阅读说明：本技术 利用气化粗渣在无水无模板剂条件下制备钙霞石分子筛的方法 (Method for preparing cancrinite molecular sieve by using gasified coarse slag under anhydrous condition without template agent ) 是由 吉文欣 冯宁 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种利用气化粗渣在无水无模板剂条件下制备钙霞石分子筛的方法,包括以下步骤：原料筛分-加碱碱融-加盐混合-晶化反应-洗涤干燥。本发明的方法不需外加纯化学试剂调节硅铝比,仅利用粗渣中的SiO-2和Al-2O-3作为硅铝源；也不需要添加无机模板剂,外加硝酸钠作为导向剂起晶体导向作用进行合成钙霞石分子筛。本发明实现了煤气化粗渣的无害化处理和资源化利用,减少了煤气化粗渣造成的巨大环境压力,同时钙霞石本身在工业中具有很多的应用功能,有一定的经济效益。而且,本发明中采用的合成工艺无需加水、无需额外添加硅铝源,亦无需添加有机模板剂,极大程度的降低了能源消耗,环境友好,操作简单,可工业化生产。(The invention discloses a method for preparing cancrinite molecular sieve by using gasified coarse slag under the condition of no water and template agent, which comprises the following steps: screening raw materials, adding alkali and alkali for melting, adding salt for mixing, performing crystallization reaction, washing and drying. The method of the invention does not need to add pure chemical reagent to adjust the silicon-aluminum ratio, and only utilizes SiO in the coarse slag 2 And Al 2 O 3 As a silica-alumina source; and an inorganic template agent is not required to be added, and sodium nitrate is added to serve as a guiding agent to play a crystal guiding role in synthesizing the cancrinite molecular sieve. The invention realizes the harmless treatment and resource utilization of the coal gasification coarse slag, reduces the huge environmental pressure caused by the coal gasification coarse slag, and meanwhile, cancrinite has a plurality of application functions in the industry and has certain economic benefit. In addition, the synthesis process adopted in the invention does not need to add water, silicon and aluminum sources and organic template agents, greatly reduces energy consumption, is environment-friendly, is simple to operate and can be used for industrial production.)

1. A method for preparing cancrinite molecular sieve by using gasified coarse slag under the condition of no water and template agent is characterized by comprising the following steps:

(1) screening raw materials: taking the coal gasification coarse slag as a raw material, drying the coal gasification coarse slag, grinding the coal gasification coarse slag by a ball mill in a dry method, and taking slag fine powder with a 200-mesh sieve;

(2) adding alkali and melting: mixing the slag fine powder and sodium hydroxide in a ratio of (1.1-1.3): 1, and then placing the mixture in a muffle furnace to be roasted for 80-100 min at 500-600 ℃;

(3) adding salt and mixing: and (3) mixing the slag after alkali melting with sodium nitrate according to the ratio of (2.0-2.5): 1.5, grinding to uniformly mix;

(4) and (3) crystallization reaction: moving the reaction kettle into a drying oven at 100-150 ℃, and keeping the temperature for 45-50 h;

(5) washing and drying: and washing the product with deionized water until the pH value is 10, and then drying at 100-110 ℃ for 5-10 h to obtain the cancrinite molecular sieve.

2. The method for preparing cancrinite molecular sieve using gasified coarse slag without water and template agent according to claim 1, wherein raw coal gasified coarse slag in step (1) has silica content of 50-55 wt%, alumina of 15-20 wt%, iron oxide of 10-12 wt%, calcium oxide of 10-11 wt% and sodium oxide of 1-2 wt%.

3. The method for preparing cancrinite molecular sieve using gasified coarse slag without water and template agent according to claim 1, wherein in the raw material coal gasified coarse slag in step (1), silica content is 53.4 wt%, alumina is 17.2 wt%, iron oxide is 11.2 wt%, calcium oxide is 10.1 wt%, and sodium oxide is 1.33 wt%.

4. The method for preparing the cancrinite molecular sieve by using the gasified coarse slag under the condition of no water and no template agent according to claim 1, wherein the raw material coal gasified coarse slag in the step (1) is dried at 120 ℃ for 45-50 h and is subjected to dry ball milling for 20-60 min.

5. The method for preparing cancrinite molecular sieve using gasified coarse slag under anhydrous condition without template agent as claimed in claim 1, wherein the mass ratio of slag fine powder to sodium hydroxide in step (2) is 1.2: 1, roasting at 550 ℃ for 90 min.

6. The method for preparing the cancrinite molecular sieve by using the gasified coarse slag under the condition of no water and no template agent according to claim 1, wherein the temperature rise rate of the muffle furnace in the step (2) is 3-5 ℃/min, and the temperature drop rate is 5-10 ℃/min.

7. The method for preparing cancrinite molecular sieve using gasified coarse slag under anhydrous condition without template agent as claimed in claim 1, wherein the mass ratio of slag after alkali melting to sodium nitrate in step (3) is 2.2: 1.5.

8. the method for preparing cancrinite molecular sieve using gasified coarse slag without water and template agent as claimed in claim 1, wherein the crystallization reaction temperature in step (4) is 120 ℃, and the constant temperature is 48 h.

9. The method for preparing cancrinite molecular sieve using gasified coarse slag without water and template agent according to claim 1, wherein drying in step (5) is carried out at 105 ℃ for 6 h.

10. The method for preparing cancrinite molecular sieve using gasified coarse slag under anhydrous condition without template agent as claimed in claim 1, wherein cancrinite molecular sieve in step (5) has chemical formula Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂·2H₂O。

Technical Field

The invention relates to the technical field of cancrinite preparation, in particular to a method for preparing a cancrinite molecular sieve by utilizing gasified coarse slag under the condition of no water and no template agent.

Background

Cancrinite is one of feldspar-like minerals, the element composition is sodium, silicon, aluminum and the like, and the cancrinite can be widely applied to various fields, for example, an angsilver composite material is prepared by nanometer-sized porous cancrinite and silver ions through a thermodynamic ion exchange method and is used as an antibacterial agent for skin tinea, various pathogenic bacteria and viruses; the cancrinite mineral is used as a base material to obtain a deodorant which has a wide removal effect on various malodors such as ammonia, amine, an adjacent solution, mercaptan and the like through metal exchange; in the field of catalysis, cancrinite is used as a base material of a catalytic cracking denitration combined catalyst for NOX; cancrinite is used as a solid acid catalyst for catalyzing the alkylation reaction of benzene; a catalyst for disproportionation reaction of trimethylamine after the cancrinite is subjected to hydrogen ion exchange, and the like. However, naturally occurring cancrinite is rare and in actual use, most cancrinite is obtained by artificial synthesis.

The artificial synthesis of cancrinite has the following problems: firstly, a silicon source, an aluminum source and a calcium source with high purity and a large amount of water are directly used for hydrothermal reaction, so that the production cost is high; secondly, in the existing methods for synthesizing cancrinite, an organic template agent or a guiding agent is required to be added to improve the selectivity of a target product, and the use of the organic template agent or the guiding agent not only increases the production cost, but also has toxicity to the environment and corrosiveness to equipment. Therefore, the search for industrial waste which can be recycled as raw material for producing cancrinite and the research and development of a method for preparing cancrinite molecular sieve under the condition of no water and no template agent are problems to be solved in the field.

The main industrial solid wastes in the field of coal chemical industry refer to coal gasifier slag, fly ash, boiler slag, desulfurized gypsum, sludge and the like, and are characterized by large production amount, fast speed increase and high homogenization degree. As for coal gasifier slag, because the carbon content is high, the coal gasifier slag cannot be used as a building material, a good treatment method is not available at present, the coal gasifier slag is treated by landfill, not only occupies valuable land resources, but also brings high transportation and treatment cost for enterprises, and meanwhile, the coal gasifier slag residual heavy metal pollution can generate pollution which is difficult to reverse on the environment, particularly underground water and soil. Therefore, it is necessary to analyze the components and structural characteristics of the coal gasifier slag, and to study the methods for treating and recycling the coal gasifier slag, and apply the methods to the preparation of cancrinite.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for preparing a cancrinite molecular sieve by using gasified coarse slag under the condition of no water or template agent, wherein the existing gasified coarse slag is directly used as a raw material to produce the cancrinite molecular sieve under the conditions of no water or template machine and no regulation of silicon-aluminum ratio.

The invention provides a method for preparing cancrinite molecular sieve by using gasified coarse slag under the condition of no water and template agent, which comprises the following steps:

(1) screening raw materials: taking the coal gasification coarse slag as a raw material, drying the coal gasification coarse slag, grinding the coal gasification coarse slag by a ball mill in a dry method, and taking slag fine powder with a 200-mesh sieve;

(2) adding alkali and melting: mixing the slag fine powder and sodium hydroxide in a ratio of (1.1-1.3): 1, and then placing the mixture in a muffle furnace to be roasted for 80-100 min at 500-600 ℃;

(3) adding salt and mixing: and (3) mixing the slag after alkali melting with sodium nitrate according to the ratio of (2.0-2.5): 1.5, grinding to uniformly mix;

(4) and (3) crystallization reaction: moving the reaction kettle into a drying oven at 100-150 ℃, and keeping the temperature for 45-50 h;

(5) washing and drying: and washing the product with deionized water until the pH value is 10, and then drying at 100-110 ℃ for 5-10 h to obtain the cancrinite molecular sieve.

Preferably, in the raw material coal gasification coarse slag in the step (1), the content of silicon dioxide is 50-55 wt%, the content of aluminum oxide is 15-20 wt%, the content of ferric oxide is 10-12 wt%, the content of calcium oxide is 10-11 wt%, and the content of sodium oxide is 1-2 wt%.

Preferably, in the raw material coal gasification coarse slag in the step (1), the content of silicon dioxide is 53.4 wt%, the content of aluminum oxide is 17.2 wt%, the content of ferric oxide is 11.2 wt%, the content of calcium oxide is 10.1 wt%, and the content of sodium oxide is 1.33 wt%

Preferably, the raw material coal gasification coarse slag in the step (1) is dried for 45-50 h at 120 ℃, and is ball-milled for 20-60 min by a dry method.

Preferably, the mass ratio of the slag fine powder to the sodium hydroxide in the step (2) is 1.2: 1, roasting at 550 ℃ for 90 min.

Preferably, in the step (2), the temperature rise rate of the muffle furnace is 3-5 ℃/min, and the temperature drop rate is 5-10 ℃/min.

Preferably, the mass ratio of the slag after alkali melting in the step (3) to the sodium nitrate is 2.2: 1.5.

preferably, the crystallization reaction temperature in the step (4) is 120 ℃, and the constant temperature is kept for 48 hours.

Preferably, the drying in step (5) is carried out at 105 ℃ for 6h

Preferably, the chemical formula of the cancrinite molecular sieve in the step (5) is Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂·2H₂O。

The working principle of the invention is as follows: the cancrinite molecular sieve mainly comprises aluminum oxide and silicon oxide, the coal gasification coarse slag comprises inorganic mineral component and residual carbon which is not completely gasified during gasification, and the main component of the inorganic mineral component is SiO₂And Al₂O₃Provides the necessary silicon-aluminum source for the crystal growth of the molecular sieve. In the process of preparing the cancrinite molecular sieve by utilizing the coal gasification coarse slag, alkali is added to be molten to be beneficial to activating a silicon-aluminum source in the coal gasification coarse slag, sodium hydroxide reacts with silicon and aluminum oxide to generate sodium silicate and sodium aluminate, and simultaneously the crystal structure of waste slag is molten to generate a certain pore structure so as to provide the environment condition for generating the mesoporous environment functional material. The addition of sodium nitrate plays a role in crystal orientation, so that the crystal grows into cancrinite crystals, and the crystallization provides proper temperature and time for the growth of the activated silicon-aluminum source in the waste residue to provide cancrinite crystals.

The invention has the beneficial effects that: the invention utilizes the method for preparing cancrinite molecular sieve by gasifying the coarse slag under the condition of no water or template agent, does not need to add a pure chemical reagent to adjust the silicon-aluminum ratio, and only utilizes SiO in the coarse slag₂And Al₂O₃As a silica-alumina source; and an inorganic template agent is not required to be added, and sodium nitrate is added to play a guiding role as a guiding agent to synthesize the cancrinite molecular sieve. The cancrinite molecular sieve prepared by the method is characterized by XRD, SEM, FT-IR and the like, the XRD result has higher matching degree with a standard card, the SEM image presents a hexagon, and FT-IR vibration shrinkage peak documents are identical, which indicates that the obtained product is the cancrinite molecular sieve. The invention realizes the harmless treatment and resource utilization of the coal gasification coarse slag, reduces the huge environmental pressure caused by the coal gasification coarse slag, reduces the environmental pollution and soilThe land occupation saves the cost of factory treatment, and meanwhile, cancrinite has a plurality of application functions in the industry and has certain economic benefit. In addition, the synthesis process adopted in the invention does not need to add water, silicon and aluminum sources and organic template agents, greatly reduces energy consumption, is environment-friendly, is simple to operate and can be used for industrial production.

Drawings

FIG. 1 is an XRD pattern of a coal gasification coarse slag;

FIG. 2 is an XRD pattern of cancrinite;

FIG. 3 is a FT-IR plot of cancrinite;

FIG. 4 is a scanning electron micrograph of coal gasification coarse slag;

fig. 5 is an adsorption-desorption isotherm.

Fig. 6 is an adsorption-desorption isotherm.

Detailed Description

In order to make the technical scheme of the invention easier to understand, the technical scheme of the invention is clearly and completely described by adopting a mode of a specific embodiment in combination with the attached drawings.

Example 1:

as shown in fig. 1, the method for preparing cancrinite molecular sieve by using gasified coarse slag under the condition of no water and no template agent of the embodiment comprises the following steps:

(1) screening raw materials: taking the coal gasification coarse slag as a raw material, drying the coal gasification coarse slag at 120 ℃ for 45h, carrying out dry milling for 20min by using a ball mill, and taking furnace slag fine powder with a 200-mesh sieve; in the raw material coal gasification coarse slag, the content of silicon dioxide is 50 wt%, the content of aluminum oxide is 20 wt%, the content of ferric oxide is 10 wt%, the content of calcium oxide is 10 wt%, and the content of sodium oxide is 2 wt%;

(2) adding alkali and melting: slag fines and sodium hydroxide were mixed in a 1.1: 1, then placing the mixture into a muffle furnace, heating the muffle furnace at a heating rate of 3 ℃/min, then roasting the mixture at 500 ℃ for 80min, and cooling the mixture to normal temperature at a cooling rate of 10 ℃/min;

(3) adding salt and mixing: mixing the slag after alkali melting with sodium nitrate according to the ratio of 2.0: 1.5, grinding to uniformly mix;

(4) and (3) crystallization reaction: moving the reaction kettle into a drying oven at 100 ℃, and keeping the temperature for 50 h;

(5) washing and drying: the product was washed with deionized water to pH 10 and then dried at 100 ℃ for 10h to yield cancrinite molecular sieve.

Example 2:

as shown in fig. 2, the method for preparing cancrinite molecular sieve by using gasified coarse slag under anhydrous condition without template agent of the embodiment comprises the following steps:

(1) screening raw materials: taking the coal gasification coarse slag as a raw material, drying the coal gasification coarse slag at 120 ℃ for 48h, carrying out dry milling for 30min by using a ball mill, and taking furnace slag fine powder with a 200-mesh sieve; in the raw material coal gasification coarse slag, the content of silicon dioxide is 53.4 wt%, the content of aluminum oxide is 17.2 wt%, the content of ferric oxide is 11.2 wt%, the content of calcium oxide is 10.1 wt%, and the content of sodium oxide is 1.33 wt%;

(2) adding alkali and melting: slag fines and sodium hydroxide were mixed in a 1.2: 1, then placing the mixture into a muffle furnace, heating the muffle furnace at a heating rate of 4 ℃/min, then roasting the mixture at 550 ℃ for 90min, and cooling the mixture to normal temperature at a cooling rate of 8 ℃/min;

(3) adding salt and mixing: mixing the slag after alkali melting with sodium nitrate according to the ratio of 2.2: 1.5, grinding to uniformly mix;

(4) and (3) crystallization reaction: moving the reaction kettle into a drying oven at 120 ℃, and keeping the temperature for 48 hours;

(5) washing and drying: the product was washed with deionized water to pH 10 and then dried at 105 ℃ for 60h to yield cancrinite molecular sieve.

Example 3:

as shown in fig. 3, the method for preparing cancrinite molecular sieve by using gasified coarse slag under the condition of no water and no template agent of the embodiment comprises the following steps:

(1) screening raw materials: taking the coal gasification coarse slag as a raw material, drying the coal gasification coarse slag for 50h at 120 ℃, carrying out dry milling for 60min by using a ball mill, and taking furnace slag fine powder with a 200-mesh sieve; in the raw material coal gasification coarse slag, the content of silicon dioxide is 55 wt%, the content of aluminum oxide is 15 wt%, the content of ferric oxide is 12 wt%, the content of calcium oxide is 11 wt%, and the content of sodium oxide is 1 wt%;

(2) adding alkali and melting: slag fines and sodium hydroxide were mixed in a 1.3: 1, then placing the mixture into a muffle furnace, heating the muffle furnace according to the heating rate of 5 ℃/min, then roasting the mixture at 600 ℃ for 100min, and cooling the mixture to the normal temperature according to the cooling rate of 5 ℃/min;

(3) adding salt and mixing: mixing the slag after alkali melting with sodium nitrate according to the ratio of 2.5: 1.5, grinding to uniformly mix;

(4) and (3) crystallization reaction: moving the reaction kettle into a drying oven at 150 ℃, and keeping the temperature for 45 hours;

(5) washing and drying: the product was washed with deionized water to pH 10 and then dried at 110 ℃ for 5h to yield cancrinite molecular sieve.

FIG. 1 is an XRD (X-ray diffraction) diagram of coal gasification coarse slag, and it can be seen that waste slag is mainly a steamed bread peak of an amorphous phase. Fig. 2 is an XRD pattern of cancrinite, and four strong diffraction peaks at 2 θ of 13.9 °, 18.718 °, 24.2 °, 27.467 ° are the four major characteristic diffraction peaks of cancrinite.

FIG. 3 is a FT-IR diagram of cancrinite zeolite from TO₄The tetrahedrons share vertices to form a three-dimensional skeleton. The T atom in the skeletal structure is usually replaced by a Si, Al or P atom. At 470, 578, 615 and 695 cm^-1Typical symmetrical T-O-T vibration sum at 960, 1120cm^-1The absorption band of the cancrinite skeleton can be obviously observed when the asymmetric T-O-T vibrates. 1425cm^-1An outstanding single band was found, due to the nitrate ion NO^3-Caused by bending as a non-framework anion.

Fig. 4 is a scanning electron microscope image of the coal gasification coarse slag, and it can be seen that the coal gasification coarse slag has a spherical shape, which is vitreous silica. Fig. 5 is a scanning electron micrograph of the synthesized cancrinite, which shows the morphology of cancrinite, which is a regular hexagon.

Fig. 6 is a sorption-desorption isotherm, and from fig. 6, it can be derived that cancrinite type zeolite exhibits a type IV isotherm (relative pressure range 0.7-0.99) of the H3 hysteresis loop, which is a typical characteristic of mesoporous materials, where the hysteresis loop is associated with the occurrence of pore condensation.

The cancrinite molecular sieve prepared by the method is characterized by XRD, SEM, FT-IR and the like, the XRD result has higher matching degree with a standard card, the SEM image presents a hexagon, the crystal structure is complete, and the FT-IR vibration shrinkage peak documents are identical, which indicates that the obtained product is the cancrinite molecular sieve.

Cancrinite prepared by the above examples and raw material gasification slag can be obtained by the BET characterization technology according to the following table:

TABLE 1 Cabernet Performance characterization

As can be seen from Table 1, cancrinite with specific surface area > 45m prepared by the method²G, pore volume > 0.17cm³The aperture is 11 +/-0.5 nm, which proves that the cancrinite has uniform aperture and good physical properties.

It should be noted that the embodiments described herein are only some embodiments of the present invention, and not all implementations of the present invention, and the embodiments are only examples, which are only used to provide a more intuitive and clear understanding of the present invention, and are not intended to limit the technical solutions of the present invention. All other embodiments, as well as other simple substitutions and various changes to the technical solutions of the present invention, which can be made by those skilled in the art without inventive work, are within the scope of the present invention without departing from the spirit of the present invention.