Method for recycling of suspensions produced in catalyst production and use thereof

Abstract

This invention discloses a method for recovering and utilizing suspended solids generated during catalyst production. The method comprises the following steps: mixing an acid solution with a soluble metal compound, adjusting the pH of the solution to 1-3, then adding the suspended solids generated during catalyst production, followed by aging and solid-liquid separation. The soluble metal compound is one or more of soluble zinc salts, alkaline earth metal salts, and rare earth compounds. This method enables rapid sedimentation and separation of materials, obtaining fine powder with a purity of over 60%, and has the advantage of arbitrarily adjusting the solid content of the fine powder slurry. It successfully achieves the goal of significantly reducing suspended solids and wastewater emissions in catalyst production units, especially catalytic cracking production units, laying a solid foundation for the high-efficiency utilization of this catalytic material.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a method for recycling and utilizing suspended solids generated during catalyst production and its application. Background Technology

[0002] Catalytic cracking is one of the main methods for lightening heavy oil. The catalyst is the core of catalytic cracking technology, characterized by strong controllability, wide control range, and rapid effect. It is currently the most consumed catalyst in oil refining and needs to meet the requirements of complex and variable feedstocks, diverse processes, significant differences in production units, operational adaptability, product distribution adjustment, and product quality upgrading. It largely determines the refinery's product structure and economic benefits. The research and development of catalytic materials is key to improving catalytic efficiency and product distribution. Catalytic cracking is a parallel sequential reaction. Oil and gas molecules first encounter the catalyst matrix and undergo a pre-cracking reaction. Then, smaller hydrocarbon molecules undergo a secondary cracking reaction on the molecular sieve. This requires catalytic materials to have excellent hydrothermal stability, a well-developed hierarchical pore structure, and acidic distribution to meet the requirements of hydrocarbon molecule diffusion, adsorption, and reaction.

[0003] In the actual production process of catalytic cracking catalysts, waste gas, wastewater, and waste residue are generated. Waste gas can be collected and treated through a tail gas recovery device to meet emission standards. Wastewater, such as the mother liquor and washing liquid from NaY synthesis, contains a large amount of silicon and aluminum and can be reused through different steps and pathways. In addition, the actual production process generates a large amount of suspended solids. These suspended solids are difficult to settle, and the resulting wastewater volume is large and cannot be directly discharged. When they encounter acidic wastewater, they produce a large amount of flocculent precipitate and turbid wastewater, which is difficult to treat and seriously affects the normal production of the entire enterprise. Furthermore, the discharge of these suspended solids forms sludge, which not only pollutes the environment but also incurs high treatment costs for the production enterprise. Statistics show that industrial fresh water costs approximately 4.5 yuan / ton, but treating one ton of wastewater costs about 10 yuan / ton, not including the cost of treating suspended solids and sludge. In fact, if these suspended solids can be effectively collected and separated, they would be excellent multi-level porous catalytic materials.

[0004] Regarding the separation and recovery of suspended solids, CN103359848A discloses a method for treating silica-containing washing wastewater during the preparation of Na-type molecular sieves. This method includes the following steps: (1) neutralizing the silica-containing washing wastewater of the Na-type molecular sieves with an acidified aluminum salt solution until pH = 6-10, forming a silica-alumina gel; (2) adding a flocculant or a combination of flocculant and filter aid to the gel for flocculation and sedimentation; (3) filtering and washing the gel obtained in step (2), reusing the filter residue, and directly discharging the filtrate. The flocculant is a complex of cationic and nonionic surfactants. This method of separating and settling suspended solids requires a complex process and filtration equipment, placing high demands on the separation equipment and requiring a large footprint. It is not suitable for large-scale continuous operation and does not mention how to reuse the filter residue.

[0005] In the synthesis and modification of hierarchical porous, highly stable catalytic materials, the main methods currently used domestically and internationally include post-treatment methods, template methods, and zeolite conversion methods for mesoporous materials. Post-treatment methods, also known as destructive methods, involve secondary treatment of existing microporous molecular sieves using acid, alkali, or hydrothermal methods to remove some metal atoms from the sieve. The resulting voids are typically mesoscopic in size. Template methods are widely used in the preparation of ordered mesoporous materials and can be divided into hard template methods and soft template methods. Patent CN 103172082 A reports a method for post-treatment synthesis of mesoporous Y-type molecular sieves, including the preparation of NaY molecular sieves, the preparation of NH4Y molecular sieves, acid treatment, and alkali treatment, resulting in mesoporous pore volumes of 0.5 mL / g to 1.5 mL / g. Patent CN 103086398 A invented a method for the rapid synthesis of mesoporous NaY molecular sieve microspheres using carbon sphere hard template agents. Patent CN 104069886 A synthesized mesoporous Y-type molecular sieves in a one-step hydrothermal crystallization process using F127, 3-aminopropyltriethoxysilane, or sodium alginate as mesoporous template agents. Tao et al. (J. Phys. Chem. B, 2003, 107, 10974-10976) hydrothermally synthesized molecular sieve / carbon composites using carbon aerosols and molecular sieve precursors. In this synthesis system, the molecular sieve grew within the three-dimensional network of carbon aerosols, and subsequently, the carbon aerosols were removed by calcination to obtain Y-type molecular sieves containing intracrystalline mesopores. Gu et al. (Chem. Mater., 2010, 22, 2442–2450) synthesized mesoporous Y-type molecular sieves using a mixed solution of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB), tert-butanol (TBA), and 1,3,5-trimethylbenzene (TMB) as template agents. Furthermore, the Sinopec Research Institute of Petroleum Processing has synthesized a Y-type molecular sieve composite material (NSY) with both microporous and mesoporous (macro) pore structures using kaolin as raw material and through crystallization treatment technology. The above-mentioned synthesis of hierarchical porous composite materials generally requires template agents, resulting in high production costs, environmental unfriendliness, and remaining at the laboratory or pilot-scale stage, making industrial application difficult. Therefore, developing low-cost, high-performance hierarchical porous composite materials has become a key research focus in industrial applications. Regarding modification: CN202010128060.7 describes the preparation process of a catalytic cracking aid containing phosphotungstic acid-modified mesoporous materials; CN201510718320.5 discloses a method of first calcining the balancing agent and then modifying it with acid and metal salts to improve the balancing agent's activity; CN201910745647.X describes modifying shape-selective molecular sieves selected from alkaline earth metal oxides, rare earth metal oxides, and non-metallic oxides to improve propylene yield and octane number.CN202010124321.8 describes the modification of all-silica mesoporous materials with dichlorodimethylsilane; CN201710630470.X describes the mixing and slurrying of catalyst particles, organic acid, ammonium salt, phosphorus-containing compounds, and water, followed by heating and pressurizing reaction, filtration, washing, and drying; then, magnesium-containing compounds are added to the catalyst particles, mixed evenly, and calcined to obtain a modified catalytic cracking catalyst to improve its activity. CN201510018286.0 describes the modification of diatomaceous earth with phosphorus and zinc; CN201710630463.X introduces a method for modifying Y-type molecular sieves with rare earth, phosphorus, and magnesium composites. Analysis of modification techniques shows that currently, for both molecular sieve materials and matrix materials, modification methods generally employ acids, bases, metal oxides, and rare earth oxides to modulate the acidity of the material.

[0006] After the catalytic materials are synthesized and modified, they still need to be separated, specifically the liquid-solid phase separation. CN201310338193.7 describes a separation process for waste catalysts in flue gas desulfurization wastewater, using flocculants to achieve sedimentation of suspended solids; CN201410361796.3 describes liquid-solid phase separation using a hydrocyclone separator; CN200810227656.1 describes a method for multi-stage liquid-solid separation of reaction slurry using a hydrocyclone separator and inorganic membranes or sintered metal tubes, with the separated titanium-silicon catalyst being recycled back into the reactor; CN201520848831.4... The liquid-solid separation equipment is a hydrocyclone separator. CN201510717262.4 and CN201911097721.8 detail a method for separating heavy oil using a hydrocyclone separator, achieving the lightening of the feedstock oil. CN201320573143.2 describes a catalytic cracking flue gas desulfurization wastewater treatment device for separating the liquid and solid phases. This wastewater treatment device mainly consists of a hydrocyclone separator, an alkali tank, a neutralization reactor, a slurry tank, an expansion drum filter, an oxidation tank, a sedimentation tank, and a screw press dewatering machine. Existing liquid-solid phase separation mainly relies on hydrocyclones, which are large in size and have long processes. In summary, the analysis of the above patented technologies reveals that the current methods for modifying and separating catalytic materials for the catalytic field suffer from a combination of prominent problems, including high cost, long process flow, low separation efficiency, and unreliable quality, making them unsuitable for industrial implementation. Summary of the Invention

[0007] The purpose of this invention is to provide a method for recovering and utilizing suspended solids generated during catalyst production, in order to solve the shortcomings of existing technologies in recovering suspended solids, such as long process flow, low separation efficiency, and inability to guarantee quality, which are not conducive to industrial implementation.

[0008] Another objective of this invention is to provide an application of the solid material obtained after recovering the suspended matter produced during catalyst production.

[0009] To achieve the above objectives, the present invention provides a method for recycling suspended solids generated during catalyst production, comprising the following steps: mixing an acid solution with a soluble metal compound, adjusting the pH of the solution to 1-3, then adding the suspended solids generated during catalyst production, aging, and performing solid-liquid separation; wherein the soluble metal compound is one or more of soluble zinc salts, soluble alkaline earth metal salts, and soluble rare earth compounds.

[0010] The present invention describes a method for recovering and utilizing suspended matter generated during the production of catalysts. The suspended matter is generated during the preparation of catalytic cracking catalysts and has a solid content of 20-35 wt%. The solid matter contains 68-86 wt% SiO2, 10-26 wt% Al2O3, and 4-6 wt% Na2O.

[0011] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention wherein the acid content in the acid solution is 10-20 wt%, preferably waste acid solution generated during industrial production, and the acid in the acid solution is one or more of hydrochloric acid, nitric acid, sulfuric acid and citric acid.

[0012] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention involves adding a soluble metal salt at an amount of 0.1 to 10 wt% of the acid solution mass.

[0013] The method for recovering and utilizing suspended solids generated during the production of the catalyst according to the present invention comprises: the soluble zinc salt being one or more of zinc chloride, zinc nitrate, and zinc sulfate; the soluble alkaline earth metal salt being one or more of magnesium chloride, magnesium nitrate, and magnesium carbonate; and the rare earth compound being one or more of rare earth chloride, rare earth nitrate, and rare earth hydroxide.

[0014] The method for recovering and utilizing suspended solids generated during the production of the catalyst according to the present invention has a mass ratio of suspended solids to acid solution of 1:1 to 1:10.

[0015] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention includes aging at 50–100°C for 10–120 min.

[0016] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention further includes an acid exchange step on the solid phase obtained from solid-liquid separation. The acid exchange conditions are: pH 2.5-6, temperature 75-95℃, and exchange time 20-60 min. The acid used for exchange is one or more of sulfuric acid, oxalic acid, hydrochloric acid, phosphoric acid, nitric acid, and citric acid, preferably hydrochloric acid and / or nitric acid.

[0017] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention further includes a water washing step after acid exchange. The washing conditions are: material:H2O = 1:1 to 25, pH value of 2.5 to 8.5, washing temperature of 30 to 95°C, and washing time of 0.5 to 2 hours.

[0018] To achieve the above objectives, the present invention also provides an application of the solid material recovered by the above method in a catalyst.

[0019] The beneficial effects of this invention are:

[0020] 1. The method of this invention is low-cost and can effectively solve environmental problems. The suspended solids generated in the catalyst production process are generally neutral or alkaline. After mixing with acidic wastewater, the suspended solids undergo flocculation, aging, and chemical reaction, resulting in a richer specific surface area for the suspended solids. The added soluble metal compounds can change the sedimentation properties of the suspended solids after flocculation, making them easier to settle. On the other hand, the aging step also functions as a modifier of ions while flocculating, thus completing the modification. Compared with the traditional method of neutralizing silicon-containing wastewater with acidic aluminum salts, the biggest advantage of this invention is that the suspended solids and soluble metal compounds do not simply neutralize each other, but undergo a chemical reaction. The metal ions migrate within the material, achieving flocculation and modification in one step without the need for additional flocculants. While reducing the number of implementation steps, it effectively increases the solid content of the separated slurry, allowing the settled substances to be further applied as catalytic materials in the field of catalysts, especially in the field of catalytic cracking catalysts.

[0021] 2. The method of the present invention can achieve rapid sedimentation and separation of materials to obtain fine powder with a purity of over 60%, and has the advantage of being able to adjust the solid content of the fine powder slurry at will. It has successfully achieved the goal of significantly reducing suspended solids and wastewater discharge in catalyst production units, especially catalytic cracking production units, laying a solid foundation for the high-efficiency utilization of this catalytic material. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the apparatus used in the solid-liquid separation step of the method of the present invention.

[0023] In the attached figures, the following labels are used:

[0024] 1. Feed pipe;

[0025] 2. Discharge pipe;

[0026] 3. Stirring device;

[0027] 4. Material pump;

[0028] 5. Overflow pipe. Detailed Implementation

[0029] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0030] This invention provides a method for recovering and utilizing suspended solids generated during catalyst production, comprising the following steps: mixing an acid solution with a soluble metal compound, adjusting the pH of the solution to 1-3, within which the soluble metal compound is more conducive to flocculation and sedimentation, then adding the suspended solids generated during catalyst production, aging, and performing solid-liquid separation; wherein the soluble metal compound is one or more of soluble zinc salts, soluble alkaline earth metal salts, and soluble rare earth compounds.

[0031] The method for recycling suspended matter generated during the production of catalysts according to the present invention refers to suspended matter generated during the preparation of catalytic cracking catalysts, with a solid content of 20-35 wt% and solid substances including 68-86 wt% SiO2, 10-26 wt% Al2O3, and 4-6 wt% Na2O.

[0032] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention wherein the acid content in the acid solution is 10-20 wt%, preferably waste acid solution generated during industrial production, and the acid in the acid solution is one or more of hydrochloric acid, nitric acid, sulfuric acid and citric acid.

[0033] The acid solution can be prepared from inorganic acids or it can be acidic waste liquid generated in industrial production, such as acidic waste liquid generated by pharmaceutical factories.

[0034] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention involves adding a soluble metal salt at an amount of 0.1 to 10 wt% of the acid solution mass.

[0035] The zinc salt in the soluble metal compound can be zinc chloride, zinc nitrate, or zinc sulfate; the alkaline earth metal salt can be carbonate, nitrate, or chloride of alkaline earth metals, as long as it is soluble in water, such as magnesium chloride, magnesium nitrate, or magnesium carbonate; the rare earth compound can be rare earth chloride, rare earth nitrate, or rare earth hydroxide, as long as it is soluble in water.

[0036] The method for recycling suspended solids generated during catalyst production according to the present invention has a mass ratio of suspended solids to acid waste of 1:1 to 1:10.

[0037] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention includes aging at 50–100°C for 10–120 min.

[0038] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention further includes an acid exchange step on the solid phase obtained from solid-liquid separation. The acid exchange conditions are: pH 3-6, temperature 80-95℃, and exchange time 20-60 min. The acid used for exchange is one or more of sulfuric acid, oxalic acid, hydrochloric acid, phosphoric acid, and nitric acid, preferably hydrochloric acid and / or nitric acid.

[0039] The method for recovering and utilizing suspended solids generated during catalyst production according to the present invention further includes a water washing step after acid exchange. The washing conditions are: material:H2O = 1:1 to 25, pH value of 2.5 to 8.5, washing temperature of 30 to 95°C, and washing time of 0.5 to 2 hours.

[0040] When performing solid-liquid separation, methods such as... Figure 1 The apparatus shown mainly includes a mixing drum containing a stirring device 3. A feed pipe 1 is located on one side of the mixing drum, in the middle of the drum. A discharge pipe 2 and an overflow pipe 5 are located on the other side. The discharge pipe 2 is horizontally higher than the feed pipe 1, and the overflow pipe 5 is also horizontally higher than the discharge pipe 1. The bottom plate of the feed pipe 1 is inclined downwards, allowing the material to slowly slide down the inclined plate into the mixing drum. Inclined baffles on the inclined plate increase the material residence time, ensuring effective separation. The cantilever end is higher than the end connected to the mixing drum. During operation, suspended solids enter the mixing drum through the feed pipe 1 via a material pump 4. As the liquid flows, the solids settle along the inclined plate inside the drum. When the clear liquid reaches the discharge pipe 2, it is discharged from the discharge pipe 2. If the liquid level is high and the discharge from the discharge pipe 2 is not timely, the clear liquid will also flow out from the overflow pipe 5, maintaining a normal liquid level inside the mixing drum. By controlling the feed rate and the rate of clear liquid discharge, effective solid-liquid separation can be achieved.

[0041] The method of the present invention will be further described in detail below through examples.

[0042] 1) Suspended solids: Industrial grade, collected from Lanzhou Petrochemical Company Catalyst Plant (a mixture of suspended solids from wastewater discharged from various workshops throughout the plant; the solids consist of approximately 70% SiO2, 16% Al2O3, and 5% Na2O, with the remainder being other impurities).

[0043] 2) Waste acid: Industrial product, sourced from a pharmaceutical factory (the acid content in the acid is 10-20 wt%, and the acid is a mixture of hydrochloric acid, citric acid, etc.)

[0044] 3) Zinc chloride: chemically pure, Xilong Chemical Co., Ltd.

[0045] 4) Zinc nitrate: chemically pure, Xilong Chemical Co., Ltd.

[0046] 5) Magnesium chloride: Chemically pure, Xilong Chemical Co., Ltd.

[0047] 6) Magnesium nitrate: Chemically pure, Xilong Chemical Co., Ltd.

[0048] Characterization methods:

[0049] The specific surface area and pore volume of the samples were measured using the classical N2 adsorption-desorption isotherm method, employing a physical adsorption apparatus and a temperature-programmed desorption apparatus. Approximately 0.06 g of catalyst sample was required. After eight hours of vacuum degassing pretreatment, adsorption-desorption operations were performed under liquid nitrogen conditions. The average values ​​of the specific surface area and pore volume of the samples were calculated using the BJH method.

[0050] Example 1

[0051] 5000g of a solution containing 10% waste acid was mixed with 100g of zinc chloride and stirred for 60min at pH 1.2. This mixture was then added to 500g of a slurry containing 26% solids and aged at 50℃ for 120min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it was swirl out through the discharge pipe, while water flowed away through the overflow outlet. The swirl-out material was first exchanged with sulfuric acid at pH 3.2 and temperature 85℃ for 1h, followed by washing with water at a ratio of H₂O: 1:24, pH 8.5, and a washing temperature of 30℃ for 30min. The mixture was then filtered and dried to obtain C⁻¹.

[0052] Example 2

[0053] 3500g of a solution containing 20% ​​waste acid was mixed with 175g of lanthanum nitrate and stirred for 60min at pH 2.0. This mixture was then added to 500g of a suspension slurry with a solid content of 31%. The mixture was aged at 60℃ for 10min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with hydrochloric acid at pH 3.8 and temperature 80℃ for 60min, followed by washing with water at a ratio of H₂O: 1:10, pH 3.5, and a washing temperature of 50℃ for 30min. The mixture was then filtered and dried to obtain C₂.

[0054] Example 3

[0055] 2000g of a solution containing 12% waste acid was mixed with 15g of magnesium nitrate and stirred for 60min at pH 3.0. This mixture was then added to 2000g of a slurry containing 20% ​​solids and aged at 100℃ for 30min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with nitric acid at pH 4.8 and temperature 95℃ for 40min, followed by washing with water at a ratio of H₂O: 1:18, pH 6.0, and temperature 90℃ for 40min. The mixture was then filtered and dried to obtain C₃.

[0056] Example 4

[0057] 4000g of a solution containing 17% waste acid was mixed with 120g of zinc nitrate and stirred for 60min at pH 2.0. This mixture was then added to 1000g of a slurry containing 25% solids and aged at 80℃ for 100min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with phosphoric acid at pH 6.0 and temperature 82℃ for 40min, followed by washing with water at a ratio of H₂O: 1:4, pH 5.0, and a washing temperature of 60℃ for 40min. The mixture was then filtered and dried to obtain C₄.

[0058] Example 5

[0059] 3000g of a solution containing 15% waste acid was mixed with 210g of magnesium chloride and stirred for 60min at pH 2.5. This mixture was then added to 500g of a suspension slurry with a solid content of 27%. The mixture was aged at 90℃ for 80min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with hydrochloric acid at pH 3.0 and temperature 85℃ for 20min, followed by washing with water at a ratio of H₂O: 1:8, pH 8.0, and a washing temperature of 90℃ for 40min. The mixture was then filtered and dried to obtain C-5.

[0060] Example 6

[0061] 4000g of a solution containing 14% waste acid and 320g of cerium chloride were stirred for 60 minutes at pH 1.0. This mixture was then added to 500g of a suspension slurry with a solid content of 32%. The mixture was aged at 70℃ for 50 minutes. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with oxalic acid at pH 3.5 and 90℃ for 30 minutes, followed by washing with water at a ratio of H₂O: 1:16, pH 4.5, and 95℃ for 120 minutes. The mixture was then filtered and dried to obtain C-6.

[0062] Example 7

[0063] 2000g of a solution containing 16% waste acid and 200g of zinc sulfate were stirred for 60 minutes at pH 2.0. This mixture was then added to 500g of a suspension slurry with a solid content of 32%. The mixture was aged at 75℃ for 60 minutes. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with citric acid at pH 2.5 and 75℃ for 30 minutes, followed by washing with water at a ratio of H₂O: 1:10, pH 5.0, and 80℃ for 30 minutes. The mixture was then filtered and dried to obtain C-7.

[0064] Comparative Example 1

[0065] Compared with Example 4, a suspension slurry with a solid content of 25% was pumped into the sedimentation separation device through the feed pipe. The slurry slowly slid down the bottom, and after separation, flowed out through the discharge pipe, while water flowed away through the overflow port. The outflowing material was first exchanged with phosphoric acid at a pH of 6.0 and a temperature of 82°C for 40 minutes, followed by water washing. The water ratio of material to H₂O was 1:4, the pH was 5.0, the washing temperature was 60°C, and the washing time was 40 minutes. The mixture was then filtered and dried to obtain C-8.

[0066] Comparative Example 2

[0067] Compared with Example 7, 2000g of a solution containing 16% waste acid and 200g of zinc sulfate were stirred for 60 minutes at pH 8.0, and then added to 500g of a suspension slurry with a solid content of 32%. The mixture was aged at 75°C for 60 minutes. The aged material was pumped into a sedimentation separator via the feed pipe, slowly sliding down the bottom. After separation, it flowed out through the discharge pipe, while water overflowed from the overflow outlet. The outflowing material was first exchanged with nitric acid at pH 2.5 and temperature 75°C for 30 minutes, followed by washing with water at a ratio of H₂O: 1:10, pH 5.0, and a washing temperature of 80°C for 30 minutes. The mixture was then filtered and dried to obtain C-9.

[0068] Comparative Example 3

[0069] Compared with Example 1, 5000g of a solution containing 10% waste acid was mixed with 100g of aluminum chloride and stirred for 60min at pH 5.0. This mixture was then added to 500g of a suspension slurry with a solid content of 26%. The mixture was aged at 50°C for 120min. The aged material was pumped into a sedimentation separator via the feed pipe, where it slowly slid down the bottom. After separation, it was swirl out from the discharge pipe, and water flowed away from the overflow outlet. The swirl-out material was first exchanged with sulfuric acid at pH 3.2 and temperature 85°C for 1h, followed by water washing. The water ratio of the material to H₂O was 1:24, the pH was 8.5, the washing temperature was 30°C, and the washing time was 30min. The mixture was then filtered and dried to obtain C-10.

[0070] Table 1 shows the comparison results of the specific surface area and pore volume of the catalyst materials in the examples and comparative examples, as well as the solid content after sedimentation. Under the same conditions, the modified sedimentation method of this invention has a higher specific surface area and a higher solid content.

[0071] Table 1. Effects of Modified Sedimentation Separation Implementation

[0072]

[0073] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for recovering and utilizing suspended solids generated during catalyst production, characterized in that, Includes the following steps: The acid solution is mixed with a soluble metal compound, the pH of the solution is adjusted to 1-3, and then the suspended solids generated during the catalyst production process are added, followed by aging and solid-liquid separation; wherein the soluble metal compound is one or more of soluble zinc salts, soluble alkaline earth metal salts, and soluble rare earth compounds. The suspended matter is a suspended matter generated during the preparation of catalytic cracking catalyst, with a solid content of 20-35 wt%, and the solid matter contains 68-86 wt% SiO2, 10-26 wt% Al2O3, and 4-6 wt% Na2O.

2. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The acid content in the acid solution is 10~20 wt%.

3. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The acid solution is waste acid solution generated during industrial production, and the acid in the acid solution is one or more of hydrochloric acid, nitric acid, sulfuric acid and citric acid.

4. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The amount of the soluble metal compound added is 0.1 to 10 wt% of the acid solution mass.

5. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The soluble zinc salt is one or more of zinc chloride, zinc nitrate, and zinc sulfate; the soluble alkaline earth metal salt is one or more of magnesium chloride, magnesium nitrate, and magnesium carbonate; and the soluble rare earth compound is one or more of rare earth chloride, rare earth nitrate, and rare earth hydroxide.

6. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The mass ratio of the suspended solids to the acid solution is 1:1 to 1:

10.

7. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, The aging conditions are aging at 50~100℃ for 10~120 minutes.

8. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 1, characterized in that, It also includes a step of acid exchange on the solid phase obtained from solid-liquid separation. The acid exchange conditions are: pH 2.5~6, temperature 75~95℃, exchange time 20~60min, and the acid used for exchange is one or more of sulfuric acid, oxalic acid, hydrochloric acid, phosphoric acid, nitric acid and citric acid.

9. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 8, characterized in that, The acids used for exchange are hydrochloric acid and / or nitric acid.

10. The method for recovering and utilizing suspended solids generated during catalyst production according to claim 8, characterized in that, After acid exchange, a water washing step is also included. The washing conditions are: material:H2O = 1:1~25, pH value 2.5~8.5, washing temperature 30~95℃, and washing time 0.5~2h.

11. The use of the solid material recovered by the method of any one of claims 1 to 10 in a catalyst.

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