Cold cloud catalyst with high silver iodide content and preparation method thereof

Abstract

The invention relates to a cold cloud catalyst with high silver iodide content and a preparation method thereof, and belongs to the technical field of figure operation. The catalyst is prepared from the following raw material components in percentage by mass: 12%-50% of silver iodide, 35%-70% of an oxidizing agent, 5%-20% of potassium iodide, 1%-5% of an additive and 1%-10% of a binder. In the catalyst, the content of the effective component silver iodide is high, the catalyst utilization rate is high, the combustion reaction is stable, the product stability is good, and no caking and few residues are generated during combustion; and powder can be prepared according to a sowing mode, and press-fitting or heating curing molding can be performed.

Description

Technical Field

[0001] The invention relates to a cold cloud catalyst with high silver iodide content and a preparation method thereof, belonging to the technical field of human shadow operation. Background Art

[0002] The commonly used ice-forming catalyst in cold cloud precipitation enhancement is silver iodide (AgI) catalyst. Under the existing technical conditions, the concentration of artificial crystal nuclei introduced into cold clouds is one of the main factors affecting the efficiency of artificial precipitation enhancement. For artificial precipitation enhancement and hail prevention, the catalyst needs to reach the operation area in a short time, and the effective ingredient ice nuclei in the catalyst need to make full use of supercooled water in a short time. This requires that the more silver iodide or silver iodide composite particles in the catalyst used, the better the effect of artificial weather modification.

[0003] In 2019, the amount of AgI used in artificial rainfall operations by aircraft alone reached 1,620 kg in my country. Among the existing silver iodide-related catalysts used for artificial weather modification, the spreading method adopts a combustion-type catalyst, which is cast or pressed into a solid powder column or a medicine block, and then assembled into a flame strip or a rocket for burning and spreading the catalyst. The content of silver iodide is usually 1% to 10%. For example, Chinese patent CN1026230C discloses a silver iodide flame agent with a high nucleation rate, in which the silver iodide content is 1% to 5%; Chinese patent application CN106234094A discloses an artificial rainfall agent and a preparation method thereof, in which the silver iodide content is 1% to 9%; Chinese patent application CN105613155A discloses an artificial weather modification catalytic bomb, in which the mass fraction of salt A is 5% to 20%, and contains a mixture of two or three of silver iodide, potassium iodide or α-Fe2O3 in any proportion.

[0004] The existing cold cloud catalysts have the defects of complex catalyst manufacturing process, low content of effective ingredients, heavy spreading device and large product mass and volume, which need to be solved urgently. Summary of the invention

[0005] In order to overcome the defects of existing catalysts such as complex manufacturing process, low content of effective ingredients, heavy spreading device and large product mass and volume, the purpose of the present invention is to provide a cold cloud catalyst with high silver iodide content and a preparation method thereof; the catalyst has the characteristics of good stability, high content of effective ingredients, simple preparation and long effective period.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A cold cloud catalyst with high silver iodide content, taking the total mass of the catalyst raw material as 100%, wherein the components and their mass fractions are as follows:

[0008]

[0009] Furthermore, preferably, the total mass of the catalyst raw material is taken as 100%, wherein the various components and their mass fractions are as follows:

[0010]

[0011] Silver iodide is in the form of powder with a particle size of 1 μm to 50 μm.

[0012] The oxidant is a powder, and preferably the oxidant is at least one of potassium perchlorate, ammonium perchlorate and potassium nitrate; further, preferably the particle size of the oxidant is 40 μm to 100 μm.

[0013] Potassium iodide is in the form of powder, and preferably has a particle size of 1 μm to 100 μm.

[0014] The additive is a powder, and preferably the additive is at least one of organic copper salt, graphene, polyacrylamide and cuprous iodide; further, the particle size of the additive is preferably 1 μm to 100 μm.

[0015] The binder is a powder, and preferably the binder is at least one of polyvinyl alcohol, polymethyl methacrylate, polyvinyl chloride, phenolic resin and maleic anhydride grafted ethylene propylene diene monomer (EPDM-g-MAH) rubber; further, the particle size of the binder is preferably 1 μm to 100 μm.

[0016] A method for preparing a cold cloud catalyst with a high silver iodide content according to the present invention, the method comprises the following steps:

[0017] Silver iodide, an oxidant and an additive are sieved and mixed uniformly to obtain a mixture; potassium iodide and a binder are added to the mixture, sieved, dried, sieved, and mixed uniformly to obtain a granular product, which is a cold cloud catalyst with a high silver iodide content and is stored in a sealed manner away from light.

[0018] Specifically, the method steps are as follows:

[0019] (1) The silver iodide, potassium iodide and binder are crushed or ground respectively, transferred to a vacuum oven at 70°C to 100°C for drying for 10 h to 48 h, and then passed through a 200-mesh copper sieve, and the residue on the 200-mesh copper sieve is taken.

[0020] (2) According to the proportion of each component, silver iodide, oxidant and additive are stirred and pre-mixed through a 40-60 mesh sieve, and then passed through a 100-mesh copper sieve. The residue on the 100-mesh copper sieve is taken to obtain a uniformly mixed mixture.

[0021] (3) adding potassium iodide and a binder to the mixture obtained in step (2), then passing through a 60-mesh copper sieve, taking the sieve residue of the 60-mesh copper sieve, transferring to a vacuum oven at 50° C. to 70° C. for drying for 10 h to 48 h, then passing through a 20-mesh to 200-mesh copper sieve, taking the sieve residue of the copper sieve, and obtaining a uniformly mixed granular product, i.e., a high silver iodide content cold cloud catalyst according to the present invention. The catalyst can be made into powder, pressed or heated and cured according to the sowing method; the catalyst needs to be stored in a sealed manner away from light.

[0022] Beneficial Effects

[0023] (1) The present invention provides a cold cloud catalyst with a high silver iodide content, wherein the catalyst has a high content of silver iodide as an effective ingredient, a high catalyst utilization rate, a stable combustion reaction, good product stability, and a small amount of caking residue during combustion.

[0024] (2) The present invention provides a cold cloud catalyst with a high silver iodide content, wherein the particle size of the effective ingredient silver iodide in the catalyst is 1 μm to 50 μm, the particle size is small and the surface area is large, and the temperature at which silver iodide sublimates can be reached more quickly when in contact with combustible ingredients such as oxidants, and the catalyst is more evenly dispersed after combustion; potassium iodide can act synergistically with silver iodide; the additive can increase the flammability of the catalyst, so that the catalyst burns fully and the effective ingredients such as silver iodide are dispersed over a large range; the binder can make the catalyst have good fluidity, and the catalyst can be made into powder, pressed or heated and cured according to the spreading method.

[0025] (3) The present invention provides a method for preparing a cold cloud catalyst with a high silver iodide content. The method is simple and easy to operate, does not require complex production equipment, and the preparation process does not require high-temperature pressure increase or decrease equipment. The operation is safe and reliable, and industrial production can be realized.

[0026] (4) The present invention provides a method for preparing a cold cloud catalyst with a high silver iodide content. The catalyst yield obtained by the method is 99% to 99.99%, and the catalyst particles have uniform particle size, good fluidity and press-fitting formability.

[0027] (5) The present invention provides a method for preparing a cold cloud catalyst with a high silver iodide content. When the catalyst is in a granular solid state, compared with a block catalyst, the catalyst has a faster burning rate when spread and burned, and the spreading amount can be controlled according to the spreading device, so that the operating conditions can be quickly utilized to achieve the effect of artificially influencing the weather. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with specific embodiments, but is not intended to limit the present invention.

[0029] In the following embodiments:

[0030] The particle size of the oxidant is 40 μm to 100 μm;

[0031] The particle size of the additive is 1 μm to 100 μm.

[0032] Example 1

[0033] A cold cloud catalyst with high silver iodide content. Taking the total mass of the catalyst raw material as 100%, the components and their mass fractions in the catalyst are as follows: 50% silver iodide, 40% ammonium perchlorate, 5% potassium iodide, 1% copper adipate and 4% phenolic resin; the purity of the phenolic resin is 98% and the molecular weight is 100-1000.

[0034] A method for preparing a cold cloud catalyst with a high silver iodide content as described in this embodiment, the method steps are as follows:

[0035] (1) Silver iodide, potassium iodide and phenolic resin are respectively subjected to air flow pulverization. Silver iodide powder is pulverized to an average particle size of 1 μm, and potassium iodide and phenolic resin are pulverized to an average particle size of 50 μm. The pulverized particles are transferred to a vacuum oven at 95° C. and dried for 12 h. The pulverized particles are then passed through a 200-mesh copper sieve and the residue on the 200-mesh copper sieve is taken.

[0036] (2) Weigh 50 g of silver iodide, 40 g of ammonium perchlorate and 1 g of copper adipate, stir and premix them through a 60-mesh sieve, then pass them through a 100-mesh copper sieve, and take the residue on the 100-mesh copper sieve to obtain a uniform mixture.

[0037] (3) Add 5 g of potassium iodide and 4 g of phenolic resin to the mixture obtained in step (2), then pass through a 60-mesh copper sieve, take the sieve residue of the 60-mesh copper sieve, transfer to a vacuum oven at 60° C. for drying for 12 h, then pass through a 100-mesh copper sieve, take the sieve residue of the copper sieve, and obtain 99.2 g of a uniformly mixed granular product, i.e., a cold cloud catalyst with a high silver iodide content. The catalyst needs to be stored in a sealed manner away from light.

[0038] The high silver iodide content cold cloud catalyst prepared in this example was tested as follows:

[0039] (1) The catalyst was pressed into a 1.03 g catalyst block according to QX / T360-2016 "Static Test Specification for Silver Iodide Weather Modification Catalysts", and the nucleation rate was measured to be 6.8×10 13 / g, in line with national standards;

[0040] (2) The Mach number of a 20 kg turbojet engine is 1.5 to 2. 1 g of the catalyst is sprayed onto the nozzle of the turbojet engine with a diameter of 40 mm. A passive cavity aerosol detector (PCASP) is used in an open space to detect a particle concentration of 5246 particles / cm2 at a distance of 5 meters from the nozzle of the turbojet engine. 3 Increased to 32785 / cm 3 .

[0041] Example 2

[0042] A cold cloud catalyst with high silver iodide content. Taking the total mass of the catalyst raw material as 100%, the various components in the catalyst and their mass fractions are as follows: 12% silver iodide, 65% potassium nitrate, 15% potassium iodide, 3% polyacrylamide, and 5% polyvinyl alcohol; the purity of the polyacrylamide is 98%, and the molecular weight is 2 million to 4 million; the purity of the polyvinyl alcohol is 99%, and the molecular weight is 70,000 to 80,000.

[0043] A method for preparing a cold cloud catalyst with a high silver iodide content as described in this embodiment, the method steps are as follows:

[0044] (1) Silver iodide, potassium iodide and polyvinyl alcohol are respectively ball-milled to grind silver iodide powder to an average particle size of 5 μm, potassium iodide and polyvinyl alcohol to an average particle size of 100 μm, and then transferred to a vacuum oven at 80° C. for drying for 15 h, and then passed through a 200-mesh copper sieve, and the sieve residue of the 200-mesh copper sieve is taken.

[0045] (2) Weigh 12 g of silver iodide, 65 g of potassium nitrate and 3 g of polyacrylamide, stir and pre-mix them through a 40-mesh sieve, then pass them through a 100-mesh copper sieve, and take the residue on the 100-mesh copper sieve to obtain a uniform mixture.

[0046] (3) Add 15 g of potassium iodide and 5 g of polyvinyl alcohol to the mixture obtained in step (2), then pass through a 60-mesh copper sieve, take the sieve residue of the 60-mesh copper sieve, transfer to a vacuum oven at 70° C. and dry for 10 h, then pass through an 80-mesh copper sieve, take the sieve residue of the copper sieve, and obtain 99.6 g of a uniformly mixed granular product, i.e., a cold cloud catalyst with a high silver iodide content. The catalyst needs to be stored in a sealed container away from light.

[0047] The high silver iodide content cold cloud catalyst prepared in this example was tested as follows:

[0048] (1) The catalyst was pressed into a 1.08 g catalyst block according to QX / T360-2016 "Static Test Specification for Silver Iodide Weather Modification Catalysts", and the nucleation rate was measured to be 1.3×10 13 / g, in line with national standards;

[0049] (2) The Mach number of a 20kg turbojet engine is 1.5 to 2. 1g of the catalyst is sprayed onto the nozzle of the turbojet engine with a diameter of 40mm. A passive cavity aerosol detector (PCASP) is used in an open space to detect a particle concentration of 1558 particles / cm2 at a distance of 5 meters from the nozzle of the turbojet engine. 3 Increased to 52024 / cm 3 .

[0050] Example 3

[0051] A cold cloud catalyst with high silver iodide content. Taking the total mass of the catalyst raw material as 100%, the components and their mass fractions in the catalyst are as follows: 30% silver iodide, 50% potassium perchlorate, 10% potassium iodide, 5% cuprous iodide, and 5% maleic anhydride grafted ethylene propylene rubber; the purity of the maleic anhydride grafted ethylene propylene rubber is 99.5%, and the grafting rate is 0.6.

[0052] A method for preparing a cold cloud catalyst with a high silver iodide content as described in this embodiment, the method steps are as follows:

[0053] (1) Silver iodide, potassium iodide and maleic anhydride grafted EPDM rubber were respectively subjected to air flow milling. Silver iodide powder was crushed to an average particle size of 50 μm, and potassium iodide and maleic anhydride grafted EPDM rubber were crushed to an average particle size of 80 μm. The particles were transferred to a vacuum oven at 90° C. and dried for 15 h. The particles were then passed through a 200-mesh copper sieve and the residue on the 200-mesh copper sieve was taken.

[0054] (2) Weigh 30 g of silver iodide, 50 g of potassium perchlorate and 5 g of cuprous iodide, stir and premix them through a 60-mesh sieve, then pass them through a 100-mesh copper sieve, and take the residue on the 100-mesh copper sieve to obtain a uniform mixture.

[0055] (3) Add 10 g of potassium iodide and 5 g of maleic anhydride-grafted EPDM rubber to the mixture obtained in step (2), then pass through a 60-mesh copper sieve, take the sieve residue of the 60-mesh copper sieve, transfer to a vacuum oven at 60° C. for drying for 12 h, then pass through an 80-mesh copper sieve, take the sieve residue of the copper sieve, and obtain 99.6 g of a uniformly mixed granular product, i.e., a cold cloud catalyst with a high silver iodide content. The catalyst needs to be stored in a sealed container away from light.

[0056] The high silver iodide content cold cloud catalyst prepared in this example was tested as follows:

[0057] (1) The catalyst was pressed into a 0.98 g catalyst block according to QX / T360-2016 "Static Test Specification for Silver Iodide Weather Modification Catalysts", and the nucleation rate was measured to be 4.7×10 13 / g, in line with national standards;

[0058] (2) The Mach number of a 20kg turbojet engine is 1.5-2. 1g of the catalyst is sprayed onto the nozzle of the turbojet engine with a diameter of 40mm. A passive cavity aerosol detector (PCASP) is used in an open space to detect a particle concentration of 4530 particles / cm2 at a distance of 5 meters from the nozzle of the turbojet engine. 3 Increased to 26853 / cm 3 .

Claims

1. A cold cloud catalyst with high silver iodide content, characterized in that: Taking the total mass of the catalyst raw material as 100%, the catalyst is characterized in that the components and their mass fractions are as follows: All components are powders, and the particle size of silver iodide is 1 μm to 50 μm.

2. A cold cloud catalyst with high silver iodide content according to claim 1, characterized in that: Taking the total mass of the catalyst raw material as 100%, the various components and their mass fractions are as follows:

3. A cold cloud catalyst with high silver iodide content according to claim 1 or 2, characterized in that: The oxidant is at least one of potassium perchlorate, ammonium perchlorate and potassium nitrate; The additive is at least one of organic copper salt, graphene, polyacrylamide and cuprous iodide; The binder is at least one of polyvinyl alcohol, polymethyl methacrylate, polyvinyl chloride, phenolic resin and maleic anhydride grafted ethylene propylene diene rubber.

4. A cold cloud catalyst with high silver iodide content according to claim 3, characterized in that: The particle size of the oxidant is 40 μm to 100 μm; The particle size of potassium iodide is 1 μm to 100 μm; The particle size of the additive is 1 μm to 100 μm; The particle size of the binder is 1 μm to 100 μm.

5. A method for preparing a cold cloud catalyst with a high silver iodide content as claimed in any one of claims 1 to 4, characterized in that: Silver iodide, an oxidant and an additive are sieved and mixed uniformly to obtain a mixture; potassium iodide and a binder are added to the mixture, sieved, dried, sieved, and mixed uniformly to obtain a granular product, which is a cold cloud catalyst with a high silver iodide content.

6. The method for preparing a cold cloud catalyst with high silver iodide content according to claim 5, characterized in that: (1) crushing or grinding silver iodide, potassium iodide and a binder respectively, transferring them to a vacuum oven at 70°C to 100°C for drying for 10 h to 48 h, and then passing them through a 200-mesh copper sieve, and taking the residue on the 200-mesh copper sieve; (2) Premixing the silver iodide, oxidant and additive according to the proportion of each component, and then passing through a 40-60 mesh sieve, and then passing through a 100-mesh copper sieve, taking the residue of the 100-mesh copper sieve to obtain a uniform mixture; (3) Potassium iodide and a binder are added to the mixture, and then the mixture is passed through a 60-mesh copper sieve. The residue on the 60-mesh copper sieve is taken and transferred to a vacuum oven at 50° C. to 70° C. for drying for 10 h to 48 h, and then the mixture is passed through a 20-200-mesh copper sieve. The residue on the copper sieve is taken to obtain a uniformly mixed granular product, i.e., a cold cloud catalyst with a high silver iodide content.

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