KR0139424B1 - Method of manufacturing the x-zeolite and p-zeolite utilizing the mordenite - Google Patents

Abstract

The present invention relates to a method for producing X-type and P-type zeolites using natural mordenite-based minerals, that is, Songji,

Unlike conventionally prepared by using silicon oxide, aluminum oxide, sodium oxide and the like at a high temperature of about 90-120 ° C., a natural mordenite mineral containing a large amount of impurities is about 4 hours at 600-1000 ° C. Calcination is carried out to improve the reactivity with NaCl or NaOH, and then NaOH or NaOH-NaCl is added and reacted at a relatively low temperature of 90-100 ° C. to remove catalysts, ion exchangers and heavy metals with high added value. It is a novel useful invention for producing X-type and P-type zeolites that can be utilized for applications.

Description

Method for preparing X-type and P-type zeolite using natural mordenite mineral.

1 is a schematic flowchart showing a manufacturing method of the present invention.

2 is a graph showing X-type zeolite yield as a function of calcination temperature.

3 is a graph showing the change in specific surface area of the synthesized zeolite as a function of calcination temperature.

4 is a graph showing X-type zeolite yield as a function of NaCl / Al ₂ O ₃ molar ratio.

5 is a graph showing X-type zeolite yield as a function of reaction time.

The present invention relates to a process for producing X-type and P-type zeolites using natural mordenite minerals (also known as Songdite).

There are natural products and synthetic products in zeolite, and the types are X, Y, A, P, Z, and so on. Hundreds of them are known and their usage is widely known for their excellent adsorption, ion exchange and catalytic properties. have. Already part of the natural mordenite zeolites used in feed, land modifiers, waste water adsorption, nicotine removal, etc., are low in purity due to high impurities other than zeolite constituents, thus limiting their utilization and poor zeolite properties. In contrast, A, X, P, and Y zeolites synthesized using reagent grade as a raw material have been invented by many researchers and are widely used.

In particular, there has been a study of synthesis through natural resource reforming, that is, the synthesis of zeolite using clay, kaolin and volcanic eruptions Shiras (Shirasu) as a raw material, but there is no invention using natural mordenite mineral (songji rock).

Conventionally, as raw materials used in the synthesis, silicon oxide, aluminum oxide, sodium oxide, etc. were used, and the production was carried out by mixing these raw materials, and then aging at low temperature (30 ° C.) in a reaction vessel and reacting at high temperature (90-120 ° C.). After the preparation was made through a filtration, drying process.

However, in the present invention, unlike natural clays, kaolin and syras, which contain a large amount of amorphous, mordenite crystalline raw materials containing a large amount of miscellaneous impurities are calcined at 600-1000 ° C. for 4 hours to react with NaCl or NaOH. The properties are modified to improve the production of X-type and P-type zeolites that can be utilized for high value-added catalysts, ion exchangers, heavy metals and the like.

Therefore, the first object of the present invention, SiO ₂ 66-75% by weight, Al ₂ O ₃ 8-15% by weight, Fe ₂ O ₃ 0.2-1% by weight, CaO 0-5% by weight, MgO 0-3% by weight , K ₂ O 1-5% by weight, Na ₂ O 1-5% by weight, the main crystalline phase is Mordenite (Mordenite), the subcrystalline phase is Clinoptilolite (specific gravity 2-2.5) After calcination by grinding the mordenite mineral, NaOH or NaOH-NaCl solution was added, aged at 25-35 ° C., and then 4-10 hours at a temperature of 90-100 ° C. It is to provide a method for producing a zeolite composed of reacting and crystallizing.

The second object of the present invention is the production method according to the first object, wherein the calcination treatment is carried out at a temperature of 700-930 ℃, the addition amount of NaOH solution of the molar ratio of Na ₂ O / SiO ₂ and H ₂ O / Na ₂ O Is to be in the range of 0.34-0.85 and 35-57, respectively, and to provide a method for producing a zeolite of X-type main crystalline phase.

The third object of the present invention is to provide a method for preparing the first and second objects, wherein the molar ratio of NaCl to NaCl / Al ₂ O ₃ is in the range of 5.7-15, and the main crystal phase is X-type zeolite. will be.

The fourth object of the present invention is the production process according to the first object, the calcination treatment carried out without or in the temperature of 700-930 ℃ of calcination and without the addition of NaCl the added amount of NaOH solution only Na ₂ O / SiO ₂ and H ₂ O / Na ₂ O molar ratio of each, and to be in the range of 0.25 to 0.45 and 20 to 35, which the main crystal phase to provide a manufacturing method of a P- type zeolite.

The chemical composition and the crystal phase of the natural raw materials used in the production method of the present invention are as shown in Table 1, and FIG. 1 is a schematic flowchart showing the production method of the present invention and will be described in that order.

Table 1. Chemical composition and crystal phase of mordenite mineral (aka Songjiam)

Natural raw materials of the composition described above used pitchstone produced from Guryongpo, Yeongil-gun, Gyeongbuk, Korea, and pulverized using a ball mill. A 325 mesh sieve is a traditional powder. The BET specific surface area is about 19㎡ / g. And the brain (Blaine) value was about 4800 cm 2 / g and then used.

As can be seen from Table 1, the composition of the rosary rock is that the amount of silica (SiO ₂ ) and alumina (Al ₂ O ₃ ) is sufficient compared to the composition of X-type and P-type zeolite, but the amount of Na ₂ O Since very few, in the present invention, NaOH is added alone or as a supplementary source of sodium oxide, or in combination with NaCl as an adjuvant for the production of sodium oxide.

Meanwhile, in the present invention, in order to improve the reactivity with the NaOH or NaOH-NaCl, the pulverized Songam is calcined at a temperature of 600-1000 ° C, preferably 700-900 ° C. As shown in FIG. 2, the yield of zeolite is low at temperatures below 700 ° C., which is not preferable, and at temperatures above 900 ° C., amorphization of the starting materials occurs, which is not preferable because the yield decreases rapidly.

The yield of zeolite according to the calcination temperature increases linearly as the calcination temperature increases, but tends to decrease rather than peaking at 900 ° C. The production rate of zeolite increases until reaching the temperature of 900 ° C. If the crystallinity is lowered as the increase, the raw material has a high entropy to increase the reactivity.

Figure 3 shows the results of measuring the specific surface area of the product according to the change in the calcination temperature when the starting material is calcined. When the raw material is not calcined as a starting material, the specific surface area of the product shows a large value, which is considered to be due to the presence of the P-type zeolite, which causes the form of pores to become an ink bottle type. On the other hand, the reason that the specific surface area of the product prepared from the raw material calcined at 900 ° C is the largest is thought to be due to the formation of many pores as the X-type zeolite was formed.

As a result of examining the pore distribution of the product according to the calcination temperature of the starting material, the pore distribution was concentrated within 20Å as the calcination temperature of the starting material increased from 700 ℃, and moved to around 30Å when the calcination temperature reached 1000 ℃. The pore volume also increases in the calcination temperature between 700 ° C and 900 ° C and decreases at 1000 ° C.

Therefore, as the calcination temperature increases to 900 ℃, the porosity and specific surface area increase, but decreases above 900 ℃. At the calcination temperature below 1000 ℃, the X-type zeolite crystallizes and microporous structure near 10Å is formed. It can be seen that.

Next, the influence of the molar ratios of Na ₂ O / SiO ₂ , NaCl / Al ₂ O _3, and H ₂ O / Na ₂ O in the present invention on zeolite production will be described.

In preparing a zeolite in which the X-type zeolite is the main crystalline phase, the molar ratio of Na ₂ O / SiO ₂ is 0.34-0.85 and the molar ratio of H ₂ O / Na ₂ O is 35-57, and preferably Na ₂ O / SiO. The molar ratio of ₂ is 0.63-0.73 and the molar ratio of H ₂ O / Na ₂ O is 35-45.

When the molar ratio of Na ₂ O / SiO ₂ is less than 0.34, P-type zeolite is predominantly formed, and thus, it is not preferable in the production of X-type zeolite, and when it exceeds 0.85, the yield of X-type zeolite is decreased. Not.

If the molar ratio of H ₂ O / Na ₂ O is less than 35, the production of P-type zeolite becomes dominant, and it is not preferable. If it exceeds 57, the yield of X-type zeolite decreases rapidly, which is not preferable.

NaCl / Al ₂ O ₃ This molar ratio is in the range of 5.7-15, and preferably in the range of 9-15 as shown in FIG. If it is out of the range it is not preferable because the yield of the X-type zeolite is reduced.

4 is a graph showing the results of the formation of X-type zeolite after hydrothermal reaction for 8 hours by adding NaCl to the raw material calcined at 900 ° C. for 4 hours, and the molar ratio of NaCl / Al ₂ O ₃ is 5.70 days. From this point, the yield gradually increased, and the yield of X-type zeolite was maximized at 11.40, because two kinds of zeolite crystals were formed from the same gel as the amount of NaCl added increased. Because it is suppressed and the production of X-type zeolite is increased.

Increasing the amount of NaCl decreases the production rate, which is thought to be low because the higher the amount of NaCl added, hydrolysis occurs by solvent water molecules, which lowers the alkali concentration of the treated solution. .

In preparing zeolites in which the P-type zeolite is the main crystalline phase, it is preferable that the molar ratio of Na ₂ O / SiO ₂ is low in the range of 0.25-0.45, and the yield is sharply decreased below 0.25, and the P-type zeolite is also formed at about 0.75. It is not preferable because the production of X-type zeolite increases rapidly when it is formed but exceeds 0.45.

In addition, the molar ratio of H ₂ O / Na ₂ O is preferably in the range of 20-35, and the yield is low at less than 20, and is not preferable because the production of X-type zeolite is superior when it exceeds 35.

In preparing the P-type zeolite, it is preferable not to add NaCl, and the addition of NaCl predominates the production of the X-type zeolite.

The reaction mixture was prepared by adding NaOH or NaOH-NaCl to the pine rock to make the molar ratio of Na ₂ O / SiO ₂ , H ₂ O / Na ₂ O, NaCl / Al ₂ O ₃ within the above-mentioned range. Are aged to make the nucleus of the crystal. Even if the aging time is changed to 48 hours, the crystal size grows, but the crystal shape remains almost unchanged.

The crystallization reaction is conducted at a temperature of 90-100 ° C. for 3-15 hours, preferably 4-10 hours. If the reaction time is less than 4 hours, the yield of the zeolite is lowered, which is not preferable. Since the increase in yield is less than 10 hours, it is not preferable in terms of economics.

The crystallization reaction is crystallized by placing the sample in a water or oil bath maintained at 90-100 ° C., leaving the top coke open for the first 30 minutes, and then reacting for 4-10 hours after the coke has been sufficiently drained.

The crystallized sample is filtered through distilled water using a filter paper, and then dried.

Hereinafter, the manufacturing method of the present invention will be described in more detail with reference to Examples.

Example 1

The natural mordenite mineral having the chemical composition, specific gravity, and crystal phase as shown in Table 1 was pulverized such that the BET specific surface area was about 19 m 2 / g and the brain specific surface area value was 4800 cm 2 / g or more. The pulverized raw material was put into an electric furnace and heated to 200 ° C. per hour, and used after heat treatment at 900 ° C. for 4 hours.

Table 2. Reaction conditions for synthesizing X-type zeolite

In the synthesis, first weigh 50g of the heat-treated natural raw material and put it in a Teflon container, and then add 3N NaOH to make the molar ratio of Na ₂ O / SiO ₂ 0.33 to the amount of SiO ₂ contained in the natural raw material and add distilled water. The mixture was mixed so that the molar ratio of H ₂ O / Na ₂ O was 35, and then the lid was closed and aged at 30 ° C. for 8 hours. After aging, the sample was put in a water bath maintained at 90 ° C., and the coke was left open for the first 30 minutes, the air was sufficiently drained, the coke was locked, synthesized and crystallized, and then filtered and dried.

As a result of synthesis, the main crystalline phase showed mordenite and the sub-crystalline phase showed zeolite P-type.

Example 2

3N NaOH is added to the natural raw material which has been heat treated at 900 ° C for 4 hours so that the molar ratio of Na ₂ O / SiO ₂ is 0.34, and the molar ratio of H ₂ O / Na ₂ O is 25.5 by adding distilled water. After aging at 30 ° C. for 8 hours, the same procedure as in Example 1 was repeated except that the mixture was reacted for 10 hours in an oil bath at 100 ° C. for 10 hours. As a result, the main crystal phase was zeolite P-type, and the subcrystalline phase was mordenite, unlike Example 1.

Example 3

The molar ratio of Na ₂ O / SiO ₂ is 0.68 by adding 3N NaOH to the natural raw material heated at 900 ° C. for 4 hours, and then the molar ratio of H ₂ O / Na ₂ O is 27 and 35 by adding distilled water. NaCl was added to Al ₂ O ₃ contained in natural raw materials. At this time, the molar ratio of NaCl / Al ₂ O ₃ was adjusted to 5.7, and the mixture was aged at 30 ° C. for 8 hours and then in an oil bath at 100 ° C. It carried out similarly to Example 1 except having synthesized by reacting for 10 hours.

As a result, when the molar ratio of H ₂ O / Na ₂ O is 27, the main crystal phase is zeolite P-type, and the sub-crystalline phase is zeolite X-type. When the molar ratio of H ₂ O / Na ₂ O is 35, the main crystal phase is X As a form, the subcrystalline phase appeared as a P-type zeolite.

Example 4

3N NaOH was added to make the molar ratio of Na ₂ O / SiO ₂ to 0.68. Then, distilled water was added to make the molar ratio of H ₂ O / Na ₂ O to 40, followed by addition of NaCl to NaCl / Al ₂ O _3. The mole ratio of was fixed to 5.7, ① ① The milled raw material was heat-treated at 500 ℃, 700 ℃, 900 ℃, 950 ℃ and 1000 ℃ was used as a raw material.

On the other hand, ② the heat-treated crushed natural raw material at 900 ℃ for 4 hours, the molar ratio of Na ₂ O / SiO ₂ is 0.68, the molar ratio of H ₂ O / Na ₂ O is added to 40 and after the addition of NaCl / Al ₂ O ₃ Experiments were done with varying molar ratios of 2.85, 5.7, 8.53, 11.4 and 14.7. ③ When the molar ratio of Na ₂ O / SiO ₂ is 0.68, the molar ratio of H ₂ O / Na ₂ O is 40, and the molar ratio of NaCl / Al ₂ O ₃ is 11.4 to the raw material heat-treated at 900 ° C. for 4 hours, the reaction time at 100 ° C. Experiments were varied by 0-15 hours.

At this time, the manufacturing method was carried out according to Examples 1 and 2, and as a result, in the case of ①, ② and ③, the main crystal phase was X-type zeolite, and the subcrystalline phase showed P-type zeolite. In the case of ①, the yield of X-type zeolite according to the heat treatment temperature was investigated. As shown in FIG. 1 and FIG. 2, the synthesis rate was 42% and the specific surface area was the highest at 370m 2 / g at 900 ° C. Indicated. In the case of ②, the ratio of NaCl / Al ₂ O ₃ was changed to 0-14.7 to obtain the production rate when the X-type zeolite was synthesized, and the results are shown in Table 3 and FIG.

Table 3. X-type zeolite production rate according to molar ratio of NaCl / Al ₂ O ₃

The production rate was 58% which is the highest value when the molar ratio of NaCl / Al ₂ O ₃ was 11.4, and the production rate was decreased when 14.7.

In the case of ③, the reaction time showed a low production rate until 2 hours, but the reaction product was slowly produced from 4 hours to 15 hours, and the results are shown in Table 4 and FIG.

Table 4. X-type zeolite production rate according to reaction time when NaCl / Al ₂ O ₃ molar ratio is 11.4

Therefore, when the X-type zeolite was synthesized using the natural mordenite mineral (songstone) from the result of Example 4, the raw material was heat treated at 900 ° C. for about 4 hours, and the Na ₂ O / SiO ₂ molar ratio was 40, When the molar ratio of NaCl / Al ₂ O ₃ was 11.4, the X-type zeolite production rate was optimal at 58-60%.

Claims (3)

66-75% SiO ₂ , 8-15% Al ₂ O ₃ , 0.2-1% Fe ₂ O ₃ , CaO 0-5%, MgO 0-3%, K ₂ O 1-5% , Na ₂ O 1-5% by weight, the main crystalline phase is mordenite (Mordenite), the sub-crystalline phase is Clinoptilolite (pullinite), the specific gravity of the natural mordenite mineral having a specific gravity of 2-2.5 After calcination, the zeolite consists of adding NaOH or NaOH-NaCl solution, aging at 25-35 ° C., and then crystallizing by reacting at a temperature of 90-100 ° C. for 4-10 hours. Method of preparation. The method according to claim 1, wherein the calcination treatment is carried out at a temperature of 700-900 ° C, and the addition amount of NaOH solution is 0.34 molar ratio of Na ₂ O / SiO ₂ , NaCl / Al ₂ O ₃ and H ₂ O / Na ₂ O, respectively. -0.85, 5.7-15 and 35-57, wherein the main crystalline phase is X-type zeolite. The molar ratio of Na ₂ O / SiO ₂ and H ₂ O / Na ₂ O according to claim 1, wherein the addition amount of the NaOH solution alone without the calcination treatment or after the calcination treatment is performed at a temperature of 700-900 ° C. without addition of NaCl. Is in the range of 0.25-0.45 and 20-35, respectively, wherein the main crystal phase is P-type zeolite.