A method for resource utilization of FCC spent catalyst

Abstract

The application provides a method for resource utilization of FCC waste catalyst, which comprises the following steps: (1) the FCC waste catalyst is subjected to dealumination and impurity removal treatment, and after first solid-liquid separation, the obtained aluminum-containing leaching solution is returned to the dealumination and impurity removal treatment for cyclic leaching, and after second solid-liquid separation, a modified FCC intermediate and an aluminum-rich leaching solution are obtained; (2) the modified FCC intermediate is subjected to dilute alkali reconstruction treatment, and after solid-liquid separation, a modified FCC catalyst and a silicate are obtained; and the aluminum-rich leaching solution is subjected to system regulation treatment to obtain an aluminum-based product. The process is simple, zero emission in the process, realizes the modification and regeneration of the FCC waste catalyst, and the separation, extraction and productization of the contained elements, can solve the environmental pollution problem caused by the FCC waste catalyst, has remarkable economic and environmental benefits, and is easy to be popularized and applied on a large scale.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, and in particular to a method for the resource utilization of spent FCC catalysts. Background Technology

[0002] Fluid catalytic cracking (FCC) is the most important secondary processing method in modern petroleum refining and a key technology for the lightening of heavy oil. FCC catalysts are crucial to the FCC process. FCC catalysts are currently the most consumed refining catalysts, with my country's annual consumption exceeding 1×10⁻⁶. 5 t, which can account for 70% of the total amount of refining catalysts used. As crude oil becomes increasingly heavy and of poor quality and catalysts are continuously recycled, the amount of harmful metals (Fe, V, Ni) deposited on FCC catalysts gradually increases, leading to a decrease in catalytic activity and a deterioration in selectivity. As a result, the catalysts can no longer be used and become waste catalysts.

[0003] Currently, the main methods for treating spent FCC catalysts are divided into harmless treatment (chemical regeneration, high-temperature melting, and solidification stabilization) and resource utilization (magnetic separation process, adsorbent preparation, rare earth recovery, catalyst preparation, molecular sieve synthesis, and geopolymer preparation). CN116020551A discloses a method for regenerating spent FCC catalysts, which involves mixing the spent FCC catalyst with hydrogen peroxide solution and heat-treating it to obtain clinker. The clinker is then further leached with an acidic solution, and after solid-liquid separation, a regenerated FCC catalyst is obtained. CN113549764A discloses a method for recovering rare earth elements, nickel, and vanadium from spent FCC catalysts, which involves acid leaching the calcined spent FCC catalyst to obtain a leachate, which is then further recovered using pH adjustment and extraction to recover rare earth elements, nickel, and vanadium. CN115957828A discloses a catalyst for the catalytic cracking of waste plastics and its preparation method. The method involves sequentially calcining, sieving, acid leaching, and pore-expansion modification of an FCC waste catalyst, followed by loading the treated FCC waste catalyst with metal oxides and calcining to obtain the catalyst for the catalytic cracking of waste plastics. However, these methods suffer from low processing efficiency, high cost, and cumbersome post-processing procedures, making it difficult to meet economic and technical requirements.

[0004] Therefore, it is evident that an efficient and low-cost treatment technology is needed to address the safe disposal of FCC waste catalysts. Consequently, developing a method for the resource utilization of FCC waste catalysts, achieving synergistic treatment of both harmless disposal and resource utilization to improve economic and environmental benefits, has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for the resource utilization of FCC waste catalyst. By sequentially performing dealuminization and impurity removal treatment and dilute alkali reconstruction treatment on the FCC waste catalyst, the detoxification, modification and regeneration of the FCC waste catalyst are realized. At the same time, the extraction and productization of aluminum and silicon elements in the waste FCC are realized. This method can solve the environmental pollution problem caused by FCC waste catalyst, with significant economic and environmental benefits and is easy to promote and apply on a large scale.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0008] (1) FCC waste catalyst is subjected to dealuminization and impurity removal treatment. After the first solid-liquid separation, the aluminum-containing leachate is returned to the dealuminization and impurity removal treatment for recycling leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate are obtained.

[0009] (2) The modified FCC intermediate is subjected to dilute alkali reconstruction treatment, and after solid-liquid separation, the modified FCC catalyst and silicate are obtained; the aluminum-rich leaching solution is subjected to system regulation treatment to obtain aluminum-based products.

[0010] The method for resource utilization of FCC waste catalysts described in this invention firstly involves using acid solution cyclic leaching to remove aluminum and impurities from the FCC waste catalyst, efficiently removing harmful metals (Fe, V, Ni) enriched on the particle surface and migrated into the molecular sieve framework structure, yielding modified FCC intermediates and aluminum-rich leachate; then, the modified FCC intermediates are subjected to dilute alkali reconstruction treatment using dilute alkali solution to restore the molecular sieve pore structure and stabilize the framework, yielding modified FCC catalysts and silicates; finally, the aluminum-rich leachate is subjected to system regulation treatment using polymerization ripening or evaporation crystallization methods to obtain aluminum-based products such as polyaluminum chloride, polyaluminum sulfate, aluminum chloride, and aluminum sulfate.

[0011] Furthermore, when the method described in this invention performs dealuminization and impurity removal treatment on FCC waste catalysts, the aluminum-containing leachate obtained is returned to the dealuminization and impurity removal treatment for cyclic leaching. This ensures that the aluminum ion concentration in the aluminum-rich leachate is high. Only after subsequent system regulation and treatment can a polyaluminum chloride product with an alumina content greater than 8% be obtained, meeting the national standard requirements.

[0012] Preferably, the leaching agent used in the dealuminization and impurity removal process in step (1) includes any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or acetic acid, wherein typical but non-limiting combinations include a combination of hydrochloric acid and sulfuric acid, a combination of nitric acid and phosphoric acid, a combination of acetic acid and hydrochloric acid or a combination of nitric acid and acetic acid.

[0013] Preferably, the mass concentration of the leachate is 10-30%, for example, it can be 10%, 12%, 15%, 20%, 25%, 28% or 30%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] Preferably, the liquid-to-solid ratio of the dealuminization and impurity removal process in step (1) is 2 to 10 mL / g, for example, it can be 2 mL / g, 3 mL / g, 5 mL / g, 7 mL / g, 8 mL / g, 9 mL / g or 10 mL / g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] Preferably, the temperature for the dealuminization and impurity removal treatment is 60 to 100°C, for example, 60°C, 65°C, 70°C, 80°C, 85°C, 90°C, or 100°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the time for the dealuminization and impurity removal treatment is 60 to 240 minutes, for example, it can be 60 minutes, 70 minutes, 100 minutes, 130 minutes, 150 minutes, 200 minutes or 240 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, the number of leaching cycles is ≥2 times, for example, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times or 8 times, preferably 3 to 6 times.

[0018] Preferably, the leaching agent used in the dilute alkali reconstruction treatment in step (2) includes sodium hydroxide solution and / or potassium hydroxide solution.

[0019] Preferably, the mass concentration of the leaching agent in the dilute alkali reconstruction treatment is 50-150 g / L, for example, it can be 50 g / L, 60 g / L, 80 g / L, 100 g / L, 110 g / L, 130 g / L or 150 g / L, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] The preferred concentration of the leaching agent in the dilute alkali reconstruction treatment of this invention is 50–150 g / L, achieving the restoration of the molecular sieve pore structure and stable reconstruction of the framework. If the concentration of the leaching agent in the dilute alkali reconstruction treatment is too high, it will lead to complete destruction of the molecular sieve framework structure, making it impossible to obtain the target molecular sieve product and the modified FCC waste catalyst. Furthermore, it will cause depolymerization of polysilicates, preventing the preparation of high-modulus silicates. If the concentration of the leaching agent in the dilute alkali reconstruction treatment is too low, the defective parts of the molecular sieve cannot be reconstructed, resulting in a decline in the performance of the molecular sieve product; it will also lead to low silicon-oxygen dissociation efficiency, low silicate yield, and poor performance.

[0021] Preferably, the liquid-to-solid ratio of the dilute alkali reconstruction treatment in step (2) is 2 to 8 mL / g, for example, it can be 2 mL / g, 2.5 mL / g, 3 mL / g, 4 mL / g, 5 mL / g, 7 mL / g or 8 mL / g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] The preferred liquid-to-solid ratio of the dilute alkali reconstruction treatment in this invention is 2–8 mL / g, which can prepare silicates with a modulus of 2.5–3.5. If the liquid-to-solid ratio of the dilute alkali reconstruction treatment is too high, more sodium ions will be coordinated in the polysilicate, thereby reducing its modulus and preventing the preparation of high-modulus silicates. If the liquid-to-solid ratio of the dilute alkali reconstruction treatment is too low, the system will fail to form a slurry, resulting in low solid-liquid reaction mass transfer efficiency and poor quality of molecular sieves and silicate products.

[0023] Preferably, the temperature of the dilute alkali reconstruction treatment is 60 to 180°C, for example, it can be 60°C, 70°C, 80°C, 100°C, 120°C, 150°C or 180°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the dilute alkali reconstruction treatment time is 60 to 240 min, for example, it can be 60 min, 70 min, 100 min, 130 min, 150 min, 200 min or 240 min, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] Preferably, the system conditioning treatment in step (2) includes polymerization maturation treatment and / or evaporation crystallization treatment.

[0026] Preferably, the alkalizing agent used in the polymerization curing treatment includes any one or a combination of at least two of calcium aluminate, aluminum hydroxide, calcium oxide, calcium hydroxide, or calcium-based solid waste. Typical but non-limiting combinations include combinations of calcium aluminate and aluminum hydroxide, combinations of calcium oxide and calcium hydroxide, combinations of calcium-based solid waste and calcium aluminate, or combinations of aluminum hydroxide and calcium hydroxide.

[0027] Preferably, the liquid-to-solid ratio of the polymerization and ripening treatment is 6 to 12 mL / g, for example, it can be 6 mL / g, 7 mL / g, 8 mL / g, 10 mL / g, 11 mL / g, 11.5 mL / g or 12 mL / g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the temperature of the polymerization curing treatment is 60 to 100°C, for example, it can be 60°C, 65°C, 70°C, 80°C, 90°C, 95°C or 100°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] Preferably, the polymerization curing time is 60 to 180 minutes, for example, 60 minutes, 70 minutes, 80 minutes, 100 minutes, 150 minutes or 180 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, the temperature of the evaporation crystallization process is 80 to 150°C, for example, it can be 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] The solid-liquid separation described in this invention is not limited, and any method known to those skilled in the art for solid-liquid separation can be used, such as filtration, sedimentation, or centrifugation.

[0032] As a preferred technical solution of the present invention, the method includes the following steps:

[0033] (1) FCC waste catalyst is subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 2-10 mL / g and a temperature of 60-100℃ for 60-240 min. After the first solid-liquid separation, the aluminum-containing leachate is returned to the dealuminization and impurity removal treatment for cyclic leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate are obtained.

[0034] The leaching agent used in the dealuminization and impurity removal treatment includes any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, or acetic acid; the mass concentration of the leaching agent is 10-30%; and the number of cyclic leaching cycles is ≥2 times.

[0035] (2) The modified FCC intermediate is subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 2-8 mL / g and a temperature of 60-180℃ for 60-240 min. After solid-liquid separation, the modified FCC catalyst and silicate are obtained. The aluminum-rich leaching solution is subjected to system regulation treatment to obtain aluminum-based products.

[0036] The leaching agent used in the dilute alkali reconstruction treatment includes sodium hydroxide solution and / or potassium hydroxide solution; the mass concentration of the leaching agent in the dilute alkali reconstruction treatment is 50-150 g / L;

[0037] The system conditioning treatment includes polymerization ripening treatment and / or evaporation crystallization treatment; the alkalizing agent used in the polymerization ripening treatment includes any one or a combination of at least two of calcium aluminate, aluminum hydroxide, calcium oxide, calcium hydroxide, or calcium-based solid waste; the liquid-to-solid ratio of the polymerization ripening treatment is 6-12 mL / g; the temperature of the polymerization ripening treatment is 60-100℃; the time of the polymerization ripening treatment is 60-180 min; and the temperature of the evaporation crystallization treatment is 80-150℃.

[0038] Secondly, the present invention also provides a modified FCC catalyst obtained by the method for resource utilization of FCC waste catalyst as described in the first aspect.

[0039] Thirdly, the present invention also provides a silicate obtained by the method for resource utilization of FCC waste catalyst as described in the first aspect, wherein the modulus of the silicate is 2.5 to 3.5, for example, it can be 2.5, 2.8, 2.9, 3, 3.2, 3.4 or 3.5, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0040] Fourthly, the present invention also provides an aluminum-based product obtained by the method of resource utilization of FCC waste catalyst as described in the first aspect, wherein the alumina content of the aluminum-based product is 8% to 15%, for example, it can be 8%, 9%, 10%, 12%, 13%, 14% or 15%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0041] The purity of the aluminum-based product is >98%, for example, it can be 98.1%, 98.2%, 98.3%, 98.5%, 99%, 99.5% or 99.7%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] (1) The present invention provides a method for the resource utilization of FCC waste catalyst. After the FCC waste catalyst is dealuminized and impurities are removed by acid solution cyclic leaching, the modified FCC intermediate is reconstructed by dilute alkali solution to obtain modified FCC catalyst and high modulus silicate with modulus between 2.5 and 3.5. The aluminum-rich leachate is subjected to system regulation treatment by polymerization ripening or evaporation crystallization to obtain aluminum-based products with alumina content of 8% to 15% and purity greater than 98%.

[0044] (2) The method for resource utilization of FCC waste catalyst provided by the present invention has a simple processing technology, zero emissions, and significant economic and environmental benefits. It can be extended to the high-value utilization of other aluminum and silicon based solid wastes. Attached Figure Description

[0045] Figure 1 This is a flowchart of a method for the resource utilization of spent FCC catalysts provided by the present invention. Detailed Implementation

[0046] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] This invention provides a method for the resource utilization of spent FCC catalysts, the flowchart of which is shown below. Figure 1 As shown, the method includes the following steps:

[0048] (1) FCC waste catalyst is subjected to dealuminization and impurity removal treatment. After the first solid-liquid separation, the aluminum-containing leachate is returned to the dealuminization and impurity removal treatment for recycling leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate are obtained.

[0049] (2) The modified FCC intermediate is subjected to dilute alkali reconstruction treatment, and after solid-liquid separation, the modified FCC catalyst and silicate are obtained; the aluminum-rich leaching solution is subjected to system regulation treatment to obtain aluminum-based products.

[0050] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0051] Example 1

[0052] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0053] (1) The FCC waste catalyst was subjected to a dealuminization and impurity removal treatment at a liquid-solid ratio of 4 mL / g and a temperature of 90℃ for 180 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 4 cycles of leaching. After the second solid-liquid separation, the modified FCC intermediate and the aluminum-rich leachate were obtained. The leaching agent used in the dealuminization and impurity removal treatment was hydrochloric acid with a mass concentration of 20%.

[0054] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 4 mL / g and a temperature of 120℃ for 120 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0055] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 50 g / L;

[0056] The system conditioning process includes a polymerization maturation treatment; the alkalizing agent used in the polymerization maturation treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization maturation treatment is 8 mL / g; the temperature of the polymerization maturation treatment is 80℃; and the time of the polymerization maturation treatment is 120 min.

[0057] Example 2

[0058] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0059] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 8 mL / g and a temperature of 80℃ for 240 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 6 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0060] The leaching agent used in the dealuminization and impurity removal treatment is hydrochloric acid with a mass concentration of 25%;

[0061] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 4 mL / g and a temperature of 90℃ for 120 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0062] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 80 g / L;

[0063] The system conditioning treatment is a polymerization ripening treatment; the alkalizing agent used in the polymerization ripening treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization ripening treatment is 8 mL / g; the temperature of the polymerization ripening treatment is 80℃; and the time of the polymerization ripening treatment is 120 min.

[0064] Example 3

[0065] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0066] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 8 mL / g and a temperature of 60℃ for 120 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 4 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0067] The leaching agent used in the dealuminization and impurity removal treatment is hydrochloric acid with a mass concentration of 15%;

[0068] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 4 mL / g and a temperature of 90℃ for 120 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0069] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 140 g / L;

[0070] The system conditioning treatment is a polymerization ripening treatment; the alkalizing agent used in the polymerization ripening treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization ripening treatment is 6 mL / g; the temperature of the polymerization ripening treatment is 80℃; and the time of the polymerization ripening treatment is 120 min.

[0071] Example 4

[0072] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0073] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 10 mL / g and a temperature of 60℃ for 180 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 5 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0074] The leaching agent used in the dealuminization and impurity removal treatment is hydrochloric acid with a mass concentration of 30%;

[0075] (2) The modified FCC intermediate was subjected to a dilute alkali reconstruction treatment at a liquid-to-solid ratio of 6 mL / g and a temperature of 180℃ for 180 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0076] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 100 g / L;

[0077] The system conditioning treatment is a polymerization ripening treatment; the alkalizing agent used in the polymerization ripening treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization ripening treatment is 10 mL / g; the temperature of the polymerization ripening treatment is 60℃; and the time of the polymerization ripening treatment is 180 min.

[0078] Example 5

[0079] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0080] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 5 mL / g and a temperature of 95℃ for 180 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 6 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0081] The leaching agent used in the dealuminization and impurity removal treatment is hydrochloric acid with a mass concentration of 10%;

[0082] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 3 mL / g and a temperature of 100℃ for 60 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0083] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 60 g / L;

[0084] The system conditioning treatment is a polymerization ripening treatment; the alkalizing agent used in the polymerization ripening treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization ripening treatment is 8 mL / g; the temperature of the polymerization ripening treatment is 95℃; and the time of the polymerization ripening treatment is 60 min.

[0085] Example 6

[0086] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0087] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 5 mL / g and a temperature of 95℃ for 160 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 6 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0088] The leaching agent used in the dealuminization and impurity removal treatment is hydrochloric acid with a mass concentration of 20%;

[0089] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 5 mL / g and a temperature of 150℃ for 180 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain polyaluminum chloride product.

[0090] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 130 g / L;

[0091] The system conditioning treatment is a polymerization ripening treatment; the alkalizing agent used in the polymerization ripening treatment is calcium aluminate; the liquid-to-solid ratio of the polymerization ripening treatment is 12 mL / g; the temperature of the polymerization ripening treatment is 70℃; and the time of the polymerization ripening treatment is 120 min.

[0092] Example 7

[0093] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0094] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 4 mL / g and a temperature of 90℃ for 180 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 4 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0095] The leaching agent used in the dealuminization and impurity removal treatment is sulfuric acid with a mass concentration of 25%;

[0096] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 5 mL / g and a temperature of 120℃ for 120 min. After solid-liquid separation, the modified FCC catalyst and sodium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain aluminum sulfate product.

[0097] The leaching agent used in the dilute alkali reconstruction treatment is a sodium hydroxide solution with a mass concentration of 50 g / L;

[0098] The system conditioning process involves evaporation and crystallization at a temperature of 100°C.

[0099] Example 8

[0100] This embodiment provides a method for the resource utilization of spent FCC catalysts, the method comprising the following steps:

[0101] (1) FCC waste catalyst was subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 9 mL / g and a temperature of 70℃ for 60 min. After the first solid-liquid separation, the aluminum-containing leachate was returned to the dealuminization and impurity removal treatment for 6 cycles of leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate were obtained.

[0102] The leaching agent used in the dealuminization and impurity removal treatment is sulfuric acid with a mass concentration of 28%;

[0103] (2) The modified FCC intermediate was subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 5 mL / g and a temperature of 90℃ for 180 min. After solid-liquid separation, the modified FCC catalyst and potassium silicate were obtained. The aluminum-rich leaching solution was subjected to system regulation treatment to obtain aluminum sulfate product.

[0104] The leaching agent used in the dilute alkali reconstruction treatment is a potassium hydroxide solution with a mass concentration of 90 g / L;

[0105] The system conditioning process involves evaporation and crystallization at a temperature of 120°C.

[0106] Comparative Example 1

[0107] This comparative example provides a method for the resource utilization of FCC waste catalyst. Except for the aluminum-containing leachate obtained in step (1) which is not recycled, the method is the same as that in Example 1.

[0108] Comparative Example 2

[0109] This comparative example provides a method for the resource utilization of FCC waste catalyst. Except for the concentration of sodium hydroxide in step (2) being 180 g / L, the method is the same as that in Example 1.

[0110] Comparative Example 3

[0111] This comparative example provides a method for the resource utilization of FCC waste catalyst. Except for the concentration of sodium hydroxide in step (2) being 40 g / L, the method is the same as that in Example 1.

[0112] Comparative Example 4

[0113] This comparative example provides a method for the resource utilization of FCC waste catalyst. Except for the liquid-to-solid ratio of 10 mL / g in the dilute alkali reconstruction treatment in step (2), the method is the same as that in Example 1.

[0114] Comparative Example 5

[0115] This comparative example provides a method for the resource utilization of FCC waste catalyst. Except for the liquid-to-solid ratio of 1 mL / g in the dilute alkali reconstruction treatment in step (2), the method is the same as that in Example 1.

[0116] The modulus of silicates, the content of alumina in polyaluminum chloride products, and the purity of aluminum sulfate products obtained from the above examples and comparative examples were detected and calculated using ICP-OES. The results are shown in Table 1.

[0117] Table 1

[0118]

[0119]

[0120]

[0121] In Table 1, " / " indicates that there is no data.

[0122] As can be seen from Table 1:

[0123] (1) As can be seen from Examples 1 to 6, the method for resource utilization of FCC waste catalyst provided by the present invention obtains high-modulus silicate with a modulus between 2.5 and 3.5 and polyaluminum chloride with an alumina content of 8% to 15% by sequentially performing dealuminization and impurity removal treatment, dilute alkali reconstruction treatment and polymerization aging treatment on the FCC waste catalyst; As can be seen from Examples 7 to 8, aluminum sulfate with a purity greater than 98% can be obtained by using evaporation crystallization treatment for system regulation treatment;

[0124] (2) It can be seen from the combined example 1 and comparative example 1 that the aluminum-containing leaching solution obtained in step (1) of comparative example 1 is not circulated for leaching, resulting in an excessively low concentration of aluminum ions in the aluminum-rich leaching solution. As a result, polyaluminum chloride products with an alumina content greater than 8% cannot be prepared by polymerization and aging, and the products do not meet the national standard requirements.

[0125] (3) Based on the comprehensive comparison of Example 1 and Comparative Examples 2-3, it can be seen that the sodium hydroxide concentration of the dilute alkali reconstruction treatment in Comparative Example 2 is 180 g / L. The alkali concentration is too high, which on the one hand leads to the inability to stably reconstruct the molecular sieve framework and obtain the modified FCC waste catalyst, and on the other hand leads to the depolymerization of polysilicate, which cannot prepare high modulus silicate. The sodium hydroxide concentration of the dilute alkali reconstruction treatment in Comparative Example 3 is 40 g / L. The alkali concentration is too low, which means that the defective parts of the molecular sieve cannot be reassembled and reconstructed, resulting in a decrease in the performance of the molecular sieve product. At the same time, it will lead to low silicon-oxygen dissociation efficiency and a 50% reduction in the yield of sodium silicate.

[0126] (4) It can be seen from the combined examples 1 and 4-5 that the liquid-solid ratio of the dilute alkali reconstruction treatment in Comparative Example 4 is 10 mL / g. The liquid-solid ratio is too high, which leads to more sodium ions coordinating in the polysilicate, thereby reducing its modulus and making it impossible to prepare high modulus silicates. The liquid-solid ratio of the dilute alkali reconstruction treatment in Comparative Example 5 is 1 mL / g. The liquid-solid ratio is too low, and the system cannot form a slurry, resulting in low mass transfer efficiency of solid-liquid reaction and poor quality of molecular sieve and sodium silicate products.

[0127] In summary, the method for resource utilization of FCC waste catalysts provided by this invention has a simple processing technology with zero emissions. It realizes the modification and regeneration of FCC waste catalysts and the cascade extraction and productization of the contained elements. It can solve the environmental pollution problem caused by FCC waste catalysts, and has significant economic and environmental benefits. It can be extended to the high-value utilization of other aluminum and silicon-based solid wastes.

[0128] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for the resource utilization of spent FCC catalysts, characterized in that, The method includes the following steps: (1) FCC waste catalyst is subjected to dealuminization and impurity removal treatment. After the first solid-liquid separation, the aluminum-containing leachate is returned to the dealuminization and impurity removal treatment for cyclic leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate are obtained. (2) The modified FCC intermediate is subjected to dilute alkali reconstruction treatment, and after solid-liquid separation, the modified FCC catalyst and silicate are obtained; the aluminum-rich leaching solution is subjected to system regulation treatment to obtain aluminum-based products; The liquid-to-solid ratio of the dilute alkali reconstruction treatment in step (2) is 2~8 mL / g; The leaching agent used in the dilute alkali reconstruction treatment in step (2) includes sodium hydroxide solution and / or potassium hydroxide solution; The mass concentration of the leaching agent used in the dilute alkali reconstruction treatment is 50~150g / L; The system conditioning process includes polymerization maturation treatment and / or evaporation crystallization treatment.

2. The method according to claim 1, characterized in that, The leaching agent used in step (1) for the dealuminization and impurity removal process includes any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, or acetic acid.

3. The method according to claim 2, characterized in that, The mass concentration of the leaching agent is 10-30%.

4. The method according to claim 1, characterized in that, The liquid-to-solid ratio of the dealuminization and impurity removal treatment in step (1) is 2~10 mL / g.

5. The method according to claim 1, characterized in that, The temperature for the dealuminization and impurity removal process is 60~100℃.

6. The method according to claim 1, characterized in that, The time for the dealuminization and impurity removal process is 60~240 min.

7. The method according to claim 1, characterized in that, The number of leaching cycles is ≥ 2 times.

8. The method according to claim 1, characterized in that, The temperature for the dilute alkali reconstruction treatment is 60~180℃.

9. The method according to claim 1, characterized in that, The dilute alkali reconstruction treatment time is 60~240 min.

10. The method according to claim 1, characterized in that, The alkalizing agent used in the polymerization and ripening treatment includes any one or a combination of at least two of calcium aluminate, aluminum hydroxide, calcium oxide, or calcium hydroxide.

11. The method according to claim 1, characterized in that, The liquid-to-solid ratio of the polymerization and ripening treatment is 6~12 mL / g.

12. The method according to claim 1, characterized in that, The polymerization and ripening treatment is performed at a temperature of 60~100℃.

13. The method according to claim 1, characterized in that, The polymerization and ripening treatment time is 60~180 min.

14. The method according to claim 1, characterized in that, The temperature for the evaporation crystallization process is 80~150℃.

15. The method according to claim 1, characterized in that, The method includes the following steps: (1) FCC waste catalyst is subjected to dealuminization and impurity removal treatment at a liquid-solid ratio of 2~10mL / g and a temperature of 60~100℃ for 60~240min. After the first solid-liquid separation, the aluminum-containing leachate is returned to the dealuminization and impurity removal treatment for cyclic leaching. After the second solid-liquid separation, modified FCC intermediate and aluminum-rich leachate are obtained. The leaching agent used in the dealuminization and impurity removal treatment includes any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, or acetic acid; the mass concentration of the leaching agent is 10-30%; and the number of cyclic leaching cycles is ≥2 times. (2) The modified FCC intermediate is subjected to dilute alkali reconstruction treatment at a liquid-to-solid ratio of 2~8 mL / g and a temperature of 60~180℃ for 60~240 min. After solid-liquid separation, the modified FCC catalyst and silicate are obtained. The aluminum-rich leaching solution is subjected to system regulation treatment to obtain aluminum-based products. The leaching agent used in the dilute alkali reconstruction treatment includes sodium hydroxide solution and / or potassium hydroxide solution; the mass concentration of the leaching agent in the dilute alkali reconstruction treatment is 50~150 g / L; The system conditioning treatment includes polymerization ripening treatment and / or evaporation crystallization treatment; the alkalizing agent used in the polymerization ripening treatment includes any one or a combination of at least two of calcium aluminate, aluminum hydroxide, calcium oxide, or calcium hydroxide; the liquid-to-solid ratio of the polymerization ripening treatment is 6~12 mL / g; the temperature of the polymerization ripening treatment is 60~100℃; the time of the polymerization ripening treatment is 60~180 min; and the temperature of the evaporation crystallization treatment is 80~150℃.

16. A modified FCC catalyst obtained by the method for resource utilization of FCC waste catalyst as described in any one of claims 1 to 15.

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