CN115650244A - Sodium-free high-purity silica gel and preparation method thereof - Google Patents
Sodium-free high-purity silica gel and preparation method thereof Download PDFInfo
- Publication number
- CN115650244A CN115650244A CN202211097909.4A CN202211097909A CN115650244A CN 115650244 A CN115650244 A CN 115650244A CN 202211097909 A CN202211097909 A CN 202211097909A CN 115650244 A CN115650244 A CN 115650244A
- Authority
- CN
- China
- Prior art keywords
- washing
- gel
- sodium
- sol
- silica gel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
The invention provides sodium-free high-purity silica gel and a preparation method thereof, and relates to the technical field of silica gel preparation. The sodium-free high-purity silica gel and the preparation method thereof comprise the following raw materials in percentage by mass: na (Na) 2 O≤0.02％、CaO≤0.01％、MgO≤0.01％、SiO 2 Not less than 99.8 percent. The sodium-free high-purity silica gel prepared by the invention has large pore volume, large specific surface area, low impurity content such as metal ions and the like, high purity of silicon dioxide, stable skeleton structure and pore structure, uniform strength, high compressive strength and good product quality, can be widely used in the fields of medicine separation and purification, liquid crystal material purification, pharmaceutical and cosmetic additives and the like, and meanwhile, the sodium-free high-purity silica gel prepared by the invention has low impurity content, does not pollute the application of the downstream field and can obviously reduce the cost pressure of environmental protection treatment of the downstream application field, is a raw material of a green and environment-friendly production process, and has better treatment effect by adopting water washing water with large specific resistance for water washing; the washing end point is judged by the pH value during operation, the judgment is easy, and the control is convenient.
Description
Technical Field
The invention relates to the technical field of silica gel preparation, in particular to sodium-free high-purity silica gel and a preparation method thereof.
Background
Silica gel, mesoporous silica product containing silicon-oxygen tetrahedron, chemical formula mSiO 2 ·nH 2 O, which is stable in chemical property, non-combustible, insoluble in any solvent, and is mainly used for drying agent, medicine separation and purification,The catalyst and catalyst carrier in petrochemical industry are also used in liquid adsorbent and gas separation.
In the prior art, the preparation methods of silica gel mainly include two methods: (1) The silica gel obtained by the method has stable silicon-oxygen chemical bond coordination bond, stable skeleton structure and high product strength, the stable skeleton structure is beneficial to the adjustment of a pore structure and the loading of a catalyst, the method is mainly adopted in the current industrial production, but the content of metal ion impurities of the silica gel obtained by the method is high, and the method is limited in some application fields requiring high purity; (2) The silica gel obtained by the method has small pore volume and pore diameter, needs hole expansion, and has reduced skeleton strength and specific surface area after hole expansion, so that the silica gel is limited in the application field.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects in the prior art, the invention provides sodium-free high-purity silica gel and a preparation method thereof.
(II) technical scheme
In order to realize the purpose, the invention is realized by the following technical scheme: the sodium-free high-purity silica gel comprises the following raw materials in percentage by mass: na (Na) 2 O≤0.02％、CaO≤0.01％、MgO≤0.01％、SiO 2 ≥99.8％。
Preferably, the preparation method of the sodium-free high-purity silica gel comprises the following steps:
s1, preparing an aqueous solution of sodium silicate: preparing sodium silicate into an aqueous solution with the mass concentration of 2-25 percent based on silicon dioxide;
s2, ion exchange: exchanging the solution of the sodium silicate with ion resin to obtain a solvent, wherein the final pH = 1.5-3.5;
s3, sol polymerization: carrying out sol polymerization reaction on the solution obtained in the step S2 and the auxiliary A in a reaction kettle under the stirring state, wherein the reaction temperature is 20-100 ℃, the reaction time is 10-200min, and the reaction pH value is 9-13 to prepare primary sol;
s4, secondary ion exchange: carrying out secondary ion exchange on the sol obtained in the step S3, wherein the end point pH =1.5-3.5, so as to obtain secondary sol;
s5, sol concentration: carrying out ultrafiltration concentration on the secondary sol obtained in the step S4 by using an ultrafiltration membrane, wherein the density of the solution after ultrafiltration is 1.05-1.5g/ml, and obtaining tertiary sol;
s6, sol-gel reaction: uniformly mixing the third sol obtained in the step S5 with the auxiliary agent B to perform sol-gel reaction at the reaction temperature of 20-400 ℃ for 0.5-48h to prepare gel;
s7, treating with gel acid: placing the gel obtained in the step S6 in a water washing tank for acid soaking, wherein the acid soaking concentration is 0.05-10%, the acid soaking temperature is 20-90 ℃, and the acid soaking time is 0.5-8h;
s8, washing gel: carrying out first washing on the gel obtained in the step S6, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, the pH value of the gel at the end of washing is 5-7, and the washing time is 5-40h to obtain the first washing gel;
s9, soaking with a gel auxiliary agent: soaking the primary washing gel obtained in the step S8 in an auxiliary agent to obtain an auxiliary agent gel;
s10, secondary water washing: carrying out secondary washing on the auxiliary agent gel obtained in the step S9, wherein the washing bath ratio is 1-0.5, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, and the washing time is 4-12h, so as to obtain secondary washing gel;
s11, drying: and (2) drying the secondary water-washed gel obtained in the step (S10) at the drying temperature of 100-700 ℃ for 5-40h, at the drying relative humidity of 5-90% and at the dry material solid content of 50-100%, and drying to obtain the sodium-free high-purity silica gel.
Preferably, in the step S3, the assistant a is one or more of ammonia water, sodium hydroxide, sodium carbonate, potassium hydroxide, and triethylamine, and in the step S6, the assistant B is one or more of ammonia water, ammonium chloride, ammonium carbonate, ammonium bicarbonate, triethanolamine, cetyltrimethylammonium bromide, and cetyltrimethylammonium chloride.
Preferably, in the step S7, the acid is one or more of sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid and nitric acid, and in the step S9, the auxiliary agent is one or more of ammonia water, ammonium carbonate, ammonium chloride, sodium hydroxide, ammonium nitrate, aluminum nitrate, ammonium sulfate and aluminum sulfate, the mass concentration of the auxiliary agent is 0.005% -3%, the soaking temperature is 25-95 ℃, the soaking time is 1-24 hours, and the soaking bath ratio is 1.
Preferably, in the step S2, the ionic resin is a hydrogen-type cationic resin, and in the step S3, the assistant a and the sol are gradually added into the reaction kettle at the same time, the pH =9-13 of the reaction kettle, and the mass concentration of the assistant a is 0.05% -5%.
Preferably, in the step S5, the ultrafiltration pressure of the ultrafiltration membrane is 0.5-5Mpa, the ultrafiltration time is 0.5-10h, and in the step S6, the rotation speed of the mixing stirrer of the tertiary sol auxiliary agent B is 5-200r/min, and the mixing time is 0.5-8h.
Preferably, the sodium-free high-purity silica gel has a pore volume of 0.4-1.3ml/g, an adsorption pore diameter of 20-140A, a desorption pore diameter of 20-120A and a specific surface area of 200-650 square meters per gram.
(III) advantageous effects
The invention provides sodium-free high-purity silica gel and a preparation method thereof. The method has the following beneficial effects:
1. the sodium-free high-purity silica gel prepared by the invention has the advantages of large pore volume, large specific surface area, low content of impurities such as metal ions and the like, high purity of silicon dioxide, stable skeleton structure and pore structure, uniform strength, high compressive strength and good product quality, can be widely used in the fields of medicine separation and purification, liquid crystal material purification, pharmaceutical and cosmetic additives and the like, simultaneously has low content of impurities of the sodium-free high-purity silica gel, can not cause pollution to the application of the downstream field, can obviously reduce the cost pressure of environmental protection treatment of the downstream application field, and is a raw material of a green and environment-friendly production process.
2. The preparation method has the advantages of simple preparation process, reasonable flow, convenient operation and easy realization of industrialization, and the low-cost sodium silicate is used as a silicon source, and metal sodium ions and the like are replaced by ion exchange; during the polymerization reaction, silicic acid is further polymerized into macromolecules, so that the framework support is provided for the next step of stabilizing the pore structure, impurities are further removed through secondary ion exchange, the gel framework structure and the pore structure are stabilized while the impurities in the framework are removed through acid bubbles, the formation of silica chemical bonds is promoted, and the quality stability of silica gel is improved; through primary water washing and assistant soaking, micropores and small holes with low adsorption and low activity are processed, so that a chemical bond stable state of the active silicon dioxide is solidified at the same time with larger pore volume, and the framework structure is stabilized while the pore volume is improved; impurities such as auxiliaries and the like in the reaction process can be removed through secondary water washing, so that the purity of the product is further improved; the drying is to remove moisture in the silica gel and stabilize the skeleton structure, thereby obtaining dry particles.
3. The invention adopts the washing water with larger specific resistance to carry out washing, so that the treatment effect is better; the washing end point is judged by the pH value during operation, and the judgment is easy and the control is convenient.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows:
the embodiment of the invention provides sodium-free high-purity silica gel which comprises the following raw materials in percentage by mass: na (Na) 2 O≤0.02％、CaO≤0.01％、MgO≤0.01％、SiO 2 ≥99.8％。
A preparation method of sodium-free high-purity silica gel comprises the following steps:
s1, preparing an aqueous solution of sodium silicate: preparing sodium silicate into an aqueous solution with the mass concentration of 2-25% calculated by silicon dioxide;
s2, ion exchange: exchanging the solution of the sodium silicate with ion resin to obtain a solvent, wherein the final pH = 1.5-3.5;
s3, sol polymerization: carrying out sol polymerization reaction on the solution obtained in the step S2 and the auxiliary A in a reaction kettle under the stirring state, wherein the reaction temperature is 20-100 ℃, the reaction time is 10-200min, and the reaction pH value is 9-13 to prepare primary sol;
s4, secondary ion exchange: carrying out secondary ion exchange on the sol obtained in the step S3, wherein the end point pH =1.5-3.5, so as to obtain secondary sol;
s5, sol concentration: carrying out ultrafiltration concentration on the secondary sol obtained in the step S4 by using an ultrafiltration membrane, wherein the density of the solution after ultrafiltration is 1.05-1.5g/ml, and obtaining tertiary sol;
s6, sol-gel reaction: uniformly mixing the third sol obtained in the step S5 with the auxiliary agent B to perform sol-gel reaction at the reaction temperature of 20-400 ℃ for 0.5-48h to prepare gel;
s7, treating with gel acid: placing the gel obtained in the step S6 in a water washing tank for acid soaking, wherein the acid soaking concentration is 0.05-10%, the acid soaking temperature is 20-90 ℃, and the acid soaking time is 0.5-8h;
s8, washing gel: carrying out first washing on the gel obtained in the step S6, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, the pH value of the gel at the end of washing is 5-7, and the washing time is 5-40h to obtain the first washing gel;
s9, soaking with a gel auxiliary agent: soaking the primary washing gel obtained in the step S8 in an auxiliary agent to obtain an auxiliary agent gel;
s10, secondary water washing: carrying out secondary washing on the auxiliary agent gel obtained in the step S9, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, and the washing time is 4-12h to prepare secondary washing gel, and the secondary washing gel is better in treatment effect by adopting washing water with larger specific resistance to carry out washing; the washing end point is judged according to the pH value during operation, and the judgment is easy and the control is convenient;
s11, drying: and (3) drying the secondary water-washed gel obtained in the step (S10), wherein the drying temperature is 100-700 ℃, the drying time is 5-40h, the drying relative humidity is 5% -90%, and the solid content of the dried material is 50% -100%, and drying is carried out to obtain the sodium-free high-purity silica gel.
In the step S3, the auxiliary agent A is one or more of ammonia water, sodium hydroxide, sodium carbonate, potassium hydroxide and triethylamine, and in the step S6, the auxiliary agent B is one or more of ammonia water, ammonium chloride, ammonium carbonate, ammonium bicarbonate, triethanolamine, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.
In the step S7, the acid is one or more of sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid and nitric acid, in the step S9, the auxiliary agent is one or more of ammonia water, ammonium carbonate, ammonium chloride, sodium hydroxide, ammonium nitrate, aluminum nitrate, ammonium sulfate and aluminum sulfate, the mass concentration of the auxiliary agent is 0.005-3%, the soaking temperature is 25-95 ℃, the soaking time is 1-24 hours, and the soaking bath ratio is 1.5-2.
In the step S2, the ionic resin is hydrogen type cationic resin, in the step S3, the auxiliary A and the sol are gradually added into a reaction kettle at the same time, the pH of the reaction kettle is =9-13, and the mass concentration of the auxiliary A is 0.05% -5%.
In the S5 step, the ultrafiltration pressure of the ultrafiltration membrane is 0.5-5Mpa, the ultrafiltration time is 0.5-10h, in the S6 step, the rotating speed of a mixing stirrer of the tertiary sol auxiliary agent B is 5-200r/min, and the mixing time is 0.5-8h.
The sodium-free high-purity silica gel has a pore volume of 0.4-1.3ml/g, an adsorption pore diameter of 20-140A, a desorption pore diameter of 20-120A and a specific surface area of 200-650 square meters/g.
The sodium-free high-purity silica gel prepared by the invention has large pore volume, large specific surface area, low impurity content such as metal ions and the like, high purity of silicon dioxide, stable skeleton structure and pore structure, uniform strength, high compressive strength and good product quality, can be widely used in the fields of medicine separation and purification, liquid crystal material purification, pharmaceutical and cosmetic additives and the like, has low impurity content, does not pollute the application of downstream fields, can obviously reduce the cost pressure of environmental protection treatment of the downstream application fields, is a raw material of a green and environment-friendly production process, takes low-cost sodium silicate as a silicon source, and replaces metal sodium ions and the like by ion exchange; during the polymerization reaction, silicic acid is further polymerized into macromolecules, so that the framework support is provided for the next step of stabilizing the pore structure, impurities are further removed through secondary ion exchange, the gel framework structure and the pore structure are stabilized while the impurities in the framework are removed through acid bubbles, the formation of silica chemical bonds is promoted, and the quality stability of silica gel is improved; through primary water washing and auxiliary agent soaking, micropores and small holes with low adsorption and low activity are processed, so that a chemical bond stable state of active silicon dioxide is solidified at the same time with larger pore volume, and the framework structure is stabilized while the pore volume is improved; impurities such as auxiliaries and the like in the reaction process can be removed through secondary water washing, so that the purity of the product is further improved; the drying is to remove moisture in the silica gel and stabilize the skeleton structure, thereby obtaining dry particles.
The second embodiment:
the embodiment of the invention provides sodium-free high-purity silica gel which comprises the following raw materials in percentage by mass: na (Na) 2 O 0.01％、CaO 0.005％、MgO 0.008％、SiO 2 99.81％。
A preparation method of sodium-free high-purity silica gel comprises the following steps:
s1, preparing an aqueous solution of sodium silicate: preparing sodium silicate into an aqueous solution with the mass concentration of 2-25 percent based on silicon dioxide;
s2, ion exchange: exchanging the solution of the sodium silicate with ion resin to obtain a solvent, wherein the final pH = 1.5-3.5;
s3, sol polymerization: carrying out sol polymerization reaction on the solution obtained in the step S2 and the auxiliary A in a reaction kettle under the stirring state, wherein the reaction temperature is 20-100 ℃, the reaction time is 10-200min, and the reaction pH value is 9-13 to prepare primary sol;
s4, secondary ion exchange: carrying out secondary ion exchange on the sol obtained in the step S3, wherein the end point pH =1.5-3.5, so as to obtain secondary sol;
s5, sol concentration: carrying out ultrafiltration concentration on the secondary sol obtained in the step S4 by using an ultrafiltration membrane, wherein the density of the solution after ultrafiltration is 1.05-1.5g/ml, and obtaining tertiary sol;
s6, sol-gel reaction: uniformly mixing the third sol obtained in the step S5 with the auxiliary agent B to perform sol-gel reaction at the reaction temperature of 20-400 ℃ for 0.5-48h to prepare gel;
s7, treating with gel acid: placing the gel obtained in the step S6 in a water washing tank for acid soaking, wherein the acid soaking concentration is 0.05-10%, the acid soaking temperature is 20-90 ℃, and the acid soaking time is 1-8h;
s8, washing gel: carrying out primary washing on the gel obtained in the step S6, wherein the washing bath ratio is 1:0.5-2, the washing water specific resistance is not less than 3000 omega-cm, the washing temperature is 20-90 ℃, the pH value of the gel at the end of washing is 5-7, and the washing time is 5-40h to obtain primary washing gel;
s9, soaking with a gel auxiliary agent: soaking the primary washing gel obtained in the step S8 in an auxiliary agent to obtain an auxiliary agent gel;
s10, secondary water washing: carrying out secondary washing on the auxiliary agent gel obtained in the step S9, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, and the washing time is 4-12h to prepare secondary washing gel, and the secondary washing gel is better in treatment effect by adopting washing water with larger specific resistance to carry out washing; the washing end point is judged according to the pH value during operation, and the judgment is easy and the control is convenient;
s11, drying: and (2) drying the secondary water-washed gel obtained in the step (S10) at the drying temperature of 100-700 ℃ for 5-40h, at the drying relative humidity of 5-90% and at the dry material solid content of 50-100%, and drying to obtain the sodium-free high-purity silica gel.
In the step S3, the auxiliary agent A is one or more of ammonia water, sodium hydroxide, sodium carbonate, potassium hydroxide and triethylamine, and in the step S6, the auxiliary agent B is one or more of ammonia water, ammonium chloride, ammonium carbonate, ammonium bicarbonate, triethanolamine, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.
In the step S7, the acid is one or more of sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid and nitric acid, in the step S9, the auxiliary agent is one or more of ammonia water, ammonium carbonate, ammonium chloride, sodium hydroxide, ammonium nitrate, aluminum nitrate, ammonium sulfate and aluminum sulfate, the mass concentration of the auxiliary agent is 0.005-3%, the soaking temperature is 25-95 ℃, the soaking time is 1-24 hours, and the soaking bath ratio is 1.5-2.
In the step S2, the ionic resin is hydrogen type cationic resin, in the step S3, the auxiliary A and the sol are gradually added into a reaction kettle at the same time, the pH of the reaction kettle is =9-13, and the mass concentration of the auxiliary A is 0.05% -5%.
In the S5 step, the ultrafiltration pressure of the ultrafiltration membrane is 0.5-5Mpa, the ultrafiltration time is 0.5-10h, in the S6 step, the rotating speed of a mixing stirrer of the tertiary sol auxiliary agent B is 5-200r/min, and the mixing time is 0.5-8h.
The sodium-free high-purity silica gel has a pore volume of 0.85ml/g, an adsorption pore diameter of 90A, a desorption pore diameter of 75A and a specific surface area of 420 square meters per gram.
Example three:
the embodiment of the invention provides sodium-free high-purity silica gel which comprises the following raw materials in percentage by mass: na (Na) 2 O 0.009％、CaO 0.006％、MgO 0.005％、SiO 2 99.8％。
A preparation method of sodium-free high-purity silica gel comprises the following steps:
s1, preparing an aqueous solution of sodium silicate: preparing sodium silicate into an aqueous solution with the mass concentration of 2-25% calculated by silicon dioxide;
s2, ion exchange: exchanging the solution of the sodium silicate with ion resin to obtain a solvent, wherein the final pH = 1.5-3.5;
s3, sol polymerization: carrying out sol polymerization reaction on the solution obtained in the step S2 and the auxiliary A in a reaction kettle under the stirring state, wherein the reaction temperature is 20-100 ℃, the reaction time is 10-200min, and the reaction pH value is 9-13 to prepare primary sol;
s4, secondary ion exchange: carrying out secondary ion exchange on the sol obtained in the step S3, wherein the end point pH =1.5-3.5, so as to obtain secondary sol;
s5, sol concentration: carrying out ultrafiltration concentration on the secondary sol obtained in the step S4 by using an ultrafiltration membrane, wherein the density of the solution after ultrafiltration is 1.05-1.5g/ml, and obtaining tertiary sol;
s6, sol-gel reaction: uniformly mixing the third sol obtained in the step S5 with the auxiliary agent B to perform sol-gel reaction at the reaction temperature of 20-400 ℃ for 0.5-48h to prepare gel;
s7, treating with gel acid: placing the gel obtained in the step S6 in a water washing tank for acid soaking, wherein the acid soaking concentration is 0.05-10%, the acid soaking temperature is 20-90 ℃, and the acid soaking time is 0.5-8h;
s8, washing gel: carrying out first washing on the gel obtained in the step S6, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, the pH value of the gel at the end of washing is 5-7, and the washing time is 5-40h to obtain the first washing gel;
s9, soaking with a gel auxiliary agent: soaking the primary washing gel obtained in the step S8 in an auxiliary agent to obtain an auxiliary agent gel;
s10, secondary water washing: carrying out secondary washing on the auxiliary agent gel obtained in the step S9, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, and the washing time is 4-12h to prepare secondary washing gel, and the secondary washing gel is better in treatment effect by adopting washing water with larger specific resistance to carry out washing; the washing end point is judged according to the pH value during operation, and the judgment is easy and the control is convenient;
s11, drying: and (3) drying the secondary water-washed gel obtained in the step (S10), wherein the drying temperature is 100-650 ℃, the drying time is 10-36h, the drying relative humidity is 10% -80%, and the solid content of the dried material is 80% -100%, and drying is carried out to obtain the sodium-free high-purity silica gel.
In the step S3, the auxiliary agent A is one or more of ammonia water, sodium hydroxide, sodium carbonate, potassium hydroxide and triethylamine, and in the step S6, the auxiliary agent B is one or more of ammonia water, ammonium chloride, ammonium carbonate, ammonium bicarbonate, triethanolamine, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.
In the step S7, the acid is one or more of sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid and nitric acid, in the step S9, the auxiliary agent is one or more of ammonia water, ammonium carbonate, ammonium chloride, sodium hydroxide, ammonium nitrate, aluminum nitrate, ammonium sulfate and aluminum sulfate, the mass concentration of the auxiliary agent is 0.005-3%, the soaking temperature is 25-95 ℃, the soaking time is 1-24 hours, and the soaking bath ratio is 1.5-2.
In the step S2, the ionic resin is hydrogen type cationic resin, in the step S3, the auxiliary A and the sol are gradually added into a reaction kettle at the same time, the pH of the reaction kettle is =9-13, and the mass concentration of the auxiliary A is 0.05% -5%.
In the S5 step, the ultrafiltration pressure of the ultrafiltration membrane is 0.5-5Mpa, the ultrafiltration time is 0.5-10h, in the S6 step, the rotating speed of a mixing stirrer of the tertiary sol auxiliary agent B is 5-200r/min, and the mixing time is 0.5-8h.
The sodium-free high-purity silica gel has a pore volume of 1.1ml/g, an adsorption pore diameter of 120A, a desorption pore diameter of 101A and a specific surface area of 280 square meters per gram.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (7)
1. A sodium-free high-purity silica gel is characterized in that: the composite material comprises the following raw materials in percentage by mass: na (Na) 2 O≤0.02％、CaO≤0.01％、MgO≤0.01％、SiO 2 ≥99.8％。
2. The method for preparing sodium-free high-purity silica gel according to claim 1, which is characterized in that: the method comprises the following steps:
s1, preparing an aqueous solution of sodium silicate: preparing sodium silicate into an aqueous solution with the mass concentration of 2-25% calculated by silicon dioxide;
s2, ion exchange: exchanging the solution of the sodium silicate with ion resin to obtain a solvent, wherein the final pH = 1.5-3.5;
s3, sol polymerization: carrying out sol polymerization reaction on the solution obtained in the step S2 and the auxiliary A in a reaction kettle under the stirring state, wherein the reaction temperature is 20-100 ℃, the reaction time is 10-200min, and the reaction pH value is 9-13 to prepare primary sol;
s4, secondary ion exchange: carrying out secondary ion exchange on the sol obtained in the step S3, wherein the end point pH =1.5-3.5, so as to obtain secondary sol;
s5, sol concentration: carrying out ultrafiltration concentration on the secondary sol obtained in the step S4 by using an ultrafiltration membrane, wherein the density of the solution after ultrafiltration is 1.05-1.5g/ml, and obtaining tertiary sol;
s6, sol-gel reaction: uniformly mixing the third sol obtained in the step S5 with the auxiliary agent B to perform sol-gel reaction at the reaction temperature of 20-400 ℃ for 0.5-48h to prepare gel;
s7, treating with gel acid: placing the gel obtained in the step S6 in a water washing tank for acid soaking, wherein the acid soaking concentration is 0.05-10%, the acid soaking temperature is 20-90 ℃, and the acid soaking time is 0.5-8h;
s8, washing gel: carrying out first washing on the gel obtained in the step S6, wherein the washing bath ratio is 1.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, the pH value of the gel at the end of washing is 5-7, and the washing time is 5-40h to obtain the first washing gel;
s9, soaking with a gel auxiliary agent: soaking the primary water-washed gel obtained in the step S8 in an auxiliary agent to obtain an auxiliary agent gel;
s10, secondary water washing: carrying out secondary washing on the auxiliary agent gel obtained in the step S9, wherein the washing bath ratio is 1:0.5-2, the washing water specific resistance is more than or equal to 3000 omega-cm, the washing temperature is 20-90 ℃, and the washing time is 4-12h, so as to obtain secondary washing gel;
s11, drying: and (3) drying the secondary water-washed gel obtained in the step (S10), wherein the drying temperature is 100-700 ℃, the drying time is 5-40h, the drying relative humidity is 5% -90%, and the solid content of the dried material is 50% -100%, and drying is carried out to obtain the sodium-free high-purity silica gel.
3. The method for preparing sodium-free high-purity silica gel according to claim 2, characterized in that: in the step S3, the auxiliary agent A is one or more of ammonia water, sodium hydroxide, sodium carbonate, potassium hydroxide and triethylamine, and in the step S6, the auxiliary agent B is one or more of ammonia water, ammonium chloride, ammonium carbonate, ammonium bicarbonate, triethanolamine, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.
4. The method for preparing sodium-free high-purity silica gel according to claim 2, characterized in that: in the step S7, the acid is one or more of sulfuric acid, acetic acid, oxalic acid, citric acid, hydrochloric acid and nitric acid, in the step S9, the auxiliary agent is one or more of ammonia water, ammonium carbonate, ammonium chloride, sodium hydroxide, ammonium nitrate, aluminum nitrate, ammonium sulfate and aluminum sulfate, the mass concentration of the auxiliary agent is 0.005% -3%, the soaking temperature is 25-95 ℃, the soaking time is 1-24 hours, and the soaking bath ratio is 1.5-2.
5. The method for preparing sodium-free high-purity silica gel according to claim 2, wherein the method comprises the following steps: in the step S2, the ionic resin is hydrogen type cationic resin, in the step S3, the assistant A and the sol are gradually added into the reaction kettle at the same time, the pH of the reaction kettle is =9-13, and the mass concentration of the assistant A is 0.05% -5%.
6. The method for preparing sodium-free high-purity silica gel according to claim 2, characterized in that: in the step S5, the ultrafiltration pressure of the ultrafiltration membrane is 0.5-5Mpa, the ultrafiltration time is 0.5-10h, and in the step S6, the rotating speed of the mixing stirrer of the tertiary sol auxiliary agent B is 5-200r/min, and the mixing time is 0.5-8h.
7. The method for preparing sodium-free high-purity silica gel according to claim 2, characterized in that: the pore volume of the sodium-free high-purity silica gel is 0.4-1.3ml/g, the adsorption aperture is 20-140A, the desorption aperture is 20-120A, and the specific surface area is 200-650 square meters per gram.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211097909.4A CN115650244A (en) | 2022-09-08 | 2022-09-08 | Sodium-free high-purity silica gel and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211097909.4A CN115650244A (en) | 2022-09-08 | 2022-09-08 | Sodium-free high-purity silica gel and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115650244A true CN115650244A (en) | 2023-01-31 |
Family
ID=84983021
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211097909.4A Pending CN115650244A (en) | 2022-09-08 | 2022-09-08 | Sodium-free high-purity silica gel and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115650244A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020040868A (en) * | 2018-09-12 | 2020-03-19 | スリー・エス コリア カンパニー リミテッド３Ｓ Ｋｏｒｅａ Ｃｏ．， Ｌｔｄ． | Method for producing synthesized quartz powder |
| CN112340742A (en) * | 2021-01-11 | 2021-02-09 | 东营一鸣新材料有限公司 | Macroporous high-purity silica-alumina gel and preparation method thereof |
-
2022
- 2022-09-08 CN CN202211097909.4A patent/CN115650244A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020040868A (en) * | 2018-09-12 | 2020-03-19 | スリー・エス コリア カンパニー リミテッド３Ｓ Ｋｏｒｅａ Ｃｏ．， Ｌｔｄ． | Method for producing synthesized quartz powder |
| CN112340742A (en) * | 2021-01-11 | 2021-02-09 | 东营一鸣新材料有限公司 | Macroporous high-purity silica-alumina gel and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US1755496A (en) | Process of preparing siliceous materials | |
| CN112194147B (en) | Large-pore-volume high-adsorption silicon dioxide additive and preparation method thereof | |
| CN115650244A (en) | Sodium-free high-purity silica gel and preparation method thereof | |
| CN112645344A (en) | Method for preparing SSZ-13 molecular sieve membrane by steam-assisted conversion | |
| CN108609622B (en) | Low-iron high-specific-surface-area beer wet silica gel and preparation method thereof | |
| CN110642605B (en) | Low-moisture ceramic slurry and application thereof in lithium ion battery diaphragm | |
| CN115722214B (en) | Ammonia-removal resin material and preparation method thereof | |
| CN114849674B (en) | Silica adsorbent for filtering soy protein and preparation method thereof | |
| CN114887586B (en) | Production method of lithium molecular sieve with low silicon-aluminum ratio | |
| CN110787768A (en) | Composite dehumidifying material and preparation method thereof | |
| CN112340742B (en) | Macroporous high-purity silica-alumina gel and preparation method thereof | |
| CN109336642A (en) | A kind of clear-water concrete component surface antiseepage enhancing processing method | |
| CN114433014B (en) | Preparation method of 5A molecular sieve adsorbent | |
| CN108046303B (en) | Preparation method of calcium carbonate for accelerating carbonation reaction | |
| CN110156057A (en) | The preparation method of high purity aluminium oxide | |
| CN111137901A (en) | Preparation method of high-performance silicon dioxide | |
| CN110898798A (en) | Amorphous composite oxide adsorbent and preparation method thereof | |
| CN103030150A (en) | Technological process of mesoporous silica gel | |
| CN103408149A (en) | Preparation process of silicate reverse osmosis scale inhibitor | |
| CN104556128A (en) | Preparation method of ultra-fine T type molecular sieve zeolite membrane | |
| CN112608353B (en) | Process for removing chloride ions in glucosamine sulfate | |
| CN107596874A (en) | A kind of environmental-friendfilm film and preparation method for being used to administer air volatile organic matter | |
| CN111017933B (en) | Preparation method of silicon dioxide with high specific surface area | |
| CN116637587A (en) | Beer silica gel and preparation method thereof | |
| CN117383571A (en) | Modified inorganic silica gel and preparation process thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |