Continuous production method and production system for molecular sieve powder

Abstract

The invention relates to the technical field of molecular sieve production, and discloses a molecular sieve powder continuous production method and a molecular sieve powder continuous production system, the method comprises the following steps: (1) a flocculant is added into crystallization slurry for pretreatment to prepare pretreatment slurry, the flocculant is ammonium salt, and the mass ratio of the flocculant to crystallization powder is 0.05-0.1: 1; (2) carrying out exchange reaction on the Na-type molecular sieve, ammonium salt and water to prepare H-type molecular sieve slurry; (3) performing activation reaction on the H-type molecular sieve, metal salt and water to prepare metal ion activated slurry; according to the method, crystallized powder is pretreated by using a flocculating agent, and the pretreated slurry is subjected to solid-liquid separation, so that the problem of penetration of a Na molecular sieve filter cake is avoided, the yield of the molecular sieve is remarkably improved, a system adopting the method can continuously produce a Na type molecular sieve, an H type molecular sieve and a metal activated molecular sieve, and the method is simple in process, low in cost and suitable for industrial production. The production efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular sieve production, and in particular to a molecular sieve powder continuous production method and production system. Background Art

[0002] Molecular sieves have a uniform and special pore structure with a large specific surface area, large pore volume, high hydrothermal stability, and strong acidity, which makes molecular sieves have excellent adsorption, ion exchange and catalytic properties. They are widely used in petrochemical and environmental protection fields.

[0003] There are naturally occurring molecular sieves, but natural molecular sieves have many impurities and different pore sizes, which leads to limitations in their performance. Therefore, artificially synthesized molecular sieves are usually used in actual use. There are many methods for artificially synthesizing molecular sieves, among which hydrothermal crystallization synthesis of molecular sieves is a more commonly used method for synthesizing molecular sieves, such as the hydrothermal synthesis method of a Na-type zeolite molecular sieve disclosed in Publication No. CN107352556B, and the method for preparing Na-A / X or Na-A / X / P co-crystallized molecular sieves by hydrothermal synthesis of lithium slag disclosed in CN103253681B. Because the hydrothermal synthesis system contains alkali, the direct product obtained is generally a Na-type molecular sieve. Na can be exchanged for H-type molecular sieves by ammonium exchange. H-type molecular sieves are widely used as catalyst supports. H-type molecular sieves can be obtained by metal ion exchange to obtain metal-activated molecular sieves, which can be applied to the needs of different fields.

[0004] At present, the domestic demand for the application of various molecular sieve powders is very huge, but the disclosed molecular sieve synthesis processes are mainly single molecular sieve synthesis, and are mainly concentrated in the laboratory synthesis stage. There are few studies on industrialized, large-scale, and continuous molecular sieve synthesis processes and devices. Therefore, the present invention explores the process and device for the continuous production of Na-type molecular sieves, H-type molecular sieves and metal-activated molecular sieves. During actual operation, it was found that Na-type molecular sieves would have filtration problems in the solid-liquid separation stage, resulting in a significant decrease in the yield of Na-type molecular sieves, thereby affecting the subsequent synthesis of H-type molecular sieves and metal-activated molecular sieves, resulting in a decrease in the molecular sieve yield. Summary of the Invention

[0005] The present invention addresses the problem in the prior art of continuous production of Na-type molecular sieves, H-type molecular sieves and metal-activated molecular sieves that Na-type molecular sieves are prone to percolation during the solid-liquid separation stage. A method and system for continuous production of molecular sieve powder are provided. The method pretreats crystallized powder using a flocculant and then performs solid-liquid separation on the pretreated slurry, thereby avoiding the percolation problem of Na molecular sieve filter cakes and significantly improving the yield of molecular sieves.

[0006] The specific technical solutions of the present invention are: A method for continuously producing molecular sieve powder comprises the following steps: (1) adding a flocculant to the crystallized slurry for pretreatment to prepare a pretreated slurry, wherein the flocculant is an ammonium salt, and the mass ratio of the flocculant to the crystallized powder is 0.05 to 0.1:1; (2) exchanging Na-type molecular sieve, ammonium salt and water to prepare H-type molecular sieve slurry; (3) The H-type molecular sieve, metal salt and water are activated to form a metal ion activation slurry.

[0007] Preferably, the mass ratio of Na-type molecular sieve, ammonium salt and water is 1:0.5 to 1:5 to 10; the mass ratio of H-type molecular sieve, metal salt and water is 1:0.1 to 1:20 to 50.

[0008] Preferably, the metal salt is one of acetate and sulfate.

[0009] Preferably, the pretreatment time is 1 to 2 hours, and the pretreatment speed is 80 to 120 rpm.

[0010] Preferably, the temperature of the exchange reaction is 80-90° C., the exchange reaction time is 1-2 h, and the stirring rate of the exchange reaction is 100-150 rpm.

[0011] Preferably, the temperature of the activation reaction is 70-80° C., the time of the activation reaction is 3-4 h, and the stirring rate of the activation reaction is 100-150 rpm.

[0012] Preferably, the pretreated slurry is subjected to solid-liquid separation, washing and calcination to form a Na-type molecular sieve; the demoulding target temperature of the calcination is 600-650°C, the target temperature holding time of the calcination is 4-6h, and the temperature rising gradient of the calcination is 50-100°C.

[0013] Preferably, the H-type molecular sieve slurry is subjected to solid-liquid separation, washing and calcination to form the H-type molecular sieve; the target temperature of the calcination is 500-550°C, the target temperature holding time of the calcination is 3-4h, and the temperature rising gradient of the calcination is 50-100°C.

[0014] Preferably, the metal ion activated slurry is subjected to solid-liquid separation, washing and calcination to form a metal ion activated molecular sieve; the target temperature of calcination is 500-550°C, the target temperature holding time of calcination is 3-4h, and the temperature rising gradient of calcination is 50-100°C.

[0015] The present invention provides a method for continuously producing molecular sieve powder. The method uses a hydrothermal synthesis process to prepare a Na-type molecular sieve, then uses the Na-type molecular sieve, an ammonium salt and water to carry out an exchange reaction to prepare an H-type molecular sieve, and then uses the H-type molecular sieve, a metal salt and water to carry out an activation reaction to prepare a metal-activated molecular sieve. The method can continuously produce Na-type molecular sieve, H-type molecular sieve and metal-activated molecular sieve, and has a simple process and high production efficiency.

[0016] In addition, the present invention found that before the Na-type molecular sieve forms a stable filter cake, the slurry will have a filtration problem when passing through the filter cloth, resulting in crystallized powder (Na-type molecular sieve particles) passing through the filter cloth in the early stage of solid-liquid separation. As a result, some crystallized powder cannot be retained in the early stage of solid-liquid separation, resulting in a decrease in the yield of Na-type molecular sieve. The present invention uses a flocculant to pretreat the slurry of crystallized powder before solid-liquid separation, and an ammonium salt flocculant is used for flocculation. The present invention reduces the exchange efficiency of ammonium ions and Na+ in Na-type molecular sieve by controlling the ratio of ammonium salt to crystallized powder, and strengthens the effect of ammonium ions on the double electric layer compression on the surface of Na-type molecular sieve, so that the crystallized powder can flocculate to form a colloid, so that the crystallized powder can be retained on one side of the filter cloth during filtration, significantly reducing the occurrence of filtration problems and significantly improving the yield of Na-type molecular sieve.

[0017] A production system using the above molecular sieve powder continuous production method comprises a crystallization synthesis section, an ammonium exchange section, a metal ion exchange section, a solid-liquid separation section, a drying and roasting section, and a crushing and packaging section which are connected in sequence.

[0018] Compared with the existing technology, this application has the following technical effects: (1) The method provided by the present invention adopts a continuous production process and system to replace the original manual operation mode, which reduces labor intensity and the number of operators; (2) The production device of the present invention adopts a steam direct contact heating method for heating and heat preservation, which has high heat conversion efficiency, fast heating rate, energy saving and economy; (3) The present invention uses a flocculant to pretreat the crystallization reaction slurry, thereby avoiding the problem of filtration during solid-liquid separation and significantly improving the yield of Na-type molecular sieve; (4) This process can directly perform ammonium exchange treatment on the wet filter cake of Na-type molecular sieve to obtain H-type powder, without the requirement of dry powder that has been dried and roasted. This saves a drying and roasting process, simplifies the process, and is energy-saving and economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the production system of the present invention using the continuous production method of molecular sieve powder.

[0020] In the figure, there are a crystallization synthesis section 1, an ammonium exchange section 2, a metal ion exchange section 3, a solid-liquid separation section 4, a drying and roasting section 5 and a crushing and packaging section 6. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the embodiments.

[0022] Example 1: A molecular sieve powder continuous production system comprises a crystallization synthesis section, an ammonium exchange section, a metal ion exchange section, a solid-liquid separation section, a drying and roasting section, and a crushing and packaging section which are connected in sequence.

[0023] The crystallization synthesis part 1 includes a template total storage tank, a pure water total storage tank, a template metering buffer tank, a template scale, a pure water metering buffer tank, a pure water scale, a crystallization kettle solid material silo, a crystallization reactor, a buffer kettle solid material silo, a buffer storage kettle, a template transport pump, a crystallization kettle template feed pump, a pure water transport pump, a crystallization kettle and buffer kettle water inlet pump, a crystallization slurry transfer pump, a crystallization kettle and buffer kettle discharge pump, a template flow meter, a crystallization kettle and buffer kettle pure water flow meter and a crystallization kettle steam flow meter; the template total storage tank outlet is connected to the template transport pump inlet, the template transport pump outlet is connected to the template metering buffer tank inlet, the template metering buffer tank is placed on the template scale, the template metering buffer tank outlet is connected to the crystallization kettle template feed pump inlet, the crystallization kettle template feed pump outlet is connected to the template flow meter inlet, the template flow meter outlet is connected to the crystallization reactor template access port, the crystallization reactor solid material silo is connected to the template feed pump inlet, the crystallization kettle template feed pump outlet is connected to the template flow meter inlet, the template flow meter outlet is connected to the crystallization reactor template access port, The warehouse outlet is connected to the solid inlet of the crystallization reactor, the pure water main storage tank outlet is connected to the pure water transport pump inlet, the pure water transport pump outlet is connected to the pure water metering buffer tank inlet, the pure water metering buffer tank is placed on the pure water scale, one of the pure water metering buffer tank outlets is connected to the crystallization reactor and buffer reactor water inlet pump inlet, the crystallization reactor and buffer reactor water inlet pump outlet is connected to the crystallization reactor and buffer reactor pure water flow meter inlet, the crystallization reactor and buffer reactor pure water flow meter outlet is divided into two routes and respectively connected to the crystallization reactor pure water inlet and the buffer storage kettle pure water inlet, the buffer kettle solid silo outlet is connected to the buffer storage kettle solid inlet, the crystallization reactor outlet is divided into two routes and respectively connected to the crystallization slurry transfer pump inlet and the crystallization reactor and buffer kettle discharge pump inlet, the crystallization slurry transfer pump outlet is connected to the buffer storage kettle inlet, the buffer storage kettle outlet is connected to the crystallization reactor and buffer kettle discharge pump inlet, the heating steam is measured by the crystallization kettle steam flowmeter and connected to the crystallization reactor steam inlet.

[0024] The ammonium exchange section 2 includes an exchange kettle-solid silo, an exchange reactor, an exchange kettle-water inlet pump, an exchange kettle-discharge pump, an exchange kettle-pure water flowmeter and an exchange kettle-steam flowmeter; the outlet of the exchange kettle-solid silo is connected to the exchange reactor-solid inlet, the outlet of the pure water metering buffer tank is connected to the exchange kettle-water inlet pump inlet, the outlet of the exchange kettle-water inlet pump is connected to the exchange kettle-pure water flowmeter inlet, the outlet of the exchange kettle-pure water flowmeter is connected to the exchange reactor-pure water inlet, the outlet of the exchange reactor is connected to the exchange reactor-discharge pump inlet, and the heating steam is measured by the exchange reactor-steam flowmeter and connected to the exchange reactor-steam inlet.

[0025] The metal ion exchange part 3 includes an exchange kettle 2 solid silo, an exchange reactor 2, an exchange reactor 2 water inlet pump, an exchange reactor 2 discharge pump, an exchange reactor 2 pure water flowmeter and an exchange reactor 2 steam flowmeter; the outlet of the exchange reactor 2 solid silo is connected to the solid inlet of the exchange reactor 2, one of the outlets of the pure water metering buffer tank is connected to the inlet of the exchange reactor 2 water inlet pump, the outlet of the exchange reactor 2 water inlet pump is connected to the inlet of the exchange reactor 2 pure water flowmeter, the outlet of the exchange reactor 2 pure water flowmeter is connected to the pure water inlet of the exchange reactor 2, the outlet of the exchange reactor 2 is connected to the inlet of the exchange reactor 2 discharge pump, and the heating steam is measured by the exchange reactor 2 steam flowmeter and connected to the steam inlet of the exchange reactor 2.

[0026] The solid-liquid separation part 4 includes a pure water metering buffer tank for washing, a washing water scale, a plate and frame filter press, a block wet filter cake collection tank, a washing water inlet pump and a washing water flow meter; the inlet of the pure water metering buffer tank is connected to the outlet of the pure water transport pump, the pure water metering buffer tank is placed on the washing water scale, the outlet of the pure water metering buffer tank is connected to the inlet of the washing water inlet pump, the outlet of the washing water inlet pump is connected to the inlet of the washing water flow meter, the outlet of the washing water flow meter is connected to the washing water inlet of the plate and frame filter press, the slurry inlet of the plate and frame filter press is connected to the crystallization kettle and the buffer kettle discharge pump outlet, the exchange kettle one discharge pump outlet and the exchange kettle two discharge pump outlet, the solid discharge port of the plate and frame filter press is connected to the inlet of the block wet filter cake collection tank, and the liquid outlet of the plate and frame filter press is connected to the waste liquid treatment system.

[0027] The drying and roasting section 5 includes a roller kiln, a block product collection tank, and an exhaust gas fan; the material in the block wet filter cake collection tank is transferred to the roller kiln inlet, and the material at the roller kiln outlet is transferred to the block product collection tank. The roller kiln exhaust gas discharge port is connected to the exhaust gas fan inlet, and the exhaust gas fan outlet is connected to the exhaust gas treatment system.

[0028] The crushing and packaging section 6 includes a crusher and a powdered product collecting tank; the material in the block product collecting tank is transferred to the crusher inlet, and the crusher outlet is connected to the powdered product collecting tank.

[0029] Example 2: A method for continuously producing molecular sieve powder comprises the following steps: (1) The pure water transported from the pipeline outside the boundary area enters the pure water main storage tank, and the pure water in the pure water main storage tank is transported to the pure water metering buffer tank through the pure water transport pump. The pure water in the pure water metering buffer tank is transported to the crystallization reactor through the crystallization kettle and the buffer kettle water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the crystallization kettle and the buffer kettle pure water flow meter. The template agent in the plate agent main storage tank is transported to the template agent metering buffer tank through the template agent transport pump. The template agent in the template agent metering buffer tank is transported to the crystallization reactor through the crystallization kettle template agent feed pump. In the kettle, the amount of template agent added is precisely controlled by the template agent scale and template agent flowmeter. The solid raw materials for the crystallization reaction are stored in the solid material bin of the crystallization kettle in advance and added to the crystallization reactor according to the synthetic feed ratio. They are fully stirred, mixed and aged. The reactor is closed and steam is introduced into the kettle for heating. The amount of steam is measured and controlled by the steam flowmeter of the crystallization kettle. The crystallization stirring rate in the crystallization reactor is 100 rpm, the crystallization temperature is 140 ° C, and the crystallization time is 100 h. After the crystallization is completed, the slurry is cooled to 85 ° C, the bottom of the kettle is discharged, and the steam is passed through the steam flowmeter. The over-crystallized slurry is transferred to the buffer storage kettle by a transfer pump, and the flocculant (ammonium sulfate) is added to the kettle from the solid material bin of the buffer kettle. The mass ratio of the crystallized slurry and the ammonium salt is 1:0.07; the pretreatment stirring rate in the buffer storage kettle is 100 rpm, and the pretreatment time is 1.5 h. After the pretreatment is completed, the material is discharged from the bottom of the kettle to obtain the Na-type molecular sieve synthesis slurry; the Na-type molecular sieve synthesis slurry is transported to a plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor, and the mother liquor is transported to the waste liquid treatment outside the boundary area through a pipeline. The system is equipped with a filtration system. After the mother liquor is completely separated, pure water is introduced to wash the filter cake. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The amount of washing water is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, the pressure is adjusted to further squeeze the solid-liquid separation, the wet filter cake is unloaded, and placed in the block wet filter cake collection tank to obtain the Na-type molecular sieve wet filter cake.

[0030] (2) The pure water in the pure water metering buffer tank is transported to the exchange reactor one through the exchange reactor one water inlet pump. The pure water feeding amount is accurately controlled by the pure water scale and the exchange reactor one pure water flowmeter. The ammonium salt (ammonium sulfate) and the Na type molecular sieve wet cake to be exchanged are added to the exchange reactor one according to the synthetic feeding ratio and fully stirred and mixed. Then steam is introduced into the reactor for heating. The steam amount is metered and controlled by the exchange reactor one steam flowmeter. The feeding mass ratio of the Na type molecular sieve wet cake, the ammonium salt and the pure water is 1:1:10. The stirring rate is 125 rpm, the exchange reaction temperature is 85 ° C., the exchange reaction time is 2 h, and the H type molecular sieve slurry obtained after the exchange reaction is discharged from the bottom of the exchange reactor one; The H-type molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The washing water consumption is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the H-type molecular sieve wet filter cake.

[0031] (3) The pure water in the pure water metering buffer tank is transported to the exchange reactor 2 through the exchange reactor 2 water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the exchange reactor 2 pure water flow meter. The metal salt (copper acetate) and the H-type molecular sieve powder to be exchanged are stored in the exchange reactor 2 solid material bin in advance. They are added to the exchange reactor 2 according to the synthetic feed ratio, fully stirred and mixed, and then steam is introduced into the reactor for heating. The steam volume is measured and controlled by the exchange reactor 2 steam flow meter. The mass ratio of H-type molecular sieve powder, metal salt and pure water is 1:0.5:35, the stirring rate is 125 rpm, the activation reaction temperature is 75 ° C, the activation reaction time is 3.5 h, and the metal activated molecular sieve slurry obtained after the activation reaction is self-exchanged. The material is discharged from the bottom of the second kettle; the metal activated molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake thoroughly. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The washing water consumption is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the metal activated molecular sieve wet filter cake.

[0032] (4) The Na-type molecular sieve wet filter cake obtained in step (1) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 625°C, the target temperature holding time is 5h, and the temperature rising gradient is 80°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the Na-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The Na-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain Na-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0033] (5) The H-type molecular sieve wet filter cake prepared in step (2) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 525°C, the target temperature holding time is 3.5h, and the temperature rising gradient is 80°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the H-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The H-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain H-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0034] (6) The metal activated molecular sieve wet filter cake obtained in step (3) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 525°C, the target temperature holding time is 3.5h, and the temperature rising gradient is 80°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. The metal activated molecular sieve block product after drying and roasting is discharged from the roller kiln outlet and transferred to the block product collection tank. The metal activated block molecular sieve block product in the block product collection tank is transferred to a crusher for crushing to obtain metal activated molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collection tank for packaging and storage as required.

[0035] Example 3: A method for continuously producing molecular sieve powder comprises the following steps: (1) The pure water transported from the pipeline outside the boundary area enters the pure water main storage tank, and the pure water in the pure water main storage tank is transported to the pure water metering buffer tank through the pure water transport pump. The pure water in the pure water metering buffer tank is transported to the crystallization reactor through the crystallization kettle and the buffer kettle water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the crystallization kettle and the buffer kettle pure water flow meter. The template agent in the plate agent main storage tank is transported to the template agent metering buffer tank through the template agent transport pump. The template agent in the template agent metering buffer tank is transported to the crystallization reactor through the crystallization kettle template agent feed pump. In the reaction kettle, the amount of template agent added is precisely controlled by the template agent scale and template agent flowmeter. The solid raw materials for the crystallization reaction are stored in the solid material bin of the crystallization kettle in advance and added to the crystallization reactor according to the synthetic feed ratio. They are fully stirred, mixed and aged. The reactor is closed and steam is introduced into the reactor for heating. The amount of steam is measured and controlled by the steam flowmeter of the crystallization reactor. The crystallization stirring rate in the crystallization reactor is 120rpm, the crystallization temperature is 160℃, and the crystallization time is 120h. After the crystallization is completed, the slurry is cooled to 90℃ and the bottom of the kettle is discharged. The crystallization slurry is transferred to the buffer storage kettle through a crystallization slurry transfer pump, and the flocculant (ammonium chloride) is added to the kettle from the solid material bin of the buffer kettle. The mass ratio of the crystallization slurry and the ammonium salt is 1:0.1; the pretreatment stirring rate in the buffer storage kettle is 120 rpm, and the pretreatment time is 2 hours. After the pretreatment is completed, the material is discharged from the bottom of the kettle to obtain the Na-type molecular sieve synthesis slurry; the Na-type molecular sieve synthesis slurry is transferred to a plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. The system is used. After the mother liquor is completely separated, pure water is introduced to wash the filter cake. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The amount of washing water is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, the pressure is adjusted to further squeeze the solid-liquid separation, the wet filter cake is unloaded, and placed in the block wet filter cake collection tank to obtain the Na-type molecular sieve wet filter cake.

[0036] (2) The pure water in the pure water metering buffer tank is transported to the exchange reactor one through the exchange reactor one water inlet pump. The pure water feeding amount is accurately controlled by the pure water scale and the exchange reactor one pure water flowmeter. The ammonium salt (ammonium chloride) and the Na type molecular sieve wet cake to be exchanged are added to the exchange reactor one according to the synthetic feeding ratio and fully stirred and mixed. Then, steam is introduced into the reactor for heating. The steam amount is metered and controlled by the exchange reactor one steam flowmeter. The feeding mass ratio of the Na type molecular sieve wet cake, the ammonium salt and the pure water is 1:1:10. The stirring rate is 150 rpm, the exchange reaction temperature is 90 ° C., and the exchange reaction time is 2 h. After the exchange reaction is completed, the H type molecular sieve slurry obtained is discharged from the bottom of the exchange reactor one. The H-type molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The washing water consumption is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the H-type molecular sieve wet filter cake.

[0037] (3) The pure water in the pure water metering buffer tank is transported to the exchange reactor 2 through the exchange reactor 2 water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the exchange reactor 2 pure water flow meter. The metal salt (copper sulfate) and the H-type molecular sieve powder to be exchanged are stored in the exchange reactor 2 solid material bin in advance. They are added to the exchange reactor 2 according to the synthetic feed ratio, fully stirred and mixed, and then steam is introduced into the reactor for heating. The steam volume is measured and controlled by the exchange reactor 2 steam flow meter. The mass ratio of H-type molecular sieve powder, metal salt and pure water is 1:1:50, the stirring rate is 150 rpm, the activation reaction temperature is 80 ° C, the activation reaction time is 4 h, and the metal activated molecular sieve slurry obtained after the activation reaction is removed from the exchange reactor 2. The bottom of the kettle is discharged; the metal activated molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake fully. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The washing water consumption is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the metal activated molecular sieve wet filter cake.

[0038] (4) The Na-type molecular sieve wet filter cake obtained in step (1) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 650°C, the target temperature holding time is 6h, and the temperature rising gradient is 100°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the Na-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The Na-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain Na-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0039] (5) The H-type molecular sieve wet filter cake obtained in step (2) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 550°C, the target temperature holding time is 4h, and the temperature rising gradient is 100°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the H-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The H-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain H-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0040] (6) The metal activated molecular sieve wet filter cake obtained in step (3) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 550°C, the target temperature holding time is 4h, and the temperature rising gradient is 100°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. The metal activated molecular sieve block product after drying and roasting is discharged from the roller kiln outlet and transferred to the block product collection tank. The metal activated block molecular sieve block product in the block product collection tank is transferred to a crusher for crushing to obtain metal activated molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collection tank for packaging and storage as required.

[0041] Example 4: A method for continuously producing molecular sieve powder comprises the following steps: (1) The pure water transported from the pipeline outside the boundary area enters the pure water main storage tank, and the pure water in the pure water main storage tank is transported to the pure water metering buffer tank through the pure water transport pump. The pure water in the pure water metering buffer tank is transported to the crystallization reactor through the crystallization kettle and the buffer kettle water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the crystallization kettle and the buffer kettle pure water flow meter. The template agent in the plate agent main storage tank is transported to the template agent metering buffer tank through the template agent transport pump, and the template agent in the template agent metering buffer tank is transported to the crystallization reactor through the crystallization kettle template agent feed pump. In the reactor, the amount of template agent added is precisely controlled by the template agent scale and template agent flowmeter. The solid raw materials for the crystallization reaction are stored in the solid material bin of the crystallization reactor in advance and added to the crystallization reactor according to the synthetic feed ratio. They are fully stirred, mixed and aged. The reactor is closed and steam is introduced into the reactor for heating. The amount of steam is measured and controlled by the steam flowmeter of the crystallization reactor. The crystallization stirring rate in the crystallization reactor is 80 rpm, the crystallization temperature is 120 ° C, and the crystallization time is 72 h. After the crystallization is completed, the slurry is cooled to 80 ° C and the bottom of the reactor is discharged. The crystallization slurry is transferred to the buffer storage kettle through a crystallization slurry transfer pump, and the flocculant (ammonium chloride) is added to the kettle from the buffer kettle solid material silo. The mass ratio of the crystallization slurry and the ammonium salt is 1:0.1. The pretreatment stirring rate in the buffer storage kettle is 80 rpm, and the pretreatment time is 1 hour. After the pretreatment is completed, the material is discharged from the bottom of the kettle to obtain the Na-type molecular sieve synthesis slurry; the Na-type molecular sieve synthesis slurry is transferred to a plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to fully wash the filter cake. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The amount of washing water is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, the pressure is adjusted to further squeeze the solid-liquid separation, the wet filter cake is unloaded, and placed in the block wet filter cake collection tank to obtain the Na-type molecular sieve wet filter cake.

[0042] (2) The pure water in the pure water metering buffer tank is transported to the exchange reactor one through the exchange reactor one water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the exchange reactor one pure water flow meter. The ammonium salt (ammonium chloride) and the Na type molecular sieve wet filter cake to be exchanged are added to the exchange reactor one according to the synthetic feed ratio and fully stirred and mixed. Then steam is introduced into the reactor for heating. The steam amount is measured and controlled by the exchange reactor one steam flow meter. The feed mass ratio of the Na type molecular sieve wet filter cake, ammonium salt and pure water is 1:0.5:5, the stirring rate is 100 rpm, the exchange reaction temperature is 80 ° C, the exchange reaction time is 1 h, and the H type molecular sieve slurry obtained after the exchange reaction is discharged from the bottom of the exchange reactor one. The H-type molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake thoroughly. The pure water comes from the pure water metering buffer tank. The pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The washing water consumption is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the H-type molecular sieve wet filter cake.

[0043] (3) The pure water in the pure water metering buffer tank is transported to the exchange reactor 2 through the exchange reactor 2 water inlet pump. The pure water feed amount is accurately controlled by the pure water scale and the exchange reactor 2 pure water flow meter. The metal salt (copper sulfate) and the H-type molecular sieve powder to be exchanged are stored in the exchange reactor 2 solid material bin in advance. They are added to the exchange reactor 2 according to the synthetic feed ratio, fully stirred and mixed, and then steam is introduced into the reactor for heating. The steam volume is measured and controlled by the exchange reactor 2 steam flow meter. The mass ratio of H-type molecular sieve powder, metal salt and pure water is 1:0.1:20, the stirring rate is 100 rpm, the activation reaction temperature is 70 ° C, the activation reaction time is 3 h, and the metal activated molecular sieve slurry obtained after the activation reaction is removed from the exchange reactor The second step is to discharge the material from the bottom of the kettle; the metal activated molecular sieve slurry is transported to the plate and frame filter press, and the pressure is adjusted to squeeze and separate the mother liquor. The mother liquor is transported to the waste liquid treatment system outside the boundary area through a pipeline. After the mother liquor is completely separated, pure water is introduced to wash the filter cake. The pure water comes from the pure water metering buffer tank, and the pure water in the pure water metering buffer tank comes from the pure water main storage tank. The pure water in the pure water metering buffer tank is transported to the plate and frame filter press through the washing water inlet pump. The amount of washing water is accurately controlled by the washing water scale and the washing water flow meter. When the pH value of the effluent filtrate is neutral, the washing is completed, and the pressure is adjusted to further squeeze the solid-liquid separation. The wet filter cake is unloaded and placed in the block wet filter cake collection tank to obtain the metal activated molecular sieve wet filter cake.

[0044] (4) The Na-type molecular sieve wet filter cake obtained in step (1) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 600°C, the target temperature holding time is 4h, and the temperature rising gradient is 50°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the Na-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The Na-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain Na-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0045] (5) The H-type molecular sieve wet filter cake obtained in step (2) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 500°C, the target temperature holding time is 3h, and the temperature rising gradient is 50°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. After the drying and roasting, the H-type molecular sieve block product is discharged from the roller kiln outlet and transferred to the block product collecting tank. The H-type molecular sieve block product in the block product collecting tank is transferred to a crusher for crushing to obtain H-type molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collecting tank for packaging and storage as required.

[0046] (6) The metal activated molecular sieve wet filter cake obtained in step (3) is placed in batches into a ceramic crucible, and the ceramic crucible is placed on a roller kiln. The roller kiln is set with different temperature intervals to implement gradient heating and heat preservation. The roasting time of the filter cake is controlled by the roller speed, and the processing temperature of the filter cake is controlled by the interval temperature. The roasting demoulding target temperature is 500°C, the target temperature holding time is 3h, and the temperature rising gradient is 50°C. The waste gas generated during the drying and roasting process is transported to the waste gas treatment system outside the boundary area through the waste gas blower. The metal activated molecular sieve block product after drying and roasting is discharged from the roller kiln outlet and transferred to the block product collection tank. The metal activated block molecular sieve block product in the block product collection tank is transferred to a crusher for crushing to obtain metal activated molecular sieve powder (greater than 500 mesh, 90% powder), which is transferred to the powder product collection tank for packaging and storage as required.

[0047] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that no flocculant is added in step (1), and the other conditions are the same as those in Example 2.

[0048] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the mass ratio of the crystallization slurry to the flocculant in step (1) is 1:0.01, and the other conditions are the same as those in Example 2.

[0049] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the mass ratio of the crystallization slurry to the flocculant in step (2) is 1:0.2, and the other conditions are the same as those in Example 2.

[0050] Test example The yield of the Na-type molecular sieve filter cake obtained by filtration in Examples 2 to 3 and Comparative Examples 1 to 2 and the quality of the Na-type molecular sieve in the filtrate were tested; Na molecular sieve filter cake yield = Na molecular sieve filter cake mass / (Na molecular sieve filter cake mass + Na molecular sieve mass in filtrate) * 100% The quality test method of the Na-type molecular sieve filter cake comprises: drying the obtained Na-type molecular sieve wet filter cake, and measuring the quality of the dried Na-type molecular sieve wet filter cake; The quality test method of Na molecular sieve in the filtrate includes: using a centrifuge to perform preliminary solid-liquid separation on the filtrate, collecting the solid and then washing the solid with pure water until it is neutral, and then drying and weighing the solid to obtain the quality of Na molecular sieve in the filtrate; the statistical results are shown in Table 1.

[0051] Table 1 Statistical results Na type molecular sieve filter cake yield (%) Na type molecular sieve filter cake mass (kg) Mass of Na molecular sieve in filtrate (kg) Example 2 99.1 543.5 4.9 Example 3 99.4 547.2 3.2 Example 4 99.5 546.4 2.9 Comparative Example 1 92.8 508.7 39.3 Comparative Example 2 94.9 521.1 28.0 As shown in Table 1, the yield of the Na-type molecular sieve filter cake prepared in Examples 2 to 4 can reach more than 99%, which can basically avoid the problem of filtration and significantly improve the yield of the Na-type molecular sieve.

[0052] No flocculant was added in Comparative Example 1. The mass of Na-type molecular sieve in the filtrate in Comparative Example 1 reached 39.3 kg, and the yield of Na-type molecular sieve filter cake was only 92.8%. Compared with Example 2, the mass of Na-type molecular sieve filtered in Comparative Example 1 was significantly improved, but there was a large filtration problem. The yield of Na-type molecular sieve filter cake in Comparative Example 1 was significantly lower than that in Example 2.

[0053] In Comparative Examples 2 and 3, the ratio of ammonium salt flocculant and crystallization slurry was investigated. The results showed that the added content of ammonium salt flocculant has an important influence on the crystallization slurry. If the added content of flocculant is too low, the problem of Na-type molecular sieve filtration cannot be effectively solved. If the added content of flocculant is too high, the slurry will mainly agglomerate, and it will be impossible to stir and block the pipeline, making subsequent treatment impossible. Therefore, it is necessary to control the usage ratio of the flocculant.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for continuous production of molecular sieve powder, characterized in that: The following steps are involved: (1) adding a flocculant to the crystallized slurry for pretreatment to prepare a pretreated slurry, wherein the flocculant is an ammonium salt, and the mass ratio of the flocculant to the crystallized powder is 0.05-0.1:1; (2) Exchanging Na-type molecular sieve, ammonium salt and water to prepare H-type molecular sieve slurry; (3) The H-type molecular sieve, metal salt and water are activated to form a metal ion activation slurry.

2. method according to claim 1, is characterized in that, Na The mass ratio of type molecular sieve, ammonium salt and water is 1:0.5~1:5~10;.

3. The method according to claim 1, wherein: The mass ratio of H-type molecular sieve, metal salt and water is 1:0.1~1:20~50.

4. The method according to claim 1 or 3, wherein: The metal salt is one of acetate and sulfate.

5. The method according to claim 1, wherein: The pretreatment conditions include: time 1~2 h.

6. The method according to claim 1 or 5, wherein: The pretreatment conditions also include: a rotation speed of 80~120 rpm.

7. The method according to claim 1, wherein: The activation reaction temperature is 70~80 ℃, the activation reaction time is 3~4 h, and the activation reaction stirring rate is 100~150 rpm.

8. The method according to claim 1, wherein: The exchange reaction temperature is 80~90 ℃, the exchange reaction time is 1~2 h, and the exchange reaction stirring rate is 100~150 rpm.

9. The method according to claim 1, wherein: The pretreated slurry is subjected to solid-liquid separation, washing, and calcination to produce a Na-type molecular sieve. The target demoulding temperature for calcination is 600-650°C, the target temperature is maintained for 4-6 hours, and the temperature gradient is 50-100°C. The H-type molecular sieve slurry is subjected to solid-liquid separation, washing and calcination to produce the H-type molecular sieve; the target temperature for calcination is 500-550°C, the target temperature is maintained for 3-4 hours, and the temperature gradient for calcination is 50-100°C; The metal ion activated slurry is subjected to solid-liquid separation, washing and calcination to prepare a metal ion activated molecular sieve; the target temperature of the calcination is 500-550°C, the target temperature holding time of the calcination is 3-4 h, and the temperature rising gradient of the calcination is 50-100°C.

10. A production system using the molecular sieve powder continuous production method according to any one of claims 1 to 9, characterized in that: The invention comprises a crystallization synthesis part, an ammonium exchange part, a metal ion exchange part, a solid-liquid separation part, a drying and roasting part and a crushing and packaging part which are connected in sequence.

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