Treatment process of methyl phosphorus dichloride distillation residual liquid

Abstract

The invention discloses a treatment process of methyl phosphorus dichloride distillation raffinate, the methyl phosphorus dichloride distillation raffinate contains sodium tetrachloroaluminate, and the process comprises the following steps: adding water into a container, and cooling the water; replacing air in the container with nitrogen, and keeping the positive pressure in the container at 0-10KPa; dropwise adding the methyl phosphorus dichloride distillation residual liquid into the cooled water, and carrying out a hydrolysis reaction; when the mass ratio of the dropwise added methyl phosphorus dichloride distillation residual liquid to the water in the container is 1: (1.55-1.65), dropwise adding is stopped, and hydrolysate is obtained; s05, cooling the hydrolysate to 45-55 DEG C, and filtering insoluble substances to obtain an aluminum trichloride mother solution; hydrochloric acid is added into the aluminum trichloride mother liquor to form a mixture, hydrogen chloride gas is introduced into the mixture, and aluminum chloride in the mixture is crystallized and separated out; and filtering and separating the separated crystallized aluminum chloride and mother liquor thereof to obtain crystallized aluminum chloride and crystallized aluminum chloride mother liquor. The polyaluminum chloride can be prepared from the residual methyl phosphorus dichloride distillation liquid, and the additional utilization rate is increased.

Description

Technical Field

[0001] The invention relates to a treatment process for methyl phosphorus dichloride distillation residue, and belongs to the technical field of by-product treatment in the production process of methyl phosphorus dichloride. Background Art

[0002] At present, methyl phosphorus dichloride is an important intermediate of the herbicide glufosinate ammonium. The method for preparing methyl phosphorus dichloride is disclosed in a Chinese patent with a publication number of CN105669748B, which discloses a synthesis method of methyl phosphorus dichloride. In this method, methyl phosphorus dichloride distillation residue is produced, which mainly includes sodium tetrachloroaluminate. In the prior art, the methyl phosphorus dichloride distillation residue is formed into solid waste residue and then processed. The Chinese patent with a publication number of CN112794868B discloses a method for treating sodium tetrachloroaluminate produced in the production process of methyl dichlorophosphine, which converts sodium tetrachloroaluminate produced in the production process of methyl dichlorophosphine into aluminum hydroxide and sodium chloride by reaction, further obtains aluminum oxide and secondary refined brine, and realizes the thorough removal of organic phosphine impurities in sodium tetrachloroaluminate; however, it is actually still based on the treatment method of sodium tetrachloroaluminate solid waste residue, which increases labor costs and is not conducive to continuous production. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a treatment process for distillation residue of methyl phosphorus dichloride, which can prepare polyaluminium chloride by using the distillation residue of methyl phosphorus dichloride and improve the additional utilization rate.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a process for treating methyl phosphorus dichloride distillation residue, wherein the methyl phosphorus dichloride distillation residue contains sodium tetrachloroaluminate, and the process steps include:

[0005] S01: Add water into a container and cool the water down;

[0006] S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa;

[0007] S03: adding the distillation residue of methyl phosphorus dichloride dropwise into the cooled water to perform a hydrolysis reaction; wherein during the reaction, the reaction temperature is controlled to be ≤75°C;

[0008] S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1: (1.55-1.65), stop adding and obtain a hydrolyzate;

[0009] S05: The hydrolyzate is cooled to 45-55°C, and the insoluble matter is filtered to obtain aluminum chloride mother liquor;

[0010] S06: adding hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and passing hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and controlling the temperature to be ≤40°C during the process;

[0011] S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain crystalline aluminum chloride and crystalline aluminum chloride mother liquor;

[0012] S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding sodium aluminate and calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 100±5°C during the reaction, and refluxing for 1.5-2.5h to obtain a polyaluminum chloride reaction solution;

[0013] S09: After the reaction is completed, the temperature is lowered, and the cooled polyaluminium chloride reaction liquid is filtered, and the clarified liquid after filtration is the polyaluminium chloride solution.

[0014] Further, in step S01, after adding water into the container, stirring is started, and cooling is performed by circulating water.

[0015] Further, in step S04, when the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.6, the dropping is stopped to obtain a hydrolyzed solution.

[0016] Further, in step S05, the hydrolyzate is cooled to 50°C.

[0017] Furthermore, in step S08, the temperature is raised to 100°C during the reaction and refluxed for 2 hours.

[0018] Further, in step S07, the crystallized aluminum chloride mother liquor is used to recover hydrochloric acid.

[0019] After adopting the above technical scheme, the method of the present invention firstly hydrolyzes methyl phosphorus dichloride distillation residue and water, and then filters out insoluble matter to obtain aluminum trichloride mother liquor, and then uses the aluminum trichloride mother liquor to add hydrochloric acid and pass hydrogen chloride gas to make aluminum chloride crystallize and precipitate, and then dissolves the crystallized aluminum chloride in water to form a crystallized aluminum chloride aqueous solution, and then adds sodium aluminate and calcium hydroxide to the crystallized aluminum chloride aqueous solution for reaction, and finally obtains a polyaluminum chloride reaction liquid, which fully utilizes the by-product distillation residue generated in the production process of methyl phosphorus dichloride, that is, sodium tetrachloroaluminate, and improves the additional utilization rate. DETAILED DESCRIPTION

[0020] The present invention provides a process for treating the residual liquid of distillation of methyl phosphorus dichloride. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It should be particularly pointed out that all similar replacements and modifications are obvious to those skilled in the art, and they all belong to the scope of protection of the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention.

[0021] A process for treating methyl phosphorus dichloride distillation residue, wherein the methyl phosphorus dichloride distillation residue is derived from a by-product in the production process of methyl phosphorus dichloride, and the methyl phosphorus dichloride distillation residue contains sodium tetrachloroaluminate. The process steps include:

[0022] S01: Add water into a container and cool the water down;

[0023] S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa;

[0024] S03: adding the distillation residue of methyl phosphorus dichloride dropwise into the cooled water to perform a hydrolysis reaction; wherein during the reaction, the reaction temperature is controlled to be ≤75°C;

[0025] S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1: (1.55-1.65), stop adding and obtain a hydrolyzate;

[0026] S05: The hydrolyzate is cooled to 45-55°C, and the insoluble matter is filtered to obtain aluminum chloride mother liquor;

[0027] S06: adding hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and passing hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and controlling the temperature to be ≤40°C during the process;

[0028] S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain crystalline aluminum chloride and crystalline aluminum chloride mother liquor;

[0029] S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding sodium aluminate and calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 100±5°C during the reaction, and refluxing for 1.5-2.5h to obtain a polyaluminum chloride reaction solution;

[0030] S09: After the reaction is completed, the temperature is lowered, and the cooled polyaluminium chloride reaction liquid is filtered, and the clarified liquid after filtration is the polyaluminium chloride solution.

[0031] Further, in step S01, after adding water into the container, stirring is started, and cooling is performed by circulating water.

[0032] Furthermore, in step S03, the temperature of the added methyl phosphorus dichloride distillation residue is controlled below 75°C.

[0033] Further, in step S04, when the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.6, the dropping is stopped to obtain a hydrolyzed solution.

[0034] Further, in step S05, the hydrolyzate is cooled to 50°C.

[0035] Furthermore, in step S08, the temperature is raised to 100°C during the reaction and refluxed for 2 hours.

[0036] Further, in step S07, the crystallized aluminum chloride mother liquor is used to recover hydrochloric acid.

[0037] According to the method, methyl phosphorus dichloride distillation residue and water are first subjected to hydrolysis reaction, and insoluble matter is filtered out to obtain aluminum trichloride mother liquor, and then aluminum trichloride mother liquor is used to add hydrochloric acid and introduce hydrogen chloride gas to make aluminum chloride crystallize, and then the crystalline aluminum chloride is dissolved in water to form a crystalline aluminum chloride aqueous solution, and then sodium aluminate and calcium hydroxide are added to the crystalline aluminum chloride aqueous solution for reaction to finally obtain a polyaluminum chloride reaction liquid, which fully utilizes the by-product distillation residue generated in the production process of methyl phosphorus dichloride, namely sodium tetrachloroaluminate, and improves the additional utilization rate.

[0038] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments.

[0039] Embodiment 1

[0040] A process for treating methyl phosphorus dichloride distillation residue, the process comprising:

[0041] S01: After adding 1600g of water into the container, start stirring and cool it down by circulating water;

[0042] S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa;

[0043] S03: 1000 g of methyl phosphorus dichloride distillation residue is added dropwise to the cooled water for hydrolysis reaction; wherein, during the reaction process, the reaction temperature is controlled at 40°C-75°C;

[0044] S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.6, stop adding and obtain a hydrolyzate;

[0045] S05: The hydrolyzate was cooled to 50°C and the insoluble matter was filtered to obtain 2280 g of aluminum chloride mother liquor;

[0046] S06: Add 500g of hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and introduce hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and control the temperature at about 30°C during the process;

[0047] S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain 518 g of crystalline aluminum chloride and crystalline aluminum chloride mother liquor; the crystalline aluminum chloride mother liquor is used to recover hydrochloric acid;

[0048] S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding 110 g of sodium aluminate and 180 g of calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 100° C. during the reaction, and refluxing for 2 hours to obtain a polyaluminum chloride reaction solution;

[0049] S09: After the reaction is completed, the temperature is lowered and the cooled polyaluminium chloride reaction liquid is filtered. The clarified liquid after filtration is 850 g of a polyaluminium chloride solution with a content of 10.2%.

[0050] Embodiment 2

[0051] A process for treating methyl phosphorus dichloride distillation residue, the process comprising:

[0052] S01: After adding 1550g of water into the container, start stirring and cool it down by circulating water;

[0053] S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa;

[0054] S03: adding the distillation residue of methyl phosphorus dichloride dropwise into the cooled water to carry out a hydrolysis reaction; wherein, during the reaction process, the reaction temperature is controlled at 60° C. to 70° C.;

[0055] S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.55, stop adding and obtain a hydrolyzate;

[0056] S05: The hydrolyzate was cooled to 45°C and the insoluble matter was filtered to obtain 2235 g of aluminum chloride mother liquor;

[0057] S06: Add 500g of hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and introduce hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and control the temperature at about 35°C during the process;

[0058] S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain 518 g of crystalline aluminum chloride and crystalline aluminum chloride mother liquor; the crystalline aluminum chloride mother liquor is used to recover hydrochloric acid;

[0059] S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding 110 g of sodium aluminate and 180 g of calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 95° C. during the reaction, and refluxing for 1.5 h to obtain a polyaluminum chloride reaction solution;

[0060] S09: After the reaction is completed, the temperature is lowered and the cooled polyaluminium chloride reaction liquid is filtered. The clarified liquid after filtration is 847 g of a polyaluminium chloride solution with a content of 10.3%.

[0061] Embodiment 3

[0062] A process for treating methyl phosphorus dichloride distillation residue, the process comprising:

[0063] S01: After adding 1650g of water into the container, start stirring and cool it down by circulating water;

[0064] S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa;

[0065] S03: adding the distillation residue of methyl phosphorus dichloride dropwise into the cooled water to perform a hydrolysis reaction; wherein, during the reaction process, the reaction temperature is controlled at 50° C. to 60° C.;

[0066] S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.65, stop adding and obtain a hydrolyzate;

[0067] S05: The hydrolyzate was cooled to 55°C and the insoluble matter was filtered to obtain 2325 g of aluminum chloride mother liquor;

[0068] S06: Add 500g of hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and introduce hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and control the temperature at about 30°C during the process;

[0069] S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain 522 g of crystalline aluminum chloride and crystalline aluminum chloride mother liquor; the crystalline aluminum chloride mother liquor is used to recover hydrochloric acid;

[0070] S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding 110 g of sodium aluminate and 180 g of calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 105° C. during the reaction, and refluxing for 2.5 hours to obtain a polyaluminum chloride reaction solution;

[0071] S09: After the reaction is completed, the temperature is lowered and the cooled polyaluminium chloride reaction liquid is filtered. The clarified liquid after filtration is 850 g of a polyaluminium chloride solution with a content of 10.1%.

[0072] Through the above three embodiments, polyaluminium chloride that meets the requirements can be prepared, achieving high added value.

[0073] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for treating methyl phosphorus dichloride distillation residue, wherein the methyl phosphorus dichloride distillation residue contains sodium tetrachloroaluminate, characterized in that: The process steps include: S01: Add water into a container and cool the water down; S02: Use nitrogen to replace the air in the container and maintain the positive pressure in the container at 0-10KPa; S03: adding the distillation residue of methyl phosphorus dichloride dropwise into the cooled water to perform a hydrolysis reaction; wherein during the reaction, the reaction temperature is controlled to be ≤75°C; S04: When the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1: (1.55-1.65), stop adding and obtain a hydrolyzate; S05: The hydrolyzate is cooled to 45-55°C, and the insoluble matter is filtered to obtain aluminum chloride mother liquor; S06: adding hydrochloric acid to the aluminum chloride mother liquor to form a mixture, and passing hydrogen chloride gas into the mixture to crystallize aluminum chloride in the mixture, and controlling the temperature to be ≤40°C during the process; S07: The precipitated crystalline aluminum chloride is separated from its mother liquor by filtration to obtain crystalline aluminum chloride and crystalline aluminum chloride mother liquor; S08: dissolving the crystalline aluminum chloride with water to form a crystalline aluminum chloride aqueous solution, adding sodium aluminate and calcium hydroxide to the crystalline aluminum chloride aqueous solution for reaction, heating to 100±5°C during the reaction, and refluxing for 1.5-2.5h to obtain a polyaluminum chloride reaction solution; S09: After the reaction is completed, the temperature is lowered, and the cooled polyaluminium chloride reaction liquid is filtered, and the clarified liquid after filtration is the polyaluminium chloride solution.

2. The treatment process according to claim 1, characterized in that: In step S01, after adding water into the container, stirring is started, and the temperature is lowered by circulating water.

3. The treatment process according to claim 1, characterized in that: In step S04, when the mass ratio of the added methyl phosphorus dichloride distillation residue to the mass ratio of the water in the container is 1:1.6, the dropping is stopped to obtain a hydrolyzed solution.

4. The treatment process according to claim 1, characterized in that: In step S05, the hydrolyzate is cooled to 50°C.

5. The treatment process according to claim 1, characterized in that: In step S08, the temperature is raised to 100°C during the reaction and refluxed for 2 hours.

6. The treatment process according to claim 1, characterized in that: In step S07, the crystallized aluminum chloride mother liquor is used to recover hydrochloric acid.