阅读说明：本技术 一种复合三元铜粉的制备方法 (Preparation method of composite ternary copper powder ) 是由 程刘备 朱恩华 曹华俊 罗燚 张寅旭 胡敬辉 于 2019-10-22 设计创作，主要内容包括：本申请公开了一种复合三元铜粉的制备方法。该方法包括：将第一种三元铜粉和第二种三元铜粉按照预设质量比均匀混合,其中,第一种三元铜粉通过氧化亚铜粉煅烧制得,第二种三元铜粉通过金属铜粉煅烧制得；将均匀混合后的混合三元铜粉以预设煅烧温度进行煅烧；将煅烧后的混合三元铜粉进行球磨和筛分,制得所述复合三元铜粉。通过两种三元铜粉制备出的复合三元铜粉,在作为“直接法”制备工艺中的催化剂时,相对于现有的三元铜粉,能够提高二甲基二氯硅烷的选择性,从而提高二甲基二氯硅烷的收率。(The application discloses a preparation method of composite ternary copper powder. The method comprises the following steps: uniformly mixing first ternary copper powder and second ternary copper powder according to a preset mass ratio, wherein the first ternary copper powder is prepared by calcining cuprous oxide powder, and the second ternary copper powder is prepared by calcining metal copper powder; calcining the uniformly mixed ternary copper powder at a preset calcining temperature; and carrying out ball milling and screening on the calcined mixed ternary copper powder to obtain the composite ternary copper powder. When the composite ternary copper powder prepared from the two ternary copper powders is used as a catalyst in a direct method preparation process, the selectivity of dimethyldichlorosilane can be improved compared with the existing ternary copper powder, so that the yield of dimethyldichlorosilane is improved.)

1. The preparation method of the composite ternary copper powder is characterized by comprising the following steps of:

uniformly mixing first ternary copper powder and second ternary copper powder according to a preset mass ratio, wherein the first ternary copper powder is prepared by calcining cuprous oxide powder, and the second ternary copper powder is prepared by calcining metal copper powder;

calcining the uniformly mixed ternary copper powder at a preset calcining temperature;

and carrying out ball milling and screening on the calcined mixed ternary copper powder to obtain the composite ternary copper powder.

2. The preparation method according to claim 1, wherein the first ternary copper powder and the second ternary copper powder are uniformly mixed according to a preset mass ratio, and the method specifically comprises the following steps: and (3) mixing the first ternary copper powder and the second ternary copper powder according to the weight ratio of 3: 1-1: 1, and uniformly mixing.

3. The preparation method according to claim 1, wherein the uniformly mixed ternary copper powder is calcined at a preset calcination temperature, and the method specifically comprises the following steps:

and calcining the uniformly mixed ternary copper powder in a rotary kiln for 1.0-3.0 hours at the calcining temperature of 350-500 ℃.

4. The method of claim 1, further comprising:

calcining the provided cuprous oxide powder at the calcining temperature of 200-300 ℃ for 0.5-2.0 hours;

and performing ball milling and screening on the calcined product to obtain the first ternary copper powder.

5. The method according to claim 4,

the mass ratio of the cuprous oxide powder in the first ternary copper powder is 25-75%; and the number of the first and second groups,

the mass percentage of the copper oxide powder in the first ternary copper powder is 30-50%.

6. The method of claim 1, further comprising:

calcining the metal copper powder at the calcining temperature of 250-350 ℃ for 1.0-5.0 hours;

and performing ball milling and screening on the calcined product to obtain the second ternary copper powder.

7. The method according to claim 6,

the mass ratio of the metal copper powder in the second ternary copper powder is 15-25%;

the mass ratio of the cuprous oxide powder in the second ternary copper powder is 25-60%; and the number of the first and second groups,

the mass percentage of the copper oxide powder in the second ternary copper powder is 15-30%.

8. The method according to claim 6,

at a current density of 750A/m²And preparing the copper metal powder by electrolyzing a copper sulfate solution under the condition that the temperature of the electrolyte is 50 ℃.

9. The method according to claim 1, wherein the composite ternary copper powder has a particle size of 1 to 15 μm.

10. The preparation method according to claim 1, wherein the mass ratio of the metal copper powder in the composite ternary copper powder is 5-15%;

the weight percentage of the cuprous oxide powder in the composite ternary copper powder is 35-75%; and the number of the first and second groups,

the mass ratio of the copper oxide powder in the composite ternary copper powder is 10-40%.

Technical Field

The application relates to the technical field of organic silicon, in particular to a preparation method of composite ternary copper powder.

Background

In the field of silicone chemistry, a large number of silicone products can be made from siloxane polymers formed by the hydrolysis and polycondensation reactions of dimethyldichlorosilane. At present, the dimethyl dichlorosilane is usually prepared by a direct method preparation process, wherein silicon powder and chloromethane are used as raw materials in the preparation process, and the dimethyl dichlorosilane is synthesized under the catalysis of ternary copper powder as a catalyst, wherein the ternary copper powder comprises uniformly distributed metallic copper powder particles, cuprous oxide powder particles and cupric oxide powder particles.

However, in the preparation process of the direct method, because the selectivity of the existing ternary copper powder is poor, the content of byproducts such as monomethyl trichlorosilane, trimethyl monochlorosilane and the like in the prepared dimethyldichlorosilane is high, and the yield of the dimethyldichlorosilane is influenced.

Disclosure of Invention

The embodiment of the application provides a preparation method of composite ternary copper powder, and the prepared composite ternary copper powder can improve the yield of dimethyldichlorosilane when being used as a catalyst in a direct method preparation process.

The embodiment of the application provides a preparation method of composite ternary copper powder, which comprises the following steps:

uniformly mixing first ternary copper powder and second ternary copper powder according to a preset mass ratio, wherein the first ternary copper powder is prepared by calcining cuprous oxide powder, and the second ternary copper powder is prepared by calcining metal copper powder;

calcining the uniformly mixed ternary copper powder at a preset calcining temperature;

and carrying out ball milling and screening on the calcined mixed ternary copper powder to obtain the composite ternary copper powder.

Preferably, the first ternary copper powder and the second ternary copper powder are uniformly mixed according to a preset mass ratio, and the method specifically comprises the following steps: and (3) mixing the first ternary copper powder and the second ternary copper powder according to the weight ratio of 3: 1-1: 1, and uniformly mixing.

Preferably, the step of calcining the uniformly mixed ternary copper powder at a preset calcining temperature specifically comprises the following steps:

and calcining the uniformly mixed ternary copper powder in a rotary kiln for 1.0-3.0 hours at the calcining temperature of 350-500 ℃.

Preferably, the method further comprises:

calcining the provided cuprous oxide powder at the calcining temperature of 200-300 ℃ for 0.5-2.0 hours;

and performing ball milling and screening on the calcined product to obtain the first ternary copper powder.

Preferably, the mass ratio of the cuprous oxide powder in the first ternary copper powder is 25-75%; and the mass percentage of the copper oxide powder in the first ternary copper powder is 30-50%.

Preferably, the method further comprises:

calcining the metal copper powder at the calcining temperature of 250-350 ℃ for 1.0-5.0 hours;

and performing ball milling and screening on the calcined product to obtain the second ternary copper powder.

Preferably, the mass ratio of the metal copper powder in the second ternary copper powder is 15-25%;

the mass ratio of the cuprous oxide powder in the second ternary copper powder is 25-60%; and the number of the first and second groups,

the mass percentage of the copper oxide powder in the second ternary copper powder is 15-30%.

Preferably, the current density is 750A/m²And preparing the copper metal powder by electrolyzing a copper sulfate solution under the condition that the temperature of the electrolyte is 50 ℃.

Preferably, the particle size of the composite ternary copper powder is 1-15 μm.

Preferably, the mass ratio of the metal copper powder in the composite ternary copper powder is 5-15%;

the weight percentage of the cuprous oxide powder in the composite ternary copper powder is 35-75%; and the number of the first and second groups,

the mass ratio of the copper oxide powder in the composite ternary copper powder is 10-40%

The embodiment of the application adopts at least one technical scheme which can achieve the following beneficial effects:

according to the composite ternary copper powder, the first ternary copper powder and the second ternary copper powder are uniformly mixed according to the preset mass ratio, then the uniformly mixed ternary copper powder is calcined at the preset calcining temperature, and the calcined mixed ternary copper powder is subjected to ball milling and screening to obtain the composite ternary copper powder. When the composite ternary copper powder prepared from the two ternary copper powders is used as a catalyst in a direct method preparation process, the selectivity of dimethyldichlorosilane can be improved compared with the existing ternary copper powder, so that the yield of dimethyldichlorosilane is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic flow chart of a specific process for preparing the composite ternary copper powder provided by the embodiment of the application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. 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 application.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

As mentioned above, when the dimethyldichlorosilane is prepared by the direct method preparation process, due to the poor selectivity of the existing ternary copper powder, the content of by-products such as monomethyltrichlorosilane, trimethylchlorosilane and the like in the prepared dimethyldichlorosilane is high, the yield of the dimethyldichlorosilane is only about 80-85 percent, the yield is low, and the ternary copper powder needs to be improved, so that the yield of the dimethyldichlorosilane is improved.

Based on the above, the embodiment of the application provides a preparation method of composite ternary copper powder, and when the composite ternary copper powder prepared by the preparation method is applied to a direct method preparation process for preparing dimethyldichlorosilane, the selectivity of dimethyldichlorosilane can be improved compared with ternary copper powder in the prior art, so that the content of byproducts such as monomethyltrichlorosilane and trimethylchlorosilane is reduced, and the yield of dimethyldichlorosilane is improved. Fig. 1 shows a specific flow diagram of the preparation method, which comprises the following steps:

step S11: and uniformly mixing the provided first ternary copper powder and second ternary copper powder according to a preset mass ratio.

The copper powder is prepared by calcining cuprous oxide powder, and the copper powder is prepared by calcining metal copper powder. It should be noted that the first and second terms herein merely represent two different types, and do not represent chronological order, product quality, grade, or other meanings.

The first ternary copper powder and the second ternary copper powder can be provided in advance, and the two provided ternary copper powders are uniformly mixed according to a preset mass ratio, for example, the two ternary copper powders are mixed according to the preset mass ratio and then put into a stirring instrument or stirred manually, so that the two ternary copper powders are uniformly mixed, and the problem that the quality of a final product is unstable due to nonuniform mixing is solved. In practical application, after the two ternary copper powders are mixed according to a preset mass ratio, the two ternary copper powders can be stirred in a stirring instrument, the stirring time of the stirring instrument is set according to factors such as the mass of a stirring material, the stirring speed and the like, and when the stirring time is reached, the two ternary copper powders are considered to be uniformly mixed.

The preset mass ratio of the first ternary copper powder to the second ternary copper powder when the first ternary copper powder and the second ternary copper powder are uniformly mixed can be 3: 1-1: 1. for example, the first ternary copper powder and the second ternary copper powder may be mixed in a ratio of 3: 1. 2.8:1, 2.5:1, 2.3:1, 2: 1. 1.9:1, 1.7:1, 1.4:1, 1.2:1, 1:1 or between 3:1 to 1:1, and uniformly mixing the mixture in other ratios.

Step S12: and calcining the uniformly mixed ternary copper powder at a preset calcining temperature.

The mixed ternary copper powder can be placed in a rotary kiln, and the mixed ternary copper powder is calcined in the rotary kiln at a preset calcining temperature. Because the rotary kiln usually adopts an indirect heating mode to heat and calcine the to-be-heated articles in the kiln, the to-be-heated articles are not directly contacted with a heat source, and the to-be-heated articles can be heated more uniformly.

The preset calcination temperature may be 350 to 500 ℃. For example, the mixed ternary copper powder may be calcined at 350 ℃, 370 ℃, 390 ℃, 400 ℃, 430 ℃, 450 ℃, 480 ℃, 500 ℃ or other temperatures between 350 ℃ and 500 ℃.

In addition, the mixed ternary copper powder is calcined at 350-500 ℃, the calcination temperature can be controlled at a constant temperature of one of 350-500 ℃, the temperature can be controlled in a preset step to change in a stepwise manner between 350-500 ℃, the mixed ternary copper powder is calcined, the temperature can be controlled in a preset step first, and then the mixed ternary copper powder is calcined at a constant temperature, and the like. For example, the initial calcination temperature is 350 ℃, the calcination is continued after 1 hour, the temperature is increased to 480 ℃ in steps of 5 ℃ per minute.

The calcination time of the mixed ternary copper powder can be usually 1.0-3.0 hours. For example, the mixed ternary copper powder may be calcined at the predetermined calcination temperature for 1.0 hour, 1.2 hours, 1.5 hours, 2.0 hours, 2.3 hours, 2.8 hours, 3.0 hours, or other time period between 1.0 hour and 3.0 hours.

Step S13: and performing ball milling and screening on the calcined mixed ternary copper powder to obtain the composite ternary copper powder.

After the mixed ternary copper powder is calcined at the preset calcining temperature, the calcined mixed ternary copper powder can be subjected to ball milling, then screening is performed, and the powder obtained through screening is used as the prepared composite ternary copper powder.

When the calcined mixed ternary copper powder is ball-milled, the ball-milling can be performed by a dry ball-milling method, for example, a dry ball-milling method is used. In the dry ball milling process, the mass ratio of the ball milling beads to the material to be ball milled (i.e., the calcined mixed ternary copper powder) may be 1: 1-5: 1. for example, the mass ratio of the ball milling beads to the material to be ball milled is 1: 1. 1.3:1, 1.8: 1.2: 1. 2.4: 1. 2.6: 1. 2.9: 1.3: 1. 3.5: 1. 3.7: 1.4: 1. 4.2: 1. 4.5: 1. 4.8: 1. 5:1, or between 1:1 to 5: other ratios between 1.

In the screening process, the size of the screen holes of the screened screen can be selected according to the particle size of the composite ternary copper powder particles. For example, the particle size of the composite ternary copper powder particles used as the catalyst in the "direct process" preparation process needs to be smaller than a first preset value, and a sieve can be selected according to the first preset value, wherein the size of the sieve pore of the selected sieve is smaller than or approximately equal to the first preset value. And in the screening process, the ternary copper powder passing through the screen holes is used as the prepared composite ternary copper powder, so that the particle size of the composite ternary copper powder meets the requirement.

When the particle size of the composite ternary copper powder serving as the catalyst needs to be larger than a second preset value, a sieve can be selected according to the second preset value, and the size of the sieve pore of the selected sieve is larger than or approximately equal to the second preset value. And in the screening process, the ternary copper powder which does not pass through the screen holes is used as the prepared composite ternary copper powder, so that the particle size of the composite ternary copper powder can be larger than a second preset value.

Of course, the composite ternary copper powder with the particle size between the first preset value and the second preset value can be finally screened out by firstly screening the first preset value selection sieve and then screening the second preset value selection sieve, or firstly screening the second preset value selection sieve and then screening the first preset value selection sieve, wherein the first preset value is larger than the second preset value.

For example, the first preset value can be set to 15 μm, the second preset value can be set to 1 μm, and the calcined mixed ternary copper powder can be generally subjected to ball milling and screening to prepare composite ternary copper powder with the particle size of 1-15 μm, which is used as a catalyst for the direct method preparation process. For example, particle sizes of 1 μm, 6 μm, 8 μm, 9 μm, 13 μm, 15 μm, or other sizes between 1 μm and 15 μm may be prepared.

The preparation method may further include steps S14 to S16, so as to prepare the first ternary copper powder.

Step S14: and preparing cuprous oxide powder.

The cuprous oxide powder can be prepared by reducing copper sulfate with sodium sulfite. The reaction temperature in the preparation process is about 100 ℃, the pH of the reaction solution is weakly acidic (for example, pH 5), the concentration of the copper sulfate solution is 500g/L, and the reaction time is about 2 hours. After the reaction is completed, the product may be washed with distilled water several times, and then centrifuged, and the centrifuged solid sample is vacuum-dried, for example, the solid sample is placed in a vacuum drying oven at 80 ℃ to be vacuum-dried, thereby obtaining the desired cuprous oxide powder.

Wherein the purity of cuprous oxide in the prepared cuprous oxide powder is 99.0-99.6%, and the mass ratio of sulfate radicals is less than or equal to 0.4%. Furthermore, particles with a particle size of 1-6 μm can be screened out from the copper protoxide powder, such as 1 μm, 2.5 μm, 4 μm, 4.7 μm, 6 μm or other values between 1 μm and 6 μm.

Step S15: and calcining the prepared cuprous oxide powder at a second preset calcining temperature.

Of course, the cuprous oxide powder may be calcined in the rotary kiln at a second preset calcination temperature, which may be 200 to 300 ℃. Such as 200 deg.c, 240 deg.c, 270 deg.c, 300 deg.c or other temperature values between 200 deg.c and 300 deg.c.

The copper oxide powder can be calcined at a certain basically constant calcining temperature of 200-300 ℃, or a preset step length can be set to control the temperature to change in a stepwise manner at 200-300 ℃, or the temperature change can be controlled at the preset step length first, and then the calcining is carried out at constant temperature, and the like.

For example, the initial calcination temperature is 230 ℃, the temperature is increased to 290 ℃ in steps of 3 ℃ per minute, and then the calcination is continued for 1 hour.

The calcination time of the cuprous oxide powder in step S15 may be 0.5 to 2.0 hours. For example, it may be 0.5 hour, 0.7 hour, 1 hour, 1.2 hours, 1.5 hours, 1.7 hours, 2.0 hours, or other time period between 0.5 hours and 2.0 hours.

Step S16: and performing ball milling and screening on the calcined product to obtain the first ternary copper powder.

When the calcined product is ball-milled, dry ball milling may be performed by a dry ball mill.

In the screening process, a sieve with about 5 mu m sieve pores and a sieve with about 15 mu m sieve pores can be selected, so that a calcined product with the particle size of 5-15 mu m can be screened out to be used as the first ternary copper powder.

According to chemical component detection, the mass ratio of cuprous oxide in the first ternary copper powder is 25-75%, and the mass ratio of cupric oxide in the first ternary copper powder is 30-50%.

The preparation method may further include steps S17 to S19, so as to prepare the second ternary copper powder.

Step S17: and preparing the metal copper powder.

In practical application, the copper metal powder can be prepared by electrolyzing copper sulfate solution. Wherein the preparation conditions for preparing the copper metal powder by electrolysis are as follows,current density 750A/m²And the temperature of the electrolyte is 50 ℃.

After the electrolytic preparation is finished, washing the electrolytic product for a plurality of times by using a benzotriazole solution, then carrying out centrifugal separation, and putting the centrifuged solid sample into a vacuum drying oven at 80 ℃ for vacuum drying, thereby preparing the required copper metal powder. In the copper powder prepared by the electrolysis method, the mass of the copper accounts for 99.0-99.6%. The particles with the particle size of 20-44 μm can be further screened out to be used as the prepared copper metal powder, such as 20 μm, 24 μm, 28 μm, 35 μm, 41 μm, 44 μm or other values between 20 μm and 44 μm.

Step S18: and calcining the prepared metal copper powder at a third preset calcining temperature.

The calcination process of step S18 may be substantially the same as step S15 except that step S18 is used to calcine the copper metal powder. The third preset calcination temperature in step S18 is 250 to 350 ℃, for example, 250 ℃, 270 ℃, 3000 ℃, 320 ℃, 350 ℃, or other temperature values between 250 ℃ and 350 ℃; the calcination time of the copper metal powder in step S18 may be 1.0 to 5.0 hours. For example, it may be 1.0 hour, 1.5 hours, 2 hours, 2.7 hours, 3.0 hours, 3.3 hours, 3.8 hours, 4.0 hours, 4.6 hours, 5 hours, or other time period between 1.0 hour and 5.0 hours.

Step S19: and performing ball milling and screening on the calcined product to obtain second ternary copper powder.

When the calcined product is subjected to ball milling, dry ball milling can also be performed by a dry ball mill.

In the screening process, a sieve with about 25 mu m sieve pores and a sieve with about 45 mu m sieve pores can be selected, so that the calcined product with the particle size of 25-45 mu m can be screened out to be used as the second ternary copper powder. According to chemical component detection, the mass ratio of the metal copper to the cuprous oxide is 15-25%, the mass ratio of the cuprous oxide is 25-60%, and the mass ratio of the cupric oxide is 15-30% in the second ternary copper powder.

The above is a specific description of the preparation method provided in the embodiments of the present application, and specific experimental tests can be combined to describe the catalytic selectivity of the composite ternary copper powder prepared by the preparation method as a catalyst.

Firstly, the composite ternary copper powder with the particle size of 1-15 microns, the mass percentage of metal copper of 5-15%, the mass percentage of cuprous oxide of 35-75% and the mass percentage of copper oxide of 10-40% is prepared by the preparation method. In the preparation process of the composite ternary copper powder, the particle size can be controlled by ball milling and screening, and the mass ratio of the metal copper, the cuprous oxide and the cupric oxide can be controlled by the mass ratio of the two ternary copper powders, the calcining temperature and the calcining time.

In the first experiment, the mass ratio of the first ternary copper powder to the second ternary copper powder is 3:1, uniformly mixing, calcining the uniformly mixed ternary copper powder in a rotary furnace at 350-500 ℃ for 1-3 hours, and then ball-milling and screening the calcined mixed ternary copper powder to prepare the composite ternary copper powder 1. Through detection, the mass percentages of the metallic copper, the cuprous oxide and the cupric oxide in the composite ternary copper powder 1 are respectively 7%, 72% and 21%.

Experiment two and experiment one adopt the same preparation conditions, the difference lies in experiment two, first kind ternary copper powder and second kind ternary copper powder mass ratio is 2:1, preparing composite ternary copper powder 2 in experiment two. Through detection, the mass percentages of the metallic copper, the cuprous oxide and the cupric oxide in the composite ternary copper powder 2 are respectively 10%, 65% and 25%.

Experiment three and experiment one adopt the same preparation conditions, and the difference is that in experiment three, the mass ratio of the first ternary copper powder to the second ternary copper powder is 1:1, preparing composite ternary copper powder 3 in experiment two. Through detection, the mass percentages of the metallic copper, the cuprous oxide and the cupric oxide in the composite ternary copper powder 3 are respectively 13%, 53% and 34%.

The catalytic performances of the composite ternary copper powder 1, the composite ternary copper powder 2 and the composite ternary copper powder 3, as well as the commercial ternary copper powder 1 and the commercial ternary copper powder 2 in the prior art are respectively tested, and the test results are shown in table 1. In table 1, M1 is monomethyltrichlorosilane; m2 is dimethyldichlorosilane; m3 is trimethylchlorosilane.

Table 1: comparison of catalytic Properties of the catalysts

As can be seen from table 1 above, the yield of dimethyldichlorosilane synthesized by using commercial ternary copper powder 1 and commercial ternary copper powder 2 as catalysts in the prior art is about 85%, while the yield of dimethyldichlorosilane synthesized by using composite ternary copper powder 1, composite ternary copper powder 2 and composite ternary copper powder 3 as catalysts is over 90%, which is obviously superior to that of two types of ternary copper powders in the prior art. Therefore, the composite ternary copper powder prepared by the preparation method through the first ternary copper powder and the second ternary copper powder can improve the selectivity to dimethyldichlorosilane and the yield of dimethyldichlorosilane compared with the existing ternary copper powder, so that the problems in the prior art are solved.

Further, it is to be noted that when commercial ternary copper powder 1 and commercial ternary copper powder 2 in the prior art are used as catalysts, the conversion rate of Si powder as a reaction raw material is about 52%. As can be seen from table 1 above, when the composite ternary copper powder 1, the composite ternary copper powder 2 and the composite ternary copper powder 3 prepared by the preparation method of the present application are used as catalysts, the conversion rate of Si powder is about 53%, so that the conversion rate of Si powder can be increased compared with the ternary copper powder in the prior art, and the waste of reaction raw materials is reduced.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.