KR102311207B1 - Method for Producing Asphalt Filler using Chlorine Bypass Dust Generated in a Cement Producing Process and Asphalt Filler made by the method - Google Patents

Abstract

The present invention relates to a method for producing an asphalt filler and an asphalt filler, and more specifically, to a method for producing an asphalt filler by using chlorine bypass dust generated in a cement producing process and an asphalt filler produced by the method. The method for producing an asphalt filler according to the present invention comprises: (a) a step of extracting combustion gas containing chlorine from a cement kiln exhaust gas flow path; (b) a step of injecting air to the extracted combustion gas and cooling the same below 400℃; (c) a step of separating coarse chlorine bypass dust (C) by injecting the cooled combustion gas into a cyclone; (d) a step of separating first fine chlorine bypass dust (D1) by passing the combustion gas passing the cyclone through a cooling device and cooling the same; (e) a step of separating second fine bypass dust (D2) by passing the combustion gas passing the cooling device through a back filter; and (f) a step of mixing the coarse bypass dust (C), the first fine chlorine bypass dust (D1), and second fine bypass dust (D1, D2).

Description

Method for Producing Asphalt Filler using Chlorine Bypass Dust Generated in a Cement Producing Process and Asphalt Filler made by the method

The present invention relates to a method for producing an asphalt fill and to an asphalt fill. More particularly, it relates to a method for producing an asphalt fill material using chlorine bypass dust generated in a cement manufacturing process, and to an asphalt fill material produced by the method.

The filler for asphalt pavement fills the gap between the aggregates in the asphalt mixture, and acts as a filler-binder in which the filler and the asphalt, which is a binder, are combined. Because of these characteristics of the filler material, the quality of the filler material is an important factor in the quality of the asphalt mixture.

According to the specifications of the filler material for asphalt pavement, the filler material is limestone powder, Portland cement, slaked lime, fly ash, recovered dust, electric furnace steelmaking dust, casting dust, various incineration ash and other suitable mineral powders. In general, limestone powder is mainly used as a filling material for asphalt pavement in industrial sites, and in factories that manufacture heated asphalt mixtures, collected dust collected when heating aggregates is mixed with limestone powder and used.

Portland cement and slaked lime are substances generated through an additional process after pyrolysis of limestone, and are not used well in industrial fields because they are considerably more expensive than limestone powder obtained by simply crushing limestone. In the case of fly ash, it is emitted from thermal power plants and is mostly used as a concrete admixture material, but it is ^{a light material with a density of 18 ~ 22g/cm 3} and the flow value among the quality characteristics according to the KS F 3501 asphalt pavement filler specification does not meet the specification. In many cases, it is not widely used. In addition, other electric furnace steelmaking dust and casting dust contain a large amount of heavy metals according to the characteristics of the generation process. Due to these problems, it is not widely used.

On the other hand, the conversion of wastes into cement raw materials and fuels is being promoted. However, as the amount of waste containing a large amount of synthetic resins increases, the amount of volatile components, such as chlorine, brought into the cement kiln is also increasing. Therefore, the chlorine bypass system which removes the chlorine content which causes problems, such as clogging of the preheater in a cement manufacturing facility, from the calcination system of a cement kiln is used.

As shown in FIG. 1, the chlorine bypass system extracts a part of combustion gas (G1) from the kiln exhaust gas flow path of the cement kiln 2 with the probe 3, and at the same time, cold air (A) from the cooling fan 4 ) to quench the extraction gas (G1), and separate the coarse powder (D1) with a cyclone (5). Further, the fine powder D2 in which chlorine contained in the extraction gas G3 is concentrated is recovered as the fine powder D4 by the bag filter 8 . The fine powder D4 and the fine powder D3 recovered from the cooler 6 are temporarily stored in a storage tank 9 as chlorine bypass dust D5, and are discharged and treated as waste by a method such as landfill.

As described above, the filler for asphalt pavement is an important factor in the quality of the asphalt mixture, but limestone powder, Portland cement, slaked lime, etc. used as main raw materials are expensive and not economical.

In addition, there is a cost to dispose of chlorine bypass dust generated by using waste as fuel in the cement manufacturing process. In particular, dust generated from chlorine bypass facilities installed in Korea is treated as waste, and most are disposed of in landfills. Currently, it is very difficult to obtain new permits for landfills due to domestic conditions, and landfills are avoiding chlorine bypass dust reclamation due to capacity limitations of landfills. Although research is being conducted on a water treatment method to replace the landfill of the dust generated by the chlorine bypass facility, it is expected that a considerable amount of time will be required because a large amount of money must be invested in constructing the treatment facility and the treatment process is difficult.

Recently, there is a demand to increase the amount of synthetic resin used in cement plants in order to solve environmental problems caused by synthetic resin waste treatment and reduce waste treatment costs. Accordingly, it is necessary to increase the chlorine bypass dust treatment facility in the cement plant. However, if the chlorine bypass facility is increased, the chlorine bypass dust treatment cost increases (increased landfill unit price, limited capacity of the landfill site), and the chlorine content of cement increases. As a result, there is a problem in that the cement is defective.

In particular, there is the following problem in that only the chlorine bypass facility cannot be increased to more than the capacity specified in the cement production facility in the existing cement plant of a fixed size. The high-temperature exhaust gas generated from the kiln (kiln) and preheater during the firing process during the cement production process is used in the process of producing mixed raw materials (mixed raw material drying), and this exhaust gas passes through the dust collector and then is discharged through the chimney. When the chlorine bypass facility is applied to this process, in order to cool the gas (900~1,000℃) extracted from the preheating chamber to 400℃ or less, the cooling air (25℃) is added 3 to 4 times. The cooled exhaust gas must be re-injected into the process of pulverizing the mixed material (if not re-injected, a separate stack and monitoring system (CleanSYS) must be established). At this time, since the amount of exhaust gas discharged during the mixed raw material grinding process is increased by about 1 to 5%, the capacity of the exhaust fan and dust collector must be increased by 1 to 5%. That is, it is difficult to increase the chlorine bypass facility in reality because it is required to increase the facility for the entire cement production facility.

The present invention is to solve the above problems, and an object of the present invention is to provide a method for producing an asphalt filler using chlorine bypass dust generated in the cement manufacturing process. In addition, an object of the present invention is to provide a new asphalt filler produced by the method of the present invention. According to the present invention, while producing and supplying asphalt filler material at a low price, at the same time reducing the waste treatment cost of chlorine bypass dust generated in a cement plant, and at the same time, the ability to treat synthetic resin waste in a cement plant without additional investment in chlorine bypass equipment A method is provided to increase the

According to one aspect of the present invention, there is provided a method for producing an asphalt filler using chlorine bypass dust generated in a cement manufacturing process. The method for producing asphalt filler according to the present invention comprises (a) extracting a combustion gas containing chlorine from a cement kiln exhaust gas flow path, and (b) cooling the extracted combustion gas to 400 ° C. or less by introducing air (c) introducing the cooled combustion gas into a cyclone to separate coarse chlorine bypass dust (C), (d) cooling the combustion gas passing through the cyclone through a cooler to cool the first fine powder A step of separating the chlorine bypass dust (D1), (e) a step of separating the second fine bypass dust (D2) by passing the combustion gas that has passed through the cooler through a bag filter, (f) the coarse powder bypass It includes the process of mixing pass dust (C), 1st fine powder chlorine bypass dust (D1), and 2nd fine powder chlorine bypass dust (D1, D2).

In some embodiments, after mixing the coarse bypass dust (C) and the first and second fine chlorine bypass dust (D1, D2), (g) screening the mixed asphalt fill to have a defined particle size and mass percentage It may further include a process of In addition, in some embodiments, the combustion gas in the cooler of the step (d) is preferably cooled to a temperature range of 100 ℃ to 200 ℃.

According to another aspect of the present invention, there is provided an asphalt filler comprising chlorine bypass dust generated in a cement manufacturing process.

Asphalt fill material according to the present invention, the coarse chlorine bypass dust (C) separated by introducing air into the combustion gas containing chlorine extracted from the cement kiln exhaust gas flow path and cooling it to 400 ° C. or less to pass through a cyclone; The first pulverized chlorine bypass dust (D1) separated by cooling the combustion gas passing through the cyclone to a temperature range of 100 ° C. to 200 ° C. by passing it through a cooler, and passing the combustion gas passing through the cooler through a bag filter and the separated second differential bypass dust D2.

According to the present invention, an environmentally friendly and inexpensive asphalt filler production method using chlorine bypass dust and a new asphalt filler manufactured by this method are provided. In addition, it is possible to reduce the waste treatment cost of chlorine bypass dust generated in the cement plant, and at the same time increase the synthetic resin waste treatment capacity in the cement plant without additional investment in chlorine bypass equipment.

In particular, when the asphalt filler is produced by the method according to the present invention, the efficiency of the chlorine bypass facility currently installed in the cement sand can be greatly increased. In addition, it is possible to process more synthetic resin waste without expanding the existing chlorine bypass facility, thereby reducing investment costs and reducing the amount of bituminous coal imports. In addition, it can help to solve environmental problems by reducing waste treatment costs and extending the lifespan of the landfill by changing the treatment method of chlorine bypass dust being landfilled.

1 is a schematic diagram of a chlorine bypass facility used in a conventional cement manufacturing process
Figure 2 is a schematic diagram for explaining a method of producing an asphalt fill material using chlorine bypass dust
3 is a table showing the particle size and mass % of the asphalt filler containing chlorine bypass dust according to the present invention;

Hereinafter, a method for producing an asphalt filler using chlorine bypass dust according to the present invention and an asphalt filler produced by the method will be described in detail with reference to the accompanying drawings.

Referring to Figure 2, the chlorine bypass system used in the cement production facility is installed in the exhaust gas flow path (m) of the kiln (a) and a probe (b) for extracting combustion gas containing chlorine, and blowing air A probe cooling fan (c) for cooling the combustion gas is provided. In addition, the cyclone (d) for separating the coarse chlorine bypass dust from the cooled combustion gas (G1), cooling the combustion gas (G2) passing through the cyclone (d) and separating the first fine chlorine bypass dust It is provided with a cooler (e) for. In addition, a bag filter (g) for separating the second fine chlorine bypass dust from the combustion gas (G3) that has passed through the cooler (e) is provided. A cooler fan f for supplying air is connected to the cooler e, and a bag filter fan i for discharging the combustion gas G3 is connected to the bag filter g. In addition, the cyclone (d), the cooler (e) and the bag filter (g) are connected to a storage tank (h) for receiving and mixing the coarse chlorine bypass dust (C) and the fine chlorine bypass dust (D1, D2). .

Hereinafter, a method for producing an asphalt filler according to the present invention will be described in detail. First, the combustion gas containing chlorine is extracted through the probe (b) installed in the kiln exhaust gas flow path (m). The temperature of the extracted combustion gas is in the range of 800 to 1100°C, and cooling air is blown into the probe cooling fan (c) to cool the combustion gas to 400°C or less. This is to cool a chlorine compound such as KCl contained in the combustion gas to below the melting point and discharge it as dust.

Next, the cooled combustion gas (G1) is introduced into the cyclone (d) to separate the coarse chlorine bypass dust (C). The coarse chlorine bypass dust C is formed by the chlorine compound sticking to the surface of the dust in the combustion gas G1. At this time, the cooling temperature of the combustion gas and the air volume of the probe cooling fan (c) are appropriately adjusted so that the particle size of the coarse chlorine bypass dust (C) is in the range of 300 µm - 600 µm.

Next, the combustion gas passing through the cyclone (d) is cooled by passing it through a cooler (e) to separate the first fine chlorine bypass dust (D1). As the cooler (e), air is supplied using a cooler fan (f) to cool the temperature of the combustion gas (G2) to be in the range of 100 to 200 °C. Next, the combustion gas passing through the cooler (e) is passed through the bag filter (g) to separate the second fine chlorine bypass dust (D2). At this time, the cooler fan f and the bag filter so that the particle size of the pulverized chlorine bypass dust D1 is in the range of 150 μm - 300 μm, and the particle size of the pulverized chlorine bypass dust D2 is in the range of 75 μm - 150 μm Adjust the air volume of the fan (i) appropriately. Next, in the storage tank (h), the coarse powder bypass dust (C), the first fine chlorine bypass dust (D1), and the second fine powder chlorine bypass dust (D1, D2) are collected and mixed.

The dust remaining in the combustion gas that has passed through the bag filter fan (i) has a low chlorine concentration and is fed back to the preheater of the cement production process and used as a raw material for cement.

In some embodiments, the asphalt filler collected and mixed in the storage tank (h) may be selected to have a particle size and a mass percentage suitable for the asphalt filler as shown in FIG. 3 .

In the case of operating a cement production plant by applying the process for producing the asphalt filler according to the present invention, it is possible to appropriately respond to changes in the operating conditions of the cement kiln, such as the concentration of chlorine supplied to the cement kiln. In the conventional cement manufacturing process shown in FIG. 1, it is configured to feed back the coarse chlorine bypass dust discharged to the cyclone to the preheater. In this case, for example, when the chlorine concentration of the raw material supplied to the cement kiln increases and it is necessary to remove more chlorine, the amount of gas extracted from the cement kiln (bypass rate) is increased, or the cyclone It is necessary to change the classification point of However, increasing the bypass rate leads to an increase in heat loss in the cement kiln, and it is difficult to frequently change the cyclone classification point during operation.

When operating a cement plant by the method according to the present invention, it is possible to stably operate the cement plant by appropriately adjusting the extraction amount of combustion gas according to the amount of chlorine contained in cement raw materials and synthetic resin waste. The table below compares the advantages of producing asphalt fillers. The comparative example in the table below is based on clinker production of 5,500 tons/day, and there may be differences depending on the equipment.

According to another aspect of the present invention, a novel asphalt fill is provided. Asphalt fill material according to the present invention, the coarse chlorine bypass dust (C) separated by introducing air into the combustion gas containing chlorine extracted from the cement kiln exhaust gas flow path and cooling it to 400 ° C. or less to pass through a cyclone; The first pulverized chlorine bypass dust (D1) separated by cooling the combustion gas passing through the cyclone to a temperature range of 100 ° C. to 200 ° C. by passing it through a cooler, and passing the combustion gas passing through the cooler through a bag filter and the separated second pulverized chlorine bypass dust (D2).

In some embodiments, it is preferable to use the asphalt filler selected to have a mass percentage passing through a sieve of a particle size as shown in FIG. 3 .

In some embodiments, the asphalt filler may further include fine limestone powder, dust collecting dust generated during heating of asphalt concrete, cement, and the like. The cement is either ordinary Portland cement, blast furnace slag cement, fly ash cement, ternary cement (blast furnace slag + fly ash + ordinary Portland cement) or four-component cement (blast furnace slag + fly ash + fine limestone powder + ordinary Portland cement). or a mixture of two or more may be used.

(a) kiln
(b) probe
(c) probe cooling fan
(d) cyclones
(e) cooler
(g) bag filter
(h) storage tank

Claims (5)

A method of producing asphalt fillers using chlorine bypass dust generated in the cement manufacturing process,
(a) extracting the combustion gas containing chlorine from the cement kiln exhaust gas flow path;
(b) a step of cooling the extracted combustion gas to 400 ° C. or less by introducing air;
(c) introducing the cooled combustion gas into a cyclone to separate coarse chlorine bypass dust (C);
(d) separating the first fine chlorine bypass dust (D1) by cooling the combustion gas that has passed through the cyclone through a cooler;
(e) separating the second fine chlorine bypass dust (D2) by passing the combustion gas that has passed through the cooler through a bag filter;
(f) mixing the coarse powder bypass dust (C), the first finely divided chlorine bypass dust (D1), and the second finely divided chlorine bypass dust (D1, D2). According to claim 1,
(g) Asphalt filler production method further comprising the step of screening the mixed asphalt filler material to have a particle size and mass percentage as shown in the table below.

According to claim 1,
In the cooler of the (d) process, the combustion gas is cooled to a temperature range of 100 °C to 200 °C. As an asphalt filling material containing chlorine bypass dust generated in the cement manufacturing process,
Crude chlorine bypass dust (C) separated by introducing air into the combustion gas containing chlorine extracted from the cement kiln exhaust gas flow path, cooling it to 400 ° C or less, and passing it through a cyclone;
The first fine chlorine bypass dust (D1) separated by cooling the combustion gas that has passed through the cyclone to a temperature range of 100°C to 200°C by passing it through a cooler;
Asphalt filling material comprising a second fine chlorine bypass dust (D2) separated by passing the combustion gas that has passed through the cooler through a bag filter. 6. The method of claim 5,
The asphalt filler is selected to have a particle size and mass percentage as shown in the table below.

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