阅读说明：本技术 一种提高粘结永磁铁氧体材料磁性能的分散剂及方法 (Dispersing agent and method for improving magnetic property of bonded permanent magnetic ferrite material ) 是由 王剑锋 王继全 张鹏杰 刘辉 孙威 刘荣明 王永齐 李炳山 魏汉中 谢光环 牛辉 于 2021-06-07 设计创作，主要内容包括：本发明公开了一种提高粘结永磁铁氧体材料磁性能的分散剂及方法,聚丙烯酸钠和葡萄糖酸钙的共同作用有利于促进铁氧体颗粒分散,防止颗粒团聚,由于聚丙烯酸钠的水溶液呈碱性,通过调节溶液PH值,防止分散剂水解,并且提高粉子间的Zeta电位,由于Zeta电位的提高的,可以使粒子间获得更强的静电斥力,提高磁粉粒子的分散度,提高永磁铁氧体的取向度和料浆的稳定性,从而达到提高粘结永磁铁氧体磁性能的目的,按照本发明方法制得的粘结永磁铁氧体的磁性能有了明显提高,在碱性研磨介质中加入组合分散剂与在碱性或弱碱性研磨介质条件下加入或单一加入分散剂相比,能明显改善永磁铁氧体磁性能。(The invention discloses a dispersant and a method for improving the magnetic property of a bonded permanent magnetic ferrite material, wherein the combined action of sodium polyacrylate and calcium gluconate is favorable for promoting the dispersion of ferrite particles and preventing the particle agglomeration, the aqueous solution of sodium polyacrylate is alkaline, the hydrolysis of the dispersant is prevented by adjusting the pH value of the solution, the Zeta potential between powders is improved, stronger electrostatic repulsion between particles can be obtained due to the improvement of the Zeta potential, the dispersion degree of magnetic powder particles is improved, the orientation degree of the permanent magnetic ferrite and the stability of slurry are improved, so that the aim of improving the magnetic property of the bonded permanent magnetic ferrite is fulfilled, the magnetic property of the bonded permanent magnetic ferrite prepared by the method is obviously improved, compared with the method of adding the combined dispersant in an alkaline grinding medium or adding the dispersant singly, can obviously improve the magnetic performance of the permanent magnetic ferrite.)

1. A method for improving the magnetic property of a bonded permanent magnetic ferrite material is characterized by comprising the following steps: the method comprises the following steps:

s01: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s02: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s03: grinding the ball milling slurry in the step S2 to 1.15um in granularity;

s04: and (5) washing, tempering, drying and powdering the ferrite ball-milling slurry obtained in the step (S3) to obtain bonded permanent magnetic ferrite powder.

2. A method for improving the magnetic property of a bonded permanent magnetic ferrite material is characterized by comprising the following steps: further comprising the steps of:

s11: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s12: adjusting the pH value of the grinding medium by using ammonia water to enable the pH value to reach 9.5;

s13: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s14: grinding the ball milling slurry in the step S13 to 1.15um in granularity;

s15: and (5) washing, tempering, drying and powdering the ferrite ball-milling slurry obtained in the step (S14) to obtain bonded permanent magnetic ferrite powder.

3. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 1, wherein the dispersing agent comprises: in the step S01, the mass ratio of the sodium polyacrylate to the calcium gluconate is 2-5: 1.

4. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 1, wherein the dispersing agent comprises: in step S02, the grinding medium: adding the dispersing agent into water, and stirring uniformly to enable the dispersing agent to be capable of fully dissolving in the water.

5. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 4, characterized in that: the pH of the grinding medium can be adjusted by ammonia water to control the pH of the solution at 8-12.

6. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 1, which is characterized in that: in step S03, the bonded permanent magnetic ferrite pre-sintered material balls and the grinding medium are added into a ball mill, and the ball mill is started to grind.

7. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 1, which is characterized in that: the mass of the pre-sintering material ball is the mass of the grinding medium: 0.5-0.75; the particle size is controlled to be 1.1-1.2 um.

8. The dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material according to claim 1, which is characterized in that: the tempering temperature is controlled to be about 920 ℃.

Technical Field

The invention relates to the technical field of industrial production, in particular to a dispersing agent and a method for improving the magnetic property of a bonded permanent magnetic ferrite material.

Background

The ferrite permanent magnetic material is a permanent magnetic material with the largest demand in the current industrial production, and is widely applied to the information and electromechanical industry, the permanent magnetic material can be divided into a bonded permanent magnetic ferrite and a sintered permanent magnetic ferrite according to different molding processes, and in the fields of electromechanics, sensors and the like, the sintered ferrite occupies most of the permanent magnetic ferrite market at present due to the characteristics of high magnetic performance, good temperature stability, low price and the like, but the ferrite permanent magnetic material also has the following characteristics: low size precision, low impact strength, difficult multi-pole magnetizing and the like. In contrast, the bonded permanent magnetic ferrite has the advantages of relatively simple molding process, easiness in manufacturing products with higher dimensional accuracy, smaller relative density and the like, and is increasingly applied to the fields of medical treatment, electronic appliances, instruments and the like in recent high and new technical fields, but the bonded permanent magnetic ferrite has relatively lower magnetic performance, and along with the production and application of high and new technical equipment, higher requirements are provided for the magnetic performance of the bonded permanent magnetic ferrite.

Therefore, we propose a dispersant and a method for improving the magnetic property of the bonded permanent magnetic ferrite material to solve the above problems.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a dispersing agent and a method for improving the magnetic property of a bonded permanent magnetic ferrite material.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for improving the magnetic property of a bonded permanent magnetic ferrite material by using a dispersing agent comprises the following steps:

s01: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s02: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s03: grinding the ball milling slurry in the step S2 to 1.15um in granularity;

s04: and (5) washing, tempering, drying and powdering the ferrite ball-milling slurry obtained in the step (S3) to obtain bonded permanent magnetic ferrite powder.

Preferably, the method further comprises the following steps:

s11: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s12: adjusting the pH value of the grinding medium by using ammonia water to enable the pH value to reach 9.5;

s13: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s14: grinding the ball milling slurry in the step S13 to 1.15um in granularity;

s15: and (5) washing, tempering, drying and powdering the ferrite ball-milling slurry obtained in the step (S14) to obtain bonded permanent magnetic ferrite powder.

Preferably, in the step S01, the mass ratio of the sodium polyacrylate to the calcium gluconate is 2-5: 1;

preferably, in step S02, the grinding medium: adding the dispersing agent into water, and stirring uniformly to enable the dispersing agent to be capable of fully dissolving in the water.

Preferably, the pH value of the grinding medium can be adjusted by ammonia water, so that the pH value of the solution is controlled to be 8-12;

preferably, in step S03, the bonded permanent magnetic ferrite pre-sintered balls and the grinding medium are added into a ball mill, and the ball mill is started to grind.

Preferably, the mass of the pre-sintering material balls is the following mass of grinding media: 0.5-0.75; the granularity is controlled to be 1.1-1.2 um;

preferably, the tempering temperature is controlled to be about 920 ℃.

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

1. according to the dispersing agent for improving the magnetic property of the bonded permanent magnetic ferrite material, sodium polyacrylate and calcium gluconate are selected as the dispersing agent, the pH value of a grinding medium is adjusted through ammonia water, the magnetic property of the bonded permanent magnetic ferrite is obviously improved, the magnetic property of a product is obviously improved, the common action of the sodium polyacrylate and the calcium gluconate is favorable for promoting the dispersion of ferrite particles and preventing the particles from agglomerating, and the hydrolysis of the dispersing agent is prevented and the Zeta potential between the powder particles is improved due to the fact that the aqueous solution of the sodium polyacrylate is alkaline and the pH value of the solution is adjusted.

2. The invention relates to a dispersing agent for improving the magnetic property of a bonded permanent magnetic ferrite material, which can obtain stronger electrostatic repulsion among particles due to the improvement of Zeta potential, improve the dispersion degree of magnetic powder particles, and improve the orientation degree of the permanent magnetic ferrite and the stability of slurry, thereby achieving the purpose of improving the magnetic property of the bonded permanent magnetic ferrite.

Drawings

FIG. 1 is a diagram of the method steps of a dispersant for improving the magnetic property of a bonded permanent magnetic ferrite material according to the present invention;

FIG. 2 is a diagram of another method for improving the magnetic property of the bonded permanent magnetic ferrite material.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

Referring to fig. 1, a method of improving a dispersant for binding magnetic properties of a permanent magnetic ferrite material includes the steps of:

s01: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s02: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s03: grinding the ball milling slurry in the step S2 to 1.15um in granularity;

s04: and (4) washing the ferrite ball-milling slurry obtained in the step (S3), tempering (920 ℃), drying and powdering to obtain the bonded permanent magnetic ferrite powder.

The following table shows the process parameters and the magnetic performance test results of the permanent magnetic ferrite:

from the above table, when the PH value of the grinding medium is controlled to be 7.5, by adding the combined dispersing agents with different proportions, the magnetic performance of the permanent magnetic ferrite is better, the remanence reaches 168mT, and the intrinsic coercive force reaches 313kA/m compared with the case that only one dispersing agent is added or not added.

Example 2

Referring to fig. 2, a method of improving the magnetic property of the bonded permanent magnetic ferrite material further includes the following steps:

s11: adding a dispersing agent into 1L of water, and uniformly stirring to ensure that the dispersing agent can be fully dissolved in the water to be used as a grinding medium, wherein the weight of calcium gluconate is 0.4 percent of that of the pre-sintered material ball, and the ratio of sodium polyacrylate to calcium gluconate is 3: 1;

s12: adjusting the pH value of the grinding medium by using ammonia water to enable the pH value to reach 9.5;

s13: adding 0.6kg of material balls and grinding media into a ball milling tank in sequence for grinding;

s14: grinding the ball milling slurry in the step S13 to 1.15um in granularity;

s15: and (5) washing, tempering, drying and powdering the ferrite ball-milling slurry obtained in the step (S14) to obtain bonded permanent magnetic ferrite powder.

The following table shows the process parameters and the magnetic performance test results of the permanent magnetic ferrite:

from the above table, when the PH of the grinding medium is controlled to be 9.5, by adding the combined dispersing agents with different proportions, the magnetic performance of the permanent magnetic ferrite is better, the remanence reaches 173mT, and the intrinsic coercivity reaches 318kA/m compared with the case that only one dispersing agent is added or not added.

As can be seen from the results of comparing the tables of example 1 and example 2, the magnetic performance of the permanent magnetic ferrite is better by adding the dispersant in different proportions compared with the case of adding no dispersant or only one dispersant. And when the grinding medium solution is alkaline, the hydrolysis of the dispersing agent can be more inhibited, the Zeta potential of the powder inspection is improved, the solution viscosity is reduced, the fine grinding is promoted, and the proportion of the ultrafine particles in the magnetic powder is reduced, so that the bonded permanent magnetic ferrite has more excellent magnetic performance.

In summary, the combined dispersing agent sodium polyacrylate and the calcium gluconate are added, the mass ratio of the combined dispersing agent is controlled to be 2-5: 1, the pH value of the grinding medium is adjusted, and the pH value of the grinding medium is controlled to be 8-12. The dispersing agent and the method for improving the magnetic property of the bonded permanent magnetic ferrite material can effectively improve the magnetic property of the bonded permanent magnetic ferrite.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

In the description of the present invention, it is to be understood that the terms indicating an orientation or positional relationship are based on the orientation or positional relationship shown in the drawings only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.