A preparation method of mefenoxam and mancozeb dry suspension

Abstract

The present application relates to the technical field of pesticides, especially to the field of IPC A01N, more particularly to a preparation method of metalaxyl-M·mancozeb dry suspension agent. The present application can reduce or even eliminate foam by first emulsifying and dispersing metalaxyl crude oil alone and then adding other raw materials such as mancozeb into a blending kettle, on the one hand, the efficiency of wet sanding is improved, and the preparation time is shortened, and the efficiency of wet sanding can be improved to 727 kg slurry / h; on the other hand, in the subsequent production spraying process, the stability of the pressure during spray drying is improved, the machine is not stopped for cleaning due to nozzle blockage, and the liquid spraying quality per unit time is improved, thereby the production capacity is improved, and the production capacity can be improved to 1100 kg / 8h.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, in particular to the field of IPC A01N, and more specifically to a method for preparing a metalaxyl-M and mancozeb dry suspension concentrate. Background Art

[0002] The DF formulation (Dry Suspension Concentrate) is the highest-end product in the Water Dispersible Granules (WG) product line. Previously known in the United States as Dry Flowable or Dry Suspension Concentrate (DF), Dry Suspension Concentrate is a pesticide suspension obtained through wet sand grinding, followed by spray drying and granulation, followed by dehydration to produce a solid microparticle product. This is the key difference between it and ordinary water dispersible granules.

[0003] During the wet sand-milling process of dry suspension concentrates, due to the characteristics of some pesticide technicals, such as the oily and viscous crude metalaxyl-M, when mixed with mancozeb technical, wetting and dispersing agents, fillers, and water, followed by dispersion, shearing, and sand-milling, bubbles inevitably form, which are difficult to eliminate. These bubbles can affect subsequent production, such as reducing sand-milling efficiency and causing pressure instability during spray drying, ultimately impacting production capacity. When bubbles appear, the common practice is to add defoamers or antifoaming agents. These agents work by reducing the surface tension of the bubbles, causing them to burst. However, this reduction in surface tension can also result in reduced product suspension efficiency and poor thermal storage stability.

[0004] In the prior art, patent document CN201610598736.2 discloses a multi-component pesticide dry suspension concentrate and its preparation method. The dry suspension concentrate is prepared using the three main ingredients: nicosulfuron, atrazine, and mesotrione. However, none of the three raw materials are oily substances. Therefore, when used in a metalaxyl-M and mancozeb dry suspension concentrate system, a large amount of bubbles will still be generated, affecting production capacity.

[0005] Patent document CN201310181266.6 discloses a fungicide composition containing cyproconazole and metalaxyl-M. By compounding the two active ingredients, a good fungicide effect is achieved. However, it does not mention the preparation method of the dry suspension containing metalaxyl-M, nor does it explore the impact of the preparation process on production capacity.

[0006] Therefore, it is necessary to develop a new preparation method for a dry suspension concentrate, which is suitable for a metalaxyl-M·mancozeb dry suspension concentrate system and can solve the problem of a large number of bubbles generated in the DF wet sand grinding process. Summary of the Invention

[0007] In order to solve the above problems, the first aspect of the present invention provides a method for preparing a metalaxyl-M and mancozeb dry suspension concentrate, comprising the following steps:

[0008] S1. Adding metalaxyl-M technical into the emulsifier, emulsifying and dispersing the mixture evenly to obtain substance 1;

[0009] S2, water, wetting agent, dispersant, filler, mancozeb technical medicine are put into feeding jar in order, disperse and stir, and then after shear reflux, wet sand milling is carried out. After wet sand milling, the mixture is poured into the mixing jar;

[0010] S3. Add substance 1 to the mixing pot at a rate of 5-10 kg / min and stir slowly to obtain a metalaxyl-M·mancozeb dry suspension concentrate slurry;

[0011] S4. The prepared dry suspension concentrate slurry is spray-dried to obtain a metalaxyl-M·mancozeb dry suspension concentrate.

[0012] Preferably, the specific process parameters of the emulsification and dispersion in step S1 are: temperature 45-65°C, time 10-30 min, and rotation speed 400-800 r / min; further preferably, the specific process parameters of the emulsification and dispersion in step S1 are: temperature 50-60°C, time 20 min, and rotation speed 500-700 r / min.

[0013] The inventors have creatively discovered that separating the metalaxyl-M technical drug from the mancozeb technical drug and related components, and then emulsifying and dispersing them separately, improves sand milling efficiency and increases finished product production capacity. This is likely due to the fact that emulsifying and dispersing the metalaxyl-M technical drug separately with a specific emulsifier under certain conditions not only allows for uniform emulsification, thereby ensuring a homogeneous mixing with other raw materials, but also separates it from other components, avoiding the large number of difficult-to-eliminate bubbles that can occur in a one-pot mixing method, impacting sand milling efficiency and production capacity. This method is particularly suitable for specific metalaxyl-M technical drugs and mancozeb technical drugs.

[0014] Preferably, in step S2, the specific parameters of dispersion stirring and shear reflux are: stirring paddle frequency 25-45 Hz, rotation speed 400-800 r / min, dispersion time 20-40 min, and shear reflux time 30-50 min; further preferably, in step S2, the specific parameters of dispersion stirring and shear reflux are: stirring paddle frequency 30-40 Hz, rotation speed 500-700 r / min, dispersion time 30 min, and shear reflux time 40 min.

[0015] Preferably, the sanding beads used in the wet grinding in step S2 include zirconia balls.

[0016] Preferably, the diameter of the zirconia ball is 0.8-1.2 mm.

[0017] Preferably, the filling amount of the sanding beads is 60-70 wt%.

[0018] Preferably, the specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 15-35 Hz, sand mill frequency 35-50 Hz, and discharge temperature ≤40°C; further preferably, the specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 20-30 Hz, sand mill frequency 40-45 Hz, and discharge temperature ≤40°C.

[0019] Preferably, the sand mill used for wet grinding in step S2 includes any one of a horizontal sand mill, a vertical sand mill, a basket sand mill, a double-cone rod sand mill, and a nano-scale horizontal sand mill; more preferably, it is a horizontal sand mill.

[0020] Preferably, the specific parameters of the stirring in step S3 are: stirring time 50-70 min, stirring paddle frequency 5-20 Hz.

[0021] The inventors have creatively discovered that, in step S3, substance one is slowly and evenly added to the mixing jar, and under the conditions of a lower stirring paddle frequency of 5-20Hz and a longer stirring time of 50-70min, the generation of foam can be further reduced and production capacity can be improved. This may be because in the mixing of substance one with the remaining raw materials, although it is quickly poured in and accompanied by high-speed stirring, the stirring time can be shortened, but fine foam is still inevitably produced during the process, and the formation of foam has a great influence on subsequent production capacity. Once the nozzle is blocked, a large amount of manpower and material resources need to be spent to clean it, and production must be suspended, which greatly reduces production capacity. Therefore, in the mixing process, the stirring time can be appropriately extended, the stirring paddle frequency can be reduced, the uniformity of the slurry can be guaranteed, the generation of foam can be reduced, the possibility of nozzle blockage can be reduced, and the production schedule can be ensured to proceed smoothly.

[0022] Preferably, the specific parameters of the spray drying in step S4 are: high-pressure pump speed 5-25 Hz, surge tank pressure ≤6.0 MPa, spray plate aperture 1.0-2.0 mm, air inlet temperature 110-140 ° C, and air outlet temperature ≤100 ° C; further preferably, the specific parameters of the spray drying in step S4 are: high-pressure pump speed 10-20 Hz, surge tank pressure ≤4.0 MPa, spray plate aperture 1.6 mm, air inlet temperature 120-130 ° C, and air outlet temperature ≤70 ° C.

[0023] Preferably, the emulsifier comprises a nonionic emulsifier.

[0024] Preferably, the nonionic emulsifier includes one or more of alkylphenol polyoxyethylene ether nonionic emulsifiers, fatty acid polyoxyethylene ester nonionic emulsifiers, castor oil polyoxyethylene ether nonionic emulsifiers, polyoxyethylene alkylamine nonionic emulsifiers, polyoxyethylene alkylamide nonionic emulsifiers, and polyoxyalkyl ether nonionic emulsifiers; further preferably, it is a polyoxyalkyl ether nonionic emulsifier.

[0025] In some preferred embodiments, the polyoxyalkyl ether is purchased from SK-355 of Xingfei Chemical.

[0026] Preferably, the wetting agent includes one or more of anionic wetting agents, nonionic wetting agents, and traditional dispersants; more preferably, it is an anionic wetting agent.

[0027] Preferably, the anionic wetting agent includes one or more of sulfosuccinate anionic wetting agents, dodecylsulfonate anionic wetting agents, lauryl sulfate anionic wetting agents, and butyl oleate sulfate anionic wetting agents; further preferably, it is a sulfosuccinate anionic wetting agent.

[0028] In some preferred embodiments, the sulfonic acid anionic wetting agent is purchased from Xingfei Chemical as SK-551EX.

[0029] Preferably, the dispersant is an organic dispersant.

[0030] Preferably, the organic dispersant includes one or more of triethylhexyl phosphate, sodium lauryl sulfate, sodium lignin sulfonate, methyl amyl alcohol, cellulose derivatives, and polyacrylamide; more preferably, sodium lignin sulfonate.

[0031] Preferably, the molecular weight of the sodium lignin sulfonate salt is 15000-25000, and the effective content is ≥90wt%; further preferably, the molecular weight of the sodium lignin sulfonate salt is 20000, and the effective content is ≥93wt%.

[0032] In some preferred embodiments, the sodium lignin sulfonate is purchased from U-NA produced by Borregaard.

[0033] Preferably, the filler includes one or more of kaolin, diatomaceous earth, bentonite, attapulgite, potassium sulfate, light calcium carbonate, sepiolite, barium sulfate, and talc; more preferably, it is kaolin.

[0034] Preferably, the kaolin is calcined kaolin.

[0035] Preferably, the particle size of the calcined kaolin is 0.5-5 μm, and the R457 whiteness is 80-95; further preferably, the particle size of the calcined kaolin is 1.5 μm, and the R457 whiteness is 89.

[0036] In some preferred embodiments, the calcined kaolin is purchased from calcined kaolin sold by Shanghai Waidian International Trading Co., Ltd.

[0037] Preferably, the mass of the active ingredient in the metalaxyl-M technical is 10-20 times the mass of the active ingredient in the mancozeb technical.

[0038] Preferably, the mass ratio of the active ingredient in the metalaxyl-M technical to the mass ratio of the emulsifier is 1:(0.5-2); more preferably, it is 1:1.

[0039] Preferably, the added mass of the water is the sum of the masses of the other components.

[0040] Preferably, the mass ratio of the filler, the wetting agent and the dispersant is 1:(0.5-2):(4-8); more preferably, it is 1:(1-1.5):(6-7).

[0041] Preferably, the total mass of the filler, wetting agent and dispersant is 10-30 wt% of the mancozeb technical; more preferably, it is 19-23 wt%.

[0042] The second aspect of the present invention provides a metalaxyl-M·mancozeb dry suspension concentrate prepared by the preparation method of the metalaxyl-M·mancozeb dry suspension concentrate.

[0043] Beneficial effects:

[0044] 1. The present invention separates the metalaxyl technical, mancozeb technical and related components and separately emulsifies and disperses them, thereby improving sand milling efficiency and increasing finished product production capacity.

[0045] 2. By ball-milling the mancozeb technical and related components separately and using a specific ball-milling process, the other components can be quickly ground into the required particle size, thereby greatly reducing the sand-milling time and improving the sand-milling efficiency while ensuring the reduction of foam, thereby increasing the production capacity of the finished product.

[0046] 3. In the present application, in step S3, the substance 1 is slowly and evenly added to the mixing pot, and under the conditions of a lower stirring frequency of 5-20 Hz and a longer stirring time of 50-70 min, the generation of foam can be further reduced and the production capacity can be improved.

[0047] 4. The present invention reduces or even eliminates foam by first emulsifying and dispersing the crude metalaxyl-M separately and then adding it to a mixing kettle containing other raw materials such as mancozeb. On the one hand, the efficiency of wet sand milling is improved, the preparation time is shortened, and the wet sand milling efficiency can be increased to 727 kg of slurry / h. On the other hand, in the subsequent production spraying process, the pressure stability during spray drying is improved, and the machine will not be shut down for cleaning due to nozzle blockage. At the same time, the spray quality per unit time is improved, thereby increasing production capacity, which can be increased to 1100 kg / 8 hours. DETAILED DESCRIPTION

[0048] Example

[0049] The raw materials used in the examples were purchased from the preferred manufacturers listed in the specification.

[0050] Example 1

[0051] Example 1 provides a method for preparing a metalaxyl-M·mancozeb dry suspension slurry, the steps of which are:

[0052] S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 55° C., a time of 20 min, and a rotation speed of 600 r / min to obtain substance 1;

[0053] S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in order, the stirring paddle frequency was 35Hz, and after dispersing for 30min under the condition of a speed of 600r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar;

[0054] S3. Slowly add substance 1 into the mixing pot with a stirring paddle at a frequency of 13 Hz and stir for 60 minutes to obtain a dry suspension slurry.

[0055] The sanding beads used in the wet grinding in step S2 are zirconia balls.

[0056] The diameter of the zirconia ball is 1.0 mm.

[0057] The filling amount of the sanding beads is 65 wt %.

[0058] The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25 Hz, sand mill frequency 43 Hz, and discharge temperature 28°C.

[0059] The sand mill used for wet grinding in step S2 is a horizontal sand mill.

[0060] The active ingredient mass of the metalaxyl-M technical was 92 wt %, and was purchased from Zhejiang Yifan Chemical.

[0061] The mass of the active ingredient of the mancozeb technical is 85 wt %, and it is purchased from INDOFIL, India.

[0062] Example 2

[0063] Example 2 provides a method for preparing a metalaxyl-M and mancozeb dry suspension concentrate, and the specific implementation method is the same as that of Example 1. The difference is that:

[0064] The steps are:

[0065] S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 50° C., a time of 20 min, and a rotation speed of 700 r / min to obtain substance 1;

[0066] S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in sequence, after dispersing for 30min under the condition of a stirring paddle frequency of 30Hz and a speed of 500r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar;

[0067] S3. Slowly add substance 1 into the mixing pot with a stirring paddle at a frequency of 15 Hz and stir for 50 minutes to obtain a dry suspension slurry.

[0068] The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25 Hz, sand mill frequency 40 Hz, and discharge temperature 25°C.

[0069] Example 3

[0070] Example 3 provides a method for preparing a dry suspension slurry of metalaxyl-M and mancozeb, and the specific implementation method is the same as that of Example 1. The difference is that:

[0071] The steps are:

[0072] S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 60° C., a time of 20 min, and a rotation speed of 500 r / min to obtain substance 1;

[0073] S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in sequence, after dispersing for 30min under the condition of a stirring paddle frequency of 40Hz and a rotating speed of 700r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar;

[0074] S3. Slowly add substance 1 into the mixing pot with a stirring paddle at a frequency of 10 Hz and stir for 70 minutes to obtain a dry suspension slurry.

[0075] The filling amount of the sanding beads is 70 wt %.

[0076] The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25 Hz, sand mill frequency 45 Hz, and discharge temperature 35°C.

[0077] Comparative Example 1

[0078] Comparative Example 1 provides a method for preparing a dry suspension concentrate of metalaxyl-M and mancozeb, wherein the specific raw materials and the quality of the raw materials are the same as those in Example 1. The difference is that:

[0079] The steps are as follows: all raw materials are put into the feeding kettle in order, the stirring frequency is 40Hz, stirring, 600r / min dispersion for 30min, and then shear reflux for 40min before wet sand grinding; the parameters of wet sand grinding are: hose pump feeding frequency 15Hz, sand mill frequency 50Hz, discharge temperature 40℃, and after wet sand grinding, the raw materials are put into the mixing kettle to obtain dry suspension slurry.

[0080] Comparative Example 2

[0081] Comparative Example 2 provides a method for preparing a dry suspension concentrate of metalaxyl-M and mancozeb, wherein the specific raw materials and the quality of the raw materials are the same as those in Example 1. The difference is that:

[0082] The steps are as follows: all raw materials are put into the feeding kettle in order, the stirring frequency is 30Hz, stirring, 600r / min dispersion for 20min, and then shear reflux for 30min before wet sand grinding; the parameters of wet sand grinding are: hose pump feeding frequency 15Hz, sand mill frequency 50Hz, discharge temperature 40℃, and after wet sand grinding, the raw materials are put into the mixing kettle to obtain dry suspension slurry.

[0083] Comparative Example 3

[0084] Comparative Example 3 provides a method for preparing a dry suspension concentrate of metalaxyl-M and mancozeb, wherein the specific raw materials and the quality of the raw materials are the same as those in Example 1. The difference is that:

[0085] The steps are as follows: all raw materials are put into the feeding kettle in order, the stirring frequency is 30Hz, stirring, dispersing at 600r / min for 20min, and then shearing reflux for 30min before wet sand grinding; the parameters of wet sand grinding are: hose pump feeding frequency 10Hz, sand mill frequency 25Hz, discharge temperature 40°C, and after wet sand grinding, the raw materials are put into the mixing kettle to obtain dry suspension slurry.

[0086] Performance testing methods

[0087] 1. Test of wet sanding efficiency

[0088] For the slurry after wet sand grinding in step S2 of Example 1-3 and Comparative Example 1-3, the particle size must meet D98: 4.0-5.0 μm. The time required for sand grinding of 2000 kg of slurry from the start to the end of sand grinding is recorded to calculate the wet sand grinding efficiency (kg / h).

[0089] The particle size test instrument and model are: Malvern laser particle size analyzer, APA2000.

[0090] The density of a dry suspension concentrate slurry is determined by placing a graduated cylinder on an electronic balance and taring it. Pour an appropriate amount of the dry suspension concentrate slurry into the graduated cylinder. Record the volume of the slurry in the graduated cylinder and the mass displayed on the electronic balance. The density of the dry suspension concentrate slurry is calculated by dividing the mass by the volume. The lower the density, the more foamy it is. Record the results in Table 1.

[0091] 2. Finished product capacity test

[0092] The dry suspension concentrate slurries prepared in Examples 1-3 and Comparative Examples 1-3 were spray dried. The specific spray drying parameters were: a high-pressure pump speed of 15 Hz, a surge tank pressure of 4.0 MPa, a spray plate aperture of 1.6 mm, an air inlet temperature of 125° C., and an air outlet temperature of 70° C. The mass of the dry suspension concentrate product sprayable within 8 hours was recorded. If the machine was shut down due to blockage during the experiment, the experiment was stopped and the nozzle was cleaned before continued use (cleaning generally takes a long time, and based on a normal working day, the machine could not be used on the same day after the shutdown). The results are recorded in Table 1.

[0093] Table 1

[0094]

[0095]

Claims

1. A method for preparing a metalaxyl-M and mancozeb dry suspension concentrate, characterized in that: The following steps are involved: S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 55° C., a time of 20 min, and a rotation speed of 600 r / min to obtain substance 1; S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in order, the stirring paddle frequency was 35Hz, and after dispersing for 30min under the condition of a speed of 600r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar; S3. Slowly add substance 1 into the mixing pot, stir at 13 Hz, and stir for 60 min to obtain dry suspension slurry. The sanding beads used in the wet grinding in step S2 are zirconium oxide balls. The diameter of the zirconia ball is 1.0 mm. The filling amount of the sanding beads is 65wt%, The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25Hz, sand mill frequency 43Hz, discharge temperature 28°C, The sand mill used for wet grinding in step S2 is a horizontal sand mill. The effective component mass of the metalaxyl technical is 92wt%, The mass of the active ingredient of the mancozeb technical is 85wt%.

2. A method for preparing a metalaxyl-M and mancozeb dry suspension concentrate, characterized in that: The following steps are involved: S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 50° C., a time of 20 min, and a rotation speed of 700 r / min to obtain substance 1; S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in sequence, after dispersing for 30min under the condition of a stirring paddle frequency of 30Hz and a speed of 500r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar; S3. Slowly add substance 1 into the mixing pot, stir at 15 Hz, and stir for 50 min to obtain dry suspension slurry. The sanding beads used in the wet grinding in step S2 are zirconium oxide balls. The diameter of the zirconia ball is 1.0 mm. The filling amount of the sanding beads is 65wt%, The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25Hz, sand mill frequency 40Hz, discharge temperature 25°C, The sand mill used for wet grinding in step S2 is a horizontal sand mill. The effective component mass of the metalaxyl technical is 92wt%, The mass of the active ingredient of the mancozeb technical is 85wt%.

3. A method for preparing a metalaxyl-M and mancozeb dry suspension concentrate, characterized in that: The following steps are involved: S1. Add 43.5 kg of metalaxyl-M technical into 40.0 kg of polyoxyalkyl ether nonionic emulsifier, and emulsify and disperse uniformly at a temperature of 60° C., a time of 20 min, and a rotation speed of 500 r / min to obtain substance 1; S2, 1000.0kg water, 20.0kg sulfosuccinate anionic wetting agent, 120.0kg lignin sulfonate sodium salt, 17.7kg calcined kaolin, 758.8kg mancozeb technical medicine were put into the feeding jar in sequence, after dispersing for 30min under the condition of a stirring paddle frequency of 40Hz and a rotating speed of 700r / min, the shear reflux time was 40min, and then wet sand milling was carried out. After the wet sand milling was completed, the mixture was poured into the deployment jar; S3. Slowly add substance 1 into the mixing pot, stir at 10 Hz, and stir for 70 minutes to obtain dry suspension slurry. The sanding beads used in the wet grinding in step S2 are zirconium oxide balls. The diameter of the zirconia ball is 1.0 mm. The filling amount of the sanding beads is 70wt%, The specific process parameters of the wet grinding in step S2 are: hose pump feeding frequency 25Hz, sand mill frequency 45Hz, discharge temperature 35°C, The sand mill used for wet grinding in step S2 is a horizontal sand mill. The effective component mass of the metalaxyl technical is 92wt%, The mass of the active ingredient of the mancozeb technical is 85wt%.

4. The dry suspension concentrate prepared according to the method for preparing the metalaxyl-M and mancozeb dry suspension concentrate according to any one of claims 1 to 3.

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