JP4903623B2 - Method for producing coal gasification slag with adjusted composition - Google Patents

Description

  The present invention relates to a method for producing a composition-adjusted coal gasification slag. More specifically, the present invention relates to a method for producing coal gasification slag suitable for providing added value by adjusting the composition of coal gasification slag generated from a combined coal gasification combined cycle facility.

  IGCC (Integrated coal Gasification Combined Cycle) is expected to be put to practical use as a highly efficient and environmentally friendly power generation system. From the coal gasification furnace, which is the core facility of this coal gasification combined cycle power generation, almost all of the ash component in the fuel coal is discharged as glassy coal gasification slag. Large amount of about 20,000 tons / year.

Various techniques for effectively using the coal gasification slag discharged in large quantities as resources have been proposed. For example, Patent Document 1, and coal selection step of selecting a coal as the content of silica in the slag after the coal gasification process (SiO ₂₎ is 45 wt% or more, the coal is treated coal gasification A technology has been proposed in which lightweight aggregate is obtained by a production method including a coal gasification step for obtaining slag and a slag firing step for firing and foaming slag, and the coal gasification slag is used as an artificial lightweight aggregate. .

In Patent Document 2, and coal selection step of selecting a coal as the content of alumina in the slag after the coal gasification process (Al 2 _{O 3)} is a 30 wt% or less, the coal gasification the coal A technology has been proposed in which a lightweight aggregate is obtained by a manufacturing method including a coal gasification step for processing to obtain slag and a slag firing step for firing and foaming slag, and using the coal gasification slag as an artificial lightweight aggregate. ing.
JP 2004-269301 A JP 2004-269302 A

  In the techniques described in Patent Documents 1 and 2, it is necessary to limit the fuel coal to a specific species in order to obtain a composition of coal gasification slag that can be effectively used as an artificial lightweight aggregate. However, without limiting the fuel coal to specific species, establish a technology that can expand the range of available coal species and obtain coal gasification slag that can be effectively used as artificial lightweight aggregates, etc. This is desirable for continuous coal gasification combined power generation.

  Therefore, it is possible to adjust the composition of coal gasification slag after coal gasification treatment by adding ores containing silica and alumina to fuel coal. Production costs will increase.

  On the other hand, since coal ash such as fly ash discharged from coal-fired power generation facilities is water-eluting, if it is disposed of as it is, there is a concern that heavy metals will elute into the environment and cause environmental pollution. Therefore, in order to dispose of coal ash such as fly ash as waste, a large amount of cost is required for detoxification.

  The present invention provides a method for producing a coal gasification slag suitable for adjusting the composition of the coal gasification slag generated by the coal gasification treatment at low cost and effectively using it as an artificial lightweight aggregate or the like. With the goal.

  Another object of the present invention is to effectively use coal ash such as fly ash discharged from coal-fired power generation facilities.

  In order to solve this problem, the method for producing coal gasification slag according to the present invention provides coal ash having a composition different from the ash component of fuel coal when supplying coal to a gasification furnace and performing coal gasification treatment. Including a step of supplying the gasification furnace to the gasification furnace, and the composition of the coal gasification slag generated by the coal gasification process is adjusted.

  By supplying coal ash having a composition different from the ash component of the fuel coal to the gasification furnace, the coal gasification slag generated by the coal gasification treatment is adjusted to a desired composition. Moreover, since the coal ash supplied to the gasification furnace is melted by the coal gasification treatment and taken into the coal gasification slag and is not eluted, elution of heavy metals and the like from the coal ash is suppressed.

  Here, the “desired composition” means an optimum composition for effective utilization of coal gasification slag. For example, the optimum composition for use as an artificial lightweight aggregate, the optimum composition for use as a soil improvement material and a rooftop greening material, and the optimum composition that enables atomization and fiberization of coal gasification slag are mentioned. It is done. In other words, when coal gasification treatment is performed by supplying fuel coal to the gasifier, the coal ash having a composition different from the ash component of the fuel coal is supplied to the gasifier, which is optimal for effective use. Coal gasification slag having a good composition is produced.

  The “ash component” means a component that exists stably as an oxide even when heated at 815 ° C. in the composition of fuel coal, mainly silicon (Si), aluminum (Al), calcium. (Ca), iron (Fe), magnesium (Mg), sodium (Na) and the like.

  Here, it is preferable to use fly ash generated in a coal-fired power generation facility as coal ash. Fuel coal used in coal-fired power generation has a higher ash melting point than fuel coal used in coal gasification combined power generation. That is, the content of silica and alumina in the ash component of fuel coal used in coal-fired power generation is higher than the content of silica and alumina in the ash component of fuel coal used in coal gasification combined power generation. Therefore, the silica and alumina content of fly ash generated in coal-fired power generation facilities is higher than the silica and alumina content of fuel coal ash components used in coal gasification combined power generation. By using fly ash generated in a thermal power generation facility, the silica content and alumina content of coal gasification slag can be increased and adjusted to a desired composition.

  Moreover, you may make it adjust the coal gasification slag generate | occur | produced by a coal gasification process to a desired composition by supplying a waste incineration residue instead of coal ash to a gasification furnace. Also in this case, the waste incineration residue supplied to the gasification furnace is melted by the coal gasification process and taken into the coal gasification slag and is not eluted, so that elution of heavy metals from the waste incineration residue is suppressed. It is done.

An example of the adjustment of the composition of coal gasification slag is as follows. The silica content of coal gasification slag is adjusted to 50 to 60% by weight, and the content of alumina (Al ₂ O ₃ ) is 10 to 30% by weight. When adjusted, the granulated material obtained by calcining and foaming the coal gasification slag has an absolute dry specific gravity of 1.6 g / cm ³ or less and a water absorption of 6% or less. Therefore, a foamable coal gasification slag very suitable for use as an artificial lightweight aggregate is obtained.

  According to the method for producing coal gasification slag according to claim 1, since coal ash having a composition different from the ash component of fuel coal is supplied to the gasification furnace, coal gasification generated by coal gasification treatment is provided. The composition of the slag can be adjusted. Therefore, an optimal composition for the effective use of coal gasification slag, for example, an optimal composition for use as an artificial lightweight aggregate, an optimal composition for use as a soil improvement material and a rooftop greening material, coal gas It is possible to produce coal gasification slag having an optimum composition that enables atomization and fiberization of gasification slag. Moreover, because the composition of the coal gasification slag is adjusted using the waste of coal ash, the increase in the production cost of coal gasification slag is suppressed, and it is no longer necessary to dispose of the coal ash. Ash disposal costs can be reduced. Furthermore, since coal ash is taken into coal gasification slag and becomes non-eluting, it is possible to prevent environmental pollution due to elution of heavy metals and the like. Moreover, the fluidity | liquidity of coal gasification slag may improve by adjusting the composition of coal gasification slag. In this case, it is possible to contribute to the expansion of the operating range of the gasifier.

  According to the method for producing coal gasification slag according to claim 2, since the content of silica and alumina in fly ash generated in a coal-fired power generation facility is higher than that of coal used in coal gasification combined power generation, By increasing the silica content and the alumina content of the coal gasification slag generated by the coal gasification treatment, it is possible to produce a coal gasification slag having a desired composition ratio suitable for effective use.

  According to the method for producing coal gasification slag according to claim 3, since the waste incineration residue having a different composition from the ash component of fuel coal is supplied to the gasification furnace, coal generated by coal gasification treatment The composition of the gasification slag can be adjusted. Therefore, an optimal composition for the effective use of coal gasification slag, for example, an optimal composition for use as an artificial lightweight aggregate, an optimal composition for use as a soil improvement material and a rooftop greening material, coal gas It is possible to produce coal gasification slag having an optimum composition that enables atomization and fiberization of gasification slag. Moreover, because the composition of coal gasification slag is adjusted using waste waste incineration residue, it is necessary to suppress the increase in production cost of coal gasification slag and to dispose of waste incineration residue. Therefore, the disposal cost of the waste incineration residue can be reduced. Furthermore, since the waste incineration residue is taken into the coal gasification slag and becomes insoluble, it is possible to prevent environmental pollution due to elution of heavy metals and the like. Moreover, the fluidity | liquidity of coal gasification slag may improve by adjusting the composition of coal gasification slag. In this case, it is possible to contribute to the expansion of the operating range of the gasifier.

According to the method for producing coal gasification slag according to claim 4, the content of silica (SiO ₂ ) in the coal gasification slag is adjusted to 50 to 60% by weight, and the content of alumina (Al ₂ O ₃ ). Is adjusted to 10 to 30% by weight, the absolute dry specific gravity of the granules obtained by firing and foaming the coal gasified slag is 1.6 g / cm ³ or less and the water absorption is 6% or less. . Therefore, it is possible to manufacture a coal gasification slag that is very suitable for use as an artificial lightweight aggregate.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  The method for producing coal gasification slag according to the present invention supplies coal ash having a composition different from the ash component of fuel coal to the gasification furnace when supplying fuel coal to the gasification furnace and performing coal gasification treatment. By including the process, the coal gasification slag generated by the coal gasification process is adjusted to a desired composition.

  Coal gasification processing is performed in a gasification furnace of a combined coal gasification combined power generation system. Here, the combined coal gasification combined power generation system is a method in which fuel coal (pulverized coal) is charged into a gasification furnace, and in the presence of a gasifying agent (oxygen, oxygen-enriched air or air), for example, 1200 to 1600 ° C., A power generation system that performs coal gasification under conditions of 2 to 3 MPa, burns the generated combustible gas to rotate the gas turbine, and uses the exhaust heat of the gas turbine to rotate the steam turbine to generate power. is there.

  The gasification furnace 1 that performs the coal gasification treatment is, for example, a pressurized two-stage entrained bed coal gasification furnace shown in FIG. This gasification furnace 1 is configured by installing two chambers of a lower combustor 3 and an upper reductor 4 in a pressure vessel 2. Molten slag (coal gasification slag) 6 flows down from the discharge port 5. Product gas and char are discharged from the furnace outlet 7, and the char is collected by a cyclone separator 8. In the combustor 3, a combustor pulverized coal burner 9 for supplying fuel coal and a combustor burner 10 for supplying char collected by the cyclone separator 8 are installed, and an air supply unit 11 for supplying air is installed. The reductor 4 is provided with a reductor pulverized coal burner 12 for supplying coal.

  Here, the gasification furnace for performing the coal gasification treatment is not limited to the spouted bed gasification furnace, and other types of gasification furnaces such as a Hycol gasification furnace manufactured by Hitachi and a gas manufactured by Shell. It is also possible to use a conversion furnace or the like.

  The method for supplying coal ash having a composition different from the ash component of the fuel coal to the gasifier 1 is not particularly limited. For example, coal ash may be mixed in advance in a fuel pulverized coal supply pipe and supplied to the gasifier 1, or the combustor pulverized coal burner 10 of the gasifier 1 may be provided with a coal ash mixing facility to provide fuel pulverized powder. It may be supplied together with charcoal, or a coal ash supply unit may be separately provided in the combustor 3 to supply coal ash.

For example, the silica content of coal gasification slag can be increased by using coal ash having a silica content higher than the ash component of fuel coal. Moreover, the alumina content rate of coal gasification slag can be raised by using coal ash whose content rate of alumina is more than the ash component of fuel coal. On the other hand, the silica content of coal gasification slag can be reduced by using coal ash having a silica content lower than the ash component of fuel coal. Moreover, the alumina content rate of coal gasification slag can be reduced by using coal ash whose content rate of alumina is less than the ash component of fuel coal. Of course, not only silica and alumina but also the content of iron oxide (Fe ₂ O ₃ ) and calcium oxide (CaO), which are main components other than silica and alumina, in the coal gasification slag can be adjusted. .

  The amount of coal ash supplied to the fuel coal is appropriately determined by the weight and composition of the ash component of the fuel coal and the weight and composition of the coal ash so that the produced coal gasification slag has a desired composition. The weight and elemental composition of the ash component of the fuel coal can be easily obtained as specifications at the time of purchasing the coal, but if not known, it can be determined based on the ash composition analyzed according to JIS-M8815. If the composition of coal ash is unknown, it can be determined based on the ash composition analyzed according to JIS-M8815. In addition, only one type of coal ash may be supplied and adjusted to a desired composition, but may be adjusted to a desired composition by supplying two or more types of coal ash in combination.

  Here, it is preferable to use fly ash generated in a coal-fired power generation facility as coal ash having a different composition from the ash component of fuel coal. In coal gasification combined cycle power generation, there is an advantage that low ash melting point coal, which is difficult to burn simply in coal-fired power generation, can be used as fuel coal. In other words, since the fuel coal used for coal-fired power generation is required to have a high ash melting point, the content of silica and alumina as ash components in the fuel coal is the fuel coal used for coal gasification combined power generation. It is higher than the content of silica and alumina in the ash component. Therefore, by supplying fly ash generated in the coal-fired power generation facility to the gasification furnace 1, the content of silica and alumina in the coal gasification slag generated by the coal gasification treatment is increased and adjusted to a desired composition. be able to.

  In addition, although cinder ash and clinker ash generated in the coal-fired power generation facility can be used, in this case, it is preferable to use fine powder. By making it fine powder, coal ash is easily melted in the gasification furnace, and the composition of the generated coal gasification slag is easily adjusted to a desired composition from the initial stage of the gasification treatment. The coal ash having a composition different from the ash component of the fuel coal is not limited to the coal ash generated in the coal-fired power generation facility, and the coal ash generated in any facility can be used as appropriate. For example, coal ash generated from a blast furnace can be used.

  Moreover, a waste incineration residue can also be used instead of coal ash. Examples of the waste incineration residue include, but are not limited to, general waste slag discharged from a garbage (general waste) treatment plant operated by the local government. About a composition of a waste incineration residue, it determines based on the ash composition analyzed according to JIS-M8815 mentioned above, and can determine the mixing amount with respect to fuel coal suitably. In addition, when using only a waste incineration residue, it is not limited, You may use coal ash and a waste incineration residue together.

  The composition of coal gasification slag is the optimum composition for effective utilization of coal gasification slag, for example, optimum composition for use as artificial lightweight aggregate, for use as soil improvement material and rooftop greening material The optimum composition is appropriately adjusted to an optimum composition that enables atomization and fiberization of coal gasification slag.

For example, by adjusting the composition of coal gasification slag so that the content of silica (SiO ₂ ) is 50 to 60% by weight and the content of alumina (Al ₂ O ₃ ) is 10 to 30% by weight. The Central Research Institute of Electric Power Industry has an absolute dry specific gravity of 1.6 g / cm ³ or less and a water absorption of 6% or less of the granules (lightweight aggregate) obtained by firing and foaming this coal gasified slag. Reported in report W03040. Therefore, it satisfies the absolutely dry density (1.3 to 1.8 g / cm ³ ) defined in the category M of JIS A 5002 “Structural Lightweight Concrete Aggregate”. In addition, since the water absorption is 6% or less, quality control of the fresh concrete can be facilitated when the lightweight aggregate is used, and the amount of moisture entering the particles of the lightweight aggregate is reduced. Therefore, it is possible to exhibit excellent freeze-thaw resistance (easiness of reduction in mechanical strength due to repeated alternately freezing and thawing). In addition, when the hydraulic composition such as mortar containing the lightweight aggregate is pumped to the construction site using a pump and a hose, the fluidity does not deteriorate due to water absorption of the lightweight aggregate. It becomes difficult to occur and it becomes possible to work smoothly.

The coal gasification slag having a silica (SiO ₂ ) content of 50 to 60% by weight and an alumina (Al ₂ O ₃ ) content of 10 to 30% by weight is obtained, for example, by the method described below. Obtainable. That is, in the coal gasification combined cycle power generation facility, there is an advantage that low ash melting point coal, which is difficult to burn simply in the coal thermal power generation facility, can be used as fuel coal. For example, fuel coal in which the content of silica in the ash component is less than 50% by weight, fuel coal in which the content of alumina in the ash component is less than 10% by weight, or the content of silica in the ash component is 50% by weight Often, fuel coal with an ash component alumina content of less than 10% by weight is selected. Therefore, such a fuel coal in performing supplied to the gasifier a coal gasification process, either one of silica than the ash component of the fuel coal (SiO ₂₎ and alumina (Al 2 _{O 3)} Or it can obtain by supplying coal ash with high content of both to the gasifier. The supply amount of coal ash to the fuel coal is appropriately determined so that the produced coal gasification slag has a desired composition according to the supply amount and composition of the ash component of the fuel coal and the composition of the coal ash. Here, the fly ash discharged from the coal-fired power generation facility is either or both of silica (SiO ₂ ) and alumina (Al ₂ O ₃ ) rather than the ash component of the fuel coal supplied to the gasifier. It is preferable to use fly ash discharged from a coal-fired power generation facility as coal ash because of the high content of coal ash.

The composition of the coal gasification slag is merely an example, and it is not denied that the composition of the coal gasification slag is adjusted to a range that deviates from this composition range. For example, when coal gasified slag is used as an artificial lightweight aggregate, even if the absolute dry density is 1.3 to 1.8 g / cm ³ and the water absorption rate is about 20%, it may be sufficiently usable. Therefore, the coal gasification slag may be appropriately adjusted to a composition range that satisfies this requirement. In addition, coal gasification slag adjusted to the above composition range may be used as a soil improvement material or a rooftop greening material, but in the case of a soil improvement material or a rooftop greening material, if a certain degree of foamability and drainage is ensured Well, even if the absolute dry specific gravity is more than 1.6 g / cm ³ and the water absorption is more than 6%, there is a case where it can sufficiently withstand use. You may adjust a composition and use as a soil improvement material or a rooftop greening material.

  Next, fiberization or atomization of coal gasification slag will be described. The fiberized coal gasification slag can be effectively used as a heat insulating material or a buffer material. In addition, the atomized coal gasification slag can be effectively used as a cement admixture with high handling properties.

  The fiberization or atomization of the coal gasification slag can be performed, for example, based on the technique described in Japanese Patent Application Laid-Open No. 2006-124253 and the Electric Power Central Research Laboratory report T01024, T03066.

  Specifically, fiberization or atomization of coal gasification slag is performed by a liquid atomization method. For example, it can be implemented by using the fiberizing and atomizing apparatus 15 shown in FIG.

  The fiberizing and atomizing device 15 roughly includes a melting chamber 16 for melting or maintaining the coal gasification slag 6 generated by the coal gasification process, and a molten slag from the melting chamber 16. And an atomizer 17 for applying a liquid atomization method to fiberize or atomize.

  The melting chamber 16 is heated by, for example, the high frequency dielectric coil 19 so that the coal gasification slag 6 in the melting chamber 16 is melted or maintained in a molten state. The melting chamber 16 is surrounded by a heat insulating material 24.

  The atomizer 17 has a molten slag discharge nozzle 20 and a fluid jet nozzle 21, and the fluid jet nozzle 21 is close to the molten slag discharge nozzle 20 and is at a position where the liquid atomization method can be applied to the molten slag 6. Be placed. The fluid jet nozzle 21 is provided with a fluid supply port 21a. The supply of the molten slag 6 to the molten slag discharge nozzle 20 is controlled by the open / close plug 23.

  Alternatively, as shown in FIG. 3, a rectifying guide 22 having a low thermal conductivity for a fluid jet is provided between the molten slag discharge nozzle 20 and the fluid jet nozzle 21 of the atomizer 17, and the fluid jet nozzle 21 serves as the rectification guide 22. The liquid atomization method may be disposed at a position close to the molten slag 6.

  The fluid jet nozzle 21 may be a gas (eg, argon, helium, nitrogen, water vapor) jet nozzle or a liquid (eg, water) jet nozzle.

  The atomizer 17 shown in FIG. 2 ejects fluid from the fluid jet nozzle 21 to increase the fluid jet pressure, monotonically increases the molten slag suction force, and the molten slag is discharged from the molten slag discharge nozzle 20, and coal gasification slag is obtained. Fiberization or atomization can be achieved. Further, the atomizer 17 shown in FIG. 3 provides higher heat insulation performance and increases the slag suction force in a wide fluid jet pressure range.

  Here, when performing fiberization, coal gasification slag with a high high temperature viscosity is used. In the case of atomization, coal gasification slag having a low high temperature viscosity is used.

  “High temperature viscosity” is the viscosity when the coal gasification slag is in a molten state.

  One of the parameters that determines the level of high temperature viscosity is the composition of coal gasification slag. Therefore, according to the present invention, the high temperature viscosity of the coal gasification slag obtained by adjusting the composition can be measured, and the optimum composition of the coal gasification slag for fiberization or atomization can be appropriately determined.

  Moreover, the judgment of the level of high temperature viscosity can also be judged from the shape of the coal gasification slag generated by the coal gasification treatment. For example, coal gasification slag having a high temperature viscosity has a lot of whiskers and needles. On the other hand, coal gasification slag with low high-temperature viscosity flows down in a thick columnar shape, and is water-pulverized to become granular. Therefore, according to the present invention, the shape of the slag obtained by adjusting the composition of the coal gasification slag can be observed, and the optimum composition of the coal gasification slag can be appropriately determined for fiberization or atomization.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, when the coal gasification slag cannot be adjusted to a desired composition only by using coal ash such as fly ash, an additive may be appropriately used as an auxiliary. For example, silica sand may be added as an additive containing a large amount of silica to increase the content of silica in fly ash, or clay powder may be added as an additive containing a large amount of alumina to increase the content of alumina in fly ash. You may make it raise a content rate. Moreover, you may make it adjust the content rate of calcium by using lime etc. as an additive, raise the fluidity | liquidity of coal gasification slag, and expand the operating range of a gasification furnace. It is also possible to use ores containing silica, alumina or the like as an additive within a range that does not significantly increase the cost.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1
China D coal was used as fuel coal for coal gasification treatment, and Australian N-coal fly ash and silica sand were mixed with this to adjust the composition of coal gasification slag, and the heating and foaming characteristics were examined.

Analysis of the composition of the ash component in China D coal as the fuel coal, the four major components _{(SiO 2, Al 2 O 3} , Fe 2 O 3, CaO) content to the total ash component of, SiO ₂ is 30. It was confirmed that 7 wt%, Al ₂ O ₃ was 12.0 wt%, Fe ₂ O ₃ was 10.6 wt%, and CaO was 33.8 wt%.

As a result of analyzing the composition of the ash component of Australian N charcoal fly ash, the content of the four main components (SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO) with respect to the total ash component is 48.7 wt% of SiO _2. %, Al ₂ O ₃ was 33.2 wt%, Fe ₂ O ₃ was 6.4 wt%, and CaO was 3.9 wt%.

As a result of analyzing the composition of the ash component of the silica sand, the content of the main four components (SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO) with respect to the entire ash component is 96.0% by weight of SiO ₂ , Al ₂ O ₃ was 2.6% by weight, and it was confirmed that Fe ₂ O ₃ and CaO were not contained.

  The mixing ratio of Australian N coal fly ash and silica sand to China D coal was 20 kg Australian N coal fly ash and 15 kg silica sand to 500 kg China D coal, and the total weight of the mixed sample was 535 kg.

  The ash component contained in 500 kg of Chinese D charcoal was 29 kg (5.8 wt%), and the ash component contained in the mixed sample was 64 kg (13.0 wt%).

  This sample is coal gasified in a coal gasification furnace (Central Research Institute of Electric Power) and coal gasification slag is sampled every hour, and the effect of the residual coal gasification slag generated in the previous test on the furnace wall Therefore, the composition analysis was performed on two samples (sample 1 and sample 2) under the condition that the composition was stable.

As a result of analyzing the composition of the ash component of Sample 1, the content of the four main components (SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO) with respect to the entire ash component was 55.3 wt% of SiO ₂ , Al ₂ O ₃ is 14.0 wt%, _Fe 2 _{O 3} is 6.6 wt%, CaO was confirmed to be 16.3 wt%.

As a result of analyzing the composition of the ash component of Sample 2, the content of the four main components (SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO) with respect to the total ash component was 55.9% by weight of SiO ₂ , Al ₂ O ₃ is 13.8 wt%, _Fe 2 _{O 3} is 6.0 wt%, CaO was confirmed to be 16.0 wt%.

Therefore, as shown in FIG. 4, the range of the composition ratio of coal gasification slag in which the heat foaming characteristics are improved by the addition of Australian N-coal fly ash and silica sand, that is, the silica content of the coal gasification slag is 50. It was revealed that the alumina content can be adjusted within the range of ˜60 wt% and the alumina content of 10˜30 wt%. In this experiment, silica sand was supplementarily added, but it is considered that the coal gasification slag can be adjusted to a desired composition by using fly ash having a high SiO ₂ content.

Next, the sample 1 and the sample 2 were heated at 900 ° C. to 1150 ° C. in an air atmosphere using a muffle furnace capable of setting an accurate temperature, and a heating foam test was performed. The results are shown in FIG. ■ in Fig. 5 shows the result of evaluation of the heating and foaming characteristics of coal gasification slag obtained by performing coal gasification using only 500 kg of Chinese D coal without mixing Australian N coal fly ash and silica sand. It is. Further, ◯ is the result of the heat foaming test of sample 1, and Δ is the result of the heat foaming test of sample 2. In coal gasification slag using only 500 kg of Chinese D coal, the absolute dry density was larger than 1.6 g / cm ^{3 at} any firing temperature, and it was confirmed that good foamability could not be obtained. On the other hand, about the sample 1 and the sample 2, it became 1.6 g / cm < ³ > or less which is the absolute dry density suitable for use as a fine aggregate by heating to the temperature of 1050 degreeC or more. Therefore, it is possible to adjust the composition ratio of coal gasification slag by mixing coal ash such as fly ash with fuel coal to be used for coal gasification combined power generation, and to effectively use it as artificial lightweight aggregate etc. It became clear that it would be possible. Moreover, it was confirmed that the coal gasification slag of sample 1 and sample 2 has higher fluidity than slag using only Chinese D coal. This is presumed to be caused by the addition of fly ash to the fuel coal, the CaO component of the coal gasification slag was relatively lowered, and the CaO content was adjusted to a fluidity increase. Is done. That is, by adjusting the composition of the coal gasification slag according to the present invention, it has been clarified that depending on the coal type, the fluidity of the coal gasification slag is increased and the operation range of the gasification furnace is expanded. .

It is a block diagram which shows an example of a gasification furnace. It is the schematic which shows a fiberization and atomization apparatus. It is the schematic which shows the other example of a fiberization and atomization apparatus. It is a figure which shows the composition of coal gasification slag which mix | blended the Australian N coal fly ash and silica sand with Chinese D coal, and was composition-adjusted. It is a figure which shows the result of the heating foaming characteristic test of the coal gasification slag which mix | blended the Australian N-coal fly ash and silica sand with Chinese D coal, and was composition-adjusted.

Explanation of symbols

1 Gasification furnace 6 Molten slag (coal gasification slag)

Claims (4)

  When performing coal gasification treatment by supplying fuel coal to a gasification furnace, the method includes supplying coal ash having a composition different from the ash component of the fuel coal to the gasification furnace, A method for producing coal gasification slag, comprising adjusting the composition of generated coal gasification slag.   The method for producing coal gasification slag according to claim 1, wherein fly ash generated in a coal-fired power generation facility is used as the coal ash. The method for producing coal gasification slag according to claim 1, wherein a waste incineration residue is used instead of the coal ash . According to claim 1, wherein the content of silica (SiO ₂₎ of the coal gasification slag is adjusted to 50-60 wt%, and adjusting the content of alumina _(Al 2 _{O 3)} 10 to 30 wt% A method for producing coal gasification slag.