阅读说明：本技术 一种从电子厂有机清洗废液制备无色异丙醇的方法 (Method for preparing colorless isopropanol from organic cleaning waste liquid of electronic factory ) 是由 孙志洋 孙垒垒 于 2020-05-27 设计创作，主要内容包括：本发明提供一种从电子厂有机清洗废液制备无色异丙醇的方法,所述方法通过将废液蒸馏得到的异丙醇馏分以曝气加热的方式去除邻苯二酚后,再加入氟化钾得到含水量低的异丙醇油相,避免了直接采用焚烧的方式处理有机废液,也无需采用高能耗和高设备要求的精馏除水方式,提高了资源利用率；且制得的异丙醇为无色产品,放置长时间不易变色,产品价值高。(The invention provides a method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory, which removes catechol from isopropanol fraction obtained by distilling the waste liquid in an aeration heating mode, and then adds potassium fluoride to obtain an isopropanol oil phase with low water content, thereby avoiding directly treating the organic waste liquid by adopting an incineration mode, avoiding adopting a rectification dewatering mode with high energy consumption and high equipment requirement, and improving the resource utilization rate; and the prepared isopropanol is a colorless product, is not easy to discolor after being placed for a long time, and has high product value.)

1. A method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory is characterized by comprising the following steps:

(1) distilling the waste liquid to obtain isopropanol fraction containing catechol;

(2) aerating and heating the isopropanol fraction to remove catechol to obtain an isopropanol solution;

(3) and adding potassium fluoride into the isopropanol solution, stirring, standing, and performing liquid-liquid separation to obtain a potassium fluoride water phase and an isopropanol oil phase.

2. The process according to claim 1, wherein the pressure of the distillation in step (1) is from-0.005 to-0.02 MPa;

preferably, the distillation temperature is 80-120 ℃.

3. The method according to claim 1 or 2, wherein the waste liquid after distillation in step (1) is subjected to incineration treatment.

4. A process according to any one of claims 1 to 3, wherein the aerated heating in step (2) is carried out in a distillation apparatus;

preferably, the distillation apparatus comprises a still;

preferably, the distillation device further comprises a condensation component arranged at the upper part of the distillation kettle;

preferably, the temperature of aeration heating is 80-90 ℃;

preferably, the time of aeration heating is 2-5 h;

preferably, the gas introduced in the aeration heating comprises air and/or oxygen.

5. The method according to any one of claims 1 to 4, wherein the potassium fluoride in step (3) comprises a potassium fluoride solution and/or a potassium fluoride solid, preferably a potassium fluoride solid;

preferably, the purity of the potassium fluoride solids is > 85 wt%;

preferably, after the potassium fluoride is added into the isopropanol solution, the mass concentration of the potassium fluoride in the isopropanol solution is 41-56 wt%.

6. The method according to any one of claims 1 to 5, wherein the stirring time in the step (3) is 10 to 60 min;

preferably, the rotating speed of the stirring is 50-500 r/min;

preferably, the standing time is 0.5-3 h.

7. The method according to any one of claims 1 to 6, further comprising a step (4): concentrating and circulating the potassium fluoride water phase obtained in the step (3) to the step (3);

preferably, the aqueous potassium fluoride phase is concentrated to a saturated solution of potassium fluoride.

8. The method according to any one of claims 1 to 7, wherein the mass concentration of isopropanol in the waste liquid is 30 to 50 wt%;

preferably, the mass concentration of catechol in the waste liquid is 0.1-10 wt%;

preferably, the waste liquid comprises a cleaning waste liquid after wafer etching and an isopropanol cleaning waste liquid.

9. A method according to any one of claims 1 to 8, characterized in that the method comprises the steps of:

(1) distilling the waste liquid at-0.005 to-0.02 MPa and at 80 to 120 ℃ to obtain an isopropanol fraction containing catechol, and incinerating the distilled waste liquid, wherein the mass concentration of the isopropanol in the waste liquid is 30 to 50 wt%, and the mass concentration of the catechol is 0.1 to 10 wt%;

(2) carrying out aeration heating on the isopropanol fraction in a distillation device with a condensation component at the upper part to remove catechol to obtain an isopropanol solution, wherein air and/or oxygen is introduced into the aeration heating at 80-90 ℃ for 2-5 h;

(3) adding potassium fluoride into the isopropanol solution until the mass concentration of the potassium fluoride in the isopropanol solution is 41-56 wt%, stirring at 50-500 r/min for 10-60 min, standing for 0.5-3 h for layering, and performing liquid-liquid separation to obtain a potassium fluoride water phase and an isopropanol oil phase;

(4) and (4) concentrating the potassium fluoride water phase obtained in the step (3) to a potassium fluoride saturated solution, and circulating the potassium fluoride saturated solution to the step (3).

10. The method for treating the organic cleaning waste liquid of the electronic factory is characterized by comprising the method for preparing the colorless isopropanol from the organic cleaning waste liquid of the electronic factory as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of semiconductors, in particular to a method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory.

Background

The development of the information industry has driven the need for materials commonly used in the microelectronics industry. Statistically, in the manufacture of integrated circuit industry, material consumption accounts for over half of the production cost, and closely related materials are high-purity reagents for micro-processing in the manufacturing process besides large-size monocrystalline silicon wafers. In the process of manufacturing submicron super large scale integrated circuit, no matter after oxidation or etching, the surface of a silicon wafer needs to be cleaned, film deposition and high temperature furnace diffusion need to be processed for many times by various chemical agents and pure water, and finally, in order to avoid water or oil marks left on devices, high-purity isopropanol needs to be used for cleaning.

The EKC solution is used as a first cleaning solution for deep holes after semiconductor wafers are etched, the cleaning solution contains quaternary ammonium hydroxide, alcohol amine, a solvent, polyether modified organic silicon, o-phenol and other substances, photoresist residues on the wafers can be effectively removed, Isopropanol (IPA) is used for cleaning after cleaning, and generally, waste liquids of the EKC solution and the isopropanol are combined and collected, so that a large amount of IPA exists in the EKC waste liquid. For example, CN105551942A discloses a method for cleaning a deep hole after etching a semiconductor wafer, which comprises performing a first cleaning on the etched semiconductor wafer with an EKC solution, wherein the EKC solution is a mixed solution of an N-methylpyrrolidone solvent and an amine with alkalinity; cleaning the semiconductor wafer for the second time by adopting an N-methyl pyrrolidone solvent; cleaning the semiconductor wafer for the third time by using an IPA solvent; cleaning the semiconductor wafer for the fourth time by adopting pure water; the semiconductor wafer is dried, and the treatment method causes that the waste liquid contains a large amount of IPA, quaternary ammonium hydroxide, alcohol amine, solvent, polyether modified organic silicon, o-phenol and the like, and the recovery treatment is difficult.

The waste liquid in the process is generally used as industrial garbage in the industry at present, and is burnt or buried to be discarded, and the treatment mode not only wastes high-purity reagents, but also increases the manufacturing cost of semiconductors and causes pollution to the environment.

CN202912802U discloses an apparatus for extracting isopropanol from waste liquid, which can recover isopropanol by heating, distilling and recovering, but this method only can be used for waste liquid with high isopropanol content and low content of other organic matters, and the cost of reverse osmosis membrane is high.

Therefore, in order to recycle resources, a low-cost method needs to be provided to comprehensively recycle the EKC waste liquid, so that the problems are overcome, and the resources are saved.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory, which comprises the steps of firstly removing other complex impurities by a distillation method, then removing pyrocatechol by aeration and heating, and finally adding potassium fluoride to prepare a colorless isopropanol oil phase.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory, the method comprising the steps of:

(1) distilling the waste liquid to obtain isopropanol fraction containing catechol;

(2) aerating and heating the isopropanol fraction to remove catechol to obtain an isopropanol solution;

(3) and adding potassium fluoride into the isopropanol solution, stirring, standing, and performing liquid-liquid separation to obtain a potassium fluoride water phase and an isopropanol oil phase.

The invention provides a method for preparing colorless isopropanol from organic cleaning waste liquid of an electronic factory, which comprises three main steps of distillation, aeration heating and potassium fluoride liquid-liquid separation, wherein the boiling point of the isopropanol is low, the isopropanol can be separated from the organic waste liquid in a distillation way, but the separated isopropanol fraction contains a small amount of catechol, water and other substances and cannot be directly used as a product, and the product is discolored due to the presence of catechol in the isopropanol product, so that the product quality is influenced; the isopropanol after catechol removal also contains a large amount of water, the water in the isopropanol can be removed by adding potassium fluoride, the high energy consumption of rectification and special equipment requirements can be effectively avoided, and the method has high industrial application value.

Preferably, the pressure of the distillation in the step (1) is-0.005 to-0.02 MPa, and may be, for example, -0.005MPa, -0.008MPa, -0.009MPa, -0.01MPa, -0.012MPa, -0.015MPa, -0.018MPa or-0.02 MPa.

Preferably, the distillation temperature is 80-120 ℃, for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃.

Preferably, the waste liquid after distillation in step (1) is subjected to incineration treatment.

In the invention, the residual waste liquid after distillation mainly contains other substances such as alcohol amine, polyether modified organic silicon and the like, has complex components and low content, and has low recycling value, so the waste liquid is directly treated by incineration.

Preferably, the aeration heating in step (2) is carried out in a distillation apparatus.

Preferably, the distillation apparatus comprises a still.

Preferably, the distillation device further comprises a condensation component arranged at the upper part of the distillation kettle.

Preferably, the temperature of the aeration heating is 80 to 90 ℃, for example, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃ or 90 ℃ and the like.

The temperature of aeration heating is strictly controlled to be 80-90 ℃, because benzoquinone is easy to decompose only in the temperature range, and the aim of better removing pyrocatechol is fulfilled.

Preferably, the time of aeration heating is 2-5 h, for example, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h, 3.8h, 4h, 4.2h, 4.5h, 4.8h or 5h, etc.

According to the invention, the time of aeration heating is controlled to be 2-5 h, so that the effect of removing catechol by aeration is better achieved, and the treatment efficiency is improved.

Preferably, the gas introduced in the aeration heating comprises air and/or oxygen.

In the invention, air and/or oxygen is continuously introduced in the aeration heating process, so that catechol in the isopropanol fraction is fully contacted with the air and/or oxygen, the catechol is better removed, and a colorless isopropanol product is prepared.

Preferably, the potassium fluoride in step (3) comprises a potassium fluoride solution and/or a potassium fluoride solid, preferably a potassium fluoride solid.

The potassium fluoride in the invention can be solid potassium fluoride, or potassium fluoride solution, or the combination of the two.

Preferably, in step (3), the potassium fluoride solid is added in the first operation, and the circulating potassium fluoride solution is added in the second operation and above.

In the invention, the potassium fluoride solid is preferably added during the first batch of operation, compared with a potassium fluoride solution, the introduction of water into the solution can be better reduced, the potassium fluoride solid does not need to be additionally dissolved, and the operation is relatively simple. When more than two batches of operations are carried out, the circulating potassium fluoride solution is directly added, so that the use amount of the potassium fluoride is reduced.

Preferably, the potassium fluoride solids have a purity of > 85 wt%, and may be, for example, 85.5 wt%, 86 wt%, 86.5 wt%, 87 wt%, 87.5 wt%, 88 wt%, 88.5 wt%, 89 wt%, 90 wt%, 92 wt%, 95 wt%, 98 wt%, or 99 wt%, etc.

Preferably, the mass concentration of the potassium fluoride in the isopropanol solution after the potassium fluoride is added is 41-56 wt%, for example, 41 wt%, 42 wt%, 45 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt% or 56 wt%.

According to the method, the mass concentration of the potassium fluoride in the isopropanol solution after the potassium fluoride is added is controlled to be 47-56 wt%, the water separation efficiency in the isopropanol is guaranteed, and the addition amount of the potassium fluoride is reduced as far as possible.

Preferably, the stirring time in step (3) is 10-60 min, such as 10min, 15min, 20min, 25min, 30min, 40min, 50min or 60 min.

Preferably, the rotation speed of the stirring is 50-500 r/min, for example, 50r/min, 100r/min, 200r/min, 250r/min, 300r/min, 350r/min, 400r/min, 450r/min or 500 r/min.

Preferably, the standing time is 0.5-3 h, for example, 0.5h, 0.8h, 1h, 1.5h, 2h, 2.2h, 2.5h, 2.8h or 3h, etc.

Preferably, the liquid-liquid separation comprises a stratified separation.

Preferably, the method further comprises step (4): and (4) concentrating the potassium fluoride water phase obtained in the step (3) and recycling the potassium fluoride water phase to the step (3).

Preferably, the cycling comprises at least 5 cycles without additional potassium fluoride solids.

Preferably, the aqueous potassium fluoride phase is concentrated to a saturated solution of potassium fluoride.

Preferably, the mass concentration of isopropanol in the waste liquid is 30-50 wt%, for example, 30 wt%, 32 wt%, 35 wt%, 37 wt%, 39 wt%, 40 wt%, 42 wt%, 44 wt%, 45 wt%, 48 wt%, or 50 wt%.

Preferably, the mass concentration of catechol in the waste liquid is 0.1-10 wt%, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight.

Preferably, the waste liquid comprises a cleaning waste liquid after wafer etching and an isopropanol cleaning waste liquid.

The method provided by the invention is particularly suitable for the combined waste liquid of the cleaning waste liquid after wafer etching and the isopropanol cleaning waste liquid, namely the EKC waste liquid, and can effectively treat substances such as o-phenol and the like in the EKC waste liquid and simultaneously recover a large amount of isopropanol in the EKC waste liquid.

As a preferred technical scheme of the invention, the method comprises the following steps:

(1) distilling the waste liquid at-0.005 to-0.02 MPa and at 80 to 120 ℃ to obtain an isopropanol fraction containing catechol, and incinerating the distilled waste liquid, wherein the mass concentration of the isopropanol in the waste liquid is 30 to 50 wt%, and the mass concentration of the catechol is 0.1 to 10 wt%;

(2) carrying out aeration heating on the isopropanol fraction in a distillation device with a condensation component at the upper part to remove catechol to obtain an isopropanol solution, wherein air and/or oxygen is introduced into the aeration heating at 80-90 ℃ for 2-5 h;

(3) adding potassium fluoride into the isopropanol solution until the mass concentration of the potassium fluoride in the isopropanol solution is 41-56 wt%, stirring at 50-500 r/min for 10-60 min, standing for 0.5-3 h for layering, and performing liquid-liquid separation to obtain a potassium fluoride water phase and an isopropanol oil phase;

(4) and (4) concentrating the potassium fluoride water phase obtained in the step (3) to a potassium fluoride saturated solution, and circulating the potassium fluoride saturated solution to the step (3).

In a second aspect, the present invention provides a method for treating an organic cleaning waste liquid from an electronic factory, the method comprising the method for preparing colorless isopropanol from the organic cleaning waste liquid from the electronic factory as described in the first aspect.

According to the treatment method of the organic cleaning waste liquid of the electronic factory, which is provided by the invention, by adopting the method for preparing the colorless isopropanol from the organic cleaning waste liquid of the electronic factory, an isopropanol product can be recovered from the colorless isopropanol product, and the resource utilization rate is improved.

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

(1) according to the method for preparing the colorless isopropanol from the organic cleaning waste liquid of the electronic factory, the potassium fluoride is added, the isopropanol in the solution can be recovered without rectification, and the process is simple and easy to operate;

(2) according to the method for preparing the colorless isopropanol from the organic cleaning waste liquid of the electronic factory, pyrocatechol is removed through aeration and heating, the isopropanol which does not discolor after being placed for a long time can be prepared, the problem that an isopropanol product prepared by directly distilling the EKC waste liquid is easy to discolor is solved, and the product value is higher;

(3) the method for preparing the colorless isopropanol from the organic cleaning waste liquid of the electronic factory provided by the invention avoids directly burning the organic liquid, recovers the isopropanol in the organic liquid, and can recycle the added potassium fluoride, thereby improving the resource utilization rate.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.