阅读说明：本技术 一种利用有机硅废渣合成介孔二氧化硅mcm-41的方法 (Method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residues ) 是由 章萍 欧阳思达 蔡悦 张凌杰 汪文俊 于 2020-07-15 设计创作，主要内容包括：本发明公开了一种利用有机硅废渣合成介孔二氧化硅MCM-41的方法,用以含硅单质和无定型二氧化硅的有机硅废渣为合成原料,将废渣与NaOH碱熔煅烧,水溶后提取硅上清液,以阳离子表面活性剂作为模板剂,与硅上清液混匀搅拌,水热反应后陈化冷却,离心洗涤固体产物,再煅烧去除模板剂,最终得到介孔二氧化硅MCM-41。本发明制备的介孔二氧化硅所用原料为有机硅企业生产产生的废渣,不仅使工业废弃物得到资源化利用,同时也为介孔二氧化硅的合成寻找到廉价硅源。本发明合成工艺流程短,操作简单,具有较好的应用前景。(The invention discloses a method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residue, which uses organic silicon waste residue containing silicon simple substance and amorphous silica as a synthetic raw material, alkali fusion calcinates the waste residue and NaOH, extracts silicon supernatant after water dissolution, uses a cationic surfactant as a template agent, uniformly mixes and stirs the waste residue and the silicon supernatant, ages and cools after hydrothermal reaction, centrifugally washes a solid product, and then calcinates to remove the template agent, thereby finally obtaining the mesoporous silica MCM-41. The raw materials of the mesoporous silica prepared by the invention are waste residues generated in the production of organic silicon enterprises, so that the industrial wastes are recycled, and a cheap silicon source is found for the synthesis of the mesoporous silica. The invention has short synthesis process flow, simple operation and better application prospect.)

1. A method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residues is characterized by comprising the following steps: the method adopts organosilicon waste residues containing silicon simple substances and amorphous silicon dioxide as synthesis raw materials, wherein the organosilicon waste residues are furnace head residues or smoke dust, and the synthesis method comprises the following steps:

(1) extracting silicon from waste residues: grinding and crushing the organic silicon waste residue material, drying until no moisture exists, and preparing the organic silicon waste residue material according to the following steps: uniformly mixing NaOH in a mass ratio of 1: 0.5-1: 3, calcining at 350-650 ℃ for 0.5-4 h, uniformly mixing the calcined product with water in a solid-liquid mass ratio of 1: 20-1: 100, dissolving the calcined product in water by using a magnetic stirrer, stirring for 2-24 h, extracting supernatant, and measuring the silicon content in the extracted supernatant by using an ICP emission spectrometer;

(2) Preparation of mesoporous silica MCM-41: taking a cationic surfactant as a template agent, and adding Na in the supernatant prepared in the step (1)₂SiO₃: cationic surfactant: mixing deionized water according to the molar ratio of 1:0.05: 100-1: 0.3:100 to prepare a mixed solution A; sequentially carrying out pH adjustment, magnetic stirring for 1-4 h and heating reaction for 6-24 h on the mixed solution A, wherein the pH is adjusted to 6.0-12.0, the heating reaction vessel is a reaction kettle with a polytetrafluoroethylene lining, and the reaction temperature is 80-160 ℃; and after the reaction is finished, sequentially carrying out aging cooling for 24-72 hours, centrifugal solid-liquid separation, deionized water washing for a plurality of times, drying, and finally calcining in a muffle furnace at 500-700 ℃ for 4-7 hours to remove the template agent to obtain the mesoporous silica MCM-41.

2. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: in the step (1), the mass ratio of the furnace head slag to the NaOH is 1: 1.2; the mass ratio of the smoke dust to the NaOH is 1: 2.

3. the method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: and (2) calcining the waste residues and NaOH in the step (1) at 550 ℃ for 2 h.

4. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: the mass ratio of the calcined product in the step (1) to water is 1:50, and the stirring time of the calcined product of the water-soluble waste residue is 6 hours.

5. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: the cationic surfactant in the step (2) is preferably cetyl trimethyl ammonium bromide; the molar ratio of the prepared supernatant to the cationic surfactant and the molar ratio of the prepared deionized water are 1:0.1: 100.

6. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: and (3) adjusting the pH value of the mixed solution A in the step (2) to 7, and magnetically stirring for 2 hours.

7. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: the hydrothermal reaction temperature in the reaction kettle in the step (2) is 120 ℃, the hydrothermal reaction time is 12 hours, and the aging, cooling and aging time after the reaction is 48 hours.

8. The method for synthesizing mesoporous silica MCM-41 from waste organosilicon residues as claimed in claim 1, wherein the method comprises the following steps: the calcination temperature for removing the template agent in the step (2) is 600 ℃, and the calcination time is 5 h.

Technical Field

The invention belongs to the technical field of resource utilization of industrial wastes and preparation of porous materials, and particularly relates to a method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residues.

Background

The M41 series mesoporous silica material is first successfully developed by Mobil corporation in 1992, and MCM-41 is the most widely used mesoporous silica, and has high application potential as a catalyst carrier, an adsorbent and other materials due to the excellent characteristics of uniform pore distribution (2-50nm), high specific surface area (1000M 2/g), good hydrothermal stability, thermal stability, hydrolytic stability and the like. The main raw material for synthesizing MCM-41 type mesoporous silica is silicon, the main sources are inorganic silicate (water glass) and organic silicate (ethyl orthosilicate), the price of the silicon is expensive, and the silicon brings many limitations for the production of the mesoporous silica, so that the search of cheap alternative silicon sources is one of the key points of the current research.

A large amount of waste residues can be generated in the production process of an organic silicon enterprise, the waste residues can be mainly divided into smoke dust collected in the incineration process of an incinerator and furnace end residues settled at the bottom, the generated waste residues need to be processed in time, and the environment can be greatly influenced by random stacking. The waste residue treatment mode usually adopted by organic silicon enterprises is mainly the treatment of cement factories or the manufacture of hollow bricks paid by enterprises, and not only has small treatment amount, but also has high treatment cost. The organic silicon waste residue contains a large amount of silicon simple substances and amorphous mesoporous silica, the silicon content is 97 percent, the reaction activity is high, and the silicon-containing organic silicon waste residue is an ideal silicon source for preparing the mesoporous silica. The waste residue generated in the production process of an organic silicon enterprise is recycled to prepare the multifunctional MCM-41 type mesoporous silica material, so that an ideal way is found for the treatment of the waste residue, the waste can be changed into valuable, and the material can be industrially applied as a new adsorption or catalysis material.

Disclosure of Invention

Aiming at the defects and problems in the prior art, the invention aims to provide a method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residues. The invention relates to a method for preparing mesoporous silica MCM-41 by carrying out hydrothermal reaction on industrial waste and a cationic surfactant, wherein organic silicon enterprise waste residues containing a large amount of silicon simple substances and amorphous silica are used as a silicon source, and the industrial waste is recycled, so that the environmental problem caused by the massive stacking of the enterprise waste residues can be solved, and the cost problem of synthesizing the mesoporous silica can be greatly reduced.

The invention is realized by the following technical scheme:

a method for synthesizing mesoporous silica MCM-41 by using organic silicon waste residues comprises the following steps:

(1) extracting silicon from waste residues: grinding and crushing waste residue materials (furnace head residue and smoke dust), drying until no moisture exists, and mixing the waste residue: uniformly mixing NaOH in a mass ratio of 1: 0.5-1: 3, calcining at 350-650 ℃ for 0.5-4 h, dissolving calcined product and water in a solid-liquid ratio of 1: 20-1: 100 at a magnetic stirrer rotating speed of 600rpm, stirring for 2-24 h, extracting supernatant, and measuring the silicon content in the waste residue supernatant by using ICP (inductively coupled plasma atomic emission spectrometry);

(2) Preparation of mesoporous silica MCM-41: taking a cationic surfactant as a template agent, and taking Na in the waste residue supernatant prepared in the step (1)₂SiO₃: cationic surfactant: mixing deionized water at a molar ratio of 1:0.05: 100-1: 0.3:100 to prepare a mixed solution A, and adding H to the mixed solution A₂SO₄And NaOH is used for adjusting the pH value of the mixed solution A to 6.0-12.0, a magnetic stirrer is used for stirring for 1-4 hours at the rotating speed of 1000rpm, the mixed solution A is placed into a reaction kettle with a polytetrafluoroethylene lining, the reaction is carried out for 6-24 hours at the reaction temperature of 80-160 ℃, after the reaction is finished, the mixed solution A is aged and cooled, the aging time is 24-72 hours, reactants are subjected to centrifugal solid-liquid separation, deionized water is used for washing 3 times of reaction products, the reaction products are dried, and then a muffle furnace is used for calcining for 4-7 hours at the temperature of 500-700 ℃ to remove the MCM agent, so that the mesoporous silica-.

Further, the mass ratio of the furnace head slag to NaOH in the step (1) is preferably 1: 1.2; the mass ratio of the smoke dust to the NaOH is preferably 1: 2; the calcination temperature in the step (1) is preferably 550 ℃; the calcination time in the step (1) is preferably 2 h; the ratio of the waste residue calcined product to the water-solid-liquid ratio in the step (1) is preferably 1: 50; the stirring time of the water-soluble waste residue calcined product in the step (1) is preferably 6 hours.

Further, the cationic surfactant used in step (2) is preferably cetyltrimethylammonium bromide (CTAB); the preferable molar ratio of the waste residue extracting solution prepared in the step (2) to the cationic surfactant and the deionized water is 1:0.1: 100; the pH value of the mixed solution A in the step (2) is preferably adjusted to be 7; the stirring time in the step (2) is preferably 2 hours; the hydrothermal reaction temperature in the reaction kettle in the step (2) is preferably 120 ℃; the hydrothermal reaction time in the reaction kettle in the step (2) is preferably 12 h; the aging, cooling and aging time after the reaction in the step (2) is preferably 48 h; the calcination temperature for removing the template by calcination in the step (2) is preferably 600 ℃; the calcination time for removing the template by calcination in the step (2) is preferably 5 h.

Compared with the prior art, the invention has the beneficial effects that:

(1) the mesoporous silica MCM-41 synthesized by the method has the advantages of uniform and controllable pores, large specific surface area, good hydrothermal stability, thermal stability and hydrolytic stability, and is a good adsorption and catalysis material.

(2) The invention synthesizes the mesoporous silicon dioxide material by taking waste residues (smoke dust and furnace head residues) as silicon sources, thereby not only leading the industrial wastes to be recycled and solving the environmental problem caused by random accumulation of industrial wastes of enterprises, but also finding cheap alternative silicon sources for synthesizing the mesoporous silicon dioxide and solving the problem of expensive silicon sources of the synthesized mesoporous silicon dioxide.

(3) The method for synthesizing mesoporous silica MCM-41 by utilizing waste residues of organic silicon enterprises in a resource manner is simple in preparation process, low in energy consumption, free of secondary pollution in the production process and capable of well realizing industrial production.

Drawings

FIG. 1 is SEM image (A) and small-angle XRD image (B) and wide-angle XRD image (inset) of synthesized example 1 in the present invention.

FIG. 2 is a graph showing the nitrogen physisorption-desorption isotherms and pore distribution of example 1 synthesized in accordance with the present invention (inset).

FIG. 3 is a SEM image (A) and a small-angle XRD image (B) of a wide-angle XRD image (inset) of example 2 synthesized by the present invention.

FIG. 4 is a graph showing the nitrogen physisorption-desorption isotherms and pore distribution of example 2 synthesized in accordance with the present invention (inset).

Detailed Description

The invention will be further described with reference to the accompanying drawings.