KR102649207B1 - Manufacturing method of zeolite-p using residual by-products generated in the indirect carbonation process - Google Patents

Abstract

It relates to a method for synthesizing zeolite, which includes preparing residual by-products by mixing industrial by-products and solvents and filtering them, and synthesizing zeolite through a hydrothermal reaction after melting NaOH in the residual by-products or a hydrothermal reaction in a NaOH solution.

Description

Zeolite-P synthesis method using residual by-products generated in the indirect carbonation process {MANUFACTURING METHOD OF ZEOLITE-P USING RESIDUAL BY-PRODUCTS GENERATED IN THE INDIRECT CARBONATION PROCESS}

The present invention relates to a method for synthesizing zeolite, and more specifically, to a method for synthesizing zeolite using residual by-products generated in the indirect carbonation process.

Indirect carbonation technology using industrial by-products has the disadvantage of generating a large amount of residual by-products after extracting calcium or magnesium from industrial by-products, which are raw materials. When calcium is eluted at a ratio of 1:200 (industrial byproduct:solvent=g:mL) using 5 tons of industrial byproduct and then subjected to indirect carbonation, 7.5 to 12.5 tons of calcium carbonate is produced, but 4.64 tons of residual byproduct is generated. . Research on synthesizing zeolite using industrial by-products rich in Si (silicon) and Al (aluminum) has been actively conducted. However, although useful components such as Si and Al remain in the residual by-products generated during the indirect carbonation process, residual by-products are Little research is being done on recycling methods.

One object of the present invention is to provide a method of synthesizing zeolite by recycling residual by-products generated in an indirect carbonation process of reacting industrial by-products with a calcium eluting solvent.

The present invention relates to a method of recycling residual by-products generated from the reaction of industrial by-products and calcium elution solvents during the indirect carbonation process, and provides a method of synthesizing zeolite by using the residual by-products with high Si and Al content.

The zeolite synthesis method for one purpose of the present invention includes the steps of mixing and stirring industrial by-products and solvents and then filtering to prepare residual by-products, and melting sodium hydroxide (NaOH) in the residual by-products followed by a hydrothermal reaction or a hydrothermal reaction in a NaOH solution. It includes the step of synthesizing zeolite through.

At this time, the industrial by-products include coal fly ash (CFA), steelmaking slag, paper sludge ash (PSA), waste concrete, cement kiln dust (CKD), fuel ash, and bottom ash. , and deinked ash may be used, but coal fly ash is preferably used.

The solvent is a solvent for eluting calcium, and includes ammonium chloride, ammonium acetate, hydrochloric acid, acetic acid, artificial seawater, citrate salt, malonate slat, adipate salt, and maleate salt. ), fumarate salt, iminodiacetate salt (nitrilotriacetate salt), and nitrilotriacetate salt can be used, but hydrochloric acid, ammonium chloride, and artificial seawater are preferred. You can use it.

Residual by-products and calcium eluate are generated through the process of mixing coal fly ash and solvent. At this time, the generated calcium eluate undergoes a carbonation process to produce calcium carbonate. The residual by-product is generated in the indirect carbonation process, and zeolite was prepared by melting NaOH in the residual by-product with high Si and Al contents and then performing a hydrothermal reaction or performing a hydrothermal reaction in a NaOH solution. The synthesized zeolite was zeolite- It was P(zeolite-P). Due to the unique structural characteristics of zeolite-P, the cation exchange capacity (CEC) and specific surface area increased by 28 to 39 times and 20 to 38 times, respectively, compared to the raw materials (coal fly ash and residual by-products), and the synthesized It was discovered that zeolite exhibits an adsorption capacity for heavy metals of more than 98%.

In the present invention, the melting temperature in the step of melting by adding NaOH is 600°C, and the temperature in the step of hydrothermal reaction is 100-180°C. In addition, the hydrothermal reaction in the NaOH solution can be performed only at 100 - 180 ° C by adding NaOH to the residual by-product without separate melting. The zeolite conversion rate of the residual by-product prepared by the above method is 82 to 87%.

Conventionally, residual by-products generated from the indirect carbonation process were not used, but the present invention proposes a recycling method for indirect carbonation residual by-products, which not only reduces the cost of processing residual by-products, but also allows zeolite to be used in various fields such as heavy metal removal. By generating positive profits, it is expected to ultimately improve the economic feasibility of indirect carbonation technology.

According to the present invention, by manufacturing zeolite using the residual by-products discarded after indirect carbonation, the residual by-products can be recycled, making it economical.

In addition, zeolite produced by the production method proposed in the present invention has the advantage of dramatically increasing cation exchange capacity and specific surface area compared to coal fly ash and residual by-products.

Figure 1 shows a schematic diagram of the indirect carbonation and the overall manufacturing process of the present invention.
Figure 2 shows an XRD graph of raw materials, which are (a) coal fly ash, (b) R-HCl, (c) R-NH ₄ Cl, and (d) R-SW.
Figure 3 shows SEM images of raw materials, which are (a) coal fly ash, (b) R-HCl, (c) R-NH ₄ Cl, and (d) R-SW.
Figure 4 shows an FT-IR graph of coal fly ash and residual by-products.
Figure 5 shows _an It is silcate.
Figure 6 shows an FT-IR graph for the solid obtained by melting the raw materials.
Figure 7 shows _the 100, (d) ZF-SW-100, (e) ZF-CFA-180, (f) ZF-HCl-180, (g) ZF-NH ₄ Cl-180, (h) ZF-SW-180.
Figure 8 shows an FT-IR graph of zeolite synthesized by melting and hydrothermal reaction at 100°C.
Figure 9 shows an FT-IR graph of zeolite synthesized by melting and hydrothermal reaction at 180°C.
Figure 10 shows SEM images of zeolites synthesized by melting and hydrothermal reaction, (a) ZF-CFA-100, (b) ZF-HCl-100, (c) ZF-NH ₄ Cl-100, (d) ZF-SW-100, (e) ZF-CFA-180, (f) ZF-HCl-180, (g) ZF-NH ₄ Cl-180, (h) ZF-SW-180, (i) pure zeolite P am.
Figure 11 is a particle size analysis graph of coal fly ash, residual by-products, zeolite synthesized by melting and hydrothermal reaction, and pure zeolite P.
Figure 12 shows the TGA graph of zeolite synthesized by melting and hydrothermal reaction at (a) 100°C and (b) 180°C.
Figure 13 shows _the (d) Z-SW-100, (e) Z-CFA-180, (f) Z-HCl-180, (g) Z-NH ₄ Cl-180, (h) Z-SW-180.
Figure 14 shows SEM images of zeolites synthesized by hydrothermal reaction, (a) Z-CFA-100, (b) Z-HCl-100, (c) Z-NH ₄ Cl-100, (d) Z- SW-100, (e) Z-CFA-180, (f) Z-HCl-180, (g) Z-NH ₄ Cl-180, (h) Z-SW-180.
Figure 15 shows the TGA graph of zeolite synthesized by hydrothermal reaction at (a) 100°C and (b) 180°C.
Figure 16 shows a graph of a copper adsorption experiment using zeolite synthesized by hydrothermal reaction, (a) Z-CFA-180, (b) Z-HCl-180, (c) Z-NH ₄ Cl-180, (d) ) It is Z-SW-180.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Since the present invention can be subject to various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features or steps. , it should be understood that it does not exclude in advance the possibility of the existence or addition of operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present application. No.

Figure 1 shows a schematic diagram of the indirect carbonation and the overall manufacturing process of the present invention.

Referring to FIG. 1, the zeolite synthesis process using residual by-products generated in the indirect carbonation process of the present invention will be described in detail.

Example 1: Preparation of residual by-products after indirect carbonation

Coal fly ash (CFA) was prepared as an industrial by-product, and coal fly ash and three solvents (ammonium chloride, hydrochloric acid, artificial seawater) were mixed at a ratio of 1:50 (g:mL) and incubated at 250 rpm for 1 hour. After stirring, the residual by-product was prepared by filtration.

Each residual by-product was analyzed by XRF (X-Ray Fluoresceince), XRD, and SEM (Scanning Electron Microscope), and the XRF results are shown in Table 1 below, and the This can be confirmed through 4.

Material SiO ₂
(Wt%) Al ₂ O ₃
(Wt%) CaO
(Wt%) _{Fe2O3 ​}
(Wt
%) MgO
(Wt%) _K2O
(Wt%) SO ₃
(Wt%) TiO ₂
(Wt%) P ₂ O ₅
(Wt%) Na ₂ O
(Wt%) Othe-rs
(Wt%) CFA 57.46 17.94 8.51 6.17 2.76 2.19 1.67 1.17 - 1.13 0.99 R-HCl 59.83 23.62 3.43 5.62 2.19 2.65 - 1.15 - - 0.32 R-NH ₄ Cl 58.19 20.82 7.52 4.91 3.14 2.51 0.14 1.21 - 0.98 0.95 R-SW 53.61 23.38 8.93 5.61 2.88 1.93 0.21 1.10 0.90 0.90 0.55

Table 1 above shows the results of XRF analysis of coal fly ash and residual by- _products after indirect carbonation. The residual by-products are indicated as RX, where It means (seawater). SiO ₂ of fly ash was 57.46 Wt% and Al ₂ O ₃ was 17.94 Wt%, but SiO ₂ of R-HCl, R-NH ₄ Cl, and R-SW was more than 53.61 Wt% and Al ₂ O ₃ was 20.82 Wt%. From the above, it was confirmed that the Si and Al contents of the residual by-products after indirect carbonation were similar to or higher than those of fly ash.

Figure 2 shows an XRD graph of raw materials, which are (a) coal fly ash, (b) R-HCl, (c) R-NH ₄ Cl, and (d) R-SW.

Referring to Figure 2, the main components of coal fly ash and all three residual by-products are quartz (SiO ₂ ), a type of silicon oxide, and mullite (3(Al ₂ O ₃ ) 2 ), a mixture of silicon and aluminum oxide. It can be confirmed that it is SiO ₂ )). SiO ₂ and mullite are known as precursors of zeolite in hydrothermal reaction methods and can be sources of Si and Al, respectively.

Figure 3 shows SEM images of raw materials, which are (a) coal fly ash, (b) R-HCl, (c) R-NH ₄ Cl, and (d) R-SW.

Referring to Figure 3, most of the fly ash had a spherical shape with a smooth surface, and adhesive substances and slight scratches were observed in some particles. In addition to spherical particles, some irregularly shaped particles were found, but pores were hardly observed on the surface of the fly ash. Likewise, spherical shapes and scratches and adhesive substances were observed in the residual by-products of indirect carbonation.

Figure 4 shows an FT-IR graph of coal fly ash and residual by-products.

Referring to Figure 4, Si-O and Al-O bonds were found in coal fly ash and all three residual by-products at 1007.5~1030.5 cm ^-1 , and Si-O-Si and Si-O bonds at 775.5~776.4 cm ^-1 . -Al bond was discovered. There was no significant difference between the FT-IR results of CFA and residual by-products, and the same binding group was observed.

Example 2: Zeolite synthesis through melting and hydrothermal reaction

22.5 M NaOH was added to coal fly ash (CFA) and residual by-products (R-HCl, R-NH ₄ Cl, R-SW) at a 1:1 ratio, and then a certain amount of distilled water was added. Then, the reactant was placed in an electric furnace at 600°C for 1 hour.

Afterwards, the molten solids were recovered, distilled water was added at a ratio of 1:10, and then hydrothermal reaction was performed for 24 hours while stirring at 100°C and 250 rpm to synthesize zeolite. The same hydrothermal synthesis experiment was also conducted at 180 °C.

Experimental Example 1-1: Melting of coal fly ash and residual by-products

XRD and FT-IR were analyzed for the solid obtained by melting coal fly ash and residual by-products by adding NaOH, which can be confirmed in Figures 5 and 6.

Figure 5 shows _an It is silcate.

Referring to Figure 5, sodium-alumino-silicate peaks can be seen in all XRD results. This result means that insoluble quartz and mullite, which were the main crystalline phases of coal fly ash and residual by-products, were completely dissolved and converted to water-soluble sodium alumino-silicate upon contact with NaOH during alkali melting.

Figure 6 shows an FT-IR graph for the solid obtained by melting the raw materials.

Referring to Figure 6, a new Si-O-Na bond was created at 578.6~597.7 cm ^-1 . It can be seen that sodium silicate required for zeolite synthesis was synthesized through the melting process.

Experimental Example 1-2: Hydrothermal synthesis of coal fly ash and residual by-products

NaOH was added to coal fly ash and residual by-products to melt them, and then a hydrothermal reaction was performed. The recovered solid was analyzed by XRD, FT-IR, SEM, particle size analysis, and TGA, as shown in Figures 7, 8, and 9. It can be confirmed in Figures 10, 11, 12, and Table 2.

Figure 7 is a graph of the XRD results of the zeolite synthesized by the method of Example 2, ●: Zeolite P, (a) ZF-CFA-100, (b) ZF-HCl-100, (c) ZF-NH ₄ Cl -100, (d) ZF-SW-100, (e) ZF-CFA-180, (f) ZF-HCl-180, (g) ZF-NH ₄ Cl-180, (h) ZF-SW-180. .

At this time, the zeolite synthesized in Figure 7 is indicated as Z-F-X-Y, where Z means zeolite and F means melting and hydrothermal reaction. And X refers to the solvent used and Y refers to the reaction temperature.

Referring to Figure 7, Zeolite-P was the only peak seen in all tested conditions. As CFA and residual by-products melted with NaOH, quartz and mullite were completely dissolved to form water-soluble sodium alumino-silicate, and sodium silicoaluminic acid underwent a hydrothermal reaction to synthesize Zeolite-P. In the alumino-silicate system, sodium was found to not only help crystallize zeolites such as ferrierite, but also play an important role in aligning the zeolite structure. Therefore, since sodium silicoaluminic acid synthesized after alkali melting played a role in helping zeolite crystallization and structural alignment, Zeolite-P was synthesized after hydrothermal reaction.

Figure 8 shows a FT-IR graph of zeolite synthesized by melting and hydrothermal reaction at 100°C, and Figure 9 shows an FT-IR graph of zeolite synthesized by melting and hydrothermal reaction at 180°C.

Referring to Figures 8 and 9, the FT-IR analysis results showed that in all cases, the characteristic peaks of zeolite were HOH bond at 1636-1640 cm ^-1 , Si-O-Al bond at 961-977 cm ^-1 , and 594-599 cm. Si-O-Na bond can be confirmed at cm ^-1 .

Figure 10 shows SEM images of zeolites synthesized by melting and hydrothermal reaction, (a) ZF-CFA-100, (b) ZF-HCl-100, (c) ZF-NH ₄ Cl-100, (d) ZF-SW-100, (e) ZF-CFA-180, (f) ZF-HCl-180, (g) ZF-NH ₄ Cl-180, (h) ZF-SW-180, (i) pure zeolite P am.

Referring to Figure 10, it can be seen that the solid surface is very rough and has many pores. This is in sharp contrast to the case of CFA and residual by-products, which had smooth surfaces. Additionally, compared to zeolite hydrothermally synthesized at 100 ℃, zeolite hydrothermally synthesized at 180 ℃ had more pores. The zeolite synthesized at 100 ℃ can be seen to have many flat areas with few pores on the surface, while the zeolite synthesized at 180 ℃ can be seen to have a sharp surface with many pores. Amorphous alumino-silicate undergoes a hydrothermal reaction and is dissolved and changed into a heterogeneous form. In particular, as the temperature rises, it begins to grow rapidly and large, and as the reaction progresses, the gaps between the alumino-silicate gel are filled, turning into zeolite crystals. Therefore, it can be confirmed that as the hydrothermal synthesis temperature increases, the zeolite crystallization is successful as the gaps between the alumino-silicates created after alkali melting at 180 degrees are filled. Comparing with the SEM image of pure zeolite P, pure zeolite P mostly had a cactus shape and some diamond shapes were observed. Pure zeolite P had many pores and a wide surface area. The diamond shape was not observed in zeolite synthesized from CFA and residual by-products.

Figure 11 and Table 2 below show the particle size analysis results of coal fly ash, residual by-products, eight zeolites synthesized through melting and hydrothermal reactions, and pure zeolite P. The particle size of the synthesized zeolite was much smaller than that of the raw material. There was little difference in particle size depending on the hydrothermal reaction temperature.

_DX50 (μm) raw materials Synthesized zeolites 100℃ 180℃ Pure zeolite P 4.74 - - Coal fly ash 35.2 7.82 6.24 R-HCl 13.6 7.05 6.31 R-NH ₄ Cl 23.2 5.28 8.99 R-SW 21.6 10.2 8.62

Figure 12 shows the TGA graph of zeolite synthesized by melting and hydrothermal reaction at (a) 100°C and (b) 180°C.

Referring to Figure 12, zeolite loses moisture physically adsorbed inside the pores of the zeolite at 40 to 200 ° C, and loses moisture from the hydration complex formed of exchangeable cations at 200 to 400 ° C. do. The weight loss of pure zeolite P at 40-400 ℃ was the highest at 18.5 wt%, followed by zeolite obtained by melting coal fly ash and three residual by-products and then hydrothermally reacting at 180 ℃, with a value of 15.2-16.1 wt%. , in the case of hydrothermal reaction at 100 ℃, the value was the lowest at 12.1-14.0 wt%.

Experimental Example 1-3: Analysis of adsorption characteristics of zeolite synthesized through melting and hydrothermal reaction

The CEC and BET of the zeolite synthesized by the method of Example 2 were measured and shown in Tables 3 and 4 below. The CEC values of CFA and residual by-products used in the experiment were 4.78 and 5.13~5.27 cmol/kg, respectively, with no significant difference, and these values were similar to the values reported in existing papers.

The CEC value of zeolite is 71.26~85.54 cmol/kg when hydrothermally reacted at 100 ℃ after alkali melting, and 106.94~131.92 cmol/kg when hydrothermally reacted at 180 ℃. It showed a CEC value about 1.5 times higher than that in the case. This is because the higher the temperature, the more actively it reacted with the aqueous alkaline solution to produce zeolite with many pores.

The BET values of coal fly ash and residual by-products were 3.3 and 4.6-6.0 m ² /g, respectively, and the BET values of residual by-products were slightly higher. These values were similar to the BET values of coal fly ash reported in existing literature. Meanwhile, the BET value of zeolite hydrothermally synthesized after alkali melting was much higher than the BET value of coal fly ash and residual by-products. In particular, the BET value of zeolite hydrothermally synthesized at 180°C after alkali melting was 65.2~111.1 m ² /g, which was about 20~37 times higher than that of CFA and residual by-products. The reason the BET value is so high is because the surface area rapidly expanded as the number of pores on the surface of the synthesized zeolite increased.

CEC (cmol/kg) raw materials Synthesized zeolites 100℃ ^* 180℃ ^* Coal fly ash 4.78 71.26 114.08 R-HCl 5.27 85.54 131.92 R-NH ₄ Cl 5.13 78.40 117.65 R-SW 5.27 78.40 106.94

*: hydrothermal reaction temperature

BET ( ^m2 /g) raw materials Synthesized zeolites 100℃ ^* 180℃ ^* Coal fly ash 3.30 14.16 106.64 R-HCl 5.99 29.87 111.11 R-NH ₄ Cl 4.63 19.92 65.16 R-SW 5.12 16.29 105.75

*: hydrothermal reaction temperature

Experimental Example 1-4: Conversion rate of zeolite synthesized by melting and hydrothermal reaction

The conversion rate of the zeolite synthesized by the method of Example 2 was calculated based on the results of TGA and is shown in Table 5 below. The value of pure zeolite P was set at 100, and the conversion rate of the synthesized zeolite was converted proportionally. After melting, the content of zeolite hydrothermally synthesized at 180°C was 86.71~82.35%, and that of zeolite hydrothermally synthesized at 100°C was significantly higher at 65.14~75.86%. The higher the temperature, the higher the conversion rate of zeolite. At each hydrothermal synthesis temperature, the conversion rates of zeolites synthesized from coal fly ash and three residual by-products were similar.

Materials Conversion factor (%) 100℃ 180℃ Pure zeolite 100 100 Z-CFA 75.86 85.73 Z-HCl 69.01 82.35 Z-NH ₄ Cl 72.73 86.38 Z-SW 65.14 86.71

Example 3: Zeolite synthesis through hydrothermal reaction

Coal fly ash and residual by-products (R-HCl, R-NH ₄ Cl, R-SW) were mixed with NaOH solution at a ratio of 1:50 (g:mL) and stirred at room temperature and 250 rpm for more than 4 hours. Afterwards, each suspension was hydrothermally reacted for 24 hours while stirring at 100°C and 250 rpm to synthesize zeolite. The same hydrothermal synthesis experiment was also conducted at 180 °C.

Experimental Example 2-1: Zeolite synthesized through hydrothermal reaction

XRD, SEM, and TGA analyzes were performed to confirm the characteristics of the zeolite synthesized by the method of Example 3, and can be seen in Figures 13, 14, and 15.

Figure 13 is a graph of the XRD results of the zeolite synthesized by the method of Example 3, ●: Zeolite P, (a) Z-CFA-100, (b) Z-HCl-100, (c) Z-NH ₄ Cl -100, (d) Z-SW-100, (e) Z-CFA-180, (f) Z-HCl-180, (g) Z-NH ₄ Cl-180, (h) Z-SW-180 .

Referring to Figure 13, Zeolite-P was synthesized in both cases of hydrothermal synthesis at 100°C and 180°C. In order to form a zeolite structure during hydrothermal synthesis, Si and Al must first be dissolved in solution, and the aging process appears to have played an important role in dissolving Si and Al. During aging for more than 4 hours, Si and Al are dissolved in NaOH solution and react with each other to form a ring structure and form hydrothermal aluminosilicate. As a result, the aging process in alkaline solution before hydrothermal synthesis promoted the synthesis of zeolite. In addition, the strengths of zeolite hydrothermally synthesized at 100 ℃ and 180 ℃ were 34,000 to 53,000 and 54,000 to 60,000, respectively, which is about 1.5 times higher than that of zeolite synthesized at 180 ℃. As the reaction temperature increases in hydrothermal synthesis, the strength This means that the total crystallinity of zeolite increases and the zeolite content also increases.

Figure 14 shows the SEM analysis results of zeolites synthesized by the method of Example 3, (a) Z-CFA-100, (b) Z-HCl-100, (c) Z-NH ₄ Cl-100, (d) ) Z-SW-100, (e) Z-CFA-180, (f) Z-HCl-180, (g) Z-NH ₄ Cl-180, (h) Z-SW-180.

Referring to Figure 14, it can be seen that the synthesized zeolite has more pores than the raw material coal fly ash or residual by-products. Zeolite hydrothermally synthesized at 100°C was spherical in shape, and many flat areas were observed on the surface. It can be observed that the zeolite synthesized at 180 ℃ was irregularly shaped rather than spherical, and its surface was not smooth and had many valleys, so it had a large surface area. The particle size of zeolite hydrothermally synthesized at 100 ℃ was smaller than that of zeolite synthesized at 180 ℃.

Figure 15 shows the TGA results of zeolite synthesized by the method of Example 3.

Referring to FIG. 15, zeolite loses moisture physically adsorbed inside the pores of the zeolite at 40 to 200 ° C, and loses moisture from the hydration complex formed with exchangeable cations at 200 to 400 ° C. Occurs. In the range of 40 to 400 ℃, the thermal weight reduction rate of pure zeolite was 18.51%, zeolite hydrothermally synthesized at 180 ℃ was 16.02 to 16.47%, and zeolite hydrothermally synthesized at 100 ℃ was 11.49 to 15.46%.

Experimental Example 2-2: Analysis of adsorption characteristics of zeolite synthesized through hydrothermal reaction

The CEC measurement results of the residual by-products after indirect carbonation and the zeolite synthesized using them at 100 ℃ and 180 ℃ can be found in Table 6, and the BET measurement results can be found in Table 7 below. The CEC and BET values of raw coal fly ash and residual by-products were low at 4.78-5.27 cmol/kg and 3.30-5.99 m ² /g, respectively. However, compared to the CEC of zeolite hydrothermally synthesized at 180°C using this raw material and the BET of 71.6-121.7 m ² /g, the CEC of zeolite synthesized using residual by-products after indirect carbonation was CEC and BET were found to increase by 28 to 39 times and 12 to 26 times, respectively.

As a result of measuring the CEC of zeolite synthesized using residual by-products after indirect carbonation, it was confirmed that the cation exchange capacity of the zeolite prepared by performing a hydrothermal reaction with the addition of NaOH was excellent.

In addition, as a result of measuring the BET of the synthesized zeolites, it was confirmed that the specific surface area was the best when artificial seawater was used as a solvent.

CEC (cmol/kg) raw materials Synthesized zeolites 100℃ ^* 180℃ ^* Coal fly ash 4.78 56.99 178.30 R-HCl 5.27 46.29 189.01 R-NH ₄ Cl 5.13 46.29 199.71 R-SW 5.27 64.13 149.46

* : Hydrathermal reaction temperature

BET ( ^m2 /g) raw materials Synthesized zeolites 100℃ ^* 180℃ ^* Coal fly ash 3.3035 63.05 87.03 R-HCl 5.9880 71.51 72.73 R-NH ₄ Cl 4.6270 29.78 71.64 R-SW 5.1190 67.96 121.70

* : Hydrathermal reaction temperature

Figure 16 shows a graph of a copper adsorption experiment using zeolite synthesized by hydrothermal reaction, (a) Z-CFA-180, (b) Z-HCl-180, (c) Z-NH ₄ Cl-180, (d) ) It is Z-SW-180.

Zeolite samples synthesized at a synthesis temperature of 180°C using the method of Example 3 were placed in copper solutions of two concentrations (0.004 M, 0.008 M) and subjected to an adsorption experiment for 24 hours. The copper removal rate from 0.004 M copper solution was 99.0-99.1% and the copper removal rate from 0.008 M copper solution was 98.7-98.8%, showing that all synthesized zeolites removed most of the copper from two concentrations of copper solution within 10 minutes. .

Experimental Example 2-3: Conversion rate of zeolite synthesized by hydrothermal reaction

The conversion rate calculated based on the TGA results of the zeolite synthesized by the method of Example 3 is shown in Table 8 below. The conversion rates of zeolite hydrothermally synthesized at 100°C and 180°C were 62.07~83.52% and 86.55~88.98%, respectively. The higher the hydrothermal synthesis temperature, the higher the conversion rate of zeolite. Zeolite hydrothermally synthesized at 180°C showed a high conversion rate of over 86%, and there was little difference in conversion rate between coal fly ash and residual by-products. This result shows that not only coal fly ash, which has been widely used as a material in existing zeolite synthesis research, but also indirect carbonation residual by-products can be used as zeolite materials to synthesize zeolites with excellent performance.

Materials Conversion factor (%) 100℃ 180℃ Pure zeolite 100 100 Z-CFA 83.52 88.98 Z-HCl 67.37 86.55 Z-NH ₄ Cl 64.88 86.60 Z-SW 62.07 86.55

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the following patent claims. You will understand that it is possible.

Claims (15)

Preparing residual by-products by mixing industrial by-products and solvents and then filtering them; and
Comprising: synthesizing zeolite by hydrothermally reacting the residual by-product after NaOH melting reaction,
The reaction of performing a hydrothermal reaction after the NaOH melting reaction is,
Adding NaOH to the residual by-product to melt it; and
Characterized in that it includes the step of recovering the molten solid and subjecting it to a hydrothermal reaction.
Zeolite synthesis method. Preparing residual by-products by mixing industrial by-products with a solvent selected from the group consisting of ammonium chloride, hydrochloric acid, and artificial seawater and then filtering them; and
Comprising a step of synthesizing zeolite by hydrothermally reacting the residual by-product in a NaOH solution.
Zeolite synthesis method. According to claim 1 or 2,
The industrial by-products include coal fly ash (CFA), steelmaking slag, paper sludge ash (PSA), waste concrete, cement kiln dust (CKD), fuel ash, bottom ash, and decarbonization. Selected from a group consisting of mukhoe,
Zeolite synthesis method. According to claim 1 or 2,
The industrial by-product is coal fly ash (CFA),
Zeolite synthesis method. According to paragraph 1,
The solvent includes ammonium chloride, ammonium acetate, hydrochloric acid, acetic acid, artificial seawater, citrate salt, malonate salt, adipate salt, maleate salt, and fumarate salt. , iminodiacetate salt, and nitrilotriacetate salt,
Zeolite synthesis method. According to paragraph 1,
The solvent is selected from the group consisting of ammonium chloride, hydrochloric acid, and artificial seawater,
Zeolite synthesis method. According to claim 1 or 2,
Characterized in that the residual by-products are generated in the indirect carbonation process,
Zeolite synthesis method. According to paragraph 1,
In the step of melting by adding NaOH, the melting temperature is 500 - 650 ° C.
Zeolite synthesis method. According to paragraph 1,
Characterized in that the temperature in the hydrothermal reaction step is 100 - 180 ℃,
Zeolite synthesis method. According to paragraph 2,
The hydrothermal reaction performed under the NaOH solution is,
Characterized in that the NaOH is added to the residual by-product and a hydrothermal reaction is performed at 100 - 180 ° C.
Zeolite synthesis method. According to claim 1 or 2,
Characterized in that the zeolite conversion rate of the residual by-product is 82 to 87%.
Zeolite synthesis method. The zeolite produced by the production method of claim 1 or 2 is characterized in that it is Zeolite-P.
Zeolite manufactured from residual by-products of indirect carbonation. According to clause 12,
Characterized in that the cation exchange capacity (CEC) of the zeolite is 107 - 200 cmol/kg.
Zeolite manufactured from residual by-products of indirect carbonation. According to clause 12,
Characterized in that the specific surface area (BET) value of the zeolite is 65 - 122 m ² /g,
Zeolite manufactured from residual by-products of indirect carbonation. According to clause 12,
Characterized in that more than 98% of copper is adsorbed within 10 minutes when copper is adsorbed using the zeolite.
Zeolite manufactured from residual by-products of indirect carbonation.