阅读说明：本技术 一种二酰基类过氧化物的处理方法 (Method for treating diacyl peroxide ) 是由 顾屹立 陈丹 唐明亮 于 2021-01-11 设计创作，主要内容包括：本发明提供了一种二酰基类过氧化物的处理方法,属于有机过氧化物制备技术领域。本发明利用过氧化(二)苯甲酰废料和氢氧化钠的氧化还原反应实现对过氧化(二)苯甲酰废料中过氧化(二)苯甲酰的处理,同时利用表面活性剂强化氧化还原反应过程中物料的分散效果,增大反应比表面,提高处理效率,有助于将没有利用价值或受污染严重的过氧化(二)苯甲酰进行处理,且处理手段温和,风险低,处理效果良好,能够显著减小固废产生、降低环境污染,是一种资源化、无害化的处理方式。(The invention provides a method for treating diacyl peroxide, belonging to the technical field of organic peroxide preparation. The invention utilizes the redox reaction of the benzoyl peroxide waste and sodium hydroxide to realize the treatment of the benzoyl peroxide in the benzoyl peroxide waste, simultaneously utilizes the surfactant to strengthen the dispersion effect of materials in the redox reaction process, increases the reaction specific surface, improves the treatment efficiency, is beneficial to treating the benzoyl peroxide without utilization value or seriously polluted, has mild treatment means, low risk and good treatment effect, can obviously reduce the generation of solid wastes and reduce the environmental pollution, and is a recycling and harmless treatment mode.)

1. A method for treating diacyl peroxides, comprising the steps of:

mixing the benzoyl peroxide (di) waste, a sodium hydroxide solution, a surfactant and water, and carrying out redox reaction on the obtained mixed material to obtain a product material; the benzoyl peroxide waste is benzoyl peroxide waste which is decomposed or seriously polluted;

carrying out first separation on the product material to obtain insoluble substances and a first filtrate;

mixing the first filtrate with acid, adjusting the pH value of the first filtrate to 1-2, carrying out acid precipitation, and carrying out secondary separation to obtain a benzoic acid crude product and a second filtrate;

and mixing the second filtrate with alkali, adjusting the pH value of the second filtrate to 5-7, and sequentially carrying out concentration, solid-liquid separation and drying to obtain sodium chloride.

2. The treatment method according to claim 1, wherein the sodium hydroxide solution is contained in an amount of 20 to 32% by mass.

3. The process according to claim 1 or 2, characterized in that the molar ratio of the (di) benzoyl peroxide waste to the sodium hydroxide in the sodium hydroxide solution is 1: (2-2.4).

4. The treatment method according to claim 1 or 2, wherein the sodium hydroxide in the sodium hydroxide solution accounts for 3.6-4.2% of the mass content of the liquid phase material in the mixed material.

5. The treatment method according to claim 1, wherein the surfactant comprises sodium dodecyl benzene sulfonate, sodium dodecyl sulfate or sodium dodecyl sulfonate, and the surfactant accounts for 0.01-0.02% of the mass of the liquid phase material in the mixed material.

6. The process of claim 5, wherein the surfactant has a purity of 99%.

7. The treatment method according to claim 1, wherein the temperature of the redox reaction is 60 to 70 ℃ and the time is 3 to 5 hours.

8. The treatment method according to claim 1, wherein the acid is hydrochloric acid, and the mass content of the hydrochloric acid is 20-36%.

9. The treatment method according to claim 1, wherein the alkali is a sodium hydroxide solution, and the mass content of the sodium hydroxide solution is 20-32%.

10. The process according to claim 1, characterized in that the concentration is carried out until the solid-to-liquid ratio of the obtained mass is 1 g: (0.5-2) mL.

Technical Field

The invention relates to the technical field of organic peroxide preparation, in particular to a method for treating diacyl peroxide.

Background

The (di) Benzoyl Peroxide (BPO) is a diacyl peroxide, is an initiator with the most extensive application, and is mainly used as an initiator and a cross-linking agent for solvent polymerization of PVC, polyacrylonitrile, acrylic ester and vinyl acetate, graft polymerization of chloroprene rubber, SBS and methyl methacrylate, curing of unsaturated polyester resin, organic glass adhesive and the like. In the rubber industry, the rubber vulcanizing agent is used as a vulcanizing agent and a crosslinking agent of silicon rubber and fluororubber; it can also be used as bleaching agent and oxidant in chemical production. In the preparation process of BPO, there are cases that BPO runs out and drips and is polluted by mechanical impurities, and the collected polluted BPO finished products cannot be sold due to unqualified quality.

Patent CN107033050A discloses a method for treating contaminated BPO, which is used to prepare paste BPO after dissolving contaminated BPO with plasticizer; patent CN107141242A discloses a method for treating BPO contaminated by mechanical impurities, wherein the contaminated BPO is treated by settling the mechanical impurities; patent CN108276322A discloses a recycling method of waste material containing dibenzoyl peroxide, which dissolves contaminated BPO with organic solvent to obtain directly marketable BPO solution. The three treatment methods can effectively realize the recycling of the slightly polluted BPO, but for BPO with no utilization value (decomposed) or serious pollution, the molecular structure of the BPO recycled by the method is changed, and the BPO cannot be sold or applied in the market and has no practical use value. Patent CN110627630A discloses a treatment method of diacyl peroxide waste, which comprises mixing the contaminated diacyl peroxide waste with hydrazine hydrate and liquid alkali, and decomposing by redox reaction; although the method can effectively treat polluted diacyl peroxide waste, the used raw material (hydrazine hydrate) is a strong reducing agent which is flammable and explosive, and has a high risk.

Disclosure of Invention

The invention aims to provide a method for treating diacyl peroxide, which is beneficial to treating the (di) benzoyl peroxide without utilization value or seriously polluted, (di) benzoyl peroxide, has mild treatment means, low risk and good treatment effect, and can obviously reduce the generation of solid waste and reduce the environmental pollution.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a method for treating diacyl peroxide, which comprises the following steps:

mixing the benzoyl peroxide (di) waste, a sodium hydroxide solution, a surfactant and water, and carrying out redox reaction on the obtained mixed material to obtain a product material; the benzoyl peroxide waste is benzoyl peroxide waste which is decomposed or seriously polluted;

carrying out first separation on the product material to obtain insoluble substances and a first filtrate;

mixing the first filtrate with acid, adjusting the pH value of the first filtrate to 1-2, carrying out acid precipitation, and carrying out secondary separation to obtain a benzoic acid crude product and a second filtrate;

and mixing the second filtrate with alkali, adjusting the pH value of the second filtrate to 5-7, and sequentially carrying out concentration, solid-liquid separation and drying to obtain sodium chloride.

Preferably, the mass content of the sodium hydroxide solution is 20-32%.

Preferably, the molar ratio of the (di) benzoyl peroxide waste to the sodium hydroxide in the sodium hydroxide solution is 1: (2-2.4).

Preferably, the mass content of sodium hydroxide in the sodium hydroxide solution in the liquid-phase material in the mixed material is 3.6-4.2%.

Preferably, the surfactant comprises sodium dodecylbenzene sulfonate, sodium dodecyl sulfate or sodium dodecyl sulfonate; the surfactant accounts for 0.01-0.02% of the mass content of the liquid-phase material in the mixed material.

Preferably, the surfactant has a purity of 99%.

Preferably, the temperature of the oxidation-reduction reaction is 60-70 ℃ and the time is 3-5 h.

Preferably, the acid is hydrochloric acid, and the mass content of the hydrochloric acid is 20-36%.

Preferably, the alkali is a sodium hydroxide solution, and the mass content of the sodium hydroxide solution is 20-32%.

Preferably, the concentration is carried out until the solid-to-liquid ratio of the obtained material is 1 g: (0.5-2) mL.

The invention provides a method for treating diacyl peroxide, which comprises the following steps: mixing the benzoyl peroxide (di) waste, a sodium hydroxide solution, a surfactant and water, and carrying out redox reaction on the obtained mixed material to obtain a product material; the benzoyl peroxide waste is benzoyl peroxide waste which is decomposed or seriously polluted; carrying out first separation on the product material to obtain insoluble substances and a first filtrate; mixing the first filtrate with acid, adjusting the pH value of the first filtrate to 1-2, carrying out acid precipitation, and carrying out secondary separation to obtain a benzoic acid crude product and a second filtrate; and mixing the second filtrate with alkali, adjusting the pH value of the second filtrate to 5-7, and sequentially carrying out concentration, solid-liquid separation and drying to obtain sodium chloride.

The invention utilizes the oxidation-reduction reaction of the benzoyl peroxide waste material and sodium hydroxide to realize the treatment of the benzoyl peroxide in the benzoyl peroxide waste material, and simultaneously adopts the sodium dodecyl benzene sulfonate as the surfactant, so that the dispersion effect of materials in the oxidation-reduction reaction process can be enhanced, the reaction specific surface is increased, the treatment efficiency is improved, the treatment of the benzoyl peroxide without utilization value or seriously polluted materials is facilitated, the treatment means is mild, the risk is low, the treatment effect is good, the generation of solid wastes can be obviously reduced, the environmental pollution is reduced, and the invention is a recycling and harmless treatment mode.

Detailed Description

The invention provides a method for treating diacyl peroxide, which comprises the following steps:

mixing the benzoyl peroxide (di) waste, a sodium hydroxide solution, a surfactant and water, and carrying out redox reaction on the obtained mixed material to obtain a product material; the benzoyl peroxide waste is benzoyl peroxide waste which is decomposed or seriously polluted;

carrying out first separation on the product material to obtain insoluble substances and a first filtrate;

mixing the first filtrate with acid, adjusting the pH value of the first filtrate to 1-2, carrying out acid precipitation, and carrying out secondary separation to obtain a benzoic acid crude product and a second filtrate;

and mixing the second filtrate with alkali, adjusting the pH value of the second filtrate to 5-7, and sequentially carrying out concentration, solid-liquid separation and drying to obtain sodium chloride.

In the present invention, unless otherwise specified, all reagents required are commercially available products well known to those skilled in the art.

The method comprises the steps of mixing the benzoyl peroxide waste, a sodium hydroxide solution, a surfactant and water, and carrying out redox reaction on the obtained mixed material to obtain a product material. The source of the benzoyl peroxide waste is not particularly limited in the present invention, and may be obtained according to a source well known in the art. In the invention, the benzoyl peroxide waste is benzoyl peroxide waste which is decomposed or seriously polluted; the content of the dibenzoyl peroxide in the dibenzoyl peroxide waste is preferably 60%; the invention preferably judges whether the benzoyl peroxide waste is decomposed by a method for detecting the content through odor, appearance and chemical titration; the process for determining whether the benzoyl peroxide waste is decomposed or not is not particularly limited in the present invention, and may be performed according to a process well known in the art. The present invention preferably determines the degree of contamination of the benzoyl peroxide waste by a density difference method or a solvent method, and determines serious contamination when valuable diacyl peroxides cannot be recovered. The specific process of the density difference method or the solvent method is not particularly limited in the present invention, and may be performed according to a conventional process well known in the art. The method preferably judges whether the material has value or not by judging whether the appearance color of the material changes, whether mechanical impurities which cannot be taken out exist in the material or not and whether the dry basis content is too low (less than or equal to 95 percent, namely no value); the specific process for judging whether the material is valuable or not is not particularly limited, and the judgment can be carried out according to the process known in the field.

In the invention, the mass content of the sodium hydroxide solution is preferably 20-32%, and more preferably 25-30%. In the present invention, the molar ratio of the (di) benzoyl peroxide waste to the sodium hydroxide in the sodium hydroxide solution is preferably 1: (2 to 2.4), more preferably 1: (2.1-2.3).

In the present invention, the surfactant preferably includes sodium dodecylbenzene sulfonate, sodium dodecyl sulfate or sodium dodecyl sulfonate; the purity of the surfactant is preferably 99%, the surfactant is used in the form of a solution, and the mass concentration of the aqueous solution of the surfactant is preferably 2%; the mass content of the surfactant in the liquid-phase material in the mixed material is preferably 0.01-0.02%, and more preferably 0.015%. The invention utilizes the surfactant to strengthen the dispersion effect of materials in the subsequent oxidation-reduction reaction, increases the reaction specific surface and improves the treatment efficiency.

In the invention, the water is preferably used in an amount such that the mass content of sodium hydroxide in the sodium hydroxide solution in the liquid-phase material in the mixed material is preferably 3.6-4.2%, and more preferably 3.8-4.0%.

The process of mixing the benzoyl peroxide waste, the sodium hydroxide solution, the sodium dodecyl benzene sulfonate and the water is not particularly limited, and the materials can be uniformly mixed according to the process well known in the art.

In the invention, the temperature of the oxidation-reduction reaction is preferably 70-80 ℃, more preferably 72-78 ℃, and further preferably 75-76 ℃; the time is preferably 3 to 5 hours, and more preferably 3.5 to 4.5 hours. The temperature is preferably raised to the redox reaction temperature by a jacket, and the rate of raising the temperature is not particularly limited in the present invention and may be carried out according to a process well known in the art.

In the present invention, the reaction occurring during the redox reaction is 2C₁₄H₁₀O₄+4NaOH→4C₇H₅NaO₂+2H₂O+O₂。

After the redox reaction is completed, the present invention preferably cools to 20 ℃ to obtain the product material.

In the present invention, the ingredients of the product material include sodium benzoate, sodium hydroxide, water, and other mechanical impurities.

After the product material is obtained, the invention performs first separation on the product material to obtain insoluble substances and first filtrate. The process of the first separation is not particularly limited in the present invention, and may be performed according to a process well known in the art; in an embodiment of the present invention, the first separation device is specifically a vacuum suction filter or a centrifuge; the rotating speed of the centrifuge is 1000rpm, and the centrifugation time is 10 min. In the present invention, the insoluble matter is various mechanical impurities (such as dust, engine oil, pebbles and leaves) in the benzoyl peroxide waste; the first filtrate contains sodium benzoate, sodium hydroxide and water.

After the first filtrate is obtained, mixing the first filtrate with acid, adjusting the pH value of the first filtrate to 1-2, carrying out acid precipitation, and after second separation, obtaining a benzoic acid crude product and a second filtrate. In the invention, the acid is preferably hydrochloric acid, and the mass content of the hydrochloric acid is preferably 20-36%, more preferably 25-35%, and even more preferably 30%. During the acidification, benzoic acid precipitates. The process of the second separation is not particularly limited in the present invention, and may be performed according to a process well known in the art; in an embodiment of the present invention, the second separation device is specifically a vacuum suction filter or a centrifuge; the rotating speed of the centrifuge is 1000rpm, and the centrifugation time is 10 min. In the present invention, the main components of the second filtrate are sodium chloride, hydrochloric acid and water.

In the invention, the benzoic acid crude product is recycled and treated for refining to obtain benzoic acid by-products.

After the second filtrate is obtained, mixing the second filtrate with alkali, adjusting the pH value of the second filtrate to 5-7, and sequentially carrying out concentration, solid-liquid separation and drying to obtain sodium chloride. In the invention, the alkali is preferably a sodium hydroxide solution, and the mass content of the sodium hydroxide solution is preferably 20-32%, more preferably 25-30%, and even more preferably 26-28%. The pH value is adjusted to 5-7, so that sodium chloride can be evaporated in the subsequent concentration step.

In the present invention, the concentration is performed so that the solid-to-liquid ratio of the obtained material is preferably 1 g: (0.5-2) mL, more preferably 1 g: (0.8-1.8) mL, more preferably 1 g: (1.0-1.5) mL.

The process of the solid-liquid separation and drying is not particularly limited in the present invention, and may be performed according to a process well known in the art. In the embodiment of the invention, the solid-liquid separation device is specifically a vacuum suction filter or a centrifuge; the rotating speed of the centrifuge is 1000rpm, and the centrifugation time is 10 min.

In the invention, the liquid material obtained by the solid-liquid separation is a sodium chloride saturated solution which is reused in the concentration step, so that the recovery rate of sodium chloride is improved.

In the invention, the purity of the sodium chloride is 98-99 wt%, and the whiteness is 80-85%.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following examples, the mass percentage of the benzoyl peroxide in the benzoyl peroxide waste material used was 60%.

Example 1

Adding 600kg of water, 78kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%), and 120kg of benzoyl peroxide waste (containing 0.3kmol of benzoyl peroxide) into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material (the mass content of sodium hydroxide in the mixed material is 3.6%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%);

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, preserving the temperature for 5 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.1, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 0.5mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.3 percent and the whiteness of 80.1 percent.

Example 2

Adding 600kg of water, 82kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%) and 120kg of benzoyl peroxide waste into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material (the mass content of sodium hydroxide in the mixed material is 3.8%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%);

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, keeping the temperature for 4 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.2, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 1mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.5 percent and the whiteness of 80.5 percent.

Example 3

Adding 600kg of water, 78kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%) and 120kg of benzoyl peroxide waste into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material (the mass content of sodium hydroxide in the mixed material is 3.6%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%);

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, preserving the temperature for 5 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.5, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 2mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.6 percent and the whiteness of 83.1 percent.

Example 4

Adding 600kg of water, 90kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%) and 120kg of benzoyl peroxide waste into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material, wherein the mass content of sodium hydroxide in the mixed material is 4.1%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%;

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, preserving the temperature for 3 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.9, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 0.5mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.4 percent and the whiteness of 81.8 percent.

Example 5

Adding 600kg of water, 90kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%) and 120kg of benzoyl peroxide waste into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material, wherein the mass content of sodium hydroxide in the mixed material is 4.1%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%;

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, preserving the temperature for 3 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.3, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 1mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.6 percent and the whiteness of 80.6 percent.

Example 6

Adding 600kg of water, 82kg of sodium hydroxide solution (32 wt%), 6kg of sodium dodecyl benzene sulfonate aqueous solution (2 wt%) and 120kg of benzoyl peroxide waste into a 1000L reaction kettle, and uniformly mixing to obtain a mixed material (the mass content of sodium hydroxide in the mixed material is 3.8%, and the mass content of sodium dodecyl benzene sulfonate in the mixed material is 0.017%);

heating by using a jacket, carrying out oxidation-reduction reaction on the obtained dispersed material when the temperature reaches 65 ℃, controlling the reaction temperature to be 70 ℃, preserving the temperature for 4 hours, then opening cooling water in a reaction kettle to cool, and cooling to 20 ℃ to obtain a product material;

sending the product material to a centrifuge for first separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), obtaining insoluble substances and first filtrate, wherein the content of the benzoyl peroxide (di) in the insoluble substances is 0%, and completely reacting;

adding 36 wt% of hydrochloric acid into the first filtrate, adjusting the pH value to 1.6, carrying out acid precipitation, and carrying out second separation on the obtained material (the centrifugal rotation speed is 1000rpm, and the centrifugal time is 10min) to obtain a white solid (a benzoic acid crude product, and recycling treatment) and a second filtrate;

and (3) adjusting the pH value of the second filtrate to 7 by using 32 wt% sodium hydroxide solution, and evaporating and concentrating until the solid-to-liquid ratio of the materials is 1 g: 2mL, performing solid-liquid separation (the centrifugal speed is 1000rpm, the centrifugal time is 10min), and recycling the obtained liquid material which is a sodium chloride saturated solution for subsequent salt steaming; and drying the obtained solid material to obtain sodium chloride with the purity of 98.1 percent and the whiteness of 82.1 percent.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.