CN119406899A

CN119406899A - A method for treating organosilicon slurry

Info

Publication number: CN119406899A
Application number: CN202411309742.2A
Authority: CN
Inventors: 匡建国; 王文金; 周立华; 姚中鹏; 辛梓杰; 张毅
Original assignee: Hubei Xingrui Silicon Material Co Ltd
Current assignee: Hubei Xingrui Silicon Material Co Ltd
Priority date: 2024-09-19
Filing date: 2024-09-19
Publication date: 2025-02-11
Anticipated expiration: 2044-09-19
Also published as: CN119406899B

Abstract

The invention discloses a method for treating organosilicon slurry, and belongs to the field of material chemical industry. The method comprises the following steps of S1, filtering organosilicon slurry to obtain a filter cake I and a high-boiling-point substance, S2, mixing and stirring the filter cake I obtained in the step S1 with a washing liquid, filtering to obtain a filter cake II and a filtrate I, S3, mixing and stirring the filter cake II obtained in the step S2 with the washing liquid, filtering to obtain a filter cake III and a filtrate II, and S4, hydrolyzing the filter cake III obtained in the step S3 to obtain silica slag and an oil phase substance. The method provided by the invention effectively recovers high-boiling residues in the silicon slurry, the particle size of the hydrolyzed silicon slag is smaller than 50 meshes, and the hydrolyzed oil phase substances can be used for preparing high-boiling silicone oil.

Description

Method for treating organosilicon slurry

Technical Field

The invention belongs to the field of material chemical industry, and in particular relates to a method for treating organosilicon slurry.

Background

The organosilicon slurry is a waste produced in the synthesis process of methyl chlorosilane monomer, and is mainly formed by mixing a large amount of high boiling point substances (high boiling point substances for short) with unreacted fine silicon powder. At present, a direct hydrolysis method is mostly adopted in the treatment mode of the silicon slurry, such as China patent application with the application number 201410433395.4, china patent with the application number 200310115386.2 and China patent application with the application number 202111455208.9. However, this method not only causes waste of a large amount of high boiling substances, but also causes uneven grain size of the obtained silicon slag, which is disadvantageous for the subsequent chemical reaction process for extracting metallic copper.

Physical crushing is widely applied to the existing silicon slurry treatment technology as a pretreatment means. For example, chinese patent CN114892004a describes a treatment process of copper-containing silica slag, wherein the first step is to crush the silica slag. In addition, you Mengsong et al (comprehensive utilization of organosilicon slurry residue hydrolysis waste materials [ J ]. You Mengsong; li; sun Yujun; organosilicon materials. 2023, 2:40-46.) also mention that the preliminary treatment of organosilicon slurry residue hydrolysis waste materials also employs a crushing mode. Nevertheless, this treatment method still has some problems including low treatment efficiency, high energy consumption, and the like.

The traditional hydrolysis method often cannot effectively utilize high-boiling substances in the silicon slurry, which not only leads to waste of resources, but also can cause environmental problems. Therefore, the search for a more efficient treatment technique is of great importance for improving resource utilization and reducing environmental pollution.

Disclosure of Invention

Aiming at the problems, the invention provides a treatment method for the organic silicon slurry, which effectively recovers high-boiling substances in the silicon slurry, ensures that the particle size of the hydrolyzed silicon slag is smaller than 50 meshes, and simultaneously ensures that the hydrolyzed oil phase substances can be used for preparing the high-boiling silicon oil.

The method for treating the organosilicon slurry comprises the following steps:

S1, filtering organic silicon slurry to obtain a filter cake I and high-boiling residues;

s2, mixing and stirring the filter cake I obtained in the step S1 with a washing liquid, and filtering to obtain a filter cake II and a filtrate I;

s3, mixing and stirring the filter cake II obtained in the step S2 with a washing liquid, and filtering to obtain a filter cake III and a filtrate II;

S4, hydrolyzing the filter cake III obtained in the step S3 to obtain silica slag and oil phase substances.

The organic silicon slurry contains high-boiling substances, and the direct hydrolysis can generate larger solid particles, and meanwhile, the high-boiling substances are wasted. The organic silicon slurry is filtered once to remove most of high-boiling substances, and then is washed and filtered by trimethylchlorosilane to replace the high-boiling substances, so that a small amount of high-boiling substances and trimethylchlorosilane remain in the silicon slurry, and the trimethylchlorosilane can be used as a blocking agent to prevent the high-boiling substances from being crosslinked, so that small-particle silicon slag can be obtained after the organic silicon slurry is hydrolyzed, and the subsequent operation is convenient.

Preferably, the mass ratio of the filter cake I to the washing liquid in the step S2 is 0.8-2:7.

Preferably, the washing solution in step S2 is trimethylchlorosilane.

Preferably, the filtrate I in the step S2 is rectified to obtain trimethylchlorosilane and high-boiling residues.

Further preferably, the temperature of the rectifying tower bottom of the rectifying tower is 110-120 ℃, and the temperature of the tower top is 56-58 ℃. The purity of the trimethylchlorosilane obtained under the rectification condition is not less than 99 percent.

Further preferably, the trimethylchlorosilane obtained by rectification is repeatedly used as a washing liquid for washing filter cakes.

Preferably, the high-boiling-point substances are cracked in a cracking kettle under the conditions of normal pressure and 130-140 ℃ by taking nitrogen-nitrogen dimethylaniline as a catalyst.

Preferably, the mass ratio of the filter cake II to the washing liquid in the step S3 is 0.8-2:7.5.

Preferably, filtrate II in step S3 is used to wash the filter cake in step S2.

Preferably, in the step S4, the mass ratio of the filter cake to water is 0.5-1.5:3.

Preferably, the hydrolysis time in the step S4 is 30-60 min.

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

1. The invention reasonably utilizes the low boiling point and end capping property of the trimethylchlorosilane, and the trimethylchlorosilane has lower boiling point and is easy to separate and recycle by a physical method such as distillation. The blocking property is favorable for blocking residual high-boiling substances in the silicon slurry washing process, and preventing the residual high-boiling substances from being excessively crosslinked and solidified with silicon powder to form massive or uneven silicon slag, and the grain size of the silicon slag obtained by adopting the treatment method of the organic silicon slurry is smaller than 50 meshes.

2. According to the method for treating the organosilicon slurry, disclosed by the invention, in the stage of washing the organosilicon slurry, the trimethylchlorosilane helps to effectively recover high-boiling substances dissolved in the trimethylchlorosilane, so that the utilization rate of byproducts is improved, and the material loss is reduced.

3. The method for processing the organosilicon slurry improves the production efficiency and the product quality. In the hydrolysis step of the silicon slurry, the use of trimethylchlorosilane can avoid excessive crosslinking of the residual high-boiling substances and silicon powder, thereby preventing formation of large-particle and uneven silicon slag and being beneficial to maintaining the consistency and quality of the product. The oil phase material obtained after the hydrolysis process can be further used for producing high-boiling silicone oil, and the silicone oil has wide application in industry and commerce, thereby improving the economic value of byproducts.

4. The method for treating the organosilicon slurry provided by the invention has the advantages that the by-products are reasonably recovered and reused, the emission of harmful wastes is obviously reduced, and the method plays a positive role in environmental protection. Compared with the traditional treatment method, the technology can effectively reduce the consumption of raw materials and the treatment cost, and simultaneously increase the output of high-value products such as high-boiling silicone oil, thereby enhancing the market competitiveness of enterprises.

Drawings

FIG. 1 is a schematic flow chart of a method for treating a silicone paste according to the present invention.

Detailed Description

The technical scheme of the invention is further described and illustrated by the following examples. The starting materials used in the examples are all commercially available or prepared by conventional methods.

Example 1

A method for treating organosilicon slurry, comprising the following steps:

s1, filtering 100 g organic silicon slurry to obtain a 20g filter cake I and 80g high-boiling-point substances;

s2, mixing and stirring the 20 g filter cake I obtained in the step S1 with 70 g trimethylchlorosilane, and filtering to obtain a filter cake II and a filtrate I;

rectifying the filtrate I, wherein the temperature of a rectifying tower kettle is 115-119 ℃, the temperature of a rectifying tower top is 57-58 ℃, the purity of the obtained trimethylchlorosilane is about 99.1%, and the obtained trimethylchlorosilane is repeatedly applied to washing filter cakes as washing liquid;

S3, mixing and stirring the filter cake II obtained in the step S2 and trimethylchlorosilane obtained by rectification according to the mass ratio of 2:7.5, and filtering to obtain a filter cake III and a filtrate II, wherein the filtrate II can be directly used for washing the filter cake in the step S2;

The high-boiling-point substances obtained in the step S1 and the step S2 are cracked in a cracking kettle by taking nitrogen-nitrogen dimethylaniline as a catalyst with the dosage of 1wt% of the high-boiling-point substances, and are cracked with HCl gas at normal pressure at the temperature of 130-140 ℃ and the effective cracking rate of about 30%;

S4, adding the filter cake III obtained in the step S3 into water according to the mass ratio of the filter cake to the water of 1:3 to hydrolyze 30 min, and adding a small amount of acidic oil phase substances and silica slag with smaller and more uniform particles.

Example 2

The process parameters of this example were identical to those of example 1, except that in step S2, the mass ratio of filter cake I to filtrate II obtained in example 1 was 2:7.1.

Comparative example 1

The process parameters of this example were identical to those of example 1, except that in step S2, the mass ratio of filter cake I to filtrate II obtained in example 2 was 2:3.5.

Comparative example 2

The process parameters of this example were identical to those of example 1, except that in step S3, the mass ratio of filter cake II to trimethylchlorosilane was 1:2.

Testing and analysis

The acid oil phases obtained in examples 1-2 and comparative examples 1-2 were subjected to acid removal and water removal and used for trial preparation of high-boiling silicone oil. The particle size of the obtained silica slag and the trial conditions of the acid oil phase are shown in Table 1.

TABLE 1 particle size of silica slag and acid oil phase trial conditions

As is clear from Table 1, the reduction of the amount of filtrate II or trimethylchlorosilane can affect the size and uniformity of the silica residue after hydrolysis, and can also lead to the inapplicability of the obtained oil phase material and the preparation of high boiling silicone oil.

It should be understood that the above examples are only for illustrating the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the teachings of the present application, and such equivalents are intended to fall within the scope of the application as defined in the appended claims.

Claims

1. A method for treating organosilicon slurry, characterized in that it comprises the following steps:

S1, filtering the organosilicon slurry to obtain filter cake I and high boiling products;

S2, mixing the filter cake I obtained in step S1 with the washing liquid, and filtering to obtain filter cake II and filtrate I;

S3, mixing the filter cake II obtained in step S2 with the washing liquid, and filtering to obtain filter cake III and filtrate II;

S4, hydrolyzing the filter cake III obtained in step S3 to obtain silicon slag and oil phase material.

2. The method for treating organic silicon slurry according to claim 1, characterized in that the mass ratio of the filter cake I to the washing liquid in step S2 is 0.8~2:7.

3. The method for treating organosilicon slurry according to claim 1, characterized in that the washing liquid is trimethylchlorosilane.

4. The method for treating organosilicon slurry according to claim 1, characterized in that the filtrate I in step S2 is distilled to obtain trimethylchlorosilane and high boiling products.

5. The method for treating organosilicon slurry according to claim 4, characterized in that the bottom temperature of the distillation tower is 110-120°C and the top temperature is 56-58°C.

6. The method for treating organosilicon slurry according to claim 4, characterized in that the trimethylchlorosilane obtained by distillation is repeatedly used as a washing liquid to wash the filter cake.

7. The method for treating organosilicon slurry according to claim 1, characterized in that the high boiling point is cracked by using nitrogen-nitrogen dimethylaniline as a catalyst and cracking it with HCl gas in a cracking kettle at normal pressure and 130-140°C.

8. The method for treating organosilicon slurry according to claim 1, characterized in that the mass ratio of filter cake II to washing liquid in step S3 is 0.8~2:7.5.

9. The method for treating organosilicon slurry according to claim 1, characterized in that the filtrate II in step S3 is used to wash the filter cake in step S2.

10. The method for treating organosilicon slurry according to claim 1, characterized in that in step S4, the mass ratio of filter cake to water is 0.5-1.5:3, and the hydrolysis time is 30-60 min.