KR102218339B1 - Method for producing high purity slaked lime and using by-product gypsum - Google Patents

Abstract

Disclosed in the present invention is a method for manufacturing slaked lime using by-product gypsum, which includes the steps of: a solvent mixing step of mixing a solvent containing a strong alkali and water with by-product gypsum to form reaction slurry; a reaction step of generating slaked lime by reacting the by-product gypsum with the strong alkali of the solvent in the reaction slurry; and a washing step of washing the reaction slurry with water to remove ionic components and separate slaked lime. Additionally, disclosed in the present invention is a method for manufacturing quicklime, which further includes a calcination step of calcining the prepared slaked lime at a calcination temperature of 500 to 700°C to form the quicklime. Therefore, it is possible to minimize the content of by-products produced while using the by-product gypsum as a raw material.

Description

Method for producing slaked lime and quicklime using Busan gypsum {Method for producing high purity slaked lime and using by-product gypsum}

The present invention relates to a method for preparing slaked lime and a method for preparing slaked lime, which can minimize the generation of impurities such as Na ₂ SO ₄ by preparing slaked lime using Busan gypsum.

Lime materials such as slaked lime and quicklime are materials used in various industries. In general, limestone (CaCO ₃ ) is calcined at high temperature to produce quicklime (CaO), or quicklime (CaO) reacts with water (H ₂ O). A method made of slaked lime (Ca(OH) ₂ ) is used. In this method, a large amount of carbon dioxide (CO ₂ ) is generated in the process of converting limestone into quicklime.

Meanwhile, in order to mitigate climate change, many countries around the world, including Korea, are reinforcing the reduction of carbon dioxide emissions for the purpose of responding to climate change and reducing greenhouse gases.

Recently, various studies have been conducted to solve the problem of greenhouse gas emission in the production process of lime material. As one of them, a method of making slaked lime and quicklime using phosphate gypsum is being developed. However, this method is still a problem because the purity of slaked lime or quicklime is too low as by-products such as Na ₂ SO ₄ are generated together with slaked lime.

An object of the present invention is to provide a method for producing slaked lime and a method for producing quicklime using by-products that can minimize the content of by-products generated while using by-product gypsum as a raw material.

In the method for preparing slaked lime using by-product gypsum of the present invention, a solvent mixing step of forming a reaction slurry by mixing a solvent containing a strong base and water with the by-product gypsum, and a strong base of the solvent in the reaction slurry reacts to form slaked lime. It characterized in that it comprises a reaction step to generate and washing the reaction slurry with water to remove ionic components and to separate slaked lime.

In addition, the method for producing slaked lime using busan gypsum of the present invention may further include a pulverizing step of pulverizing the busan gypsum to 10 mesh or less before the solvent mixing step.

In addition, the busan gypsum is a phosphate gypsum or desulfurized gypsum containing CaSO ₄ , and the strong base may be a basic solution having an -OH group.

In addition, the strong base may be NaOH.

In addition, the strong base may be KOH.

In addition, the busan gypsum is a phosphate gypsum or desulfurized gypsum containing CaSO ₄ , and the strong base may be an aqueous solution of ammonium (NH3).

In addition, the strong base is the calcium of Busan gypsum (Ca ²⁺⁾ and OH ^- can be mixed so that the ^- (/ Ca ²⁺ OH) is 1.5 to 1.9 molar ratio.

In addition, the solvent may be mixed with the water to be 270 to 320 (ml) based on 100 g of the weight of the Busan gypsum.

Further, the reaction step may be performed for at least 5 to 30 minutes.

In addition, the slaked lime may be included in at least 90% by weight of the total weight of the solid components after the washing step.

In addition, in the method for preparing slaked lime using busan gypsum of the present invention, slaked lime is prepared by mixing a solvent containing NaOH and water, which is a strong base, with a busan gypsum containing CaSO ₄ , and the strong base and the busan gypsum are calcium (Ca ²⁺ ) and OH ^- molar ratio of (OH ^- / Ca ²⁺⁾ are mixed such that 1.5 to 1.9, wherein said solvent is characterized in that the water is mixed at a 270 to 320 (ml) weight 100g preparation of the gypsum Busan .

In addition, the method for producing quicklime using Busan gypsum of the present invention is characterized in that it includes a firing step of firing the slaked lime at a firing temperature of 500 to 700°C to form quicklime.

In addition, the quicklime may be included in at least 90% by weight of the total weight of solid components formed after the firing step.

The slaked lime manufacturing method and quicklime manufacturing method using the Busan gypsum of the present invention can minimize the generation of by-products such as Na ₂ SO ₄ while using the Busan gypsum as a raw material.

1 is a flowchart of a method of manufacturing slaked lime and a method of manufacturing quicklime using Busan gypsum according to an embodiment of the present invention.
2 to 9 are XRD graphs of the solid components of Examples 1 to 8 according to the method of manufacturing slaked lime using Busan gypsum of the present invention.
10 to 14 are XRD graphs of solid components of Comparative Examples 1 to 5 for the method of manufacturing slaked lime using Busan gypsum of the present invention.
15 is an XRD graph of the solid component according to the quicklime production method using Example 2 according to the slaked lime production method using Busan gypsum of the present invention.

Hereinafter, a method of manufacturing slaked lime and a method of manufacturing quicklime using Busan gypsum according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings and examples.

First, a method of manufacturing slaked lime using Busan gypsum according to an embodiment of the present invention will be described.

1 is a flowchart of a method of manufacturing slaked lime using Busan gypsum according to an embodiment of the present invention.

The method for producing slaked lime using Busan gypsum of the present invention, referring to FIG. 1, includes a solvent mixing step (S20), a reaction step (S30), and a washing step (S40). In addition, the method of manufacturing slaked lime using the Busan gypsum may further include a Busan gypsum crushing step (S10).

In addition, the method for producing quicklime using Busan gypsum of the present invention may include a firing step (S50) of firing the quicklime according to the slaked lime production method, referring to FIG. 1.

In the method for preparing slaked lime using Busan gypsum, the slaked lime is prepared by using a solvent in which NaOH, which is a strong base, and water are mixed. The slaked lime manufacturing method using the by-product gypsum can minimize the generation of by-products such as Na ₂ SO ₄ generated in the half process by controlling the concentration of a strong base and the amount of the solvent. More specifically, the slaked lime method using the gypsum is calcium Busan Busan gypsum (Ca ²⁺⁾ and OH ^- produced by mixing the calcium hydroxide is a strong base that is from 1.5 to 1.9 ^- (/ Ca ²⁺ OH) mol ratio of can do. In addition, in the method for preparing slaked lime using Busan gypsum, a solvent may be mixed in an amount of 270 to 320 (ml) based on 100 g of the weight of the Busan gypsum.

Here, the by-product gypsum refers to gypsum generated as a by-product of various industrial activities, such as phosphate gypsum (phosphogypsum) and desulfurization gypsum (Flue Gas Desulfurization Gypsum). The phosphate gypsum is a gypsum generated during the production of phosphorus fertilizer, and the desulfurized gypsum may be a gypsum generated in a process of absorbing and removing sulfur oxides generated when fuel is burned in a thermal power plant. The Busan gypsum may contain CaSO ₄ . In addition, the Busan gypsum may be made of a component of CaSO _{4 ·} 2H ₂ O.

The Busan gypsum crushing step (S10) is a step of pulverizing the Busan gypsum into a powder having a predetermined size or less. Since the byproduct gypsum is a reaction by-product, the size of the powder may be different and may include a large powder. Since the by-product gypsum reacts while being in contact with a solvent, it is advantageous to have a relatively small and even powder size. The Busan gypsum may preferably be crushed to less than 10 mesh. In addition, the Busan gypsum may be selected only a size of 10 mesh or less through sieving after grinding.

The solvent mixing step (S20) is a step of forming a reaction slurry by mixing a solvent containing a strong base and water with the by-product gypsum. The strong base and water may be first mixed with a solvent and then mixed with the Busan gypsum. In addition, the strong base and water may be mixed with the Busan gypsum, respectively. Hereinafter, a description will be given focusing on a case where a strong base and water are first mixed with a solvent and then mixed with the by-product gypsum.

The strong base may be a basic solution having an -OH group. The strong base may be a NaOH solution. The strong base may be a 40% NaOH solution. The strong base may be a KOH solution. The strong base may be an aqueous ammonia (NH ₃ ) solution. The strong base may be mixed with the Busan gypsum in a certain ratio. At this time, the strong base may be mixed in a certain ratio so that by-products such as Na ₂ SO ₄ are not generated. Hereinafter, the case where the strong base is NaOH solution will be mainly described. The strong base may be mixed in an unsaturated content in relation to the content of Na ⁺ and Ca ²⁺ . More specifically, the strong base is ^may be mixed so as to provide a 1.5 to 1.9 molar ratio of (OH / Ca ^2+). The Busan gypsum contains various Ca compounds in which Ca ²⁺ is combined with various components (fluorine, phosphorus, etc.) in addition to CaSO ₄ ·2H ₂ O, and it was confirmed that all of these Ca compounds may not be dissolved in a strong base. Accordingly, in the present invention, the strong base may be mixed in a content lower than 2:1, which is the molar ratio of the theoretical reaction formula with the by-product gypsum. In the present invention, the molar ratio was in the range of 1.5 to 1.9 so that the by-product gypsum was completely dissolved. Since the content of the strong base is relatively small, it is possible to reduce the amount of by-products such as Na ₂ SO ₄ generated by the reaction between Na + and SO ₄ ^{2- of} by-product gypsum.

If the molar ratio of the strong base is too low, the formation ratio of slaked lime may be low. That is, the rate at which the Busan gypsum is converted into slaked lime may be low. If the molar ratio of the strong base is too high, Na ⁺ and SO ₄ ^2- may react, thereby increasing the amount of by-products such as Na ₂ SO ₄ . That is, a large amount of precipitated Na ₂ SO ₄ is generated by the common ion effect, and the purity of slaked lime may be lowered. On the other hand, it is possible to control the purity of slaked lime prepared by adjusting the mixing molar ratio of the strong base.

The solvent may be mixed in an amount of 270 to 320 (ml) based on 100 g of Busan gypsum. That is, the solvent may be 2.7 to 3.2 times by volume compared to the weight of the Busan gypsum. The solvent ^- are mixed with (OH / Ca ²⁺⁾ molar ratio of the strong base is a mixture such that from 1.5 to 1.9 of the water is low. The solvent is dissolved in an ionic state with the by-product gypsum and a strong base. In addition, the solvent separates Na ⁺ and SO ₄ ^{2- so} that it does not precipitate as Na ₂ SO ₄ and exists in an ionic state. In addition, the solvent allows the generated Na ₂ SO ₄ to be dissolved in Na ⁺ and SO ₄ ^2- . If the content of the solvent is too small, Na ⁺ and SO ₄ ^2- react in the process of formation of slaked lime due to a common ion effect, and by-products such as Na ₂ SO ₄ may be generated. If the content of the solvent is too high, the secondary treatment amount to be treated with wastewater after the reaction may be increased. Meanwhile, the purity of slaked lime prepared may be adjusted by adjusting the mixing amount of the solvent.

The reaction step (S30) is a step of producing slaked lime by reacting by-product gypsum and a strong base of a solvent in the reaction slurry. The reaction step (S30) may be performed while the Busan gypsum and the strong base are mixed in the solvent mixing step (S20).

The by-product gypsum and the solvent may produce slaked lime according to the reaction formula of Equation 1) below.

Ca compound + xNaOH → Ca(OH) ₂ + xNa ⁺ + SO ₄ ^2- + 2H ₂ O --- Equation 1)

(Here, the Ca compound includes CaSO ₄ ·2H ₂ O and various Ca compounds contained in Busan gypsum. x is 1.5 ~ 1.9)

The strong base in the reaction slurry is Na ⁺ and OH ^- are dissolved in, the Busan gypsum Ca + and a strong base OH ^- are combined to form a slaked lime. In addition, since Na ⁺ of the strong base is present in an amount less than the theoretical molar ratio in the reaction slurry, the reaction with SO ₄ ^2- is minimized, and the formation of Na ₂ SO ₄ is minimized. Further, according to the content of Na ⁺ is Na + may not be a Na ₂ SO ₄ produced does not react with the SO ₄ ^2-. That is, SO ₄ ^2- of the by-product gypsum and Na ⁺ of a strong base do not react with each other in the reaction slurry, and may remain separated. Accordingly, in the present invention, Na ₂ SO _{4, which} is a reaction by-product generated in the conventional method, may not be generated or may be generated to a minimum. The reaction slurry may be formed in a state in which slaked lime and unreacted ions SO ₄ ² and Na ⁺ coexist. In addition, the reaction slurry may contain other solid components that are reaction by-products.

The reaction step (S30) may be performed at room temperature. The reaction step may proceed for at least 5 to 30 minutes. In addition, in the reaction step (S30), stirring may be performed in a state in which the Busan gypsum and the solvent are mixed. In this case, the by-product gypsum and the solvent can react more efficiently.

The washing step (S40) is a step of washing the reaction slurry with water to remove SO ₄ ^2- and Na ⁺ to separate slaked lime. In the reaction slurry, SO ₄ ^2- and Na ⁺ , which are ionic components present in an ionic state, are present together with slaked lime produced by the reaction. The washing step removes SO ₄ ^2- and Na ⁺ present together with slaked lime in the reaction slurry. Therefore, in the washing step (S40), a solid component including slaked lime may be separated and recovered from the reaction slurry. The washing step (S40) may be performed by first separating the solid component from the reaction slurry and washing the solid component with water. In the reaction slurry, other solid components such as SO ₃ and Na ₂ O may be present together as by-products depending on the type of by-product gypsum during the reaction process. In addition, the slurry may further contain by-products such as CaCO _3, and CaCO ₃ may be generated by absorbing a part of carbon dioxide (CO ₂ ) gas in the air by prepared Ca(OH) ₂ . The slaked lime may contain at least 90% by weight of Ca(OH) ₂ in the total content of solid components.

The firing step (S50) is a step of firing slaked lime at a predetermined firing temperature to produce quicklime. The firing step may be performed at a firing temperature of 500 to 700°C. The quicklime (CaO) produced in the firing step (S50) may be included in at least 90% by weight of the total weight of the solid components formed after the firing step (S50).

Next, specific examples of the slaked lime manufacturing method and quicklime manufacturing method of the present invention will be described.

2 to 9 are XRD graphs of the solid components of Examples 1 to 8 according to the method of manufacturing slaked lime using Busan gypsum of the present invention. 10 to 14 are XRD graphs of solid components of Comparative Examples 1 to 5 for the method of manufacturing slaked lime using Busan gypsum of the present invention. 15 is an XRD graph of the solid component according to the quicklime production method using Example 2 according to the slaked lime production method using Busan gypsum of the present invention.

<Example 1>

In Example 1, phosphate gypsum was used as Busan gypsum. It was mixed so that the / Ca ²⁺ molar ratio of ^1.5 with phosphoric acid gypsum strong base is OH. In addition, the solvent was mixed in a volume of 2.9 times the weight of phosphate gypsum. That is, the solvent was mixed with 290 mL in 100 g of gypsum phosphate. The prepared reaction slurry was reacted with stirring for 30 minutes. After the solid component was first separated from the reaction slurry, the separated solid component was washed to remove the ionic component. The washed solid component was dried to prepare slaked lime. The crystal structure of slaked lime was observed using XRD.

<Example 2>

Example 2 is a phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed at a 1.7. In addition, the solvent was mixed in a volume of 2.8 times the weight of the phosphate gypsum.

The rest of Example 2 was the same as in Example 1.

<Example 3>

Example 3 is a phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed at a 1.7. In addition, the solvent was mixed in a volume of 3.0 times the weight of the phosphate gypsum.

The rest of Example 3 was the same as Example 1.

<Example 4>

Example 4 is a phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed so that 1.9. In addition, the solvent was mixed in a volume of 2.9 times the weight of phosphate gypsum.

The rest of Example 4 was the same as Example 1.

<Example 5>

Example 5 is a phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed so that 1.9. In addition, the solvent was mixed in a volume of 3.1 times the weight of the phosphate gypsum.

The rest of Example 5 was the same as Example 1.

<Example 6>

In Example 6, desulfurized gypsum was used as Busan gypsum. Example 6 is a desulfurization gypsum and a strong base OH ^- is the molar ratio of / Ca ²⁺ were mixed so that 1.6. In addition, the solvent was mixed in a volume of 2.9 times the weight of phosphate gypsum.

The rest of Example 6 was the same as Example 1.

<Example 7>

Example 7 is a desulphurization gypsum with a strong base OH ^- is the molar ratio of / Ca ²⁺ were mixed so that 1.9. In addition, the solvent was mixed in a volume of 2.8 times the weight of the phosphate gypsum.

The rest of Example 7 was the same as Example 6.

<Example 8>

Example 8 is a desulfurization gypsum and a strong base OH ^- is the molar ratio of / Ca ²⁺ were mixed so that 1.9. In addition, the solvent was mixed in a volume of 3.0 times the weight of the phosphate gypsum.

The rest of Example 8 was the same as in Example 6.

<Comparative Example 1>

In Comparative Example 1, phosphate gypsum was used as Busan gypsum. Comparative Example 1 is the phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed at a 1.3. In addition, the solvent was mixed in a volume of 2.8 times the weight of the phosphate gypsum.

The rest of Comparative Example 1 was the same as in Example 1.

<Comparative Example 2>

Comparative Example 2 is a phosphoric acid and a strong base plaster OH ^- molar ratio of / Ca ²⁺ were mixed so that 1.9. In addition, the solvent was mixed in a volume of 2.6 times the weight of the phosphate gypsum.

The rest of Comparative Example 2 was the same as in Example 1.

<Comparative Example 3>

In Comparative Example 3, desulfurized gypsum was used as Busan gypsum. Comparative Example 3 is the desulfurization gypsum and strongly basic OH ^- is the molar ratio of / Ca ²⁺ were mixed so that 1.4. In addition, the solvent was mixed in a volume of 2.8 times the weight of the phosphate gypsum.

The rest of Comparative Example 3 was the same as in Example 1.

<Comparative Example 4>

Comparative Example 4 is a desulphurization gypsum with a strong base OH ^- and mixed with a molar ratio of / Ca ²⁺ to 2.1. In addition, the solvent was mixed in a volume of 2.6 times the weight of the phosphate gypsum.

The rest of Comparative Example 4 was the same as in Example 1.

<Comparative Example 5>

Comparative Example 5 is a desulfurization gypsum and a strong base OH ^- and mixed with a molar ratio of / Ca ²⁺ to 2.1. In addition, the solvent was mixed in a volume of 3.1 times the weight of the phosphate gypsum.

The rest of Comparative Example 5 was the same as in Example 1.

Constituents of Examples and Comparative Examples are summarized in Tables 1 and 2.

number Busan plaster
Kinds Molar ratio
(OH ^- / Ca ²⁺⁾ Solvent ratio XRD
result Example 1 Phosphate plaster 1.5 2.9 times Figure 2 Example 2 1.7 2.8 times Figure 3 Example 3 1.7 3.0 times Fig. 4 Example 4 1.9 2.9 times Figure 5 Example 5 1.9 3.1 times Fig. 6 Example 6 Desulfurization plaster 1.6 2.9 times Fig. 7 Example 7 1.9 2.8 times Fig. 8 Example 8 1.9 3.0 times Fig. 9

number Busan plaster
Kinds The molar ratio (OH ^- / Ca ²⁺⁾ Solvent ratio XRD
result Comparative Example 1 Phosphate plaster 1.3 2.8 times Fig. 10 Comparative Example 2 1.9 2.6 times Fig. 11 Comparative Example 3 Desulfurization plaster 1.4 2.8 times Fig. 12 Comparative Example 4 2.1 2.6 times Fig. 13 Comparative Example 5 2.1 3.1 times Fig. 14

Component analysis was performed on the solid components according to Examples 1 to 8 using XRD. XRD graphs of the solid components of Examples 1 to 8 are shown in FIGS. 2 to 9. 2 to 9, in Examples 1 to 8, the peak of slaked lime (Ca(OH) ₂ ) was mainly observed, and it can be seen that slaked lime (Ca(OH) ₂ ) constitutes the main component. In addition, in Examples 1 to 8, a small amount of by-products such as CaCO ₃ were detected depending on the type of the by-products gypsum. Examples 1 to 8 it can be seen that not detected the peak of Na ₂ SO ₄ Na ₂ SO ₄ is not generated. Meanwhile, SiO ₂ is considered to be an impurity contained in the Busan gypsum.

In addition, the content of slaked lime was analyzed through XRF analysis for the solid component of Example 2. In the solid component of Example 2, the content of slaked lime was 91.27% by weight, and the rest was identified as by-products such as SO ₃ and Na ₂ O in addition to SiO ₂ . Therefore, in Example 2, the content of slaked lime was confirmed to be 90% by weight or more.

On the other hand, Comparative Example 1, FIG. 10, the ^{result is} confirmed that the molar ratio of (OH / Ca ²⁺⁾ low of unreacted residual Busan gypsum with calcium hydroxide. In addition, in Comparative Example 1, impurities such as SiO ₂ were detected.

In Comparative Example 2, referring to FIG. 11, it can be seen that Na ₂ SO ₄ is generated because the content of the solvent is low. Also, in Comparative Example 2, impurities such as SiO ₂ were detected.

Comparative Example 3, Referring to Figure 12, the ^{result is} confirmed that the molar ratio of (OH / Ca ²⁺⁾ low of unreacted residual Busan gypsum with calcium hydroxide. In addition, in Comparative Example 3, impurities such as SiO ₂ were detected.

Comparative Example 4, Referring to Figure ^{13, (OH - / Ca 2+} ) As the molar ratio is high, the supply of an excess of Na ⁺ can be confirmed that the Na ₂ SO ₄ produced. In addition, in Comparative Example 4, solid components such as SiO ₂ and CaCO ₃ were detected.

Comparative Example 5, Referring to Figure 14, OH ^- it can be confirmed that the molar ratio of / Ca ²⁺⁾ to be high, Na ₂ SO ₄ is produced. In addition, in Comparative Example 5, solid components such as SiO ₂ and CaCO ₃ were detected similarly to the examples.

Next, the solid component of Example 2 was calcined at 650°C to convert slaked lime into quicklime. XRF analysis was performed on the quicklime. As shown in Fig. 15, it can be seen that most of the solid components are converted to quicklime.

What has been described above is only one embodiment for carrying out the slaked lime manufacturing method and quicklime manufacturing method using Busan gypsum according to the present invention, and the present invention is not limited to the above-described embodiment, and is claimed in the following claims. As described above, without departing from the gist of the present invention, anyone of ordinary skill in the field to which the present invention belongs will have the technical spirit of the present invention to the extent that various changes can be implemented.

Claims (13)

A solvent mixing step of forming a reaction slurry by mixing a solvent containing a strong base and water with the by-product gypsum,
A reaction step of producing slaked lime by reacting by-product gypsum and a strong base of a solvent in the reaction slurry, and
A washing step of washing the reaction slurry with water to remove ionic components and separating slaked lime,
The Busan gypsum is a phosphate gypsum or desulfurized gypsum containing CaSO ₄ ,
The strong base is a basic solution having an -OH group,
The strong base is the calcium of Busan gypsum (Ca ²⁺⁾ and OH ^- are mixed ^- (/ Ca ²⁺ OH) is such that 1.5 to 1.9, a molar ratio of
The solvent is a method for producing slaked lime using Busan gypsum, characterized in that the water is mixed so as to be 270 to 320 (ml) based on 100 g of the weight of the Busan gypsum. The method of claim 1
Before the solvent mixing step
A method for producing slaked lime using Busan gypsum, further comprising a step of crushing the Busan gypsum to less than 10 mesh. delete The method of claim 1,
The method for producing slaked lime using Busan gypsum, wherein the strong base is NaOH. The method of claim 1,
The method for producing slaked lime using Busan gypsum, wherein the strong base is KOH. delete delete delete The method of claim 1,
The reaction step is a method for producing slaked lime using Busan gypsum, characterized in that it proceeds for at least 5 to 30 minutes. The method of claim 1,
The slaked lime production method using Busan gypsum, characterized in that the slaked lime is contained in at least 90% by weight of the total weight of the solid components after the washing step. Slaked lime is prepared by mixing a solvent containing NaOH and water, which is a strong base, with Busan gypsum containing CaSO ₄ ,
The strong base and Busan gypsum is calcium (Ca ²⁺⁾ and OH ^- are mixed so that the ^- (/ Ca ²⁺ OH) is 1.5 to 1.9, a molar ratio of
The solvent is a method for producing slaked lime using Busan gypsum, characterized in that the water is mixed so as to be 270 to 320 (ml) based on 100 g of the weight of the Busan gypsum. A method for producing quicklime using Busan gypsum, further comprising a firing step of firing the slaked lime according to claim 1 at a firing temperature of 500 to 700°C to form quicklime. The method of claim 12,
The quicklime manufacturing method using busan gypsum, wherein the quicklime is contained in at least 90% by weight of the total weight of the solid components formed after the firing step.

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