阅读说明：本技术 一种钾交换率高的3a型沸石分子筛制备方法 (Preparation method of 3A type zeolite molecular sieve with high potassium exchange rate ) 是由 陈长昊 滕龙 张华� 张新峰 刘延东 田锋 骆雨 郭永久 赵峰 周爱民 于 2021-01-25 设计创作，主要内容包括：本发明公开了一种钾交换率高的3A型沸石分子筛制备方法,所述方法包括：将4A分子筛原粉加水打浆,后采用带有第一滤饼的设备进行固液分离,以获得第二滤饼；将浓度为10～15mol/L的KCl溶液进行预热,以获得预热离子交换液；将所述预热离子交换液对所述第二滤饼进行淋洗,以进行离子交换,后经洗涤和烘干,以获得3A型沸石分子筛。本发明实施例人通过实验证实,通过淋洗的方式使得离子交换液在交换过程中维持较高的钾离子浓度,从而提高3A型沸石分子筛钾交换率,本发明的钾交换率高达63.9～88.4％,达到降低废液中钾离子含量,降低3A型沸石分子筛成本,简化交换流程,提高生产效率的目的。(The invention discloses a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate, which comprises the following steps: adding water into the 4A molecular sieve raw powder for pulping, and then performing solid-liquid separation by adopting equipment with a first filter cake to obtain a second filter cake; preheating a KCl solution with the concentration of 10-15 mol/L to obtain a preheated ion exchange solution; and leaching the second filter cake by using the preheated ion exchange liquid to perform ion exchange, and then washing and drying to obtain the 3A type zeolite molecular sieve. Experiments prove that the ion exchange liquid maintains higher potassium ion concentration in the exchange process in a leaching mode, so that the potassium exchange rate of the 3A type zeolite molecular sieve is improved, the potassium exchange rate of the invention is as high as 63.9-88.4%, and the purposes of reducing the potassium ion content in waste liquid, reducing the cost of the 3A type zeolite molecular sieve, simplifying the exchange process and improving the production efficiency are achieved.)

1. A preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate is characterized by comprising the following steps:

adding water into the 4A molecular sieve raw powder for pulping, and then performing solid-liquid separation by adopting equipment with a first filter cake to obtain a second filter cake;

preheating a KCl solution with the concentration of 10-15 mol/L to obtain a preheated ion exchange solution;

and leaching the second filter cake by the preheated ion exchange liquid to perform ion exchange, and then washing and drying to obtain the 3A type zeolite molecular sieve.

2. The method for preparing 3A zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the volume ratio of the mass of 4A molecular sieve raw powder to the water in the pulping is as follows: 1 ton: 0.7 to 1m³。

3. The method for preparing the 3A type zeolite molecular sieve with high potassium exchange rate according to claim 1, characterized in that the equipment with the first filter cake is a vertical filter press.

4. The method for preparing 3A zeolite molecular sieve with high potassium exchange rate according to claim 1 or 3, wherein the thickness of the first filter cake is 40-60 mm.

5. The method for preparing the 3A zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the leaching equipment used in the leaching comprises one of a tape filter, a moving disk filter and a flat disk filter.

6. The preparation method of the 3A type zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the elution flow rate in the elution is 20-40 m³/h。

7. The method for preparing the 3A type zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the preheating temperature is 25-95 ℃.

8. The method for preparing the 3A type zeolite molecular sieve with high potassium exchange rate according to claim 6, wherein the preheating temperature is 50-85 ℃.

9. The preparation method of the 3A type zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the leaching time is 2-3 min.

10. The preparation method of the 3A zeolite molecular sieve with high potassium exchange rate according to claim 1, wherein the drying temperature is 90-100 ℃, and the drying time is 2-4 h.

Technical Field

The invention relates to the field of molecular sieve synthesis, in particular to a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate.

Background

The molecular sieve is an aluminosilicate, mainly consists of silicon and aluminum which are connected through oxygen bridges to form a hollow framework structure, and a plurality of pore passages with uniform pore diameters and cavities with orderly arrangement and large internal surface area are arranged in the structure. In addition, the metal ion with lower electrovalence and larger ionic radius and the water in a compound state are also contained. The molecular sieve is characterized in that water molecules are continuously lost after heating, but the crystal skeleton structure is unchanged, a plurality of cavities with the same size are formed, a plurality of micropores with the same diameter are connected with one another in the cavities, substance molecules with the diameter smaller than that of the pore passage are adsorbed in the cavities, and molecules with the diameter larger than that of the pore passage are excluded, so that the molecules with different sizes and shapes are separated, and the molecular sieve plays a role in sieving molecules. When molecules of a gas or liquid mixture pass through such a substance, they can be separated from each other according to different molecular characteristics.

The synthesized molecular sieve is white powder, is insoluble in water and organic solvent, is generally soluble in strong acid, and is molded into proper shape, usually spherical and strip, by adding a certain amount of adhesive into the molecular sieve raw powder in order to meet the requirement of industrial application. The molecular sieve has small external surface area (about 1 percent of the total surface area), good high thermal stability and very high internal surface area (600-1000 m) after dehydration²(g), open framework structure, the pore volume accounts for 28% -35% of the total volume, can hold a considerable amount of adsorbate molecules. High polarization of the surface of the inner crystal, strong electrostatic field in the crystal cavity and uniform micropore distribution, and is a high-efficiency and high-selectivity adsorbent, catalyst and catalystAn agent carrier. It is mainly used for deep drying of various gases and liquids, separation and purification of gases and liquids, catalyst carriers and the like, so that it is widely applied to oil refining, petrochemical industry, chemical industry, metallurgy, electronics, national defense industry and the like, and is increasingly widely applied to various aspects of medicine, light industry, agriculture, environmental protection and the like. Molecular sieve (also known as synthetic zeolite) is an aluminosilicate microporous crystal which is a framework structure composed of SiO and AIO tetrahedrons. Metal cations (e.g., Na, K, Ca, etc.) are present in the molecular sieve lattice to balance the excess negative charge in the tetrahedra. The types of molecular sieves are mainly classified by their crystal structures: type A, type X, type Y, etc. Type A: mainly comprising aluminosilicate with a pore size ofReferred to as 4A (also known as na type a) molecular sieves; with Ca²⁺Exchange of Na in 4A molecular sieve⁺Form aThe pore diameter of the zeolite is 5A (also called calcium A type) molecular sieve; by K⁺Exchange of Na for 4A molecular sieves⁺Form aThe pore diameter of the zeolite is the 3A (also called as potassium A type) molecular sieve.

The 3A type zeolite molecular sieve is prepared by reacting 4A molecular sieve and KCl solution at 70-90 deg.C for 3-5 hr, separating, washing, and drying to obtain 3A zeolite molecular sieve. In the preparation process of the 3A type zeolite molecular sieve, K⁺Can not completely react with Na in the 4A molecular sieve⁺Exchange, the K ion exchange rate is low, generally between 38 and 55 percent. Because the exchange rate of potassium ions is low, in the separation and washing processes of slurry after exchange, the generated waste liquid contains a large amount of potassium ions and sodium ions, the waste liquid cannot be recycled, the cost is increased, and the environment is polluted by directly discharging the waste liquid containing potassium ions.

Therefore, how to develop a preparation method of the 3A type zeolite molecular sieve with high potassium exchange rate becomes a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate, which maintains higher potassium ion concentration of an ion exchange solution in an exchange process in a leaching mode so as to improve the potassium exchange rate of the 3A type zeolite molecular sieve.

In order to achieve the above object, the present invention provides a method for preparing a 3A type zeolite molecular sieve having a high potassium exchange rate, the method comprising:

adding water into the 4A molecular sieve raw powder for pulping, and then performing solid-liquid separation by adopting equipment with a first filter cake to obtain a second filter cake;

preheating a KCl solution with the concentration of 10-15 mol/L to obtain a preheated ion exchange solution;

and leaching the second filter cake by using the preheated ion exchange liquid to perform ion exchange, and then washing and drying to obtain the 3A type zeolite molecular sieve.

Further, in the pulping, the volume ratio of the mass of the 4A molecular sieve raw powder to the water is as follows: 1 ton: 0.7 to 1m³。

Further, the equipment with the first filter cake is a vertical filter press.

Further, the thickness of the first filter cake is 40-60 mm.

Furthermore, the equipment adopted during leaching comprises one of a tape filter, a movable disc filter and a flat disc filter.

Further, the flow rate adopted in the leaching is 20-40 m³/h。

Further, the preheating temperature is 25-95 ℃.

Further, the preheating temperature is 50-85 ℃.

Further, the leaching time is 2-3 min.

Further, the drying temperature is 90-100 ℃, and the drying time is 2-4 hours.

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

the practice of the embodiment of the invention finds that the reason for low potassium ion exchange rate is as follows: in the process of exchanging potassium ions with the 4A molecular sieve in the reaction kettle, the concentration of the potassium ions is continuously changed from high to low, so that the exchange of potassium and sodium ions reaches the exchange balance under the lower potassium exchange rate. Experiments prove that 4A molecular sieve raw powder is pulped by adding water, and then solid-liquid separation is carried out by adopting equipment with a first filter cake to obtain a second filter cake; preheating a KCl solution with the concentration of 10-15 mol/L to obtain a preheated ion exchange solution; leaching the second filter cake by the preheated ion exchange liquid to perform ion exchange, and then washing and drying to obtain the 3A type zeolite molecular sieve; the ion exchange liquid maintains higher potassium ion concentration in the exchange process through a leaching mode, so that the potassium exchange rate of the 3A type zeolite molecular sieve is improved, the potassium exchange rate of the embodiment of the invention is as high as 63.9-88.4%, and the aims of reducing the potassium ion content in waste liquid, reducing the cost of the 3A type zeolite molecular sieve, simplifying the exchange process and improving the production efficiency are fulfilled.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate provided by the embodiment of the invention.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the embodiments of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that the present embodiments and examples are illustrative of the present invention and are not to be construed as limiting the present invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention belong. If there is a conflict, the present specification will control.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the examples of the present invention are commercially available or can be prepared by an existing method. The terms "first", "second", and the like in the embodiments of the present invention do not denote any order, and may be understood as nouns.

According to an exemplary embodiment of the present invention, there is provided a method for preparing a 3A type zeolite molecular sieve having a high potassium exchange rate, comprising:

s1, adding water into the 4A molecular sieve raw powder for pulping, and then performing solid-liquid separation by using equipment with a first filter cake to obtain a second filter cake;

s2, preheating a KCl solution with the concentration of 10-15 mol/L to obtain a preheated ion exchange solution;

and S3, leaching the second filter cake by the preheated ion exchange liquid to perform ion exchange, and then washing and drying to obtain the 3A type zeolite molecular sieve.

In order to solve the technical problems, the embodiment of the invention provides the following general ideas:

the practice of the embodiment of the invention finds that the reason for the low exchange rate of potassium ions is: in the process of exchanging potassium ions with the 4A molecular sieve in the reaction kettle, the concentration of the potassium ions is continuously changed from high to low, so that the exchange of potassium and sodium ions reaches the exchange balance under the lower potassium exchange rate. Experiments prove that the ion exchange liquid maintains higher potassium ion concentration in the exchange process in a leaching mode, so that the potassium exchange rate of the 3A type zeolite molecular sieve is improved, the potassium exchange rate of the embodiment of the invention is as high as 63.9-88.4%, and the purposes of reducing the potassium ion content in waste liquid, reducing the cost of the 3A type zeolite molecular sieve, simplifying the exchange process and improving the production efficiency are achieved.

As an alternative embodiment, in the beating, the ratio of the mass of the 4A molecular sieve to the volume of the water is: 1 ton: 0.7 to 1m³. Too little water is not beneficial to pulping, and too much water is not beneficial to subsequent separation.

As an alternative embodiment, the apparatus with the first filter cake is a vertical filter press.

As an alternative embodiment, the equipment adopted during the leaching comprises one of a tape filter, a moving disc filter and a flat disc filter. The leaching carried out by adopting the equipment in the embodiment of the invention belongs to a plane washing mode, and can ensure that the ion exchange liquid maintains higher potassium ion concentration in the exchange process, thereby improving the potassium exchange rate of the 3A type zeolite molecular sieve.

The reason why the concentration of the KCl solution is 10-15 mol/L is as follows: by maintaining a higher concentration of potassium ions during the exchange process, the potassium exchange rate of the 3A type zeolite molecular sieve can be improved. It was also confirmed that the ion exchange of potassium and sodium can be completed in a very short time. The concentration is too low to improve the potassium exchange rate; if the concentration is too high, hardening of filter cakes is easily caused, so that the exchange effect is influenced;

as an optional implementation mode, the flow rate adopted in the leaching process is 20-40 m³H is used as the reference value. If the flow is too small, the utilization rate of potassium ions is favorably improved, but the productivity and the equipment utilization rate are low; if the flow is too high, the utilization rate of potassium ions is low.

As an optional embodiment, the preheating temperature is 25-95 ℃. Preferably, the preheating temperature is 50-85 ℃. At this temperature, the rate of ion exchange is high, and too high or too low a temperature is not favorable for ion exchange.

As an optional implementation mode, the leaching time is 2-3 min; the thickness of the first filter cake is 40-60 mm. The thickness of the first filter cake determines the time of ion exchange, the common filter cake thickness is 40-60 mm, and the time of ion exchange is 2-3 min under the thickness, so the time of leaching is proper for 2-3 min.

The following will explain in detail the preparation method of the 3A type zeolite molecular sieve with high potassium exchange rate in this application by combining the examples, comparative examples and experimental data.

Example 1

The embodiment of the invention provides a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate, which comprises the following steps:

1 ton of S1 and 4A molecular sieve raw powder is added into the added water with the thickness of 0.8m³Pulping in an exchange tank, and performing solid-liquid separation by using a vertical filter press to obtain a second filter cake; the thickness of a first filter cake in the vertical filter press is 50 mm;

s2, heating the exchange solution with the potassium ion concentration of 10mol/L to 65 ℃ to obtain preheated ion exchange solution;

s3, adding the obtained preheated ion exchange liquid to 25m³And (2) at the flow rate of/h, exchanging the filter cake by adopting a plane washing mode, namely leaching, wherein the exchange time is 2.5 minutes, washing the exchanged filter cake on a vertical filter press, and drying the washed filter cake to obtain the 3A type zeolite molecular sieve product.

Example 2

The embodiment of the invention provides a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate, which comprises the following steps:

1 ton of S1 and 4A molecular sieve raw powder is added into the added water with the thickness of 0.8m³Pulping in an exchange tank, and performing solid-liquid separation by using a vertical filter press to obtain a second filter cake; the thickness of a first filter cake in the vertical filter press is 50 mm;

s2, heating the exchange solution with the potassium ion concentration of 12mol/L to 50 ℃ to obtain preheated ion exchange solution;

s3, mixing the obtained preheated ion exchange liquid with the volume of 20m³And (2) at the flow rate of/h, exchanging the filter cake by adopting a plane washing mode, namely leaching, wherein the exchange time is 3 minutes, washing the exchanged filter cake on a vertical filter press, and drying the washed filter cake to obtain the 3A type zeolite molecular sieve product.

Example 3

The embodiment of the invention provides a preparation method of a 3A type zeolite molecular sieve with high potassium exchange rate, which comprises the following steps:

1 ton of S1 and 4A molecular sieve raw powder is added into the added water with the thickness of 0.8m³Pulping in an exchange tank, and performing solid-liquid separation by using a vertical filter press to obtain a second filter cake; the thickness of a first filter cake in the vertical filter press is 50 mm;

s2, heating the exchange solution with the potassium ion concentration of 15mol/L to 85 ℃ to obtain preheated ion exchange solution;

s3, mixing the obtained preheated ion exchange liquid with the volume of 40m³And (2) at the flow rate of/h, exchanging the filter cake by adopting a plane washing mode, namely leaching, wherein the exchange time is 2 minutes, washing the exchanged filter cake on a vertical filter press, and drying the washed filter cake to obtain the 3A type zeolite molecular sieve product.

Comparative example 1

Adding 1 ton of 4A molecular sieve raw powder and 360Kg of solid KCl into 3m of water³Pulping in an exchange tank, heating to 75 ℃, directly exchanging in the exchange tank for 4 hours, separating and washing by a vertical filter press, and drying a filter cake to obtain the 3A type zeolite molecular sieve product.

Comparative example 2

Adding 1 ton of 4A molecular sieve raw powder and 500Kg of solid KCl into 3m of water³Pulping in an exchange tank, heating to 90 ℃, directly exchanging in the exchange tank for 3 hours, separating and washing by a vertical filter press, and drying a filter cake to obtain the 3A type zeolite molecular sieve product.

Comparative example 3

In this comparative example, the KCl solution was used at a concentration of 1mol/L, and the procedure was as in example 1.

Comparative example 4

In this comparative example, the KCl solution was 20mol/L, and the procedure was the same as in example 1.

Comparative example 5

In this comparative example, the flow rate used in the rinsing was 60m³The rest of the procedure was as in example 1.

Experimental example 1

The 3A type zeolite molecular sieve products prepared in examples 1-3 and comparative examples 1-2 were subjected to performance measurement, and statistics are shown in Table 1;

TABLE 1

Sample numbering	SiO2(％)	Ai2O3(％)	K2O(％)	Na2O(％)	Degree of exchange%	Adsorption of water%	Potassium ion exchange Rate%
								Example 1	31.75	27.89	13.23	8.63	45.7	24.25	88.4
Example 2	31.54	27.61	12.67	8.28	45.6	24.61	63.9
								Example 3	31.36	27.47	12.96	8.16	68.1	24.65	79.2
Comparative example 1	31.17	27.14	11.48	8.4	43.1	24.86	36.4
								Comparative example 2	31.42	27.12	11.13	8.5	54.9	24.21	44.1
Comparative example 3	31.02	27.36	11.74	8.26	51.3	24.16	51.6
								Comparative example 4	31.11	27.33	12.05	8.31	52.5	24.24	54.2
Comparative example 5	31.24	27.41	11.56	8.34	53.6	24.11	56.7

From the data in table 1, it can be seen that:

in comparative example 1, the potassium ion exchange rate was only 36.4% by the conventional ion exchange method;

in comparative example 2, the potassium ion exchange rate was only 44.1% by the conventional ion exchange method;

in the comparative example 3, the concentration of the KCl solution is 1mol/L, which is less than the range of 10-15 mol/L in the embodiment of the invention, and the exchange rate of potassium ions is only 51.6%;

in the comparative example 4, the concentration of the KCl solution is 20mol/L, which is larger than the range of 10-15 mol/L in the embodiment of the invention, and the exchange rate of potassium ions is only 54.2%;

in comparative example 5, the flow rate used in the rinsing was 60m³H is more than 20 to 40m of the embodiment of the invention³Range of/h, potassium ion exchangeThe rate is only 56.7%;

in examples 1 to 3, the exchange rate of potassium ion was as high as 63.9 to 88.4%.

In summary, experiments prove that the ion exchange solution maintains higher potassium ion concentration in the exchange process in a leaching manner, so that the potassium exchange rate of the 3A type zeolite molecular sieve is improved, the potassium exchange rate of the embodiment of the invention is as high as 63.9-88.4%, and the purposes of reducing the potassium ion content in waste liquid, reducing the cost of the 3A type zeolite molecular sieve, simplifying the exchange process and improving the production efficiency are achieved.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the embodiments of the present invention and their equivalents, the embodiments of the present invention are also intended to encompass such modifications and variations.