CN114057200B - Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel - Google Patents
Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel Download PDFInfo
- Publication number
- CN114057200B CN114057200B CN202210052736.8A CN202210052736A CN114057200B CN 114057200 B CN114057200 B CN 114057200B CN 202210052736 A CN202210052736 A CN 202210052736A CN 114057200 B CN114057200 B CN 114057200B
- Authority
- CN
- China
- Prior art keywords
- molecular sieve
- mother liquor
- silica gel
- zsm
- type silica
- 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.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/141—Preparation of hydrosols or aqueous dispersions
- C01B33/142—Preparation of hydrosols or aqueous dispersions by acidic treatment of silicates
- C01B33/143—Preparation of hydrosols or aqueous dispersions by acidic treatment of silicates of aqueous solutions of silicates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/146—After-treatment of sols
- C01B33/148—Concentration; Drying; Dehydration; Stabilisation; Purification
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
- Silicon Compounds (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
The invention provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and the C-type silica gel, and the application comprises the following steps: (1) stirring the ZSM-5 molecular sieve mother liquor and adding acid to adjust the pH value to 6-9 to obtain slurry A; (2) filtering the slurry A, washing a filter cake, adding water and pulping to obtain slurry B; (3) and carrying out flash evaporation drying on the slurry B to obtain the C-type silica gel. The method recycles the effective components in the molecular sieve mother liquor, recycles silicon oxide compounds such as silicate and the like in the molecular sieve mother liquor, and avoids the influence of the cyclic use of the molecular sieve mother liquor on the quality of the ZSM-5 molecular sieve.
Description
Technical Field
The invention relates to the field of molecular sieve mother liquor recovery, and particularly relates to application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel.
Background
The synthesis of the commonly used molecular sieve generally adopts a hydrothermal or solvent thermal crystallization way based on a non-equilibrium state to complete the nucleation and crystal growth of the molecular sieve in a strong alkali medium. The synthetic mother liquor is strongly alkaline waste liquor, has the characteristics of large quantity, strong alkalinity and easy gelling, and becomes one of chemical industrial pollution sources. In the synthesis of molecular sieve, the Si/Al ratio of the materials in the formula plays an important role in the structure and composition of the final product, and the zeolite with low Si/Al ratio is generally obtained by crystallization from an original material system with high feeding alkalinity and low Si/Al ratio; the high-silicon zeolite is obtained by crystallization from raw materials with low feeding alkalinity and high silicon-aluminum ratio. Therefore, the silicon-aluminum ratio in the feeding proportion is always higher than that of the crystallized product, and the residual silicon is remained in the mother liquor.
The synthesis technology of the ZSM-5 molecular sieve mainly adopts a hydrothermal crystallization method, and the conventionally synthesized raw materials are silicon sources such as water glass, ethyl silicate, silica sol, silicon oxide and the like; aluminum sulfate, aluminum isopropoxide and the like are used as aluminum sources, and ammonia water, sodium hydroxide and the like are added as raw materials. The synthesis of the ZSM-5 molecular sieve needs a template agent, and commonly used template agents comprise tetrapropylammonium hydroxide, n-butylamine, ethylenediamine, ethanol, hexamethylenediamine and the like. The synthesis mother liquor of ZSM-5 molecular sieve is generally Na-containing+And silicate, sulfate, and a template agent.
The recovery and utilization of the synthesized molecular sieve mother liquor mainly aims to utilize effective components in the mother liquor, recycle effective components for subsequent synthesis or prepare valuable products, and simultaneously reduce discharge pollution. At present, the method for synthesizing the molecular sieve mother liquor can be divided into direct utilization and indirect utilization. The direct utilization means that the synthetic mother liquor is collected and then is treated or not treated, and all or part of the mother liquor is directly used for synthesizing the same molecular sieve, and the mother liquor after treatment and reuse must meet the following conditions: the treated intermediate can be used for synthesizing the same molecular sieve; secondly, the treatment process cannot be too complex, and the treatment cost cannot be too high; thirdly, the number of the processed intermediates cannot be too large, and influence factors for generating mixed crystals are not contained. In order to realize that the synthetic mother liquor is directly utilized without being treated, the conditions are more severe, and the following conditions must be met: the total amount of the mother liquor cannot be too large, the feed ratio in the cyclic synthesis cannot be influenced by the amount of the mother liquor, and the balance is kept in the cyclic use; secondly, the concentration of various ions in the mother liquor can not be increased or decreased gradually when the mother liquor is recycled, namely the concentration of various ions in the mother liquor keeps relative balance; and thirdly, the mother solution does not contain influence factors for generating mixed crystals. CN105329915A proposes a method for recovering ZSM-5 molecular sieve mother liquor; the CN 104860333a patent discloses another method for utilizing ZSM-5 molecular sieve mother liquor; CN 110627088A develops a recycling method of low-silicon X molecular sieve synthetic mother liquor; CN105668587A/B discloses a recycling method of SAPO-34 synthesized molecular sieve mother liquor.
The indirect utilization of the molecular sieve mother liquor means that the mother liquor is used for synthesizing other molecular sieves or preparing other products by treatment or non-treatment, so that the purposes of fully utilizing effective components in the molecular sieve mother liquor and reducing environmental pollution are achieved. The indirect utilization technology is different from the direct utilization technology in that the same molecular sieve does not need to be generated, the problem of recycling of the mother liquor does not exist, the problem of accumulation of ions in the mother liquor does not need to be considered, but the indirect utilization technology of the mother liquor also faces the application problem of a new synthesized product. CN 101468805A discloses a method for producing ZSM-5 molecular sieve by using titanium silicalite molecular sieve crystallization mother liquor; CN 105000572A proposes a method for synthesizing a ZSM-5 molecular sieve by using silica gel prepared by NaY zeolite crystallization mother liquor; CN 108128789 a developed a method using alkali in the mother liquor of molecular sieve; CN110787768A proposes to synthesize amorphous material by directly using the uncrystallized silicon source in the molecular sieve mother liquor.
Another research proves that the micropore volume of the molecular sieve is from 367cm after direct cyclic utilization of ZSM-5 molecular sieve mother liquor for 6 cycles3The/g is reduced to 280cm3Per g, surface area 584m2The/g is reduced to 403m2The result shows that the molecular sieve mother liquor has a large influence on the quality of the ZSM-5 molecular sieve by utilizing circulation. Silicate notes also on page 2775 at stage 10 of volume 34, Na in ZSM-5 molecular sieve mother liquor2O／SiO2Has an important influence on the crystalline phase of the molecular sieve, Na2O／SiO2Too high a ratio can produce MOR heterocrystalline phases, which can affect the performance of the ZSM-5 molecular sieve.
Disclosure of Invention
In order to solve the above technical problems, the inventors found that, due to the need of controlling the silica-alumina ratio, the excess of the silicon source is usually controlled in the formula for synthesizing the ZSM-5 molecular sieve, i.e. the silicon content in the mother liquor for synthesizing the molecular sieve is higher. Based on the discovery, the invention aims to provide the application of the C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and the C-type silica gel, recover effective components in the molecular sieve mother liquor, utilize silicon compounds such as silicate groups and the like in the molecular sieve mother liquor in a resource manner, and avoid the influence of the cyclic use of the molecular sieve mother liquor on the quality of the ZSM-5 molecular sieve.
In order to achieve the aim, the invention provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which comprises the following steps:
(1) stirring the ZSM-5 molecular sieve mother liquor and adding acid to adjust the pH value to 6-9 to obtain slurry A;
(2) filtering the slurry A, washing a filter cake, adding water and pulping to obtain slurry B;
(3) and carrying out flash evaporation drying on the slurry B to obtain the C-type silica gel.
The slurry A is pasty, which is the phenomenon that silica gel is generated after the mother liquor of the ZSM-5 molecular sieve is adjusted in pH value. As shown in the following reaction formula, the silica gel generated by the reaction of silicate ions and hydrogen ions has larger granularity when the pH value of the solution is 6-9, and is conveniently pressed out by a filter press. When the pH value of the solution is more than 9, no obvious precipitate is generated in the solution, when the pH value is less than 6, the precipitate has smaller granularity, and a filter cake cannot be formed on a filter press.
Na2SiO3+H2SO4→Na2SO4+H2SiO3↓
According to a specific embodiment of the present invention, in the above application, preferably, the ZSM-5 molecular sieve mother liquor has a silicon content of 1-3 wt%.
According to a specific embodiment of the invention, in the above application, the ZSM-5 molecular sieve mother liquor has a silicon content of 1.82-1.876 wt%.
According to a specific embodiment of the invention, in the above application, the pH value of the ZSM-5 molecular sieve mother liquor before adding the acid is 10.5-11.
According to a specific embodiment of the present invention, preferably, in the above application, the acid is 98% concentrated sulfuric acid.
According to the specific embodiment of the invention, in the application, the stirring speed in the step (1) is 70-100 r/min, and the stirring time is 20-40 min.
According to a specific embodiment of the present invention, in the above application, the temperature of the flash evaporation is 150-180 ℃.
According to a specific embodiment of the present invention, in the above application, the filtration mode is filter pressing, and the pressure of the filter pressing is 0.8-1.2 Mpa.
According to a specific embodiment of the invention, in the above application, a plate and frame filter is used for filtering the slurry A.
According to a specific embodiment of the invention, in the above application, the content of sodium ions in the filter cake after washing is less than or equal to 0.1 wt%. Washing the filter cake washes off residual Na in the filter cake+、SO4 2-And a template agent to improve the quality of the C-type silica gel product.
According to a specific embodiment of the present invention, preferably, in the above application, the manner of washing the filter cake is: adding water into the filter cake, pulping and filtering for the second time.
According to a particular embodiment of the present invention, preferably, as shown in fig. 1, the above application specifically comprises the following steps:
(1) collecting and storing ZSM-5 molecular sieve mother liquor, wherein the pH value is 10.5-11.1, and the Si content is 1-3 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), and adjusting the pH to be 6-9, wherein the slurry is pasty, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.8-1.2 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to below 0.01 wt%;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) sending the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 150-.
The invention also provides the C-type silica gel obtained by the application.
According to a specific embodiment of the present invention, preferably, the quality indexes of the type C silica gel are as follows: the average particle size is 6.5-7.2mm, the abrasion rate is 6.8-7.2%, the bulk density is 418-425g/l, the pore volume is 0.76-0.78ml/g, the percent of pass of the spherical particles is 75-76%, and the heating loss is 4.4-4.7%. The C-type silica gel prepared by the invention meets the requirements of HG/T2765.2-2005C-type silica gel.
The invention also provides an application of the method in ZSM-5 molecular sieve mother liquor treatment.
According to a specific embodiment of the present invention, preferably, the wastewater produced by the above method comprises a filtrate obtained by filtering the slurry a, and a washing liquid obtained by washing the filter cake. The pH value of the wastewater is 7.5-8.4, the chroma is 8-10, the Suspended Solid (SS) is 4.3-5.1mg/L, the Chemical Oxygen Demand (COD) is 45.8-48.5 ppm, and the Biochemical Oxygen Demand (BOD)5) 19.5-25.3ppm and 28.6-30.5 ppm ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
The technical scheme provided by the invention has the following beneficial effects:
(1) the C-type silica gel preparation method is applied to the treatment of the ZSM-5 molecular sieve mother liquor, so that the influence of the cyclic use of the molecular sieve mother liquor on the quality of the ZSM-5 molecular sieve is avoided, the problem of recycling of silicon compounds such as silicate groups and the like in the molecular sieve mother liquor is fundamentally solved, the molecular sieve mother liquor can be truly changed into valuable, the hidden dangers caused by recycling and dosing of the molecular sieve mother liquor are avoided, the mother liquor generated by synthesizing the ZSM-5 molecular sieve is recycled, new solid wastes are not generated, and the environmental pollution caused by organic amine and other substances in the solid wastes is avoided;
(2) the C-type silica gel obtained by the invention can be recycled as a raw material and can also be sold as a commodity, and the product quality meets the requirements of HG/T2765.2-2005; wastewater generated in the ZSM-5 molecular sieve mother liquor treatment process meets the GB8978-1996 integrated wastewater discharge standard and can be directly discharged;
(3) the invention can ensure the unlimited reuse of the C-type silica gel because the sodium sulfate is washed from the C-type silica gel, and the influence on a molecular sieve synthesis system due to ion enrichment can be avoided.
Drawings
FIG. 1 is a schematic flow chart of the application of the preparation method of C-type silica gel in ZSM-5 molecular sieve mother liquor treatment.
Detailed Description
The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.
Example 1
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 11.0, and the Si content is 1.876 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 6.0, and making the slurry pasty, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.8 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.09wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 150 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 6.5mm, the abrasion rate is 6.8%, the bulk density is 420g/l, the pore volume is 0.78ml/g, the qualified rate of spherical particles is 75%, and the heating loss is 4.6%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater generated in the step (4) and the step (6), and detecting that the wastewater has a pH value of 8.4, a color of 8, SS of 4.3mg/L, COD of 47.6 ppm, BOD525.3ppm and 15.5 ppm ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
Example 2
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 10.8, and the Si content is 1.85 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 7.2, and making the slurry into paste, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.8 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.08wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 162 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 6.8mm, the abrasion rate is 7.2%, the bulk density is 425g/l, the pore volume is 0.76ml/g, the qualified rate of spherical particles is 76%, and the heating loss is 4.5%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater produced in the step (4) and the step (6), and detecting that the wastewater has a pH value of 8.1, a color of 9, SS of 4.5mg/L, COD of 48.5 ppm, BOD522.7 ppm and 19.5 ppm ammonia nitrogen content, which meets the GB 8979 and 1996 integrated wastewater discharge standard.
Example 3
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 10.5, and the Si content is 1.82 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 8.1, and making the slurry into paste, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.8 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.07wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 180 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 7.2mm, the abrasion rate is 6.9%, the bulk density is 418g/l, the pore volume is 0.77ml/g, the qualified rate of spherical particles is 75%, and the heating loss is 4.7%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater produced in the step (4) and the step (6), and detecting that the wastewater has a pH value of 7.9, a color of 8, SS of 4.7mg/L, COD of 45.8 ppm, BOD520.3 ppm and 18.6 ppm of ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
Example 4
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) collecting and storing 50kg of ZSM-5 molecular sieve mother liquor, wherein the pH value is 10.7, and the Si content is 1.868 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 9.0, and making the slurry pasty, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 1.2 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.09wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 168 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 7.7mm, the abrasion rate is 7.0%, the bulk density is 421g/l, the pore volume is 0.78ml/g, the qualified rate of spherical particles is 76%, and the heating loss is 4.4%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater produced in the step (4) and the step (6), and detecting that the wastewater has a pH value of 7.5, a color of 10, SS of 5.1mg/L, COD of 47.2 ppm, BOD519.5 ppm and 19.7 ppm of ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
Example 5
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 10.9, and the Si content is 1.0 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 6.0, and making the slurry pasty, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.7 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.09wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 150 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 6.5mm, the abrasion rate is 6.75%, the bulk density is 422g/l, the pore volume is 0.77ml/g, the qualified rate of spherical particles is 75.5%, and the heating loss is 4.4%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater produced in the step (4) and the step (6), and detecting that the wastewater has a pH value of 8.3, a color of 8, SS of 4.1mg/L, COD of 42.1 ppm, BOD528.2 ppm and 11.5ppm ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
Example 6
The embodiment provides an application of a C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 11.3, and the Si content is 3.0 wt%;
(2) adding the molecular sieve mother liquor obtained in the step (1) into a neutralization kettle, and stirring for 30min at the rotating speed of a stirring motor of 80 r/min;
(3) adding 98% concentrated sulfuric acid into the neutralization tank in the step (2), adjusting the pH value to 6.0, and making the slurry pasty, which is a phenomenon of generating silica gel;
(4) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 1.2 Mpa;
(5) unloading the filter cake from the filter, adding water and pulping;
(6) sending the slurry obtained in the step (5) into a plate and frame filter with a squeezing function through a pneumatic diaphragm pump for secondary filtration, and thoroughly washing off the residual Na in the silica gel+And SO4 2-Ion, to remove Na from the filter cake+The content can be reduced to less than 0.09wt per thousand;
(7) adding water into the filter cake obtained in the step (6) for the second time for pulping, and stirring for 30 min;
(8) and (4) feeding the slurry prepared in the step (7) into a flash evaporation drying tower, wherein the flash evaporation temperature is 150 ℃, and thus obtaining the C-type silica gel product.
Through detection, the quality indexes of the type C silica gel obtained in this example are: the average particle size is 6.6mm, the abrasion rate is 6.2%, the bulk density is 410g/l, the pore volume is 0.74ml/g, the qualified rate of spherical particles is 75.2%, and the heating loss is 4.6%, thus meeting the requirements of HG/T2765.2-2005C type silica gel.
Collecting and mixing the wastewater produced in the step (4) and the step (6), and detecting that the wastewater has a pH value of 8.1, a color of 8, SS of 4.9mg/L, COD of 32.4 ppm, BOD518.6 ppm and 11.2 ppm ammonia nitrogen content, and meets the GB 8979 and 1996 integrated wastewater discharge standard.
Comparative example 1
The comparative example provides a method for treating ZSM-5 molecular sieve mother liquor wastewater, which specifically comprises the following steps:
(1) 50kg of ZSM-5 molecular sieve mother liquor is collected and stored, the pH value is 10.7, and the Si content is 1.86 wt%;
(2) adding 2.7g of Polyacrylamide (PAM) and 180g of 26% polyaluminium chloride (PAC) into the molecular sieve mother liquor obtained in the step (1), stirring for 30min, wherein the rotating speed of a stirring motor is 80r/min, and then, precipitation appears;
(3) pumping the slurry into a plate and frame filter with a squeezing function by using a pneumatic diaphragm pump for filtering, and then squeezing, wherein the squeezing pressure is 0.8 Mpa;
(4) unloading the filter cake from the filter, namely the waste produced by the molecular sieve;
(5) and (4) adding the filtrate generated in the step (4) into a neutralization tank, adding 98% concentrated sulfuric acid, and adjusting the pH value to 9.0 to obtain the discharged wastewater.
The detection shows that the solid waste obtained in the comparative example is a silicon-aluminum mixture which contains 30% of silicon, 10% of aluminum and 40% of water, wherein silicon and aluminum elements cannot be directly utilized, and the treatment method of the comparative example has no recovery value because effective elements in ZSM-5 molecular sieve mother liquor waste water are not recovered.
Collecting the wastewater generated in the step (6), and detecting that the wastewater has a pH value of 7.5, a chroma of 10, an SS of 5.1mg/L, a COD of 47.2 ppm, and a BOD519.5 ppm, 29.7 ppm ammonia nitrogen content, and GB 8979-1996 comprehensive sewage discharge standard. In this comparative example, the number of filters required to treat the same amount of water was 2 to 4 times that of examples 1 to 4. Therefore, the application of the method can not only recycle the silicon element in the ZSM-5 molecular sieve mother liquor wastewater, but also greatly improve the wastewater treatment capacity, shorten the process flow and save the cost of manpower and material resources.
Claims (5)
1. The application of the C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment is characterized by comprising the following steps:
(1) stirring the ZSM-5 molecular sieve mother liquor and adding acid to adjust the pH value to 6-9 to obtain slurry A;
(2) filtering the slurry A, washing a filter cake, adding water and pulping to obtain slurry B;
(3) carrying out flash evaporation drying on the slurry B, wherein the flash evaporation temperature is 150-180 ℃, and obtaining C-type silica gel;
the content of silicon in the ZSM-5 molecular sieve mother liquor is 1-3.5 wt%;
before adding acid, the pH value of the ZSM-5 molecular sieve mother liquor is 10.5-11;
the content of sodium ions in the filter cake after washing is less than or equal to 0.1wt per thousand;
the quality indexes of the C-type silica gel are as follows: the average particle size is 6.5-7.2mm, the abrasion rate is 6.8-7.2%, the bulk density is 418-425g/l, the pore volume is 0.76-0.78ml/g, the percent of pass of the spherical particles is 75-76%, the heating decrement is 4.4-4.7%, and the prepared C-type silica gel meets the requirements of HG/T2765.2-2005C-type silica gel;
the wastewater generated by the method comprises filtrate obtained by filtering the slurry A and washing liquid obtained by washing filter cakes, wherein the pH value of the wastewater is 7.5-8.4, the chroma is 8-10, the suspended solid content is 4.3-5.1mg/L, the chemical oxygen demand is 45.8-48.5 ppm, the five-day biochemical oxygen demand is 19.5-25.3ppm, the ammonia nitrogen content is 28.6-30.5 ppm, and the comprehensive discharge standard of GB 8979 and 1996 is met.
2. The use of claim 1, wherein the ZSM-5 molecular sieve mother liquor has a silicon content of 1.82-1.876 wt%.
3. The use according to claim 1, wherein the stirring speed in step (1) is 70-100 r/min and the stirring time is 20-40 min.
4. The use according to claim 1, wherein the filtration mode is filter pressing, and the pressure of the filter pressing is 0.8-1.2 Mpa.
5. Silica gel form C obtained by the use according to any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210052736.8A CN114057200B (en) | 2022-01-18 | 2022-01-18 | Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210052736.8A CN114057200B (en) | 2022-01-18 | 2022-01-18 | Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114057200A CN114057200A (en) | 2022-02-18 |
| CN114057200B true CN114057200B (en) | 2022-04-19 |
Family
ID=80231260
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210052736.8A Active CN114057200B (en) | 2022-01-18 | 2022-01-18 | Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114057200B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559955A (en) * | 2008-04-17 | 2009-10-21 | 中国石油天然气集团公司 | Method of preparing ZSM-5 molecular sieves |
| CN101591021A (en) * | 2009-06-29 | 2009-12-02 | 青岛中能集团有限公司 | A kind of preparation method of thick-hole block silica gel |
| CN102079527A (en) * | 2009-11-27 | 2011-06-01 | 姜小宁 | Manufacturing method of micro-powder macroporous silicon gel |
| CN102757069A (en) * | 2011-04-29 | 2012-10-31 | 山东齐鲁华信高科有限公司 | Method for reusing mother liquor generated in ZSM (zeolite socony mobil)-5 molecular sieve preparation |
| CN110330027A (en) * | 2019-07-31 | 2019-10-15 | 山东齐鲁华信实业股份有限公司 | Low silica-alumina ratio selects the production method of type molecular sieve ZSM-5 |
| CN110342534A (en) * | 2019-07-31 | 2019-10-18 | 山东齐鲁华信实业股份有限公司 | Molecular sieve externally discharged waste water reuse produces the production method for selecting type molecular sieve ZSM-5 |
| CN112694098A (en) * | 2020-12-31 | 2021-04-23 | 山东齐鲁华信实业股份有限公司 | Method for recovering and synthesizing molecular sieve ZSM-5X from silicon-containing sewage |
-
2022
- 2022-01-18 CN CN202210052736.8A patent/CN114057200B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559955A (en) * | 2008-04-17 | 2009-10-21 | 中国石油天然气集团公司 | Method of preparing ZSM-5 molecular sieves |
| CN101591021A (en) * | 2009-06-29 | 2009-12-02 | 青岛中能集团有限公司 | A kind of preparation method of thick-hole block silica gel |
| CN102079527A (en) * | 2009-11-27 | 2011-06-01 | 姜小宁 | Manufacturing method of micro-powder macroporous silicon gel |
| CN102757069A (en) * | 2011-04-29 | 2012-10-31 | 山东齐鲁华信高科有限公司 | Method for reusing mother liquor generated in ZSM (zeolite socony mobil)-5 molecular sieve preparation |
| CN110330027A (en) * | 2019-07-31 | 2019-10-15 | 山东齐鲁华信实业股份有限公司 | Low silica-alumina ratio selects the production method of type molecular sieve ZSM-5 |
| CN110342534A (en) * | 2019-07-31 | 2019-10-18 | 山东齐鲁华信实业股份有限公司 | Molecular sieve externally discharged waste water reuse produces the production method for selecting type molecular sieve ZSM-5 |
| CN112694098A (en) * | 2020-12-31 | 2021-04-23 | 山东齐鲁华信实业股份有限公司 | Method for recovering and synthesizing molecular sieve ZSM-5X from silicon-containing sewage |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114057200A (en) | 2022-02-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2719832C2 (en) | Method of treating silicon-containing waste water and method of use thereof, as well as method and system for producing molecular sieve | |
| CN104030499B (en) | A kind of integrated conduct method of extraordinary molecular sieve synthesis mother liquid | |
| CN111099630A (en) | Method for synthesizing SSZ-13 molecular sieve in sodium-free system at low cost | |
| CN110407361A (en) | A kind of zero-emission of silica gel waste water and recycling treatment process and silica gel waste water treatment system | |
| CN110877914A (en) | Method for preparing high-purity high-white calcium carbonate by mineralizing and fixing carbon dioxide with phosphogypsum | |
| CN114057200B (en) | Application of C-type silica gel preparation method in ZSM-5 molecular sieve mother liquor treatment and C-type silica gel | |
| CN208516954U (en) | A kind of system of calcium remover and nanofiltration membrane combined treatment evaporated waste ammonia liquid | |
| CN110342559A (en) | A kind of system and method being recycled evaporated waste ammonia liquid joint-producing anhydrous sodium carbonate | |
| CN109592696A (en) | A kind of preparation method of nano-sheet clinoptilolite molecular sieve | |
| CN208586063U (en) | A kind of system being recycled evaporated waste ammonia liquid joint-producing anhydrous sodium carbonate | |
| CN215403115U (en) | Resource system for organic wastewater rich in sodium sulfate and ammonium sulfate | |
| US5401487A (en) | Process to obtain zeolite 4A starting from bauxite | |
| CN110330027A (en) | Low silica-alumina ratio selects the production method of type molecular sieve ZSM-5 | |
| CN112142063A (en) | Preparation method of X molecular sieve | |
| CN112371165A (en) | Method for preparing catalytic cracking catalyst by recycling silica-alumina gel | |
| CA2057588C (en) | A process to obtain zeolite 4a starting from bauxite | |
| CN110194467A (en) | A method of 13X molecular sieve is prepared by NaY mother liquor | |
| CN103752083A (en) | Filtering separation method for nanometer molecular sieve slurry | |
| CN117658363A (en) | Graphite purification waste liquid treatment system and graphite purification waste liquid treatment method | |
| CN112551548B (en) | Recycling system for organic wastewater rich in sodium sulfate and ammonium sulfate | |
| CN110330192A (en) | A method of for the full reuse of process water in ZSM-5 molecular sieve production | |
| CN110330030B (en) | Production method for producing selective molecular sieve ZSM-5 by using low caustic ratio sodium metaaluminate | |
| CN1038496C (en) | Method for directly preparing Lemery salt by using salt-cake (gypsum) type bittern or mother liquid for preparing salt (saptpetre) or mirabilite mineral bittern | |
| CN111960813B (en) | High-value utilization post-treatment system and method for molecular sieve synthesis waste liquid | |
| CN217868495U (en) | Calcium chloride type wastewater treatment system |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |