, and char, which is a fuel carbon material for sintering, is a product that has been dry-distilled. By increasing or decreasing the amount of fuel (liquid fuel, gaseous fuel) supplied to the burner 2, the dry distillation treatment temperature is adjusted to increase or decrease. Note that the combustion air amount is also increased or decreased in accordance with the fuel supply amount. In addition, the change in the dry distillation treatment temperature can be adjusted by changing the fuel to another fuel having a different calorific value.

  The exhaust gas generated by dry distillation of the raw material coal in the rotary kiln 1 is analyzed by the exhaust gas analyzer 3 to determine the composition of the exhaust gas and measure the concentration. The exhaust gas from the exhaust gas analyzer 3 is sent to an exhaust gas processing device (not shown).

  FIG. 3 shows the relationship between the treatment temperature (° C.) when coal is subjected to carbonization at various temperatures and the volatile content (VM) of char as a solid fuel subjected to carbonization treatment. The relationship is that the VM included in the char decreases as the processing temperature increases.

  Here, when char with a high VM is used as a solid fuel for sintering in a real machine sintering machine, a part of the VM generated in the low temperature region during the sintering process is sucked into the dust collector and blower without contributing to combustion, There is a risk of dust collector trouble.

  For this reason, it is desirable to use a char as a fuel carbon material for sintering used in an actual machine having a VM of 10% or less. Then, according to FIG. 3, it corresponds to a dry distillation treatment temperature of 650 ° C. or more when producing char. In addition, since the VM of the char manufactured at the carbonization temperature of 600 degreeC is high, it is not preferable.

  On the other hand, char as a fuel carbon material for sintering having a VM of 1.0% or more has a characteristic that the chemical structure is easily cut and the reaction starts at a low temperature in the sintering process. According to FIG. 3, the dry distillation treatment temperature is 850 ° C. It corresponds to the following. In addition, since the char manufactured at the carbonization temperature of more than 850 ° C. has too low VM, the chemical structure is difficult to cut in the sintering process, and the reaction start temperature is high. Here, the low reaction start temperature can shorten the time from the start to the end of combustion in the combustion process in the sintering machine, increase the feed speed of the raw material in the sintering machine, and increase the production of sintered ore. be able to.

  Next, when coal is carbonized, that is, pyrolyzed, the composition of gas generated varies depending on the carbonization temperature during the coal pyrolysis process, and tar components are generated at a low temperature of about 200 to 400 ° C. At 400 to 650 ° C, hydrocarbon gas centered on methane and ethane is generated, and at 650 to 850 ° C, hydrogen is generated.

  Therefore, in order to improve the sinterability, hydrogen is left in the char which is a fuel carbon material for sintering as much as possible, and the char which is easy to cut the chemical structure and starts the reaction at a low temperature is used as a solid fuel for sintering. It is important to use it as a carbon material for sintering. Note that when the processing temperature exceeds 850 ° C., most of the hydrogen is lost, so it is not suitable as a fuel carbon material for sintering.

  In FIG. 3, the VM at the processing temperature of 850 ° C. is 1.0%. Even at this processing temperature, hydrogen is still present in the char as shown in FIG. That is, there is a correlation between VM and the atomic ratio H / C (ratio of the number of hydrogen atoms per carbon atom), and a VM ratio of 1.0% or more corresponds to an atomic ratio H / C of 0.040 or more. .

  Therefore, in the present embodiment, in order to obtain char containing hydrogen without a tar component and a hydrocarbon gas component as a product property of char that is a fuel carbon material for sintering that is a product manufactured by the rotary kiln 1. When the exhaust gas component analyzed by the exhaust gas analyzer 3 is hydrogen, the dry distillation treatment conditions of the rotary kiln 1 are adjusted so that the generation of hydrogen gas is maintained and the dry distillation temperature is maintained in the range of 650 to 850 ° C.

  One of the dry distillation treatment conditions is the dry distillation treatment temperature, and the other dry distillation treatment conditions are the residence time in the rotary kiln, the raw material supply amount, the raw material change, and the dry distillation temperature is adjusted to 650-850 ° C. only by adjusting the dry distillation treatment temperature. The dry distillation temperature may be maintained in the range of 650 to 850 ° C. by combining the dry distillation treatment temperature and one or more of these other dry distillation treatment conditions.

  When the hydrogen gas concentration analyzed by the exhaust gas analyzer 3 tends to increase, the dry distillation treatment temperature is increased, and when the hydrogen gas concentration tends to decrease, the dry distillation treatment temperature is decreased to leave hydrogen. Manufactures char as fuel carbon for sintering.

  In addition, as adjustment of dry distillation treatment conditions other than the dry distillation treatment temperature, when the hydrogen gas concentration tends to increase, the residence time is extended, the raw material supply amount is decreased, and the raw material is changed with a low H / C. When the hydrogen gas concentration tends to decrease, the residence time can be shortened, the raw material supply amount can be increased, and the raw material can be changed with a large amount of H / C.

  On the other hand, the adjustment of the carbonization temperature can be performed by increasing or decreasing the amount of fuel supplied to the combustion and the amount of heat generated by the fuel.

  Moreover, although the coal used as a raw material is not particularly limited, low-grade coal such as lignite or sub-bituminous coal can be used from the viewpoint of cost reduction. In particular, since lignite and subbituminous coal have a large amount of volatile matter, it is possible to produce a char that sufficiently releases tar components and VM of hydrocarbon gas.

Second Embodiment In the above-described first embodiment, coal, which is a raw material for sintering fuel carbon material, is continuously supplied to the rotary kiln 1, and the fuel fuel for sintering, which is a product, is continuously discharged and manufactured. However, as shown in FIG. 2, a predetermined amount of coal, which is a raw material, is accommodated in the batch type carbonization furnace 10, and fuel such as combustion gas is burned in the combustion chamber to perform dry distillation treatment. And the exhaust gas in the carbonization process discharged from the chimney 11 is analyzed by the exhaust gas analyzer 3, and when the analyzed exhaust gas component is hydrogen as in the first embodiment, the dry distillation temperature is in the range of 650 to 850 ° C. Adjust the carbonization conditions to maintain.

DESCRIPTION OF SYMBOLS 1 Rotary kiln 2 Burner 3 Exhaust gas analyzer 10 Batch type carbonization furnace 11 Chimney

Claims (5)

  Coal is used as a raw material, and when this is carbonized in a rotary kiln or batch type carbonization furnace, the gas composition in the exhaust gas is measured, and the specific gas emission is maintained, and at least the carbonization temperature is 650 to 850 ° C. A method for producing a fuel carbon material for sintering, characterized in that the char is produced as a fuel carbon material for sintering.   The specific gas is hydrogen, and when the hydrogen concentration tends to increase, the dry distillation treatment temperature is increased, and when the hydrogen gas concentration tends to decrease, the dry distillation treatment temperature is lowered. The manufacturing method of the fuel carbon material for sintering as described in 2.   The dry distillation treatment conditions other than the dry distillation treatment temperature are residence time, raw material supply amount, raw material change in a rotary kiln, and one or more of these other dry distillation treatment conditions are combined to increase the specific gas concentration. The retention time is extended, the raw material supply amount is decreased, the raw material is changed with a low specific gas composition, and when the specific gas concentration is decreasing, the retention time is shortened, 3. The method for producing a fuel carbon material for sintering according to claim 1 or 2, wherein the raw material supply amount is increased and the raw material is changed with a large composition of a specific gas.   The method for producing a fuel carbon material for sintering according to any one of claims 1 to 3, wherein the carbonization temperature is adjusted by increasing or decreasing the amount of fuel supplied to the combustion and the amount of heat generated by the fuel. The method for producing a fuel carbon material for sintering according to any one of claims 1 to 4, wherein the raw material is low-grade coal such as lignite or sub-bituminous coal.

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