KR101067390B1 - An apparatus for mixing coal and quicklime, and a method for removing water of coal and desulfurizing coal by using quicklime - Google Patents

Abstract

The present invention is a housing; A coal inlet formed at an upper portion of the housing and into which coal containing moisture is introduced; A quicklime inlet formed in an upper portion of the housing and into which quicklime (CaO) is introduced; A lower nozzle positioned under the housing to inject air into the housing; A mixing unit located above the lower nozzle to mix air, coal, and quicklime; An evaporating water outlet formed at an upper portion of the housing and discharging moisture removed from the coal by heat generated by the exothermic reaction of moisture in the coal and quicklime; And a mixing outlet formed at a lower portion of the housing to discharge calcined lime (Ca (OH) ₂ ) formed by a chemical reaction and dry coal from which moisture is removed by a chemical reaction.

Quicklime, Coal, High Moisture, Desulfurization, Moisture Removal

Description

Mixing apparatus of coal and quicklime, and method of removing and desulfurizing coal by using quicklime {AN APPARATUS FOR MIXING COAL AND QUICKLIME, AND A METHOD FOR REMOVING WATER OF COAL AND DESULFURIZING COAL BY USING QUICKLIME}

The present invention relates to a method of removing and desulfurizing coal by using a mixing device of coal and quicklime and quicklime, and more particularly, by using quicklime as a desulfurization reagent to remove moisture in coal to improve combustion efficiency and combustion stability of coal. In addition, the present invention relates to a coal mixing device capable of desulfurization even at a low temperature at the beginning of a combustion furnace, and a method for removing water and desulfurization of coal using quicklime.

In general, coal contains moisture. The higher the water content in the coal, the lower the quality of the coal. Combustion of high moisture quality coal causes the coal to be incompletely burned, releasing exhaust gases containing a large amount of harmful components such as sulfur dioxide or sulfur trioxide, resulting in environmental pollution. In addition, the high moisture coal blocks the coal handling equipment, such as a coal storage, a coal feeder, a hopper located under the combustion furnace, and causes a malfunction of the coal handling equipment.

Despite having the above problems, the high quality of coal has not attracted much attention because of the relatively low price of coal as a fuel. However, due to the recent rise in the price of imported coal coupled with a surge in oil prices, the need for coal is increasing.

High-quality coal is a low calorie-rich coal with high moisture, sulfur and ash, which is converted into high-calorie and low-sulfur coal through physical and chemical unit operations. Generally, ash is removed through a washing process, sulfur is removed through a desulfurization process, and moisture is removed by heating, cooling, adsorption, absorption and vacuum.

On the other hand, limestone was conventionally used as a desulfurization reagent to remove sulfur dioxide (SO ₂ ) generated during the combustion of coal. In general, limestone decomposes into quicklime (CaO) above 850 ° C according to chemical reaction formula (1). Decomposed quicklime (CaO) chemically reacts with sulfur dioxide (SO ₂ ) to produce calcium sulfate (CaSO ₄ ), in which sulfur dioxide (SO ₂ ) is removed from the combustion furnace.

CaCO _{3 → CaO + CO 2 - 42.52kcal /} mole (850 ℃ ~ reaction at 898 ℃) ... … … (One)

CaO + SO ₂ + ½ O ₂ → CaSO ₄ . … … … … … … … … … … … … … … … … … … … (2)

However, when the temperature of the combustion furnace is 900 ℃ or more, limestone decomposed into quicklime has only a residence time in the combustion furnace of only 5 to 6 seconds, and does not efficiently remove sulfur dioxide (SO ₂ ). In order to solve this problem, conventionally, an excessive amount of limestone is introduced into the combustion furnace, but this causes an increase in operating costs.

On the other hand, when the temperature of the furnace not more than 850 ℃, limestone does not remove the sulfur dioxide (SO ₂₎ generated during the combustion can not not produce sulfur dioxide, calcium oxide (CaO) a (SO ₂₎ and the chemical reaction of coal. Therefore, when the temperature of the combustion furnace is 850 ° C. or less, the harmful substances formed by the combustion of coal are discharged to the outside without desulfurization, thereby polluting the environment.

Accordingly, the present invention has been made to solve the above problems, the first object of the present invention is to improve the combustion efficiency and combustion stability of coal in the combustion furnace by removing moisture in the coal using quicklime. And a mixing device of quicklime.

A second object of the present invention is to provide a mixing device of coal and quicklime which prevents clogging of the coal handling facility by removing moisture in the coal by using quicklime to prevent operation failure of the coal handling facility.

The third object of the present invention is to use quicklime as a desulfurization reagent, to remove sulfur dioxide even at low temperatures at the beginning of the combustion furnace, and to be contained in the exhaust gas discharged to the outside of the combustion furnace due to its higher desulfurization efficiency than limestone. It is an object of the present invention to provide a method of water removal and desulfurization of coal using quicklime to reduce the concentration of sulfur.

The present invention is a housing; A coal inlet formed at an upper portion of the housing and into which coal containing moisture is introduced; A quicklime inlet formed in an upper portion of the housing and into which quicklime (CaO) is introduced; A lower nozzle positioned under the housing to inject air into the housing; A mixing unit located above the lower nozzle to mix air, coal, and quicklime; An evaporating water outlet formed at an upper portion of the housing and discharging water removed from the coal by heat generated by the exothermic reaction of moisture and quicklime in the coal; And a mixing outlet formed at a lower portion of the housing to discharge calcined lime (Ca (OH) ₂ ) formed by a chemical reaction and dry coal from which moisture is removed by a chemical reaction.

Coal and quicklime mixing device of the present invention is connected to the quicklime inlet is located inside the housing, it is rotatable, characterized in that it further comprises a rotating nozzle for evenly spraying the quicklime injected into the quicklime inlet into the housing.

The mixing portion is a plurality of screws rotatable spaced apart from each other; And a motor for rotating the plurality of screws.

The present invention is a method for removing the moisture of the coal supplied to the combustion furnace, and to remove sulfur dioxide (SO ₂ ) generated during the combustion of coal, (a) in the mixing device of coal and quicklime, coal containing moisture , Quicklime (CaO) and air are mixed; (b) exothermic reaction of the mixed quicklime and water, and the calcined lime (Ca (OH) ₂ ) is formed due to the exothermic reaction and heat is generated; (c) removing moisture from the coal by heat to form dry coal, and the moisture evaporated from the coal is discharged to the outside of the mixing device of coal and quicklime; (d) dry coal and slaked lime are discharged from the coal and quicklime mixing device; (e) feeding dry coal and slaked lime into the furnace; (f) in the combustion furnace, sulfur dioxide formed during the combustion of dry coal reacts with slaked lime to form calcium sulfate (CaSO ₄ ); And (g) calcium sulfate is discharged from the combustion furnace.

In step (a), the coal, quicklime and air are mixed with each other by a plurality of screws in the coal and quicklime mixing device.

The present invention configured as described above has the following effects.

The 1st effect of this invention is to make it possible to improve the combustion efficiency and combustion stability of coal in a combustion furnace by removing moisture in coal using quicklime.

A second effect of the present invention is to prevent clogging of the coal handling equipment by removing moisture in the coal using quicklime so as to prevent operation failure of the coal handling equipment.

The third effect of the present invention is that quick lime is used as a desulfurization reagent, so that sulfur dioxide can be removed even at a low temperature at the beginning of the combustion furnace, and the desulfurization efficiency is higher than that of limestone, so it is contained in the exhaust gas discharged to the outside of the furnace. It is to reduce the concentration of sulfur to prevent environmental pollution.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a side view of a coal and quicklime mixing device according to an embodiment of the present invention, Figure 2 is a front view of a coal and quicklime mixing device. Figure 3 is a schematic diagram showing the connection relationship with other structures of the coal and quicklime mixing device according to an embodiment of the present invention.

As shown in Figures 1 to 3, the present invention coal and quicklime mixing device 100 is a housing 110, coal inlet 111, quicklime inlet 112, rotary nozzle 113, lower nozzle 114 ), The mixing unit 120, the evaporation water outlet 130 and the mixing outlet 140.

Coal inlet 111 is formed on the upper portion of the housing (110). The coal (C) containing moisture is introduced into the housing 110 through the coal inlet 111.

The quicklime inlet 112 is formed at an upper portion of the housing 110. Quicklime (CaO) is introduced into the housing 110 through the quicklime inlet (112). The input of quicklime is 2.5 to 3.5 times the sulfur content of coal, which corresponds to 0.75 to 1.00% of the coal input.

On the other hand, the rotary nozzle 113 is located inside the housing 110. The rotating nozzle 113 is connected to the quicklime inlet 112 and is a rotatable nozzle. The rotary nozzle 113 evenly sprays the quicklime (Cao) injected into the quicklime inlet 112 evenly into the housing 110. The rotary nozzle 113 is positioned above the plurality of screws 121, 122, 123, and 124.

The lower nozzle 114 is positioned below the housing 110 to inject air A into the housing 110. Air A injected into the housing 110 through the lower nozzle 114 promotes contact between the quicklime Ca and the coal C in the housing 110. Flow rate of the air (A) injected through the lower nozzle 114 is 1.0 to 3.0 m / sec, the pressure of the air (A) is 0.1 to 0.2kg / cm ² to be.

Meanwhile, the mixing unit 120 includes a plurality of screws 121, 122, 123, and 124 and motors 125 and 126. The motors 125 and 126 are devices connected to the plurality of screws 121, 122, 123 and 124 and installed on the outer surface of the housing 110 to rotate the plurality of screws 121, 122, 123 and 124. .

The plurality of screws 121, 122, 123, and 124 are spaced apart from each other inside the housing 110. The plurality of screws 121, 122, 123, and 124 are positioned above the lower nozzle 114. The plurality of screws 121, 122, 123, and 124 are rotatable members that uniformly mix the coal C and the quicklime CaO while changing the rotation direction. In the mixing process, air (A) promotes contact between coal (C) and quicklime (CaO). Accordingly, quicklime (CaO) rapidly contacts with moisture in coal (C) to cause a chemical reaction. Chemical reaction formula (3) of water and quicklime (CaO) in coal (C) is as follows.

CaO + H ₂ O → Ca (OH) ₂ + 15.6 kcal / mole... … … … … … … … … … … … … … … (3)

Water in the coal C is removed by the heat (15.6 kcal / mole) generated by the chemical reaction 3, and the coal C becomes dry coal C _d . In addition, by the chemical reaction (3), quicklime (CaO) becomes calcined lime (Ca (OH) ₂ ). Therefore, dry coal (C _d ), calcined lime (Ca (OH) ₂ ) and moisture (M) removed from the coal are present in the housing 110.

Evaporation water outlet 130 is formed on the upper portion of the housing (110). Through the evaporation water outlet 130, the water (M) removed from the coal is discharged to the outside of the housing 110 together with the air (A).

On the other hand, the mixing outlet 140 is formed in the lower portion of the housing 110. Through the mixed discharge port 140, hydrated lime (Ca (OH) ₂ ) and dry coal (C _d ) is discharged to the outside of the housing (110). However, in this case, the dry coal (C _d ) and the slaked lime (Ca (OH) ₂ ) may be in a state of being aggregated with each other due to the chemical reaction (3).

The mixing outlet 140 is connected to the grinder 200. Compactor 200 receives supplies of coal and in the form of binary chunk from the mixing device 100 of the burnt lime dry coal (C _d) and calcium hydroxide (Ca (OH) _2), drying the binary chunk type of coal (C _d) and the calcium hydroxide (Ca (OH) ₂ ) is ground.

Dry coal (C _d ) and calcined lime (Ca (OH) ₂ ) pulverized in the crusher 200 are supplied to the combustion furnace 300. Dry coal (C _d ) is burned in the combustion furnace 300 to produce sulfur dioxide (SO ₂ ).

In the combustion furnace 300, calcined lime (Ca (OH) ₂ ) chemically reacts with sulfur dioxide (SO ₂ ) and oxygen ( ₄ ) to produce calcium sulfate (CaSO ₄ ), in the process of sulfur dioxide (SO ₂ ) Is removed.

Ca (OH) ₂ + SO ₂ + 1 / 2O ₂ → CaSO ₄ + H ₂ O... … … … … … … … … … … … … … … … (4)

Ca (OH) ₂ → CaO + H ₂ O (reaction at 580 ° C.). … … … … … … … … … … … … … … (5)

Ca (OH) ₂ → CaCO ₃ + H ₂ O + 5.77 kcal / mole. … … … … … … … … … … … … … … (6)

Meanwhile, the slaked lime (Ca (OH) ₂ ) formed according to the chemical reaction formula ( ₃ ) is converted to limestone (CaCO ₃ ) according to the chemical reaction formula (6) when the concentration of carbon dioxide (CO ₂ ) in the combustion furnace is high. However, hydrated lime (Ca (OH) ₂ ) formed according to chemical reaction formula (3) is converted to quicklime (CaO) at 580 ° C or higher according to chemical reaction formula (5), unless the concentration of carbon dioxide (CO ₂ ) in the combustion furnace is high. Decompose

The quicklime (CaO) produced according to the chemical reaction formula (5) generates a calcium sulfate (CaSO ₄ ) by chemical reaction (2) with sulfur dioxide (SO ₂ ) according to the above chemical reaction formula (2), and burns in the process. Sulfur dioxide (SO ₂ ) in the furnace 300 is removed.

Calcium sulfate (CaSO ₄ ) is stored in the hopper 311 below the combustion furnace 300 together with the coal ash 312 and is discharged to the outside 400 through the discharge pipe 410 connected to the hopper 311.

So far, the mixing apparatus 100 of coal and quicklime has been described with reference to FIGS. 1 to 3.

Hereinafter, referring to FIG. 4, the method of removing water and desulfurizing coal (C) will be described.

4 is a flowchart illustrating a method of removing water and desulfurization of coal using quicklime.

Water removal and desulfurization method of coal using the quicklime of the present invention is a method for removing the moisture of the coal supplied to the combustion furnace in the mixing device using the quicklime and to remove sulfur dioxide generated during the combustion of coal in the combustion furnace.

First, coal (C), quicklime (CaO), and air (A) containing moisture are introduced into the housing 110 of the mixing device 100 of coal and quicklime. Subsequently, coal (C), quicklime (CaO), and air (A) are mixed by the rotation of the plurality of screws 121, 122, 123, and 124 located inside the housing 110 (step S1).

As coal (C), quicklime (CaO) and air (A) are mixed with each other, quicklime (CaO) is brought into chemical reaction (3) in contact with moisture in coal (C), and Q) occurs. In addition, by the chemical reaction (3), quicklime (CaO) becomes hydrated lime (Ca (OH) ₂ ) (step S2).

On the other hand, with the heat Q generated by the chemical reaction 3, the coal C is dehydrated to become dry coal C _d . Water (M) removed from the coal is discharged to the outside of the housing 110 through the evaporation water outlet 130 (step S3).

Slaked lime (Ca (OH) ₂ ) and dry coal (C _d ) formed through the above-described process are discharged through the mixing outlet 140 (step S4).

Slaked lime (Ca (OH) ₂ ) and dry coal (C _d ) discharged through the mixing outlet 140 is pulverized in the crusher 200 is supplied to the combustion furnace 300 (step S5).

Dry coal (C _d ) is burned in the combustion furnace 300 to generate a harmful gas containing sulfur dioxide (SO ₂ ). Slaked lime (Ca (OH) ₂ ) chemically reacts with sulfur dioxide (SO ₂ ) to produce calcium sulfate (CaSO ₄ ), in which sulfur dioxide (SO ₂ ) in the furnace 300 is removed (S6). step).

Calcium sulfate (CaSO ₄ ) formed through the step S6 is stored in the hopper 311 located in the lower portion of the combustion furnace 300, discharge pipe 410 connected to the hopper 311 with the coal ash 312 in the hopper 311 Is discharged to the outside 400 through (S7 step).

So far, the method for removing water and desulfurization of coal using quicklime has been described.

Hereinafter, with reference to Tables 1 to 3, look at the experimental example for the water removal and desulfurization method of coal using quicklime.

Experimental Example

Table 1 shows the water removal rate in the coal according to the quicklime input ratio, Table 2 shows the water removal rate and the slaked lime production rate according to the total moisture content in the coal when the input of quicklime (CaO) is the same, and Table 3 shows the combustion rate of the combustion furnace The sulfur dioxide reduction rate according to the temperature-dependent desulfurization reagent is shown.

Referring to Table 1, we will look at the water removal rate in the coal according to the quicklime input ratio. Quicklime input ratio is the ratio of quicklime input to total moisture in coal (quicklime input / total moisture in coal).

division In coal (C)
Total water content (%) Quicklime charges
Moisture removal rate (%) 1 hour later 2 hours later Sample A 15.33 0 2.5 10.2 Sample B 14.43 0.47 10.0 22.9 Sample C 15.32 0.58 11.5 23.2 Sample D 14.51 0.67 13.5 23.7 Sample E 14.81 0.72 10.5 21.3 Sample F 19.92 0.76 13.3 25.1 Sample G 22.48 0.77 13.8 25.0 Sample H 17.45 1.18 19.7 31.9

Samples A to H shown in Table 1 are the same kind of coal. However, Samples A to H differ in total water content and quicklime input ratio in coal, respectively.

As shown in Table 1, when quicklime (CaO) was not introduced into the housing 110, only 2.5% of the total moisture was removed after 1 hour of coal (sample A). However, if quicklime (CaO) is introduced into the housing (110), for example, if quicklime (CaO) is added by 0.47 times the total water content in the coal, the water removal rate of coal (sample B) after 1 hour is 10 % And the moisture removal rate of coal (sample B) after 2 hours was 22.9%. In addition, when quicklime (CaO) was added by 1.18 times the total water content in coal, the water removal rate of coal (sample H) after 1 hour was 19.7%, and the water removal rate of coal (sample H) after 2 hours was 31.9%. It was.

Through Table 1, it can be seen that as the quicklime input ratio increases, the water removal rate increases.

Hereinafter, referring to Table 2, when the input amount of quicklime is the same, the water removal rate and the slaked lime production rate according to the type of coal will be described. The rate of slaked lime production is the ratio of the amount of slaked lime produced to the total amount of slaked lime (the amount of slaked lime / totaled slaked). The chemical reaction of quicklime with moisture in coal follows the chemical reaction formula (3). In addition, experimental conditions were as follows. Quicklime input ratio (quicklime input / total water content in coal): 0.27, Rotational speed of the mixing device of coal and quicklime: 20 rpm.

Coal A test shot 1 A test shot 2 Trial 3 Total water content in coal (%) 9% 12% 16% Moisture removal rate (%) 13.3 19.2 20.5 Slag production rate (%) 72.4 85.1 83.9

As shown in Table 2, even when the quicklime input ratio (= 0.27) by type of coal was the same, when the total water content in the coal was 9% (test coal 1), the water removal rate was only 13.3%, but the total water content in the coal was In the case of 16% (test bullet 3), the water removal rate was 20.5%. From Table 2, it can be seen that the water removal rate increases as the total water content in the coal increases. Accordingly, quicklime is effective in removing moisture in coal.

On the other hand, since quicklime (CaO) reacts with water in the coal to generate calcined lime, the calcined lime (Ca (OH) ₂ ) produced by the chemical reaction (3) has a small amount of total moisture in the coal even when the calcined lime input ratio is the same. It is more produced when the total amount of moisture in coal is higher.

Hereinafter, with reference to Table 3, it looks at the sulfur dioxide reduction rate according to the desulfurization reactant for each combustion temperature of the combustion furnace.

Desulfurization Reagent
Sulfur dioxide reduction rate (%) 500 ℃ 600 ℃ 700 ℃ 800 ℃ 900 ℃ Limestone 0 2.2 7.5 68.3 75.6 quicklime 21.0 58.4 92.3 95.2 94.7

The results shown in Table 3 were obtained under the following conditions.

Combustion operating time: 8 hours

Coal: Imported anthracite coal containing 0.55% sulfur and 10% moisture,

Coal input speed: 5kg / hr,

Ca / S molar ratio: 2.7,

Limestone input: 208gr / hr,

Quicklime input: 117 gr / hr.

In general, limestone has conventionally been used as a desulfurization reagent. Limestone (CaCO ₃ ) is decomposed into quicklime (CaO) at 850 ° C. or higher according to the chemical reaction formula (1) described above. The calcium oxide (CaO) decomposition from limestone is sulfur dioxide (SO ₂₎ in the furnace in the process of combustion generates sulfur dioxide (SO ₂₎ and calcium sulphate to the chemical reaction within the furnace according to the above chemical equation (2), and removed .

Through Table 3, it can be seen that limestone has a desulfurization effect of removing 75.6% of sulfur dioxide (SO ₂ ) at 900 ° C. or more in which limestone is decomposed into quicklime (CaO). However, limestone does not remove sulfur dioxide (SO ₂ ) in the combustion furnace at a temperature lower than 800 ° C. at which limestone cannot be decomposed into quicklime (CaO).

On the other hand, in the present embodiment, the quicklime (CaO) used as the desulfurization reactant is introduced into the mixing device 100 of coal and quicklime to be chemically reacted with moisture in the coal (3) to become slaked lime (Ca (OH) ₂ ) It is put into the furnace in the state. Calcined lime (Ca (OH) ₂ ) chemically reacts with sulfur dioxide (SO ₂ ) in the furnace to produce calcium sulfate, in which sulfur dioxide (SO ₂ ) in the furnace is removed.

Calcined lime (Ca (OH) ₂ ) is decomposed into quicklime (CaO) at 580 ° C. or higher according to the above chemical reaction formula (5). The quicklime (CaO) produced according to Chemical Reaction (5) is chemically reacted with sulfur dioxide (SO ₂ ) in the furnace to produce calcium sulfate, and in this process, sulfur dioxide (SO ₂ ) in the furnace is removed.

Table 3 shows that quicklime (CaO) removes sulfur dioxide (SO ₂ ) in a combustion furnace from 500 ° C or higher, unlike when limestone is used as a desulfurization inhibitor. In addition, the desulfurization efficiency of quicklime (CaO) is higher than that of limestone, about 56% above 600 ° C, about 85% above 700 ° C, about 27% above 800 ° C, and about 20% above 900 ° C. Able to know. Therefore, when the quicklime (CaO) is used as the desulfurization reagent, the sulfur concentration of the exhaust gas discharged from the combustion furnace is prevented than the case where the limestone is used as the desulfurization reactant to prevent environmental pollution.

The exemplary embodiments described above are intended to be illustrative, not limiting, in all aspects of the invention. Accordingly, the present invention is capable of many modifications and detailed implementations which may be obtained from those contained within the specification by those skilled in the art. All such modifications and variations are to be considered as within the scope and spirit of the invention as defined by the following claims.

1 is a side view of a mixing device of coal and quicklime according to an embodiment of the present invention.

2 is a front view of a coal and quicklime mixing device according to an embodiment of the present invention.

Figure 3 is a schematic diagram showing the connection relationship with other structures of the coal and quicklime mixing device according to an embodiment of the present invention.

Figure 4 is a flow chart for the water removal and desulfurization method of coal using quicklime according to an embodiment of the present invention.

Claims (5)

housing; A coal inlet formed at an upper portion of the housing and into which coal containing moisture is introduced; A quicklime inlet formed in an upper portion of the housing and into which quicklime (CaO) is introduced; A lower nozzle positioned under the housing to inject air into the housing; A mixing unit located above the lower nozzle to mix the air, the coal, and the quicklime; An evaporating water outlet formed on an upper portion of the housing and discharging water removed from the coal by heat generated by an exothermic reaction of moisture in the coal and the quicklime; And The mixing device of the coal and quicklime formed in the lower portion of the housing, comprising a mixed discharge port for discharging the dried coal (Ca (OH) ₂ ) formed by the chemical reaction and the moisture is removed by the chemical reaction . According to claim 1, wherein the coal and quicklime mixing device And a rotating nozzle connected to the quicklime inlet and positioned inside the housing to be rotatable, to evenly spray the quicklime injected into the quicklime inlet into the housing. The method of claim 1, wherein the mixing unit A plurality of screws rotatable spaced apart from each other; And Mixing device for coal and quicklime, characterized in that it comprises a motor for rotating the plurality of screws. In the method for removing the moisture of the coal supplied to the combustion furnace, and remove sulfur dioxide (SO ₂ ) generated during the combustion of the coal, (a) mixing coal and quicklime (CaO) and air containing water in a mixing device of coal and quicklime; (b) exothermic reaction between the mixed quicklime and moisture, and the calcined lime (Ca (OH) ₂ ) is formed and heat is generated by the exothermic reaction; (c) removing the moisture from the coal by the heat to form dry coal, and discharging the moisture evaporated from the coal to the outside of the mixing device of the coal and quicklime; (d) discharging the dry coal and the slaked lime from the mixing device of the coal and quicklime; (e) feeding the dry coal and the slaked lime into the combustion furnace; (f) in the combustion furnace, the sulfur dioxide formed during the combustion of the dry coal reacts with the slaked lime to form calcium sulfate (CaSO ₄ ); And (g) water removal and desulfurization of coal using quicklime, characterized in that the calcium sulfate is discharged from the combustion furnace. The method of claim 4, wherein In the step (a), the coal, the quicklime and the air is a water removal and desulfurization method of coal using quicklime, characterized in that the mutual mixing by a plurality of screws in the mixing device of the coal and quicklime.

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