阅读说明：本技术 高效溶剂油母液中抗氧剂300的回收方法 (Method for recovering antioxidant 300 in high-efficiency solvent oil mother liquor ) 是由 张胜传 崔华松 于海宝 李雪松 于 2020-07-17 设计创作，主要内容包括：本发明属于化工技术领域,具体的涉及一种高效溶剂油母液中抗氧剂300的回收方法。本发明所述的高效溶剂油母液中抗氧剂300的回收方法,包括以下步骤：(1)母液浓缩：把含有抗氧剂300的母液减压蒸馏浓缩,蒸出母液总体积30％-60％的200#溶剂油；(2)浓缩液降温：回收釜夹套中通冷冻水,把温度为130-140℃的浓缩液放入回收釜,搅拌至浓缩液温度为50-80℃；(3)结晶：回收釜加入浓缩液体积10％-20％的正己烷,继续搅拌至温度为-10℃～-5℃后再搅拌2-3h；(4)静置离心：停止搅拌,静置,然后离心得到抗氧剂300。本发明结晶时间短,回收效率高,离心难度小,操作安全性高。(The invention belongs to the technical field of chemical industry, and particularly relates to a method for recovering an antioxidant 300 in high-efficiency solvent oil mother liquor. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor comprises the following steps: (1) and (3) concentrating the mother liquor: carrying out reduced pressure distillation and concentration on the mother liquor containing the antioxidant 300 to evaporate 200# solvent oil accounting for 30-60% of the total volume of the mother liquor; (2) cooling the concentrated solution: introducing chilled water into a recovery kettle jacket, putting the concentrated solution with the temperature of 130-; (3) and (3) crystallization: adding n-hexane accounting for 10-20% of the volume of the concentrated solution into the recovery kettle, continuously stirring until the temperature is-10 to-5 ℃, and then stirring for 2-3 hours; (4) standing and centrifuging: stopping stirring, standing, and centrifuging to obtain the antioxidant 300. The invention has the advantages of short crystallization time, high recovery efficiency, small centrifugation difficulty and high operation safety.)

1. A method for recovering antioxidant 300 in high-efficiency solvent oil mother liquor is characterized by comprising the following steps: the method comprises the following steps:

(1) and (3) concentrating the mother liquor: carrying out reduced pressure distillation and concentration on the mother liquor containing the antioxidant 300 to evaporate 200# solvent oil accounting for 30-60% of the total volume of the mother liquor;

(2) cooling the concentrated solution: introducing chilled water into a recovery kettle jacket, putting the concentrated solution with the temperature of 130-;

(3) and (3) crystallization: adding n-hexane accounting for 10-20% of the volume of the concentrated solution into the recovery kettle, continuously stirring until the temperature is-10 to-5 ℃, and then stirring for 2-3 hours;

(4) standing and centrifuging: stopping stirring, standing, and centrifuging to obtain the antioxidant 300.

2. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the pressure in the reduced pressure distillation of the step (1) is-0.09 to-0.06 MPa; the temperature is 130-140 ℃.

3. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the temperature of the freezing water is-10 ℃ to-15 ℃.

4. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the stirring frequency of the step (2) is 20-30 Hz; and (3) adding n-hexane in the step (3), continuously stirring at the frequency of 20-30Hz, and cooling and then stirring at the frequency of 20-30 Hz.

5. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: and (4) standing for 6-12 h.

6. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the centrifugation time is 20-40 min.

7. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the No. 200 solvent oil is miscible with n-hexane, which has a solubility for the antioxidant 300 lower than that of the No. 200 solvent oil.

8. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the difference between the boiling points of the 200# solvent oil and the n-hexane is 60-80 ℃.

9. The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor according to claim 1, wherein the method comprises the following steps: the recycling kettle is provided with a stirring device, and a frequency converter is arranged on the stirring motor.

Technical Field

The invention belongs to the technical field of chemical industry, and particularly relates to a method for recovering an antioxidant 300 in high-efficiency solvent oil mother liquor.

Background

The antioxidant 300 is a thiobisphenol antioxidant with excellent performance, is a high-efficiency main antioxidant for rubber, polyolefin, plastic and other products, and particularly has an outstanding antioxidant effect when being used for polyethylene cable and wire materials.

The content of antioxidant byproducts in the solvent oil used for refining and purifying the antioxidant 300 is more and more in the recycling process, about 5% -8% of the antioxidant 300 is dissolved, and the antioxidant 300 needs to be recycled when the solvent oil is recycled.

The common recovery method comprises distilling out part of solvent oil from the solvent oil mother liquor, placing the rest part of feed liquid into a storage tank for standing and cooling for 3-4 days, centrifuging after the antioxidant 300 is separated out of crystals, and separating out the antioxidant 300.

The method has poor recovery effect, and only about 20 to 30 percent of antioxidant can be recovered. Meanwhile, the feed liquid after distillation is very viscous at normal temperature, the antioxidant 300 is slowly crystallized, 3 to 4 days are needed, the centrifugal separation is difficult, the centrifugal time is long, and 5 to 6 hours are needed. In addition, the solvent oil is flammable and explosive dangerous goods, the centrifugal machine is high-speed operation equipment, and the possibility of accidents occurring in long-time operation is increased.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor, which has the advantages of short crystallization time, high recovery efficiency, small centrifugation difficulty and high operation safety.

The method for recovering the antioxidant 300 in the high-efficiency solvent oil mother liquor comprises the following steps:

(1) and (3) concentrating the mother liquor: carrying out reduced pressure distillation and concentration on the mother liquor containing the antioxidant 300 to evaporate 200# solvent oil accounting for 30-60% of the total volume of the mother liquor;

(2) cooling the concentrated solution: introducing chilled water into a recovery kettle jacket, putting the concentrated solution with the temperature of 130-;

(3) and (3) crystallization: adding n-hexane accounting for 10-20% of the volume of the concentrated solution into the recovery kettle, continuously stirring until the temperature is-10 to-5 ℃, and then stirring for 2-3 hours;

(4) standing and centrifuging: stopping stirring, standing, and centrifuging to obtain the antioxidant 300.

Preferably, the pressure is-0.09 MPa to-0.06 MPa when the vacuum distillation is carried out; the temperature is 130-140 ℃.

Preferably, the temperature of the freezing water is-10 ℃ to-15 ℃.

Preferably, the stirring frequency in the step (2) is 20-30 Hz; and (3) adding n-hexane in the step (3), continuously stirring at the frequency of 20-30Hz, and cooling and then stirring at the frequency of 20-30 Hz.

Preferably, the step (4) is kept still for 6 to 12 hours, and the centrifugation time is 20 to 40 min.

Preferably, the No. 200 solvent oil is miscible with n-hexane, and the solubility of the n-hexane to the antioxidant 300 is lower than that of the No. 200 solvent oil; the boiling points of the 200# solvent oil and the n-hexane are different by 60-80 ℃, and an azeotrope is not formed.

Preferably, the recycling kettle is provided with a stirring device, and a frequency converter is arranged on the stirring motor.

Compared with the prior art, the invention has the following beneficial effects:

(1) the concentrated solution is cooled by using chilled water, the crystallization time is short, a large number of crystals are obtained, the recovery efficiency is high, the recovery amount of the antioxidant 300 is increased by 50-100% compared with that at normal temperature, and the crystallization time is shortened to 1/3-1/4 at normal temperature;

(2) according to the invention, the n-hexane is added, so that the solubility of the antioxidant 300 in the mixed solvent is reduced, the crystallization is fast, and more crystals are obtained; meanwhile, the viscosity of the concentrated solution is low, so that the problems of viscosity, slow crystallization and high centrifugation difficulty of the concentrated solution at low temperature are solved;

(3) the boiling points of the No. 200 solvent oil and the n-hexane have a difference of 60-80 ℃, no azeotrope is formed, and the solvent oil and the n-hexane can be easily separated by simple distillation;

(4) the stirring motor is provided with the frequency converter, so that the stirring is carried out at a low speed during crystallization, the crystals are large, and the centrifugation is carried out after the crystallization;

(5) the invention reduces the operation danger due to short centrifugation time.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description