阅读说明：本技术 伊利石黏土水热碱法合成方沸石的方法以及方沸石 (Method for synthesizing analcite from illite clay by hydrothermal-alkaline process and analcite ) 是由 孙红娟 周灿 彭同江 罗利明 于 2021-07-29 设计创作，主要内容包括：本发明提供了一种伊利石黏土水热碱法合成方沸石的方法以及方沸石,所述伊利石黏土水热碱法合成方沸石的方法包括步骤：将伊利石粉体与无机碱、含硅助剂和溶剂混合,老化得到反应物料的悬浮液；将所述反应物料的悬浮液进行水热合成,得到方沸石悬浮液；将所述方沸石悬浮液过滤得到滤饼和滤液,所述滤饼经洗涤和干燥得到方沸石粉体,所述溶剂为水或所述滤液。本发明具有合成工艺技术条件易实现、合成方法工序简易、操作方便、合成产物纯度较高、性能优异、合成过程绿色环保、产生的滤液可进行回收利用等优点。(The invention provides a method for synthesizing analcite by illite clay hydrothermal alkali method and analcite, wherein the method for synthesizing analcite by illite clay hydrothermal alkali method comprises the following steps: mixing illite powder with inorganic base, silicon-containing auxiliary agent and solvent, and aging to obtain a suspension of reaction materials; carrying out hydro-thermal synthesis on the suspension of the reaction materials to obtain a analcime suspension; and filtering the analcime suspension to obtain a filter cake and a filtrate, washing and drying the filter cake to obtain analcime powder, wherein the solvent is water or the filtrate. The method has the advantages of easy realization of technical conditions of the synthesis process, simple working procedures of the synthesis method, convenient operation, higher purity of the synthesized product, excellent performance, green and environment-friendly synthesis process, capability of recycling the generated filtrate and the like.)

1. A method for synthesizing analcite from illite clay by a hydrothermal alkaline process, which is characterized by comprising the following steps:

mixing illite powder with inorganic base, silicon-containing auxiliary agent and solvent, and aging to obtain a suspension of reaction materials;

carrying out hydro-thermal synthesis on the suspension of the reaction materials to obtain a analcime suspension;

and filtering the analcime suspension to obtain a filter cake and a filtrate, washing and drying the filter cake to obtain analcime powder, wherein the solvent is water or the filtrate.

2. The method for synthesizing analcite by the illite clay hydrothermal-alkaline process according to claim 1, wherein the illite powder has a particle size of 74 μm to 0.15mm, and is obtained by drying, crushing, grinding and classifying the illite clay.

3. The illite clay hydrothermal alkali synthesis method according to claim 2A method for preparing zeolite, wherein the illite clay comprises 20-80 wt% of illite, 10-60 wt% of quartz and 5-40 wt% of montmorillonite, and the chemical composition of the illite clay comprises SiO₂、Al₂O₃、Fe₂O₃And K₂O。

4. The method of illite clay thermoalcaline synthesis of analcite according to claim 1, wherein the inorganic base comprises NaOH, KOH, Al (OH)₃At least one of the silicon-containing auxiliary agents comprises at least one of white carbon black, sodium silicate and potassium silicate.

5. The method for synthesizing analcite by the illite clay hydrothermal-alkaline process as claimed in claim 1, wherein the illite powder, the inorganic base, the siliceous auxiliary agent and the water are mixed according to the mass ratio of (0.01-1): 0.03-0.1): 1-10.

6. The method for synthesizing analcite from illite clay by hydrothermal-alkaline process according to claim 1, wherein the molar ratio of the mixed mixture is 3-20 NaOH: 2-20 SiO₂:A1₂O₃:50～800H₂O, wherein the molar ratio of Si to Al is 2-20; the molar ratio of the addition of the inorganic base is 0.3-2.0 of NaOH/(Si + Al).

7. The method for synthesizing analcite by the illite clay hydrothermal-alkaline process according to claim 1, wherein the aging temperature is 10-60 ℃ and the aging time is 1-12 h.

8. The method for synthesizing analcite from illite clay by the hydrothermal-alkaline process according to claim 1, wherein the hydrothermal synthesis temperature is 100-260 ℃, the pressure is 1-5 MPa, and the time is 2-72 h.

9. The process for the hydrothermal alkaline synthesis of analcite from illite clay according to claim 1, characterized in that said washing and drying comprise the steps of:

washing the filter cake for 3-6 times by using water until the filter cake is neutral, and drying the filter cake at the temperature of 60-100 ℃ until the water content is 5% -15%.

10. A analcime obtainable by the process according to any one of claims 1 to 8, wherein the analcime is a powder having a particle size of 10 μm or less, and has a crystal type of analcime and a crystal content of 60 to 95%.

Technical Field

The invention relates to the technical field of novel inorganic functional materials, in particular to a method for synthesizing analcite by illite clay through a hydrothermal alkaline process and the analcite.

Background

Analcite is a sodium aluminosilicate mineral with a framework structure, and is a microporous zeolite with irregular channels formed by 4-, 6-and 8-membered rings. The analcime has the characteristics of short pore passage, wide active point position distribution and the like, shows excellent catalytic performance in reactions of oil refining, petrochemical industry and the like, can be used as a catalyst carrier and a chromatographic column filler, has excellent adsorption performance on wastewater treatment and radioactive elements such as fluorine-containing ions, carbonate ions, heavy metals and the like, and also has adsorption and separation effects on a solution containing lithium ions. However, the natural analcime has the disadvantages of small reserves, low purity, large particle size and the like, which can not meet the requirements of industrial production, and the synthetic analcime is required to be adopted in the application fields of environmental pollution energy-saving control, hydrocarbon separation, bifunctional catalysis and the like.

Illite belongs to 2: a non-swellable phyllosilicate of type 1 structure. The structure is formed by two layers of silicon-oxygen tetrahedrons sandwiching a layer of aluminum-oxygen octahedrons, wherein a part of silicon is replaced by aluminum. The illite mineral resources in China are rich and widely distributed, wherein the stock of prospect minerals in Zhejiang, Henan and Hebei all exceed hundred million tons. At present, the processing and application of illite at home and abroad are generally in a primary stage, and a plurality of natural illite minerals are directly used for producing ceramics, potash fertilizers, industrial fillers and the like, so that the added value of products is low. Therefore, the research on preparing the analcite with high added value by taking the illite as the raw material is of great significance.

The patent application number is CN103046111A, which is named as 'a method for preparing nano analcite by using fly ash', and discloses a method for preparing nano analcite by using fly ash as a raw material; the patent application number CN103318910A entitled "method for preparing large-size analcime by geopolymer hydrothermal crystallization" discloses a method for preparing large-size analcime by using chemically synthesized aluminosilicate active powder as solid raw material and sodium silicate as activator. However, the above two patents use high temperature roasting process in the process of preparing analcime, which consumes much energy and has high cost.

Disclosure of Invention

The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, one of the objectives of the present invention is to provide a method for synthesizing analcite by hydrothermal alkali method with no calcination, low energy consumption, environmental protection and short production period. For another example, another object of the present invention is to provide a analcime having a wide source of raw materials, high purity, excellent properties, and a wide range of applications.

In order to achieve the above object, the present invention provides, in one aspect, a method for synthesizing analcite from illite clay by hydrothermal alkali method, the method comprising the steps of:

mixing illite powder with inorganic base, silicon-containing auxiliary agent and solvent, and aging to obtain a suspension of reaction materials;

carrying out hydro-thermal synthesis on the suspension of the reaction materials to obtain a analcime suspension;

and filtering the analcime suspension to obtain a filter cake and a filtrate, washing and drying the filter cake to obtain analcime powder, wherein the solvent is water or the filtrate.

In an exemplary embodiment of an aspect of the present invention, the illite powder may have a particle size of 74 μm to 0.15mm, and the illite powder may be obtained by drying, crushing, grinding and classifying illite clay.

In an exemplary embodiment of an aspect of the present invention, the illite clay may include 20 to 80 wt% of illite, 10 to 60 wt% of quartz, and 5 to 40 wt% of montmorillonite, and the chemical composition of the illite clay may include SiO₂、Al₂O₃、Fe₂O₃And K₂O。

In an exemplary embodiment of an aspect of the present invention, the inorganic base may include NaOH, KOH, Al (OH)₃The silicon-containing auxiliary agent can comprise at least one of white carbon black, sodium silicate and potassium silicate.

In an exemplary embodiment of one aspect of the invention, the illite powder, the inorganic base, the silicon-containing assistant and the water can be mixed according to the mass ratio of (0.01-1): (0.03-0.1): 1-10.

In the inventionIn an exemplary embodiment of the aspect, the molar ratio in the mixed mixture may be 3 to 20NaOH:2 to 20SiO₂:A1₂O₃:50～800H₂O, wherein the molar ratio of Si to Al can be 2-20; the molar ratio of the added inorganic base is 0.3-2.0% of NaOH/(Si + Al).

In an exemplary embodiment of an aspect of the present invention, the aging temperature may be 10 to 60 ℃ and the aging time may be 1 to 12 hours.

In an exemplary embodiment of an aspect of the present invention, the temperature of the hydrothermal synthesis may be 100 to 260 ℃, the pressure may be 1 to 5MPa, and the time may be 2 to 72 hours.

In one exemplary embodiment of an aspect of the present invention, the washing and drying may include the steps of:

washing the filter cake for 3-6 times by using water until the filter cake is neutral, and drying the filter cake at the temperature of 60-100 ℃ until the water content is 5% -15%.

According to another aspect of the present invention, there is provided a analcime obtainable by a process as described in any one of the preceding claims, wherein the analcime is a powder having a particle size of 10 μm or less, the crystal type is analcime, and the crystal content is 60% to 95%.

Compared with the prior art, the beneficial effects of the invention can comprise at least one of the following:

(1) the synthesis raw materials of the invention are illite clay, inorganic base and silicon source, the silicon and aluminum components in the illite clay are fully utilized, and the illite clay is converted into the porous inorganic material, thus having certain economic value;

(2) the invention has low material cost, simple synthetic method process, convenient operation and mild reaction condition;

(3) the synthetic product of the invention is analcime powder with the content of 60-95 percent, can be used as an adsorbent or a purifying agent in the aspect of treating heavy metal polluted water, and can be used as a curing agent in the aspects of saline-alkali soil remediation and heavy metal polluted soil remediation;

(4) the process of the invention is green and environment-friendly, and the generated filtrate and washing liquid can be recycled.

Drawings

Fig. 1 shows an XRD pattern of illite clay according to an exemplary embodiment of the present invention;

figure 2 shows the XRD pattern of the analcime prepared in example 1;

figure 3 shows the XRD pattern of the analcime prepared in example 2;

FIG. 4 shows a morphology of the analcime prepared in example 1;

figure 5 shows the morphology of the analcime prepared in example 2.

Detailed Description

Hereinafter, the method for synthesizing analcite by the illite clay hydrothermal alkali method and analcite of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

Fig. 1 shows an XRD pattern of illite clay according to an exemplary embodiment of the present invention; figure 2 shows the XRD pattern of the analcime prepared in example 1; figure 3 shows the XRD pattern of the analcime prepared in example 2; FIG. 4 shows a morphology of the analcime prepared in example 1; figure 5 shows the morphology of the analcime prepared in example 2.

In a first exemplary embodiment of the present invention, a method for synthesizing analcite from illite clay by a hydrothermal-alkaline process includes the steps of:

the first step is as follows: and mixing the illite powder with inorganic base, silicon-containing auxiliary agent and water in proportion, and aging to obtain a suspension of the reaction material. Here. The particle size of the illite powder can be 74 mu m-0.15 mm, and the illite powder is obtained by drying, crushing, grinding and grading illite clay. The illite clay (clay) raw material can comprise 20-80 wt% of illite, 10-60 wt% of quartz and 5-40 wt% of montmorillonite, and the main chemical component of the illite clay can comprise SiO₂、Al₂O₃、Fe₂O₃And K₂And O. Specifically, illite clay raw material is pretreated to obtain illite powder with the granularity of 74 mu m-0.15 mm. Mixing illite powder, inorganic base, silicon-containing auxiliary agent and water or filtrate in proportion, adding into a high-pressure reaction kettle, and aging for a certain time under the condition of stirring to obtainA homogeneous suspension of the reaction mass is obtained. Fig. 1 shows an XRD pattern of illite clay according to an exemplary embodiment of the present invention. Here, the abscissa 2 θ (°) represents twice the incident angle of x-rays, and the ordinate Intensity (a.u) represents the Intensity after diffraction (the same applies hereinafter). As shown in figure 1, illite clay mainly comprises three mineral crystal phases of illite, quartz and montmorillonite, wherein the illite accounts for 20-wt 80%, the quartz accounts for 10-wt 60%, and the montmorillonite accounts for 5-40%.

The second step is that: and carrying out hydrothermal synthesis on the suspension of the reaction materials to obtain the analcime suspension. The temperature of the hydrothermal synthesis can be 100-260 ℃, the pressure can be 1-5 MPa, and the time can be 2-72 h. Specifically, the homogeneous suspension of the reaction material obtained in the first step is hydrothermally synthesized, and the reaction material is crystallized during the hydrothermal synthesis to obtain the analcime suspension. Here, when the temperature of the hydrothermal synthesis (i.e., crystallization temperature) is controlled within this range, the obtained analcime has good crystallinity and uniform particle size, and if it is less than 100 ℃, analcime cannot be formed, and if it is more than 260 ℃, energy is wasted and cost is increased; by controlling the crystallization time within the range, the analcime with good crystallinity and uniform particle size can be obtained, if the crystallization time is less than 2h, the analcime is not formed, and if the crystallization time is more than 72h, the production cycle is prolonged. Furthermore, the crystallization temperature of the hydrothermal synthesis is controlled within the range of 120-200 ℃, and the crystallization time is controlled within the range of 36-72 hours.

The third step: filtering the analcime suspension to obtain a filter cake and a filtrate; and washing, drying and grinding the filter cake to obtain the analcime powder, and returning the filtrate to the first step to be used as water for recycling.

In the present exemplary embodiment, the inorganic base may include NaOH, KOH, Al (OH)₃At least one of the silicon-containing auxiliary agents can comprise at least one of white carbon black, sodium silicate and potassium silicate.

In the exemplary embodiment, the illite powder, the inorganic base, the silicon-containing assistant and the water can be mixed according to the amount of the substances of (0.01-1), (0.03-0.1) and (1-10). For example, when the inorganic base is NaOH and the silicon-containing auxiliary agent is sodium silicate, mixing is carried outThe suspension of the resultant reaction mass may comprise (2-20) SiO in terms of molar ratio₂:(10～60)NaOH:(0.5～5)A1₂O₃:(50～800)H₂And O, wherein the molar ratio of Si to Al is 2-20, and the molar ratio of NaOH addition is 0.3-2.0.

In the exemplary embodiment, the temperature of the aging may be 10 to 60 ℃, and the time of the aging may be 1 to 12 hours. The ageing is carried out in order to react the powder and the solution sufficiently to obtain a homogeneous suspension and to increase the solubility of the silicate in the aqueous phase.

In the present exemplary embodiment, the washing and drying may include the steps of: washing the filter cake with water (e.g., tap water) for 3-6 times to neutrality, and drying at 60-100 ℃ until the water content is 5% -15%. Here, the washing liquid resulting from the washing may be added to the filtrate and returned to the first step together instead of water for recycling.

In another aspect of the invention, a analcime is provided.

In a second exemplary embodiment of the present invention, analcime may be synthesized by the method of the first exemplary embodiment described above. Here, the analcime is a powder having a particle diameter of 10 μm or less, and the powder has a crystal type of analcime and a crystal content of about 60% to 95%.

For a better understanding of the invention, the following further illustrates the invention in connection with specific examples 1 and 2, but the invention is not limited to the following examples only.

Example 1

(1) According to n (SiO)₂):n(NaOH):n(A1₂O₃):n(H₂Weighing a certain amount of illite powder and Na, wherein O is 8:16:1:410₂SiO₃·9H₂Placing O and NaOH into a container, adding a proper amount of industrial water for dissolving, aging for 1.5h under the stirring condition until obtaining a uniform suspension of reaction materials, then placing the materials into a closed reaction kettle, and crystallizing for 48h at 200 ℃;

(2) washing the obtained product with industrial water for 4 times until the pH value is neutral, drying at 60 deg.C for 8 hr, and grinding to obtain the desired product. The XRD spectrum is shown in figure 2, and the SEM spectrum is shown in figure 4. In fig. 4, the magnification is 2000 times. As can be seen from fig. 2 and 4, the cristobalite has good crystallinity, a crystallinity of about 75%, a crystal content of 94.7%, and a coarse and irregular shape in which other impurities are adsorbed on the crystal surface, as compared with the ideal cristobalite crystal grains.

Example 2

(1) According to n (SiO)₂):n(NaOH):n(A1₂O₃):n(H₂Weighing a certain amount of illite powder and Na (O) ═ 14:28:1:500₂SiO₃·9H₂Placing O and NaOH into a hydrothermal reaction kettle, adding a proper amount of industrial water for dissolving, aging for 2 hours under the stirring condition to obtain a uniform suspension of reaction materials, placing the materials into a closed reaction kettle, and crystallizing for 48 hours at 200 ℃;

(2) washing the obtained product with industrial water for 4 times until the pH value is neutral, drying at 60 deg.C for 8 hr, and grinding to obtain the desired product. The XRD spectrum is shown in figure 3, and the SEM spectrum is shown in figure 5. In fig. 5, the magnification is 1000 times. As can be seen from fig. 3 and 5, the cristobalite has good crystallinity, a crystallinity of about 75%, a crystal content of 89.3%, and a coarse and irregular shape in which other impurities are adsorbed on the crystal surface, as compared with the ideal cristobalite crystal grains.

The preparation conditions and the crystal contents of the resulting analcime for examples 3, 4, 5 are given in table 1.

Table 1 examples 3, 4, 5 crystal content in the preparation of analcime

Wherein the raw material addition ratio is n (SiO)₂):n(NaOH):n(A1₂O₃):n(H₂O) ratio. As can be seen from Table 1, the overall differences in the crystal contents of the analcime prepared under different conditions are small, and the crystal contents of the analcime prepared increase with the increase of the crystallization temperature.

In summary, the beneficial effects of the invention can include at least one of the following:

(1) the synthesis raw materials of the invention are illite clay, inorganic base and silicon source, the silicon and aluminum components in the illite clay are fully utilized, and the illite clay is converted into the porous inorganic material, thus having certain economic value;

(2) the invention has low material cost, simple synthetic method process, convenient operation and mild reaction condition;

(3) the synthetic product of the invention is analcime powder with the content of 60-95 percent, can be used as an adsorbent or a purifying agent in the aspect of treating heavy metal polluted water, and can be used as a curing agent in the aspects of saline-alkali soil remediation and heavy metal polluted soil remediation;

(4) the process of the invention is green and environment-friendly, and the generated filtrate and washing liquid can be recycled.

While the present invention has been described above in connection with the accompanying drawings and exemplary embodiments, it will be apparent to those of ordinary skill in the art that various modifications may be made to the above-described embodiments without departing from the spirit and scope of the claims.