Preparation method of modified superfine sodium hypophosphite

Abstract

The application discloses a preparation method of modified superfine sodium hypophosphite and belongs to the technical field of sodium hypophosphite preparation. The preparation method of the modified superfine sodium hypophosphite comprises the following steps: step (1), mixing quicklime and water to prepare lime milk, then adding a sodium hydroxide solution into a reaction kettle containing the lime milk, uniformly mixing and obtaining a mixed solution; step (2), heating the mixed solution while introducing nitrogen, adding yellow phosphorus into the reaction kettle, heating and reacting to obtain a reaction solution, collecting generated gas through a pipeline during the reaction process, and treating the gas; and step (3), adding a modified surfactant into the reaction solution, stirring and mixing, filtering, removing calcium, adjusting pH, concentrating, crystallizing, centrifuging, drying and obtaining the modified superfine sodium hypophosphite. The prepared sodium hypophosphite has small and uniform particle size, and the content of phosphine gas in the preparation process is low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sodium hypophosphite preparation, and particularly relates to a preparation method of modified superfine sodium hypophosphite. BACKGROUND

[0002] Since the United States first applied sodium hypophosphite to chemical nickel plating in the 1940s, sodium hypophosphite not only promotes the rapid development of chemical nickel plating technology, but also promotes the overall progress of the hypophosphite industry. In recent years, with the continuous innovation and application of surface treatment technology, such as fine chemical industry, flame retardant, water treatment agent and synthesis of new materials, the demand for sodium hypophosphite is increasing by 10% to 15% per year. And with the enhancement of environmental awareness and the deepening of the concept of sustainable development, the preparation process of modified superfine sodium hypophosphite also pays more attention to green and low carbon. Therefore, it is necessary to develop a low-energy and low-emission production process to reduce the generation of by-products and waste emissions, and to maximize the use of resources and protect the environment.

[0003] Patent CN102502545B discloses a preparation method of sodium hypophosphite, which adopts aeration and lime-iron salt method to remove arsenic and fluorine impurities in the sodium hypophosphite, and obtains a mixed solution of sodium hypophosphite and sodium phosphite. By using evaporation concentration, crystallization and ethanol distillation-recrystallization method, high-purity industrial-grade sodium hypophosphite and sodium phosphite products are obtained. This method improves the comprehensive utilization rate of effective phosphorus elements in mud phosphorus, the extraction agent ethanol can be recycled, resources are saved, and environmental pollution is avoided. However, the particle size uniformity and fineness of the sodium hypophosphite prepared by this method still have room for improvement, and the waste pollution generated in the preparation process still has room for reduction. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of modified superfine sodium hypophosphite, which solves the technical problems of non-uniform particle size of the prepared sodium hypophosphite and high concentration of waste gas generated in the preparation process in the prior art.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a preparation method of modified superfine sodium hypophosphite, comprising the following steps:

[0007] Step (1): mixing lime with water, stirring uniformly to prepare lime milk, then adding sodium hydroxide solution into the reaction kettle containing the lime milk, starting the stirring system, and uniformly mixing to obtain a mixed solution;

[0008] Step (2): open the heating system of the reaction kettle, heat the mixed solution while passing nitrogen, add yellow phosphorus to the reaction kettle, heat the reaction, continue to stir, and obtain a reaction solution. During the reaction, the generated gas is collected through a pipeline and treated;

[0009] Step (3): add a modified surfactant to the reaction solution, stir and mix, filter, remove calcium, adjust the pH, concentrate, crystallize, centrifuge, and dry to obtain modified superfine sodium hypophosphite.

[0010] Preferably, in step (1), the amount ratio of quicklime, water and sodium hydroxide solution is (1-3) g:(16-48) mL:(3.6-10.8) mL, the concentration of sodium hydroxide solution is 1 mol / L, and the mixing time is 5-8 h.

[0011] Preferably, in step (2), the heating temperature is 40-45℃, the amount ratio of yellow phosphorus and mixed solution is (1-3) g:(20-30) mL, the heating reaction temperature is 95-98℃, and the reaction time is 2-4 h.

[0012] Preferably, in step (2), the generated gas is treated by a tail gas absorption treatment device, which is composed of a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column, a constant temperature water bath, a phosphine detection tube and a tail gas absorption bottle. The adsorption oxidation column contains a modified adsorbent, and the preparation method of the modified adsorbent comprises the following steps:

[0013] Q1: Mix tetrapropylammonium hydroxide with distilled water, add silica sol, stir vigorously, and then add to the reaction kettle. After heating and crystallization, cool down to obtain a mixed solution;

[0014] Q2: Add sodium hydroxide and sodium aluminate to distilled water, stir until completely dissolved, slowly add silica sol, stir, then add the mixed solution, continue to stir, and obtain an initial gel. Add the initial gel to the reaction kettle, heat and react, cool down, filter, wash, dry, calcine, and ion exchange to obtain solid particles;

[0015] Q3: Add the solid particles to a cerium nitrate solution, ultrasonic oscillation treatment to make them completely mixed and uniform, dry and calcine to obtain a powder material. Press, crush and sieve the powder material to obtain a modified adsorbent.

[0016] In the above process, the silica sol is used as the silicon source and the tetrapropyl ammonium hydroxide is used as the template agent to prepare a mixed solution under heating. Then, under alkaline conditions, the sodium aluminate reacts with the silicate ions in the mixed solution to form a silicate gel. With the reaction proceeding, the silicate gel gradually forms an initial gel. Heating promotes the further condensation and crystallization of the gel to form more stable solid particles. Subsequently, through ultrasonic treatment, the cerium ions in the cerium nitrate solution are adsorbed to the surface of the solid particles to form a modified adsorbent through complexation.

[0017] Preferably, in Q1, the molar ratio of the tetrapropyl ammonium hydroxide, distilled water and silica sol is (0.2-0.4):(20-40):(1-2), the stirring time is 4-6h, the heating crystallization temperature is 90-100℃, and the crystallization time is 22-24h; in Q2, the molar ratio of the sodium hydroxide, sodium aluminate, distilled water and silica sol is (0.05-0.15):(0.013-0.016):(15-35):(1-1.2), the stirring time is 3-5h, the continued stirring time is 1-2h, the heating reaction temperature is 140-180℃, the reaction time is 4-24h, the drying temperature is 90-110℃, and the calcination temperature is 500-600℃.

[0018] Preferably, in Q3, the ratio of the amount of the solid particles to the cerium nitrate solution is (2-4)g:(6-10)mL, the concentration of the cerium nitrate solution is 0.8g / mL, the oscillation treatment time is 2-4h, the drying temperature is 100-120℃, the time is 10-12h, the calcination temperature is 400-500℃, and the time is 5-8h.

[0019] Preferably, in step (3), the ratio of the amount of the reaction solution to the modified surfactant is (20-25)mL:(10-20)g, the stirring and mixing time is 6-8h, and the pH is adjusted to 7-7.4.

[0020] Preferably, the preparation method of the modified surfactant comprises the following steps:

[0021] S1: potassium carbonate and 1,3-dibromopropane are added to a container, then acetonitrile is added, and heated to reflux under stirring. 3-hydroxybenzaldehyde is added to acetonitrile, and after dissolution, a 3-hydroxybenzaldehyde solution is obtained. The solution is added dropwise to the container. After the dropwise addition is completed, the reaction is continued. Nitrogen is introduced during the reaction. After the reaction is completed, cooling is performed, and suction filtration is performed. The obtained filtrate is added to distilled water and dichloromethane, respectively. After mixing, the organic phase is taken, washed, dried, eluted, dissolved, recrystallized, and vacuum dried to obtain product 1;

[0022] S2: after dissolving product 1 in methanol, slowly drop into a container containing diethylamine aqueous solution, after the end of dropping, continue to react, nitrogen is introduced during the reaction, after the reaction, rotary evaporation, extraction, combine organic phase, dry rotary evaporation, elution, vacuum rotary evaporation, dry, product 2 is obtained;

[0023] S3: dissolve product 2 in acetonitrile, add butylsulfonyl lactone, stir at room temperature, nitrogen is introduced during the reaction, after the reaction, filter, wash, recrystallize at low temperature, vacuum dry, modified surfactant is obtained.

[0024] In the above process, the synthesis reaction formula of the modified surfactant is as follows:

[0025]

[0026] The mass spectrum analysis result is: m / z: 357.16 (100.0%), 358.16 (19.6%), 359.16 (4.7%), 359.17 (2.7%).

[0027] As preferred, in the S1, the mass ratio of potassium carbonate, 1,3-dibromopropane and 3-hydroxybenzaldehyde is (45.3-90.6):(150-300):(20-40), the dropping speed is 1 drop / 2s, and the continuous reaction time is 10-12h.

[0028] As preferred, in the S2, the dosage ratio of product 1, methanol and diethylamine aqueous solution is (20-24)g:(200-240)mL:(190-228)g, the mass fraction of diethylamine aqueous solution is 40wt%, and the continuous reaction time is 6-8h; in the S3, the dosage ratio of product 2, acetonitrile and butylsulfonyl lactone is (13-26)g:(400-800)mL:(10-20)g, and the stirring reaction time is 110-120h.

[0029] In summary, due to the adoption of the above technical scheme, the present application has the following advantages:

[0030] 1. The present application firstly uses tetrapropylammonium hydroxide, silica sol, sodium silicate and cerium nitrate as raw materials to prepare a modified adsorbent, and then uses potassium carbonate, 1,3-dibromopropane, 3-hydroxybenzaldehyde, diethylamine and butylsulfonyl lactone as raw materials to prepare a modified surfactant, the modified adsorbent is used for adsorbing phosphine gas generated in the preparation process of modified ultrafine sodium hypophosphite, and the modified surfactant is used in the preparation process of modified ultrafine sodium hypophosphite, which not only can obtain highly uniform ultrafine particles, but also can reduce the generation of phosphine gas and reduce environmental pollution.

[0031] 2. The application uses tetrapropylammonium hydroxide, silica sol, sodium silicate and cerium nitrate as raw materials to prepare a modified adsorbent, which is used to absorb phosphine gas generated in the preparation process of sodium hypophosphite. The cerium ions in the modified adsorbent can promote the chemical reaction between phosphine gas and the active sites on the surface of the adsorbent during the adsorption process, accelerate the conversion and fixation of phosphine molecules, and improve the adsorption efficiency. The presence of cerium ions can also enhance the chemical activity of the adsorbent surface, allowing phosphine gas molecules to form more stable chemical bonds with the adsorbent surface, which helps to improve the adsorption capacity and stability. The porous structure and large specific surface area of the solid particles provide opportunities for the contact between the adsorbent and the phosphine gas, improving the adsorption efficiency. The formed silicate matrix is treated by heating and calcination during the preparation process, forming a stable chemical structure to ensure the use effect of the modified adsorbent in complex environments.

[0032] 3. The application uses potassium carbonate, 1,3-dibromopropane, 3-hydroxybenzaldehyde, diethylamine and butyl sulfone lactone as raw materials to prepare a modified surfactant. The modified surfactant is added to the preparation process of superfine sodium hypophosphite, which can effectively improve the particle size uniformity and smallness of sodium hypophosphite. The molecular structure and properties of the modified surfactant allow sodium hypophosphite to play a template or guiding role during the preparation process. The zwitterionic part contained in the modified surfactant can be adsorbed on the surface of the sodium hypophosphite crystals being formed, limiting the growth rate and direction of the crystals through steric hindrance effect and charge effect. The uniform distribution of the modified surfactant in the solution is conducive to the formation of uniform crystal nucleus distribution, avoiding local supersaturation leading to crystal aggregation and uneven particles. At the same time, the modified surfactant can reduce the free energy of the crystal surface, making the crystal tend to form a more stable and smaller structure during the growth process, thereby obtaining finer and more uniform sodium hypophosphite particles. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0034] Embodiment 1: The embodiment discloses a preparation method of a modified adsorbent, comprising the following steps:

[0035] Q1: 1.02g of tetrapropylammonium hydroxide is mixed with 9mL of distilled water, then 1.5g of silica sol is added, and after 4h of vigorous stirring, it is added to a reaction kettle, and after 24h of heating crystallization at 100℃, it is cooled to obtain a mixed solution;

[0036] Q2: 0.09 g of sodium hydroxide and 0.035 g of sodium aluminate were added to 7.5 mL of distilled water, after stirring to complete dissolution, 1.1 g of silica sol was slowly added dropwise, stirred for 3 h, then 1.2 mL of mixed solution was added, and stirring was continued for 2 h to obtain an initial gel, which was added to a reaction kettle, heated at 140°C for 20 h, cooled, filtered, washed, dried at 100°C, calcined at 550°C, and ion exchanged to obtain solid particles;

[0037] Q3: 3 g of solid particles were added to 8 mL of cerium nitrate solution with a concentration of 0.8 g / mL, ultrasonic oscillation treatment was performed for 4 h to make it completely mixed and uniform, dried at 120°C for 12 h, and calcined at 400°C for 6 h to obtain a powder material, which was tabletted, broken, and sieved to obtain a modified adsorbent.

[0038] The embodiment discloses a preparation method of a modified surfactant, comprising the following steps:

[0039] S1: 68 g of potassium carbonate and 225 g of 1,3-dibromopropane were added to a container, then 250 mL of acetonitrile was added, heated to reflux under stirring, 30 g of 3-hydroxybenzaldehyde was added to 20 mL of acetonitrile, dissolved to obtain a 3-hydroxybenzaldehyde solution, which was added dropwise to the container, the dropwise adding speed was 1 drop / 2 s, after the dropwise adding was completed, the reaction was continued for 12 h, nitrogen was introduced during the reaction, after the reaction was completed, cooling was performed, suction filtration was performed, the obtained filtrate was added to 250 mL of distilled water and 250 mL of dichloromethane respectively, after being fully mixed, the organic phase was taken, washed, dried, eluted, dissolved, recrystallized, and vacuum dried to obtain product 1;

[0040] S2: 22 g of product 1 was dissolved in 220 mL of methanol and then slowly added dropwise to a container containing 209 g of a 40wt% diethylamine aqueous solution, after the dropwise adding was completed, the reaction was continued for 8 h, nitrogen was introduced during the reaction, after the reaction was completed, rotary evaporation was performed, the organic phases were combined, dried, rotary evaporated, eluted, vacuum rotary evaporated, and dried to obtain product 2;

[0041] S3: 19.5 g of product 2 was dissolved in 600 mL of acetonitrile, 15 g of butylsulfonyl lactone was added, and stirring reaction was performed at room temperature for 120 h, nitrogen was introduced during the reaction, after the reaction was completed, suction filtration was performed, washed, recrystallized at low temperature, and vacuum dried to obtain a modified surfactant.

[0042] The embodiment discloses a preparation method of superfine sodium hypophosphite, comprising the following steps:

[0043] Step (1): 2 g of quicklime was mixed with 32 mL of water to prepare lime milk, then 7.2 mL of a 1 mol / L sodium hydroxide solution was added to a reaction kettle containing the lime milk, the stirring system was started, and a mixed solution was obtained after mixing for 6 h;

[0044] Step (2): Start the heating system of the reaction kettle, heat 25 mL of the mixed solution to 45℃, while nitrogen is introduced, 2g of yellow phosphorus is added to the reaction kettle, and the reaction is carried out at 98℃ for 4h. After continuous stirring, the reaction solution is obtained. During the reaction process, the generated gas is collected through the pipeline and treated. The generated gas is treated by using a tail gas absorption treatment device. The tail gas absorption treatment device is composed of a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column (containing a modified adsorbent), a constant temperature water bath, a phosphine detection tube and a tail gas absorption bottle.

[0045] Step (3): 15g of modified surfactant is added to 23mL of the reaction solution, and after stirring and mixing for 8h, filtration, calcium removal, pH adjustment to 7, concentration, crystallization, centrifugation and drying, modified superfine sodium hypophosphite is obtained.

[0046] Example 2: The present embodiment discloses a preparation method of a modified adsorbent, comprising the following steps:

[0047] Q1: 0.68g of tetrapropylammonium hydroxide is mixed with 12mL of distilled water, then 1g of silica sol is added, and after vigorous stirring for 4h, it is added to the reaction kettle. After heating and crystallization at 100℃ for 24h, the temperature is lowered to obtain a mixed solution;

[0048] Q2: 0.03g of sodium hydroxide and 0.03g of sodium aluminate are added to 10.5mL of distilled water, and after stirring until completely dissolved, 1g of silica sol is slowly added dropwise, stirred for 3h, then 1.2mL of the mixed solution is added, and continues to stir for 2h to obtain an initial gel. The initial gel is added to the reaction kettle, heated at 140℃ for 20h, cooled, filtered, washed, dried at 100℃, calcined at 550℃, and ion exchanged to obtain solid particles;

[0049] Q3: 2g of solid particles are added to 10mL of cerium nitrate solution with a concentration of 0.8g / mL, ultrasonic oscillation treatment is carried out for 4h to make them completely mixed and uniform, dried at 120℃ for 12h, and calcined at 400℃ for 6h to obtain a powder substance. The powder substance is tableted, crushed and sieved to obtain a modified adsorbent.

[0050] The present embodiment discloses a preparation method of a modified surfactant, comprising the following steps:

[0051] S1: 45.3 g of potassium carbonate and 150 g of 1,3-dibromopropane were added to a container, followed by 250 mL of acetonitrile, heated to reflux under stirring, 40 g of 3-hydroxybenzaldehyde was added to 20 mL of acetonitrile, and after dissolution, a 3-hydroxybenzaldehyde solution was obtained, which was added dropwise to the container, the dropwise addition rate was 1 drop / 2 s, after the dropwise addition was completed, the reaction was continued for 12 h, nitrogen was introduced during the reaction, after the reaction was completed, it was cooled, filtered, the obtained filtrate was added to 250 mL of distilled water and 250 mL of dichloromethane respectively, after mixing, the organic phase was taken, washed, dried, eluted, dissolved, recrystallized, and vacuum dried to obtain product 1;

[0052] S2: 24 g of product 1 was dissolved in 240 mL of methanol and slowly added to a container containing 228 g of a 40 wt% diethylamine aqueous solution, after the dropwise addition was completed, the reaction was continued for 8 h, nitrogen was introduced during the reaction, after the reaction was completed, it was rotary evaporated, extracted, the organic phases were combined, dried, rotary evaporated, eluted, vacuum rotary evaporated, and dried to obtain product 2;

[0053] S3: 13 g of product 2 was dissolved in 800 mL of acetonitrile, 20 g of butylsulfinyl butane was added, and the reaction was stirred at room temperature for 120 h, nitrogen was introduced during the reaction, after the reaction was completed, it was filtered, washed, recrystallized at low temperature, and vacuum dried to obtain a modified surfactant.

[0054] The embodiment discloses a preparation method of superfine sodium hypophosphite, and comprises the following steps:

[0055] Step (1): 1 g of quicklime was mixed with 16 mL of water, and after stirring, lime milk was prepared, then 10.8 mL of a 1 mol / L sodium hydroxide solution was added to a reaction kettle containing the lime milk, the stirring system was started, and after mixing for 6 h, a mixed solution was obtained;

[0056] Step (2): The heating system of the reaction kettle was started, 20 mL of the mixed solution was heated to 45 DEG C, and nitrogen was introduced at the same time, 1 g of yellow phosphorus was added to the reaction kettle, and the reaction was carried out at 98 DEG C for 4 h, after continuous stirring, a reaction solution was obtained, during the reaction, the generated gas was collected through a pipeline and treated, the generated gas was treated by using a tail gas absorption treatment device, and the tail gas absorption treatment device was composed of a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column (containing a modified adsorbent), a constant-temperature water bath, a phosphine detection tube and a tail gas absorption bottle;

[0057] Step (3): 10 g of a modified surfactant was added to 20 mL of the reaction solution, after stirring and mixing for 8 h, filtration, calcium removal, pH adjustment to 7, concentration, crystallization, centrifugation and drying, modified superfine sodium hypophosphite was obtained.

[0058] Example 3: This example discloses a method for preparing a modified adsorbent, comprising the following steps:

[0059] Q1: After mixing 1.36 g of tetrapropylammonium hydroxide with 6 mL of distilled water, 2 g of silica sol is added, and after stirring vigorously for 4 h, it is added to a reaction kettle, and after crystallization at 100°C for 24 h, it is cooled to obtain a mixed solution;

[0060] Q2: After adding 0.15 g of sodium hydroxide and 0.04 g of sodium aluminate to 4.5 mL of distilled water, stirring until completely dissolved, slowly adding 1.2 g of silica sol, stirring for 3 h, then adding 1.2 mL of the mixed solution, continuing to stir for 2 h, an initial gel is obtained, which is added to a reaction kettle, heated at 140°C for 20 h, cooled, filtered, washed, dried at 100°C, calcined at 550°C, and after ion exchange, solid particles are obtained;

[0061] Q3: 4 g of the solid particles are added to 6 mL of a cerium nitrate solution with a concentration of 0.8 g / mL, ultrasonic oscillation treatment is performed for 4 h to make them completely mixed and uniform, dried at 120°C for 12 h, and after calcination at 400°C for 6 h, a powder material is obtained, which is tabletted, broken, and sieved to obtain a modified adsorbent.

[0062] This example discloses a method for preparing a modified surfactant, comprising the following steps:

[0063] S1: 90.6 g of potassium carbonate and 300 g of 1,3-dibromopropane are added to a container, followed by the addition of 250 mL of acetonitrile, heated to reflux under stirring conditions, 20 g of 3-hydroxybenzaldehyde is added to 20 mL of acetonitrile, dissolved to obtain a 3-hydroxybenzaldehyde solution, which is added dropwise to the container, the dropwise addition speed is 1 drop / 2 s, after the dropwise addition is completed, the reaction is continued for 12 h, nitrogen is introduced during the reaction, after the reaction is completed, it is cooled, suction filtered, the obtained filtrate is added to 250 mL of distilled water and 250 mL of dichloromethane respectively, after fully mixing, the organic phase is taken, washed, dried, eluted, dissolved, recrystallized, vacuum dried to obtain product 1;

[0064] S2: After dissolving 20 g of product 1 in 200 mL of methanol, it is slowly added dropwise to a container containing 190 g of a 40wt% mass fraction diethylamine aqueous solution, after the dropwise addition is completed, the reaction is continued for 8 h, nitrogen is introduced during the reaction, after the reaction is completed, rotary evaporation is performed, the organic phases are combined, dried, eluted, vacuum rotary evaporated, dried to obtain product 2;

[0065] S3: 26 g of product 2 is dissolved in 40 mL of acetonitrile, 10 g of butylsulfonyl lactone is added, stirred at room temperature for 120 h, nitrogen is introduced during the reaction, after the reaction is completed, suction filtered, washed, recrystallized at low temperature, vacuum dried to obtain a modified surfactant.

[0066] The embodiment discloses a preparation method of superfine sodium hypophosphite, and comprises the following steps:

[0067] Step (1): 3g of lime is mixed with 48mL of water, and a lime milk is prepared after uniform stirring; then 3.6mL of a sodium hydroxide solution with a concentration of 1mol / L is added into a reaction kettle containing the lime milk, a stirring system is started, and a mixed solution is obtained after 6h of mixing;

[0068] Step (2): a heating system of the reaction kettle is started, 30mL of the mixed solution is heated to 45℃, nitrogen is introduced at the same time, 3g of yellow phosphorus is added into the reaction kettle, and reaction is carried out at 98℃ for 4h; after continuous stirring, a reaction solution is obtained; in the reaction process, the generated gas is collected through a pipeline and treated; the generated gas is treated by using a tail gas absorption treatment device; the tail gas absorption treatment device is composed of a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column (containing a modified adsorbent), a constant-temperature water bath, a phosphine detection tube and a tail gas absorption bottle;

[0069] Step (3): 20g of a modified surfactant is added into 25mL of the reaction solution; after 8h of stirring and mixing, filtration, calcium removal, pH adjustment (pH=7), concentration, crystallization, centrifugation and drying are carried out, modified superfine sodium hypophosphite is obtained.

[0070] The embodiment discloses a preparation method of a modified adsorbent, and comprises the following steps:

[0071] Q1: 0.85g of tetrapropylammonium hydroxide is mixed with 7.5mL of distilled water, 1.2g of silica sol is added, and after 4h of intense stirring, the mixture is added into a reaction kettle; after 24h of heating crystallization at 100℃, temperature is lowered, and a mixed solution is obtained;

[0072] Q2: 0.06g of sodium hydroxide and 0.032g of sodium aluminate are added into 6mL of distilled water, stirring is carried out until complete dissolution, 1.05g of silica sol is slowly added dropwise, stirring is carried out for 3h, then 1.2mL of the mixed solution is added, and stirring is continued for 2h, an initial gel is obtained; the initial gel is added into a reaction kettle, after 20h of heating reaction at 140℃, temperature is lowered, filtration, washing, drying at 100℃ and calcination at 550℃ are carried out, and solid particles are obtained after ion exchange;

[0073] Q3: 2.5g of the solid particles is added into 7mL of a cerium nitrate solution with a concentration of 0.8g / mL, ultrasonic oscillation treatment is carried out for 4h, so that the solid particles are completely mixed and uniform; after 12h of drying at 120℃ and 6h of calcination at 400℃, a powder substance is obtained; the powder substance is subjected to tabletting, crushing and sieving, and a modified adsorbent is obtained.

[0074] The embodiment discloses a preparation method of a modified surfactant, and comprises the following steps:

[0075] S1: 56.65 g of potassium carbonate and 250 g of 1,3-dibromopropane were added to a container, followed by 250 mL of acetonitrile, heated to reflux under stirring, 25 g of 3-hydroxybenzaldehyde was added to 20 mL of acetonitrile, and after dissolution, a 3-hydroxybenzaldehyde solution was obtained, which was added dropwise to the container, the dropwise addition was at a rate of 1 drop / 2 s, after the dropwise addition was completed, the reaction was continued for 12 h, nitrogen was introduced during the reaction, after the reaction was completed, it was cooled, filtered, the obtained filtrate was added to 250 mL of distilled water and 250 mL of dichloromethane respectively, after mixing, the organic phase was taken, washed,

[0076] dried, eluted, dissolved, recrystallized, vacuum dried to obtain product 1;

[0077] S2: 21 g of product 1 was dissolved in 230 mL of methanol and slowly added to a container containing 199.5 g of a 40wt% mass fraction diethylamine aqueous solution, after the dropwise addition was completed, the reaction was continued for 8 h, nitrogen was introduced during the reaction, after the reaction was completed, it was rotary evaporated, extracted, the organic phases were combined, dried, rotary evaporated, eluted, vacuum rotary evaporated, and dried to obtain product 2;

[0078] S3: 15 g of product 2 was dissolved in 500 mL of acetonitrile, 12 g of butylsulfinyl butane was added, and the reaction was stirred at room temperature for 120 h, nitrogen was introduced during the reaction, after the reaction was completed, it was filtered, washed, recrystallized at low temperature, and vacuum dried to obtain a modified surfactant.

[0079] The embodiment discloses a preparation method of superfine sodium hypophosphite, and comprises the following steps:

[0080] Step (1): 2.5 g of quicklime was mixed with 30 mL of water, and after stirring, lime milk was prepared, then 9 mL of a 1 mol / L sodium hydroxide solution was added to a reaction kettle containing the lime milk, the stirring system was started, and after mixing for 6 h, a mixed solution was obtained;

[0081] Step (2): The heating system of the reaction kettle was started, 28 mL of the mixed solution was heated to 45 DEG C, and nitrogen was introduced at the same time, 1.5 g of yellow phosphorus was added to the reaction kettle, and the reaction was carried out at 98 DEG C for 4 h, after continuous stirring, a reaction solution was obtained, during the reaction, the generated gas was collected through a pipeline and treated, the generated gas was treated by using a tail gas absorption treatment device, the tail gas absorption treatment device comprises a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column (containing a modified adsorbent), a constant-temperature water bath, a phosphine detection tube and a tail gas absorption bottle;

[0082] Step (3): 12 g of a modified surfactant was added to 21 mL of the reaction solution, after stirring and mixing for 8 h, filtration, calcium removal, pH adjustment to 7, concentration, crystallization, centrifugation and drying were carried out, and a modified superfine sodium hypophosphite was obtained.

[0083] Example 5: This example discloses a method for preparing a modified adsorbent, comprising the following steps:

[0084] Q1: After mixing 1.19 g of tetrapropylammonium hydroxide with 10.5 mL of distilled water, 1.7 g of silica sol was added, and after stirring vigorously for 4 h, it was added to a reaction kettle, and after crystallization at 100°C for 24 h, it was cooled to obtain a mixed solution;

[0085] Q2: 0.12 g of sodium hydroxide and 0.038 g of sodium aluminate were added to 9 mL of distilled water, and after stirring until completely dissolved, 1.15 g of silica sol was slowly added dropwise, stirred for 3 h, and then 1.2 mL of the mixed solution was added, and stirring was continued for 2 h to obtain an initial gel, which was added to a reaction kettle, and after heating at 140°C for 20 h, it was cooled, filtered, washed, dried at 100°C, calcined at 550°C, and ion exchanged to obtain solid particles;

[0086] Q3: 3.5 g of the solid particles were added to 9 mL of a cerium nitrate solution with a concentration of 0.8 g / mL, and ultrasonic oscillation treatment was performed for 4 h to completely mix and homogenize, and after drying at 120°C for 12 h and calcination at 400°C for 6 h, a powder material was obtained, which was tabletted, crushed, and sieved to obtain a modified adsorbent.

[0087] This example discloses a method for preparing a modified surfactant, comprising the following steps:

[0088] S1: 79.3 g of potassium carbonate and 175 g of 1,3-dibromopropane were added to a container, followed by the addition of 250 mL of acetonitrile, and heated to reflux under stirring conditions, 35 g of 3-hydroxybenzaldehyde was added to 20 mL of acetonitrile, and after dissolving, a 3-hydroxybenzaldehyde solution was obtained, which was added dropwise to the container, and the dropwise addition rate was 1 drop / 2 s, after the dropwise addition was completed, the reaction was continued for 12 h, and nitrogen was introduced during the reaction, after the reaction was completed, it was cooled, suction filtered, and the obtained filtrate was added to 250 mL of distilled water and 250 mL of dichloromethane, respectively, after mixing thoroughly, the organic phase was taken, washed,

[0089] dried, eluted, dissolved, recrystallized, vacuum dried to obtain product 1;

[0090] S2: 23 g of product 1 was dissolved in 210 mL of methanol, and then slowly added dropwise to a container containing 218.5 g of a 40 wt% mass fraction diethylamine aqueous solution, after the dropwise addition was completed, the reaction was continued for 8 h, and nitrogen was introduced during the reaction, after the reaction was completed, it was rotary evaporated, extracted, the organic phases were combined, dried, rotary evaporated, eluted, vacuum rotary evaporated, and dried to obtain product 2;

[0091] S3: 21 g of product 2 was dissolved in 700 mL of acetonitrile, 18 g of butylsulfinyl lactone was added, the reaction was stirred at room temperature for 120 h, nitrogen was introduced during the reaction, after the reaction was completed, filtration, washing, low temperature recrystallization and vacuum drying were carried out to obtain the modified surfactant.

[0092] The embodiment discloses a preparation method of superfine sodium hypophosphite, and comprises the following steps:

[0093] Step (1): 1.5 g of quicklime was mixed with 44 mL of water to prepare lime milk, and then 5.4 mL of 1 mol / L sodium hydroxide solution was added to a reaction kettle containing the lime milk,

[0094] The stirring system was started, and a mixed solution was obtained after 6 h of mixing;

[0095] Step (2): The heating system of the reaction kettle was started, 22 mL of the mixed solution was heated to 45 DEG C, nitrogen was introduced, 2.5 g of yellow phosphorus was added to the reaction kettle, and the reaction was carried out at 98 DEG C for 4 h; after continuous stirring, a reaction solution was obtained; during the reaction, the generated gas was collected through a pipeline and treated; the generated gas was treated by using a tail gas absorption treatment device; the tail gas absorption treatment device comprises a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column (containing a modified adsorbent), a constant temperature water bath, a phosphine detection tube and a tail gas absorption bottle.

[0096] Step (3): 18 g of modified surfactant was added to 24 mL of the reaction solution, and after 8 h of stirring and mixing, filtration, calcium removal, pH adjustment to 7, concentration, crystallization, centrifugation and drying were carried out to obtain modified superfine sodium hypophosphite.

[0097] Comparative Example 1: Compared with Example 1, Comparative Example 1 does not add cerium nitrate solution in the preparation of the modified adsorbent, and other conditions are unchanged.

[0098] Comparative Example 2: Compared with Example 1, Comparative Example 2 does not add 3-hydroxybenzaldehyde in the preparation of the modified surfactant, and other conditions are unchanged.

[0099] Comparative Example 3: Compared with Example 1, Comparative Example 3 does not add the modified adsorbent in the preparation of the modified superfine sodium hypophosphite, and other conditions are unchanged.

[0100] Comparative Example 4: Compared with Example 1, Comparative Example 4 does not add the modified surfactant in the preparation of the modified superfine sodium hypophosphite, and other conditions are unchanged.

[0101] Experimental example: the content of phosphine gas generated in the production process is determined by using a HL-210 type phosphine gas concentration detector, and the particle size of sodium hypophosphite is determined by a laser particle size measurement method, and the test results are shown in Table 1:

[0102] Table 1

[0103] Item Phosphine concentration / mg-m -3 ]] Particle size range / pm Example 1 0.10 0.04-0.07 Example 2 0.11 0.05-0.07 Example 3 0.11 0.05-0.08 Example 4 0.12 0.06-0.09 Example 5 0.13 0.06-0.09 Comparative Example 1 0.25 0.07-0.10 Comparative Example 2 0.13 0.09-0.17 Comparative Example 3 0.28 0.06-0.10 Comparative Example 4 0.14 0.10-0.19

[0104] From the test results in Table 1, it can be seen that the sodium hypophosphite prepared by Examples 1-5 has a small particle size and a uniform particle size range, and the concentration of phosphine generated in the preparation process is low. From the comparison of Comparative Example 1 and Examples 1-5, it can be seen that the addition of cerium nitrate solution can effectively reduce the content of phosphine gas in the preparation process; from the comparison of Comparative Example 2 and Examples 1-5, it can be seen that the addition of 3-hydroxybenzaldehyde can effectively improve the uniformity and smallness of the particle size of sodium hypophosphite; from the comparison of Comparative Example 3 and Examples 1-5, it can be seen that the addition of modified adsorbent can effectively reduce the content of phosphine gas in the preparation process; from the comparison of Comparative Example 4 and Examples 1-5, it can be seen that the addition of modified surfactant can effectively improve the uniformity and smallness of the particle size of sodium hypophosphite.

[0105] The above is only a preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

[0106] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details, nor limit the application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited by the claims and their entire scope and equivalents.

Claims

1. A method for preparing modified ultrafine sodium hypophosphite, characterized by, Comprise the following steps: Step (1): the quicklime is mixed with water, after stirring evenly, lime milk is prepared, then sodium hydroxide solution is added to the reaction kettle containing lime milk, the stirring system is opened, after mixing evenly, a mixed solution is obtained; Step (2): the heating system of the reaction kettle is opened, the mixed solution is heated, nitrogen is introduced at the same time, yellow phosphorus is added to the reaction kettle, heating reaction, after continuous stirring, a reaction solution is obtained, in the reaction process, the gas produced is collected through the pipeline, and the gas is treated, wherein the tail gas absorption treatment device is used to treat the gas produced, the tail gas absorption treatment device is composed of a collection tank, a pressure valve, a mass flow meter, an adsorption oxidation column, a constant temperature water bath, a phosphine detection tube and a tail gas absorption bottle, wherein the adsorption oxidation column contains modified adsorbent, and the preparation method of the modified adsorbent comprises the following steps: Q1: after mixing tetrapropylammonium hydroxide with distilled water, silica sol is added, after stirring vigorously, it is added to the reaction kettle, after heating crystallization, cooling, a mixed solution is obtained; Q2: sodium hydroxide and sodium aluminate are added to distilled water, stirred until completely dissolved, then silica sol is slowly added, stirred, then the mixed solution is added, continue to stir, obtain the initial gel, add the initial gel to the reaction kettle, heat reaction, cooling, filtration, washing, drying, calcination, ion exchange to obtain solid particles; Q3: the solid particles are added to the cerium nitrate solution, ultrasonic oscillation treatment is carried out to make them completely mixed and uniform, dried and calcined to obtain a powder material, which is tableted, broken and sieved to obtain a modified adsorbent; Step (3): modified surfactant is added to the reaction solution, after stirring and mixing, filtration, calcium removal, pH adjustment, concentration, crystallization, centrifugation, drying, modified ultrafine sodium hypophosphite is obtained; The preparation method of the modified surfactant comprises the following steps: S1: potassium carbonate and 1,3-dibromopropane are added to a container, then acetonitrile is added, heated to reflux under stirring conditions, 3-hydroxybenzaldehyde is added to acetonitrile, dissolved to obtain a 3-hydroxybenzaldehyde solution, which is added dropwise to the container, after the dropwise addition is completed, continue to react, nitrogen is introduced during the reaction, after the reaction is completed, cool, suction filtration, the obtained filtrate is added to distilled water and dichloromethane respectively, after fully mixing, the organic phase is taken, washed, dried, eluted, dissolved, recrystallized, vacuum dried to obtain product 1; S2: product 1 is dissolved in methanol and slowly added to a container containing a diethylamine aqueous solution, after the dropwise addition is completed, continue to react, nitrogen is introduced during the reaction, after the reaction is completed, rotary evaporation, extraction, combine the organic phases, dry rotary evaporation, elution, vacuum rotary evaporation, drying, to obtain product 2; S3: product 2 is dissolved in acetonitrile, butyl sulfone lactone is added, room temperature stirring reaction, nitrogen is introduced during the reaction, after the reaction is completed, suction filtration, washing, low temperature recrystallization, vacuum drying, to obtain a modified surfactant; The mass ratio of potassium carbonate, 1, 3-dibromopropane and 3-hydroxybenzaldehyde in S1 is (45.3-90.6):(150-300):(20-40), the dropping speed is 1 drop / 2s, and the continuous reaction time is 10-12h; The dosage ratio of product 1, methanol and diethylamine aqueous solution in S2 is (20-24)g:(200-240)mL:(190-228)g, the mass fraction of diethylamine aqueous solution is 40wt%, and the continuous reaction time is 6-8h; the dosage ratio of product 2, acetonitrile and butylsulfonyl lactone in S3 is (13-26)g:(400-800)mL:(10-20)g, and the stirring reaction time is 110-120h.

2. The method of claim 1, wherein the modified ultrafine sodium hypophosphite is prepared by the process of claim 1, wherein the process is performed at a temperature of 20 to 80°C. In step (1), the dosage ratio of quicklime, water and sodium hydroxide solution is (1-3)g:(16-48)mL:(3.6-10.8)mL, the concentration of sodium hydroxide solution is 1mol / L, and the mixing time is 5-8h.

3. The method for preparing modified ultrafine sodium hypophosphite according to claim 1, characterized in that, In step (2), the heating temperature is 40-45℃, the dosage ratio of yellow phosphorus and mixed solution is (1-3)g:(20-30)mL, the heating reaction temperature is 95-98℃, and the reaction time is 2-4h.

4. The method for preparing modified ultrafine sodium hypophosphite according to claim 1, characterized in that, In Q1, the molar ratio of tetrapropylammonium hydroxide, distilled water and silica sol is (0.2-0.4):(20-40):(1-2), the vigorous stirring time is 4-6h, the heating crystallization temperature is 90-100℃, and the crystallization time is 22-24h; in Q2, the molar ratio of sodium hydroxide, sodium aluminate, distilled water and silica sol is (0.05-0.15):(0.013-0.016):(15-35):(1-1.2), the stirring time is 3-5h, the continuous stirring time is 1-2h, the heating reaction temperature is 140-180℃, the reaction time is 4-24h, the drying temperature is 90-110℃, and the calcination temperature is 500-600℃.

5. The method for preparing modified ultrafine sodium hypophosphite according to claim 1, characterized in that, In Q3, the dosage ratio of solid particles and cerium nitrate solution is (2-4)g:(6-10)mL, the concentration of cerium nitrate solution is 0.8g / mL, the oscillation treatment time is 2-4h, the drying temperature is 100-120℃, the time is 10-12h, the calcination temperature is 400-500℃, and the time is 5-8h.

6. The method for preparing modified ultrafine sodium hypophosphite according to claim 1, characterized in that, In step (3), the dosage ratio of reaction solution and modified surfactant is (20-25)mL:(10-20)g, the stirring mixing time is 6-8h, and the pH is adjusted to 7-7.4.

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