Method for strengthening glyphosate crystallization in wastewater

Abstract

The invention discloses a method for strengthening crystallization of glyphosate in waste water, which comprises the following steps: 1) adding a polyhydroxy straight-chain alcohol-based solvating-out agent into supersaturated concentrated glyphosate waste liquid, adjusting the pH and temperature of the obtained mixed solution, and carrying out ultrasonic dispersion to obtain a homogeneous solution in which glyphosate molecules are uniformly dispersed; 2) carrying out first cooling induced nucleation on the obtained homogeneous solution under ultrasonic and laminar flow control conditions to obtain a glyphosate suspension containing uniform crystal nucleuses; and 3) adding a small molecule solvating-out agent into the obtained glyphosate suspension, properly increasing the temperature according to the particle dissolution condition, then carrying out second cooling to induce crystal growth, and then carrying out solid-liquid separation and washing to obtain a glyphosate solid. The invention mainly aims to provide a strengthening method for glyphosate crystallization in wastewater, and finally a glyphosate solid with large particle size and uniform particle size distribution is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of waste liquid resource utilization, and particularly relates to a crystallization intensification method of glyphosate in waste water. BACKGROUND

[0003] Glyphosate crystallization is usually completed by using dimethyl phosphite supersaturation one-step method. The crystal product formed in the rapid crystallization or precipitation process of the enriched glyphosate solution has a low grade, and the size of the crystalline particles is seriously uneven. Moreover, the glyphosate product contains a large amount of organic phosphorus impurities. In the traditional preparation process, due to the too fast reaction rate of the homogeneous nucleation process, the existence of a large amount of solid phase base substances in the system leads to a large increase in the probability of heterogeneous nucleation reaction, and the product particle size distribution is unstable, and the obtained crystalline product is mostly irregular agglomerated crystals. In addition, due to the unevenness of the crystal surface, the aspect ratio is not the same, and fine particles are entrained, which is easy to further cause caking and other problems, bringing many inconveniences to the filtration, storage and transportation process, and it is difficult to meet the requirements of downstream industrial applications. It is a technical problem urgently to be solved in the field to further explore the intensification method of glyphosate crystallization in waste water to obtain large-size and uniform particle-size glyphosate crystals. SUMMARY

[0004] In view of the above problems, the main purpose of the present application is to provide an intensification method of glyphosate crystallization in waste water, which controls the homogeneous nucleation and heterogeneous growth kinetics process of the solvent-out crystallization by steps, and finally obtains glyphosate solids with large particle size and uniform particle size distribution.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is: An intensification method of glyphosate crystallization in waste water, comprising the following steps: 1) adding a multi-hydroxy linear alcohol-based solvent-out agent to the concentrated glyphosate waste liquid, adjusting the pH and temperature of the obtained mixed solution, and performing ultrasonic dispersion to obtain a homogeneous solution in which glyphosate molecules are uniformly dispersed; 2) performing first temperature reduction induced nucleation under ultrasonic and laminar flow control conditions to obtain a glyphosate suspension containing uniform nuclei; 3) adding a small molecule solvent-out agent to the obtained glyphosate suspension, appropriately increasing the temperature according to the particle dissolution, then performing second temperature reduction induced crystal growth, and then performing solid-liquid separation and washing to obtain glyphosate solids.

[0006] In the above scheme, the supersaturated concentrated glyphosate waste liquid in step 1) is obtained by sequentially subjecting the glyphosate synthesis mother liquor waste liquid prepared by the glycine-dimethyl phosphite method to acid addition and dealcoholization treatment.

[0007] Preferably, the temperature of the glyphosate production waste liquid is 100-130℃, for example, it can be 100-120℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0008] Preferably, the pH value of the glyphosate synthesis mother liquor waste liquid is 0.5-4.0, for example, it can be 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 or 4.0, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0009] Preferably, the ultrasonic dispersion time of the glyphosate synthesis mother liquor waste liquid is 15-30 min, for example, it can be 15, 16, 17, 18, 19, 20, 25 or 30 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0010] In the above scheme, the main components in the glyphosate synthesis mother liquor and the mass percentage thereof include: glyphosate 1.2-1.7%, N-(phosphonomethyl)iminodiacetic acid 3.8-4.0%, and phosphorous acid 1.7-2.7%; and the pH value is 0.5-2.0.

[0011] In the above scheme, the acid addition and dealcoholization treatment step includes: adding formic acid with a mass fraction of 1-1.5%, and controlling the evaporation temperature.

[0012] Further, the main components in the supersaturated concentrated glyphosate waste liquid and the mass percentage thereof include: glyphosate 12-20%, N-(phosphonomethyl)iminodiacetic acid 0.01-0.1%, and phosphorous acid 5-10%.

[0013] In the above scheme, step 1) controls the pH value to be 4-6 and the temperature to be 100-130℃.

[0014] In the above scheme, the ultrasonic dispersion time in step 1) is 15-30 min.

[0015] Preferably, the polyhydroxy linear alcohol-based eluent can be one or more of pentaerythritol, neopentyl glycol (NPG), diethylene glycol (EG·), dipropylene glycol (I) (PG), trimethylolpropane (TMP), etc., but is not limited to the listed types, and other compounds not listed are also applicable.

[0016] Preferably, the amount of the polyhydroxy linear alcohol-based eluent in step 1) accounts for 0.5-5 wt% of the mass of the concentrated glyphosate waste liquid, for example, it can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 or 5 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0017] Preferably, the terminal temperature of the first cooling induced nucleation cooling is 70~80℃, for example, it can be 70, 72, 75, 78 or 80℃, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0018] Preferably, the cooling time of the first cooling induced nucleation is 20~100 min, for example, it can be 20, 22, 24, 26, 28n, 30, 40, 50, 60, 80 or 100 min, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0019] Preferably, the ultrasonic dispersion power in step 2) is in the range of 30~50 kHz, for example, it can be 30, 32, 34, 36, 38, 40, 45 or 50 kHz, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0020] Preferably, in the laminar flow control of step 2), the laminar flow velocity Reynolds number Re=1500~1800, for example, it can be 1500, 1525, 1550, 1575, 1600, 1625, 1650, 1675, 1700 or 1800, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0021] Preferably, the small molecule solventing agent in step 3) can be selected from one or more of methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, etc., but not limited to the listed types, other unlisted small molecule solvent compounds are also applicable.

[0022] Preferably, the amount of small molecule solventing agent in step 3) is 0.5~1.0wt% of the mass of the concentrated glyphosate waste liquid, for example, it can be 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0wt%, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0023] Preferably, the cooling time of the second cooling induced crystallization in step 3) is 40~100 min, for example, it can be 40, 42, 44, 46, 48, 50, 60, 70, 80, 90 or 100 min, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0024] Preferably, the temperature of the second cooling induced crystallization in step 3) is 65℃~80℃, for example, it can be 65, 66, 67, 68, 69, 70, 75 or 80℃ but not limited to the listed values, other values not listed in the range of values are also applicable.

[0025] Preferably, a secondary solvent dimethyl phthalate is added before the crystal growth reactor in step 3).

[0026] Preferably, the crystallization is kept for 1-2 hours after step 3), for example, 1, 1.2, 1.4, 1.6, 1.8 or 2 hours, but not limited to the listed values, other values not listed in the range are also applicable.

[0027] Further, the device system used in the method for strengthening the crystallization of glyphosate in wastewater comprises a peristaltic pump, a laminar flow control valve, a spiral crystallization reactor and a crystal growth reactor; the outlet of the spiral crystallization reactor is connected with the inlet of the crystal growth reactor.

[0028] The outlet of the cooling liquid of the spiral crystallization reactor is connected with the outlet of the water bath of the crystal growth reactor.

[0029] The crystal growth reactor is provided with a stirring device.

[0030] In view of the problems of uneven distribution of crystals, difficulty in filtration, storage and transportation during the crystallization of glyphosate wastewater, the application provides a method for strengthening the crystallization of glyphosate in wastewater. The application adopts a nucleation-growth two-step process based on solvent crystallization. First, under specific pH and temperature conditions of a multi-hydroxy straight-chain alcohol solvent, large crystal nuclei in the supersaturated glyphosate solution are dissolved. The position distribution of the supersaturation point in the obtained solution is relatively uniform and there is no solid material interference. Then, the homogeneous supersaturated solution is slowly added to a crystallization reactor to form a relatively uniform crystal nucleus suspension under the conditions of ultrasonic and laminar flow control. Then, the solution is transferred to a crystal growth reactor (crystal growth reactor) for a second temperature reduction induced crystallization. The crystal size is enlarged and grown, which can effectively avoid the precipitation of fine crystals caused by the dramatic change of local supersaturation after mixing. In addition, the problem of uneven particle size in the crystal nucleation stage has been eliminated, so that larger and more uniform crystal particles can be obtained in the glyphosate growth stage.

[0031] Compared with the traditional process of directly crystallizing a higher concentration of supersaturated glyphosate solution, the application can avoid the problems of uneven crystal size and difficulty in dispersion, effectively improve the uneven particle size and difficulty in filtration of glyphosate crystallization.

[0032] The glyphosate crystal prepared according to the above scheme has a relatively uniform rod-like structure in morphology and size, an average particle size of 120-220 μm, and a length-diameter ratio of 3-4:1. The obtained glyphosate solid has a large particle size and uniform particle size distribution. The purity is above 94%, and the crystallization rate is above 86%.

[0033] Compared with the prior art, the application has the following advantages: (1) The seed crystal control and induced nucleation process based on the two-step solvus nucleation-crystal growth method can effectively optimize and strengthen the crystallization process of glyphosate, and the obtained glyphosate crystals have uniform morphology and size.

[0034] (2) The glyphosate seed crystals with smooth surface prepared by the solvus crystallization-homogeneous nucleation can quickly consume the supersaturation in the solution, so that the crystal nucleus is not easy to grow into an aggregate on the contact surface after collision and contact, thereby achieving the purpose of reducing or preventing the agglomeration of glyphosate crystals or the scattering of fine crystals, facilitating the storage and transportation of the product, and effectively ensuring and improving the flowability evaluation grade of the obtained glyphosate crystals.

[0035] (3) The crystallization process disclosed by the present application has simple operation, controllable conditions, and good reproducibility of the crystal morphology, and is easy to realize industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 Figure 1 is a structural schematic diagram of a crystallization system adopted in the present application, wherein A is a structural diagram of a spiral nucleation crystallization reactor, and B is a structural schematic diagram of a crystallization.

[0037] Figure 2 Figure 2 is a scanning electron microscope image of the glyphosate crystals obtained in Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0039] In the following examples, the glyphosate mother liquor is a by-product of the preparation of glyphosate by the glycine-dimethyl phosphite method, wherein the main components and their mass percentages include: glyphosate 1.6%, nonglyphosate 3.8%, and phosphorous acid 2.2%; pH = 1.5.

[0040] Example 1 A method for strengthening the crystallization of glyphosate in wastewater, comprising the following steps: (1) Concentrated waste liquid pretreatment and homogeneous nucleation: The glyphosate mother liquor is sequentially washed with 15% formic acid solution and evaporated at 120°C to remove alcohol to obtain a concentrated waste liquid (pH = 1.5, composition: glyphosate 13.5%, nonglyphosate 0.08%, and phosphorous acid 8.6%). 3 wt% trimethylolpropane solvus agent is added to the waste liquid, ultrasonic dispersion is performed at 100-130°C and pH 5-6 for 20 min, and then the flow rate is adjusted by controlling the Reynolds number (Re = 1300) through a peristaltic pump, and the concentrated waste liquid is slowly injected into a spiral nucleation crystallization reactor (see Figure 1A, model: SSC-100-D, double helix structure, PTFE coating). Trigger homogeneous nucleation by cooling to 80℃ to form a supersaturated solution.

[0041] (2) Crystal growth and regulation: The supersaturated solution was transferred to the crystal growth reactor through the outlet of the spiral crystallization tube, 1 wt% ethanol desolventizing agent was added, the temperature was raised to 90℃, then the stirring was started, and the temperature was uniformly reduced to 70℃ within 20 min (the desolventizing agent was added for 0.5 h). The total residence time was controlled to be 1.5 h to promote the directional growth of the crystals.

[0042] (3) Solid-liquid separation and product recovery: The crystal slurry obtained in step (2) was filtered and washed by a filtering device to obtain high-purity glyphosate crystals.

[0043] Example 2 A method for enhancing the crystallization of glyphosate in wastewater, comprising the following steps: (1) The glyphosate mother liquor was sequentially subjected to formic acid addition and dealcoholization to obtain concentrated glyphosate waste liquid, the treatment temperature was 100℃, the pH value was 3, the glyphosate concentration in the concentrated liquid was 20.5%, the glyphosine was 0.68%, and the phosphorous acid was 13.5%.

[0044] The concentrated glyphosate waste liquid was subjected to 20 min ultrasonic dispersion, then diethylene glycol (EG) was added to control the temperature to be reduced to 75℃ within 3.5 h, and the dissolution reaction was performed for 3 h to obtain a highly dispersed and uniform supersaturated solution; The mass ratio of the diethylene glycol desolventizing agent to the concentrated glyphosate waste liquid was 4%, and the dosing agent time was 0.5 h.

[0045] (2) The upper part of the supersaturated solution obtained in step (1) was sequentially subjected to layer flow through the top liquid inlet of the spiral tube nucleation crystallization reactor to control the Reynolds number Re=1200, adjust the pump speed, and add the pH adjusting agent NaOH to pH=3.8, then reduce the temperature to 65℃, and then add the desolventizing agent (ethylene glycol solution) with a mass ratio of 1.3 wt% of the total reaction solution to perform secondary desolventization, the entire crystallization reaction time was 1.5 h, and a secondary desolventization mixed liquid was obtained.

[0046] The mass of the upper part of the crystallization liquid accounted for 5% of the mass of the glyphosate dealcoholization liquid fed into the spiral tube nucleation crystallization reactor.

[0047] (3) The first mixed solution obtained in step (2) is transferred from the bottom liquid outlet of the spiral nucleation crystallization reactor to the crystal growth reactor containing the remaining crystallization solution in sequence, and is fully stirred and mixed to obtain a second mixed solution, the addition time of the solution is 1.5 h, the pH value of the second mixed solution is 4.5, and then the mixed solution is cooled to 20°C for crystal growth reaction. After the crystal growth reaction is completed, the crystal slurry is introduced into a filtering device through the bottom liquid outlet of the reactor for filtration and washing to obtain glyphosate crystals.

[0048] Example 3 The present embodiment provides a method for strengthening the crystallization of glyphosate in wastewater, which comprises the following steps: In a 5 L dissolving kettle, a dissolving solution of glyphosate with a solid content of 15% is configured, hydrochloric acid and dimethyl sulfoxide are used as solvents, the pH of the solution is adjusted to 2-3 to form an acidic environment, and the temperature of the reaction solution is maintained at 90°C.

[0049] Subsequently, the pH of the solution is adjusted to 6-7, the solution is pumped into a dissolving reaction device through a feed pump, and a dissolving agent, neopentyl glycol, is added in the device to alleviate the problem of fine crystal precipitation caused by uneven temperature distribution and local increase in supersaturation. The operating conditions are controlled as follows: the temperature is maintained at 85°C, the stirring speed is 400 rad / min, and the residence time is 1 h.

[0050] The obtained supersaturated solution enters a nucleation reaction kettle (model: Teflon-lined reaction kettle) through a laminar flow impeller, the Reynolds number Re corresponding to the center flow velocity of the supersaturated solution pipeline is controlled to be 1800 to ensure that the flow is in a laminar state. The nucleation reaction kettle is controlled by a water bath, the initial temperature is 85°C, and the cooling rate is 0.5 ℃ / min. The reaction time is 1 h.

[0051] Subsequently, after adding a secondary dissolving agent, dimethyl phthalate (DMP, 0.6 wt%) in the above solution, the solution is transferred to a crystal growth reactor (model: Teflon-lined reaction kettle), which aims to dissolve small crystal nuclei and promote selective growth of crystals. The stirring speed of the crystal growth reactor is set to 500 rad / min, and the residence time is 1 h.

[0052] Then, the stirring speed is controlled at 300 rad / min, and the temperature of the crystal slurry is gradually reduced until the liquid level of the crystal slurry exceeds the outlet branch, and then flows into the third-stage crystallizer. The crystallization temperature of the third-stage crystallizer is set to 20°C, and the residence time is 1 h. When the crystal slurry exceeds the outlet branch, it flows into a receiving device for solid-liquid separation to obtain glyphosate crystal products.

[0053] Comparative Example 1 A method for enhancing crystallization of glyphosate from wastewater, comprising the following steps: (1) Concentrated waste liquid pretreatment and homogeneous nucleation: The glyphosate mother liquor is sequentially washed with 15% formic acid solution and evaporated at 120°C to remove alcohol, obtaining a concentrated waste liquid (pH = 1.5, composition: glyphosate 13.5%, glyphosine 0.08%, phosphorous acid 8.6%). 3 wt% glycerol desolventizing agent is added to the waste liquid, which is ultrasonically dispersed at 100-130°C and pH 4-6 for 20 min, and then slowly injected into a spiral nucleation crystallization reactor (see Figure 1 A, model: SSC-100-D, double helix structure, PTFE coating) through a peristaltic pump to control the Reynolds number (Re = 1300) within 2 h. The temperature is lowered to 80°C to trigger homogeneous nucleation and form a supersaturated solution.

[0054] (2) Crystal growth and regulation: The supersaturated solution is transferred from the spiral crystallization tube outlet to the crystal growth reactor, 1 wt% ethanol desolventizing agent is added, the temperature is raised to 90°C, stirring is started, and the temperature is uniformly lowered to 70°C within 20 min (the desolventizing agent is added for 0.5 h). The total residence time is controlled to be 1.5 h to promote directional growth of the crystals.

[0055] (3) Solid-liquid separation and product recovery: The crystal slurry obtained in step (2) is filtered and washed by a filtering device to obtain high-purity glyphosate crystals.

[0056] Comparative Example 2 4 g of low-grade industrial glyphosate crude containing impurities is dissolved in 200 mL of mixed solvent prepared by mixing ethanol and water in a mass ratio of 1:1, and the obtained mixed solution is placed in a 1 L crystallizer. Formic acid is used to adjust the pH to 1.4-1.5, and the solution is stirred thoroughly for 2 h to form a homogeneous solution. 1.25 wt% of ethylene glycol (EG) and 1.5 wt% of dimethyl phthalate (DMP) are added to the entire system at one time, the flow rate ratio of the desolventizing agent to water is controlled to be 1:3, the temperature is continuously raised to 80°C, and the concentrated glyphosate mother liquor contains 15.8% of glyphosate. The temperature of the reaction solution is raised to 100°C, the solution is fed into the first-stage crystallizer through a feeding pump, the crystallizer temperature is 80°C, the stirring speed is 400 rad / min, and the residence time is 1 h. The crystal slurry exceeds the outlet branch and enters the second-stage crystallizer, the crystallizer temperature is 20°C, the stirring speed is 200 rad / min, and the residence time is 0.5 h. The crystal slurry exceeds the outlet branch and enters the receiving device for solid-liquid separation. The solid is washed with anhydrous ethanol and then vacuum dried at a drying temperature of 80°C, a vacuum degree of 0.1 MPa, and a drying time of 2 h to obtain glyphosate crystals.

[0057] Comparative Example 3 A method for enhancing crystallization of glyphosate from wastewater, comprising the following steps: (1) Concentrated waste liquid pretreatment and homogeneous nucleation: The glyphosate mother liquor was sequentially washed with 15% formic acid solution and evaporated at 120℃ to remove alcohol, obtaining a concentrated waste liquid (pH = 1.5, composition: glyphosate 13.5%, N- phosphonomethylglycine 0.08%, phosphorous acid 8.6%). 3 wt% glycerol desolventizing agent was added to the waste liquid, and ultrasonic dispersion was performed at 100℃ and pH 4-6 for 20 min.

[0058] (2) The temperature of the reaction solution was raised to 100℃, the solution was fed into the first-stage crystallizer through a feed pump, the crystallizer temperature was 80℃, the stirring speed was 400 rad / min, and the residence time was 1 h; the crystal slurry exceeded the outlet branch and entered the crystal growth reactor, 1 wt% ethanol desolventizing agent was added, the temperature was raised to 90℃, then stirring was started, and the temperature was uniformly reduced to 70℃ within 20 min (the desolventizing agent was added for 0.5 h). The total residence time was controlled to be 1.5 h to promote the directional growth of the crystals.

[0059] (3) Solid-liquid separation and product recovery: the crystal slurry obtained in step (2) was filtered and washed by a filtering device to obtain high-purity glyphosate crystals.

[0060] The glyphosate products prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to crystal form, particle size, bulk density, and product content monitoring analysis, respectively. The crystal form was determined by polarized light microscopy; the bulk density was determined according to the national standard GB / T 33810-2017 Pesticide Bulk Density Determination Method; the particle size was determined using a Malvern laser particle size analyzer, and D10, D50, and D90 represent different particle size distributions; the product content was monitored according to the HPLC method; and the results of various tests are shown in Table 1: Table 1 Performance test results of glyphosate solids obtained in Examples 1-3 and Comparative Examples 1-2

[0061] The present application is not limited to the above embodiments, and those skilled in the art can make several improvements and refinements without departing from the principles of the present application, which are also considered within the scope of protection of the present application. The contents not described in detail in the specification are the existing technology known to those skilled in the art.

Claims

1. A method for enhancing glyphosate crystallization in wastewater, characterized in that, Includes the following steps: 1) Add a polyhydroxy linear alcohol solvent to the supersaturated concentrated glyphosate waste liquid, adjust the pH and temperature of the resulting mixture, and perform ultrasonic dispersion to obtain a homogeneous solution; 2) The obtained homogeneous solution was subjected to a first cooling-induced nucleation under ultrasonic and laminar flow control conditions to obtain a glyphosate suspension; 3) Add a small molecule solvent to the obtained glyphosate suspension, perform a second cooling-induced crystallization, and then perform solid-liquid separation and washing to obtain glyphosate solid.

2. The strengthening method according to claim 1, characterized in that, The supersaturated concentrated glyphosate waste liquid is obtained by sequentially adding acid and removing alcohol from the glyphosate synthesis mother liquor waste liquid.

3. The strengthening method according to claim 2, characterized in that, The main components and their mass percentages in the glyphosate synthesis mother liquor include: glyphosate 1.2~1.7%, glyphosate 3.8~4.0%, phosphorous acid 1.7~2.7%; pH value 0.5~2.

0.

4. The strengthening method according to claim 1, characterized in that, Step 1) Control the pH value to 4~6 and the temperature to 100~130℃.

5. The strengthening method according to claim 1, characterized in that, The polyhydroxy linear alcohol solvent is one or more of pentaerythritol, neopentyl glycol, diethylene glycol, dipropylene glycol, and trimethylolpropane.

6. The strengthening method according to claim 1, characterized in that, The endpoint temperature for the first cooling-induced nucleation cooling is 70~80℃; the cooling time for the first cooling-induced nucleation is 20~100 min.

7. The strengthening method according to claim 1, characterized in that, In the laminar flow control, the Reynolds coefficient of the laminar flow velocity is Re = 1500~1800.

8. The strengthening method according to claim 1, characterized in that, Step 3) The small molecule solvent is one or more of methanol, ethanol, acetonitrile, acetone, isopropanol, and tetrahydrofuran.

9. The strengthening method according to claim 1, characterized in that, Step 3) The cooling time for the second cooling-induced crystallization is 40~100 min; Step 3) The temperature for the second cooling-induced crystallization is 65~80℃.

10. The glyphosate solid prepared by the strengthening method according to claims 1 to 9 has a rod-shaped structure with relatively uniform morphology and size, an average particle size of 120 to 220 μm, and an aspect ratio of 3 to 4:1.

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