Manganese zinc ferrite material and preparation method thereof

Abstract

The invention provides a manganese-zinc ferrite material and a preparation method thereof, the manganese-zinc ferrite material comprises a main component and an auxiliary component, the main component comprises the following components by mole ratio: 45-50 mol% of Fe2O3, 11.5-17.5 mol% of ZnO, and 32.5-43.5 mol% of MnO; according to the total weight of the main components, the auxiliary components comprise the following components in parts by weight: 200 to 2000 ppm of CaCO3, 200 to 2000 ppm of Bi2O3, 200 to 20000 ppm of Co2O3 and 200 to 20000 ppm of NiO, and the auxiliary components do not comprise SnO2, TiO2, CuO and Nb2O5. Due to the specific main formula range and the auxiliary component range, the obtained manganese-zinc ferrite material has high initial permeability, high Curie temperature, high frequency and high impedance.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic materials, and in particular to a manganese-zinc ferrite material and a preparation method thereof. Background Art

[0002] In recent years, with the advancement of the third industrial revolution and the development of science and technology, human beings have gradually entered the electronic information age, and electronic products have become an indispensable tool for human work, office, leisure, entertainment, learning, and video conferencing. However, while bringing convenience to humans, electronic products also bring certain environmental pollution-electromagnetic interference. Because it can be widely used in signal transmission and its anti-electromagnetic interference technology, high magnetic permeability manganese zinc ferrite materials came into being, but manganese zinc ferrite materials have high magnetic permeability, low resistivity, and low cutoff frequency, and can only be used in low frequency bands; nickel zinc ferrite is widely used in high frequency band filtering due to its high resistivity, cutoff frequency, and high frequency and high impedance, but its magnetic permeability is low, low frequency filtering is poor, and the price is expensive; although nanocrystalline materials can be used in low frequency and high frequency band filtering, their cost is high, and they can only make magnetic cores of simple shapes, so their development is also limited. For the above reasons, scientists have developed iron-poor manganese zinc ferrite materials, which have the advantages of high magnetic permeability, high Curie temperature, high frequency and high impedance, and low price, so they have attracted much attention.

[0003] However, only a few companies have achieved mass production of poor iron manganese zinc ferrite materials, such as JPZ-4 material of Anci, which has a magnetic permeability of 4000 and a Curie temperature of >105°C. Although this material has a high magnetic permeability, its Curie temperature is low, so its application range is relatively small.

[0004] China's invention patent CN110156451B authorizes a high-impedance iron-poor manganese-zinc ferrite material. By limiting the content of iron oxide to 46-49.8 mol%, the content of zinc oxide to 17-23 mol%, and the rest to manganese oxide, the magnetic permeability μ of the manganese-zinc ferrite material is achieved. i =2500±25%, it has good high impedance performance under 1MHz~500MHz conditions, but its Curie temperature is only 120℃.

[0005] Chinese invention patent CN111138180A discloses a wide temperature range high permeability manganese zinc ferrite material. By limiting the content of iron oxide to 46-50 mol%, the content of zinc oxide to 9-12.9 mol%, and the rest to manganese oxide, the obtained manganese zinc ferrite has a wide-band high impedance performance and a Curie temperature greater than 180°C. However, its magnetic permeability is low, μ i >1000.

[0006] For the above reasons, developing a high-frequency, high-impedance iron-poor manganese-zinc ferrite material that can simultaneously meet the requirements of high magnetic permeability and high Curie temperature, and breaking through the existing bottleneck in the development of soft magnetic ferrites, is an important issue that needs to be solved in this field. Summary of the invention

[0007] The main purpose of the present invention is to provide a manganese-zinc ferrite material and a preparation method thereof, so as to solve the problem that the existing soft magnetic ferrite materials cannot simultaneously meet the requirements of high magnetic permeability and high Curie temperature.

[0008] In order to achieve the above-mentioned purpose, the present invention provides a manganese-zinc ferrite material on the one hand, which includes a main component and an auxiliary component, wherein the main component is composed of the following components in molar ratio: Fe2O3 is 45-50mol%, ZnO is 11.5-17.5mol%, and MnO is 32.5-43.5mol%; based on the total weight of the main component, the content of each component of the auxiliary component is: CaCO3 is 200-2000ppm, Bi2O3 is 200-2000ppm, Co2O3 is 200-20000ppm, and NiO is 200-20000ppm, and the auxiliary component does not include SnO2, TiO2, CuO and Nb2O5.

[0009] Furthermore, the molar ratios of the main components in the above-mentioned manganese-zinc ferrite material are: Fe2O3 is 48.5-49.5mol%, ZnO is 16-17mol%, and MnO is 33.5-35.5mol%; based on the total weight of the main components, the contents of the auxiliary components are: CaCO3 is 200-1000ppm, Bi2O3 is 200-1000ppm, Co2O3 is 10000-20000ppm, NiO is 1000-10000ppm, and the auxiliary components do not include SnO2, TiO2, CuO and Nb2O5.

[0010] Furthermore, the weight ratio of Co2O3 to NiO in the auxiliary components is 10 to 15:1; the weight ratio of CaCO3 to Bi2O3 in the auxiliary components is 1:5 to 5:1.

[0011] Furthermore, in the above manganese-zinc ferrite material, the molar ratio of the main components is: Fe2O3: 46mol%, MnO: 41.9mol%, ZnO: 12.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 47mol%, MnO: 39.4mol%, ZnO: 13.6mol 1%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of each component of the main component is: Fe2O3: 48mol%, MnO: 36.9mol%, ZnO: 15.1mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of each component of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of each component of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm O3: 200ppm, Bi2O3: 600ppm, Co2O3: 10000ppm; or the molar ratio of the main components is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm, Co2O3: 15000ppm, NiO: 1000ppm, based on the total weight of the main components.

[0012] Another aspect of the present invention provides a method for preparing the above-mentioned manganese-zinc ferrite material, the method comprising:

[0013] Step S1, weighing the main components according to the proportion to obtain a first raw material and putting the raw material into a ball mill to obtain a first mixed slurry through a first ball mill;

[0014] Step S2, pre-calcining the first mixed slurry to obtain a pre-calcined material, wherein the pre-calcining temperature is 980-1035° C.;

[0015] Step S3, weighing the pre-sintered material and the auxiliary components according to a ratio to obtain a second raw material, subjecting the raw material to a second ball mill to obtain a second mixed slurry, and subjecting the second mixed slurry to spray granulation to obtain ferrite particles;

[0016] Step S4, pressing the ferrite particles into a blank, and sintering the blank to obtain a manganese-zinc ferrite material.

[0017] Furthermore, the particle size of the powder in the first mixed slurry is 1 to 1.5 μm, and the particle size of the powder in the second mixed slurry is 1 to 1.5 μm.

[0018] Furthermore, the pre-burning step of step S2 is carried out in a rotary kiln, and the rotary kiln is fed by a spray gun device arranged thereon; preferably, the feeding speed is 400-500 kg / h.

[0019] Furthermore, the first ball milling in step S1 is wet ball milling, using steel balls as grinding media and water as dispersion medium, wherein the weight ratio of steel balls, the first raw material and water is (3-5):1:1; the second ball milling in step S2 is wet ball milling, using steel balls as grinding media and water as dispersion medium, wherein the weight ratio of steel balls, the second raw material and water is (3-5):1:1.

[0020] Furthermore, the second ball milling step in step S3 also includes adding a binder and a dispersant; preferably, the binder is PVA and the dispersant is citric acid; preferably, based on the total weight of the pre-burned material, the binder is 7.5-12.5wt% and the dispersant is 1-5wt%.

[0021] Furthermore, the sintering step of step S4 is carried out in a nitrogen atmosphere with an oxygen content of 3 to 21 vol%, a sintering temperature of 1300 to 1400°C, and a sintering time of 4 to 10 hours; preferably, the oxygen content is 3 to 5 vol%, and the sintering time is 6 to 8 hours; preferably, the cooling stage of the sintering step is carried out under a balanced oxygen partial pressure.

[0022] By applying the technical solution of the present invention, the specific main formula range and auxiliary component range enable the manganese-zinc ferrite material to have high initial magnetic permeability, high Curie temperature, and high-frequency high impedance, so that it has high impedance in the range of 1MHZ to 120MHz, and has good filtering effects in low and high frequency bands. At the same time, the higher Curie temperature enables it to meet higher ambient temperature requirements. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0024] As described in the background technology, the existing soft magnetic ferrite materials have the problem of not being able to simultaneously meet the requirements of high magnetic permeability and high Curie temperature. In order to solve the above technical problems, the present application provides a manganese-zinc ferrite material, which includes a main component and an auxiliary component, wherein the main component is composed of the following components in molar ratio: Fe2O3 is 45-50mol%, ZnO is 11.5-17.5mol%, and MnO is 32.5-43.5mol%; based on the total weight of the main component, the content of each component of the auxiliary component is: CaCO3 is 200-2000ppm, Bi2O3 is 200-2000ppm, Co2O3 is 200-20000ppm, NiO is 200-20000ppm, and the auxiliary component does not include SnO2, TiO2, CuO and Nb2O5.

[0025] The above main component and auxiliary component formula can make the obtained manganese-zinc ferrite material have high initial magnetic permeability, high Curie temperature and high frequency and high impedance. The crystal structure of the manganese-zinc ferrite in this application is a spinel crystal structure, and the chemical formula can be written as MeFe2O4, where Me is Fe 2+ , Mn 2+ and Zn 2+ , the saturation magnetization intensity is adjusted by Fe 3+ , Mn 2+ and Zn 2+ The ratio is controlled by the main component. 3+ The addition of ions increases the number of magnetic ions at the A position in the crystal structure, which enhances the A-B exchange reaction and increases the Curie temperature. However, an excessively high Fe2O3 ratio will lead to Fe 2+ Ion generation, Fe 2+ ~Fe 3+ The electron migration between Mn and Nn increases, which leads to a decrease in the resistivity of the material and a decrease in the frequency of use. 2+ It prefers to occupy the B position, so the appropriate amount of Mn 2+ The B-site magnetic moment increases, thereby increasing the saturation magnetic moment of the obtained material; an appropriate amount of Zn 2+ The ions can increase the saturation magnetization of the obtained manganese-zinc ferrite, but their ratio is negatively correlated with the Curie temperature of the manganese-zinc ferrite. In the specific implementation process, the adjustment of the dosage of the above-mentioned elements will have an unexpected performance impact on the saturation magnetization and Curie temperature of the manganese-zinc ferrite. The inventors have unexpectedly improved the various properties of the manganese-zinc ferrite by controlling the three main components within the above range based on a large number of creative explorations, and obtained a material with excellent comprehensive performance such as high initial magnetic permeability, high Curie temperature, high frequency and high impedance.

[0026] Adding other specific metal oxides to manganese-zinc ferrite can improve the performance of the obtained manganese-zinc ferrite by promoting the solid phase reaction of ferrite and improving its magnetic properties. 2+ The Ca2+ content in the above range is added to form a high resistance layer at the grain boundary. 2+ On the one hand, it promotes sintering, and on the other hand, the high resistivity of the generated layer can improve its broadband impedance characteristics; the appropriate amount of Bi2O3 doping can promote the growth of its grains, and larger grains can better meet the high magnetic permeability requirements of the material; Co2O3 and NiO can replace the main components in the material and dissolve in its lattice. Co2O3 and NiO in the above range are selected as auxiliary components to selectively regulate the saturation magnetic flux density, Curie temperature and thermal expansion coefficient of the resulting material.

[0027] At the same time, the present application does not use SnO2, TiO2, CuO and Nb2O5 as additives that are commonly used in the conventional knowledge in this field, because the inventors found that introducing the above-mentioned metal oxides into the above-mentioned specific main components will cause the performance of the obtained manganese-zinc ferrite to deteriorate.

[0028] The present invention is based on the above specific main formula range and auxiliary component range, so that the manganese-zinc ferrite material has high initial magnetic permeability, high Curie temperature and high-frequency high impedance, so that it has high impedance in 1MHZ~120MHz, and has good filtering effect in low frequency band and high frequency band. At the same time, the higher Curie temperature enables it to meet higher ambient temperature requirements.

[0029] In a preferred embodiment, the molar ratio of each component of the main component in the manganese-zinc ferrite material is: Fe2O3 is 48.5-49.5mol%, ZnO is 16-17mol%, and MnO is 33.5-35.5mol%; based on the total weight of the main component, the content of each component of the auxiliary component is: CaCO3 is 200-1000ppm, Bi2O3 is 200-1000ppm, Co2O3 is 10000-20000ppm, NiO is 1000-10000ppm, and the auxiliary components do not include SnO2, TiO2, CuO and Nb2O5. On the basis of the above, the main components and auxiliary components in the manganese-zinc ferrite in this application are further optimized so that the control effects of each component are better matched to each other, thereby obtaining a soft magnetic ferrite material with better performance.

[0030] The anisotropy constant of this type of spinel ferrite is negative, while the anisotropy constant K1 of Co2O3 in the auxiliary component is greater than 0. NiO can occupy the B position to reduce the constant. On this basis, the weight ratio of Co2O3 to NiO is controlled to be 10-15:1, so that the two can coordinately regulate the K1 value of the obtained material to approach 0, thereby obtaining a higher magnetic permeability. And as mentioned above, the auxiliary components CaCO3 and Bi2O3 both play a role in regulating the various properties of manganese-zinc ferrite by regulating the grain microstructure of manganese-zinc ferrite. The weight ratio of CaCO3 to Bi2O3 is controlled to be 1:5-5:1, so as to obtain a higher density and a more uniform grain size structure, thereby further improving the resistivity of the obtained material.

[0031] In several typical embodiments, the molar ratio of the main components is: Fe2O3: 46mol%, MnO: 41.9mol%, ZnO: 12.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 47mol%, MnO: 39.4mol%, ZnO: 13.6mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 48mol%, MnO: 36.9mol%, ZnO: 15.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 48mol%, MnO: 36.9mol%, ZnO: 15.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; 2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of each component of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of each component of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each component of the auxiliary component is CaCO 3: 200ppm, Bi2O3: 600ppm, Co2O3: 10000ppm; or the molar ratio of each component of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, and the content of each component of the auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm, Co2O3: 15000ppm, NiO: 1000ppm, based on the total weight of the main component. The present application further optimizes the above range for each component of manganese-zinc ferrite through a large number of experiments, and the use of a formula within this range can obtain a soft magnetic ferrite material with better performance.

[0032] Another aspect of the present invention provides a method for preparing the above-mentioned manganese-zinc ferrite material, the method comprising:

[0033] Step S1, weighing the main components according to the proportion to obtain a first raw material and putting the raw material into a ball mill to obtain a first mixed slurry through a first ball mill;

[0034] Step S2, pre-calcining the first mixed slurry to obtain a pre-calcined material, wherein the pre-calcining temperature is 980-1035° C.;

[0035] Step S3, weighing the pre-sintered material and the auxiliary components according to a ratio to obtain a second raw material, subjecting the raw material to a second ball mill to obtain a second mixed slurry, and subjecting the second mixed slurry to spray granulation to obtain ferrite particles;

[0036] Step S4, pressing the ferrite particles into a ring-shaped blank of size H25X15X8, and sintering the blank to obtain a manganese-zinc ferrite material.

[0037] In the method for preparing manganese-zinc ferrite material of the present application, by limiting the range of the main formula and the range of auxiliary ingredients and controlling each process step in the process, a low-iron manganese-zinc ferrite material with high initial magnetic permeability, high Curie temperature, high frequency and high impedance is prepared. In step S1, the main component powder is subjected to a preliminary first ball milling to refine the powder particles while completing the preliminary mixing of the components to improve its uniformity in order to achieve a better sintering effect; in step S2, the first slurry obtained by ball milling is pre-fired and the pre-fired temperature is controlled to be 980-1035°C. This temperature range is determined according to the properties and proportions of the main components in the present application, so that the three materials of the main component can fully react, and the shrinkage rate of the product during sintering is reduced through solid-phase reaction, thereby effectively improving the density of the obtained manganese-zinc ferrite material. The higher temperature range of 980-1035°C can intensify the lattice vibration of the crystal and increase the thermal vibration amplitude of the metal ions at the nodes, thereby breaking away from the original The nodes are displaced and ion diffusion is completed. Specifically, setting the pre-firing temperature in the range of 980-1035°C can make the solid phase reaction of the three solid raw materials complete, and at the same time, oxygen ions will not be lost due to dissociation; the second ball mill in step S3 will make the raw materials that have not undergone oxidation reaction during the pre-firing process appear, and make the added auxiliary components and the main components be mixed evenly and collide and rub against each other, so as to create better conditions for the subsequent solid phase reaction. At the same time, spray granulation makes the powder form a whole to avoid breakage during subsequent sintering, thereby increasing the internal density of the molding material; step S4 performs final sintering so that the raw materials can be fully ferritized to achieve the best performance effect.

[0038] In order to enhance the activity of each raw material in the main component to a greater extent and enable them to fully blend so that corresponding reactions can occur, the powder particle size in the first mixed slurry is controlled to be 1-1.5 μm; similarly, in order to achieve better crystal activity and mixing effect and protect its structure from damage, the powder particle size in the second mixed slurry is controlled to be 1-1.5 μm.

[0039] In a preferred embodiment, the pre-burning step of step S2 is carried out in a rotary kiln, and the rotary kiln is fed through a spray gun device arranged thereon. The sintering process can be achieved through a variety of equipment. The rotary kiln is selected in this application because it has better airtightness and can meet the atmosphere control requirements in the sintering step of this application. At the same time, it has higher heating efficiency, fast heating and low heat storage, greatly reducing heat loss, and making full use of thermal energy, thereby reducing preparation costs; preferably, the feeding speed is 400-500kg / h, and the material moves at this speed, which can increase the heated area, enhance the effects of heat conduction and heat radiation, and achieve better sintering effect.

[0040] The first ball milling can be achieved in a variety of ways. In order to improve the mixing efficiency and prevent heat and temperature rise, the present application adopts wet ball milling, and uses steel balls as grinding media and water as dispersion medium to make the materials mixed evenly and fully, and at the same time change the state of the raw materials, wherein the weight ratio of steel balls, raw materials and water is (3-5):1:1, and selecting this ball milling condition is conducive to controlling the sand milling particle size within the range of 1.0-1.5 μm; the second ball milling of step S2 also adopts wet ball milling to improve efficiency and keep the temperature within a certain range without excessive increase, and uses steel balls as grinding media and water as dispersion medium to make the materials mixed evenly and fully, and at the same time change the state of the raw materials, wherein the weight ratio of steel balls, raw materials and water is (3-5):1:1, and similarly, selecting this ball milling condition is conducive to controlling the sand milling particle size within the range of 1.0-1.5 μm.

[0041] In order to obtain a better dispersion effect in the second ball milling process and to make it into spherical particles with a certain strength in the subsequent spray drying operation to create favorable conditions for obtaining a better sintering effect, a binder and a dispersant are added in the second ball milling step. Preferably, the binder is PVA and the dispersant is citric acid, so as to obtain a better bonding and dispersion effect. Based on the total weight of the pre-sintered material, the binder is preferably 7.5-12.5wt% and the dispersant is 1-5wt%. Controlling the two within the above range can achieve a better bonding and dispersion effect while not affecting the complete evaporation of the two during the sintering process.

[0042] In order to avoid the redox reaction of ferrite, the sintering step is carried out in a nitrogen atmosphere with an oxygen content of 3 to 21 vol%, preferably 3 to 5 vol%, and the oxygen content is more strictly controlled to further avoid the oxidation and reduction of ferrite and the precipitation of another phase, thereby protecting its performance to a better state. In order to make the formation reaction of ferrite complete and control its internal structure to achieve the required electromagnetic and other physical properties, the sintering temperature is controlled to be 1300 to 1400 ° C and the sintering time is 4 to 10 hours according to the types of each component of the main component and the auxiliary component. On this basis, the sintering time is further preferably 6 to 8 hours to achieve a better sintering effect. In a preferred embodiment, the cooling stage of the sintering step is carried out under a balanced oxygen partial pressure. At this time, the oxide and ferrite are neither oxidized nor reduced, that is, the absorbed oxygen is equal to the released oxygen, and they are in a chemical equilibrium state, so as to achieve a more satisfactory composition, ionic state and microstructure, and obtain more superior electromagnetic properties.

[0043] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0044] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0045] Example 1

[0046] A manganese-zinc ferrite material:

[0047] The three main components of Fe2O3: 49mol%, MnO: 34.4mol%, and ZnO: 16.6mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1; the powder particle size in the obtained slurry was 1-1.5μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020℃ at a speed of 450kg / h; 400kg of the pre-burned material was weighed and put into a sand mill, and then 1.5wt% Co2O3, 200ppm CaCO3, 600ppm m of Bi2O3, 1000ppm of NiO, 8wt% of binder PVA and 1.5wt% of dispersant citric acid, and ball milling for 150min, the powder particle size in the obtained slurry is 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation is used to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure, so as to obtain manganese-zinc ferrite material.

[0048] Example 2

[0049] A manganese-zinc ferrite material:

[0050] The three main components of Fe2O3: 49mol%, MnO: 34.4mol%, and ZnO: 16.6mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1, and the powder particle size in the obtained slurry was 1-1.5μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020℃ at a speed of 450kg / h; 400kg of the pre-burned material was weighed and put into a sand mill, and then 1wt% Co2O3, 200ppm CaCO3, 600ppm Bi2O3, 8wt% binder PVA and 1.5wt% dispersant citric acid, ball milling for 150min, the obtained slurry has a powder particle size of 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure to obtain manganese-zinc ferrite material.

[0051] Example 3

[0052] A manganese-zinc ferrite material:

[0053] The three main components of Fe2O3: 49 mol%, MnO: 34.4 mol%, and ZnO: 16.6 mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1, and the powder particle size in the obtained slurry was 1-1.5 μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020°C at a speed of 450 kg / h; 400 kg of the pre-burned material was weighed and put into a sand mill, and then 200 ppm of CaCO3, 600 ppm of m Bi2O3, 8wt% binder PVA and 1.5wt% dispersant citric acid, ball milling for 150min, the powder particle size in the obtained slurry is 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure, so as to obtain manganese-zinc ferrite material.

[0054] Example 4

[0055] A manganese-zinc ferrite material:

[0056] The three main components of Fe2O3: 48 mol%, MnO: 36.9 mol%, and ZnO: 15.1 mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1, and the powder particle size in the obtained slurry was 1-1.5 μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020°C at a speed of 450 kg / h; 400 kg of the pre-burned material was weighed and put into a sand mill, and then 200 ppm of CaCO3, 600 ppm of m Bi2O3, 8wt% binder PVA and 1.5wt% dispersant citric acid, ball milling for 150min, the powder particle size in the obtained slurry is 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure, so as to obtain manganese-zinc ferrite material.

[0057] Example 5

[0058] A manganese-zinc ferrite material:

[0059] The three main components of Fe2O3: 47mol%, MnO: 39.4mol%, and ZnO: 13.6mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1, and the powder particle size in the obtained slurry was 1-1.5μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020℃ at a speed of 450kg / h; 400kg of the pre-burned material was weighed and put into a sand mill, and then 200ppm of CaCO3, 600ppm of m Bi2O3, 8wt% binder PVA and 1.5wt% dispersant citric acid, ball milling for 150min, the powder particle size in the obtained slurry is 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure, so as to obtain manganese-zinc ferrite material.

[0060] Example 6

[0061] A manganese-zinc ferrite material:

[0062] The three main components of Fe2O3: 46mol%, MnO: 41.9mol%, and ZnO: 12.1mol% were weighed and mixed in a ball mill for 30 minutes, wherein the ball-to-water ratio was 4:1:1, and the powder particle size in the obtained slurry was 1-1.5μm; the mixed slurry was sprayed into a rotary kiln through a spray gun and pre-burned at 1020℃ at a speed of 450kg / h; 400kg of the pre-burned material was weighed and put into a sand mill, and then 200ppm of CaCO3, 600ppm of m Bi2O3, 8wt% binder PVA and 1.5wt% dispersant citric acid, ball milling for 150min, the powder particle size in the obtained slurry is 1-1.5μm; the slurry after ball milling is subjected to component analysis correction, and then spray granulation to obtain ferrite particles; the ferrite particles are pressed into H25×15×8 blank samples, sintered at 1360°C for 6-8 hours under the condition of N2 controlling the oxygen content to 3-5vol%, and the cooling stage is carried out under balanced oxygen partial pressure, so as to obtain manganese-zinc ferrite material.

[0063] Example 7

[0064] A manganese-zinc ferrite material:

[0065] The difference from Example 1 is that the amount of Bi2O3 added is 200 ppm.

[0066] Example 8

[0067] A manganese-zinc ferrite material:

[0068] The difference from Example 1 is that the added amounts of CaCO3 and Bi2O3 are both 2000ppm.

[0069] Example 9

[0070] A manganese-zinc ferrite material:

[0071] The difference from Example 1 is that the added amount of NiO is 1500 ppm.

[0072] Example 10

[0073] A manganese-zinc ferrite material:

[0074] The difference from Example 1 is that the added amount of Co2O3 is 8000ppm.

[0075] Embodiment 11

[0076] A manganese-zinc ferrite material:

[0077] The difference from Example 1 is that the pre-firing temperature is 950°C.

[0078] Example 12

[0079] A manganese-zinc ferrite material:

[0080] The difference from Example 1 is that the pre-firing temperature is 1050°C.

[0081] Comparative Example 1

[0082] A manganese-zinc ferrite material:

[0083] The difference from Example 6 is that 200 ppm of SnO2 is added as an auxiliary component.

[0084] Comparative Example 2

[0085] A manganese-zinc ferrite material:

[0086] The difference from Example 6 is that 200 ppm of Nb2O5 is added as an auxiliary component.

[0087] Comparative Example 3

[0088] A manganese-zinc ferrite material:

[0089] The difference from Example 6 is that the molar ratio of each component in the main component is Fe2O3: 52 mol%, ZnO: 18 mol%, MnO: 30 mol%.

[0090] Comparative Example 4

[0091] A manganese-zinc ferrite material:

[0092] The difference from Example 6 is that the molar ratio of each component in the main component is Fe2O3: 44.5 mol%, ZnO: 11 mol%, MnO: 44.5 mol%.

[0093] The performance test results of the manganese-zinc ferrite material prepared by the above method are shown in Table 1, wherein the test condition of the rated impedance (ZN) is: Zn=Z*Le / Ae.

[0094] Table 1. Initial magnetic permeability, Curie temperature and rated impedance of the obtained materials under different MHz conditions

[0095]

[0096]

[0097] The initial magnetic permeability of the manganese-zinc ferrite material prepared by the above method at different temperatures is shown in Table 2.

[0098] Table 2. Initial magnetic permeability of the obtained materials at different temperatures

[0099]

[0100]

[0101] From the above description, it can be seen that the best embodiment of the present invention achieves a high magnetic permeability of μi of 4000, and the Curie temperature also reaches 160°C.

[0102] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A manganese-zinc ferrite material, characterized in that: The manganese-zinc ferrite material includes a main component and an auxiliary component, wherein the main component is composed of the following components in molar ratio: Fe2O3 is 45-50mol%, ZnO is 11.5-17.5mol%, and MnO is 32.5-43.5mol%; based on the total weight of the main component, the content of each component of the auxiliary component is: CaCO3 is 200-2000ppm, Bi2O3 is 200-2000ppm, Co2O3 is 200-20000ppm, and NiO is 200-20000ppm, and the auxiliary component does not include SnO2, TiO2, CuO and Nb2O5.

2. The manganese-zinc ferrite material according to claim 1, characterized in that: The molar ratio of each component of the main component is: Fe2O3 is 48.5-49.5mol%, ZnO is 16-17mol%, and MnO is 33.5-35.5mol%; based on the total weight of the main component, the content of each component of the auxiliary component is: CaCO3 is 200-1000ppm, Bi2O3 is 200-1000ppm, Co2O3 is 10000-20000ppm, NiO is 1000-10000ppm, and the auxiliary component does not include SnO2, TiO2, CuO and Nb2O5.

3. The manganese-zinc ferrite material according to claim 1 or 2, characterized in that: Among the auxiliary components, the weight ratio of the Co2O3 to the NiO is 10 to 15:1; among the auxiliary components, the weight ratio of the CaCO3 to the Bi2O3 is 1:5 to 5:

1.

4. The manganese-zinc ferrite material according to any one of claims 1 to 3, characterized in that: The molar ratio of the main components is: Fe2O3: 46mol%, MnO: 41.9mol%, ZnO: 12.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 47mol%, MnO: 39.4mol%, ZnO: 13.6mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 48mol%, MnO: 36.9mol%, ZnO: 15.1mol%, and the content of the auxiliary components is CaCO3: 200ppm, Bi2O3: 600ppm based on the total weight of the main components; the molar ratio of the main components is: Fe2O3: 49 mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm; the molar ratio of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm, Co2O3: 10000ppm; or the molar ratio of the main component is: Fe2O3: 49mol%, MnO: 34.4mol%, ZnO: 16.6mol%, based on the total weight of the main component, the content of each auxiliary component is CaCO3: 200ppm, Bi2O3: 600ppm, Co2O3: 15000ppm, NiO: 1000ppm.

5. A method for preparing the manganese-zinc ferrite material according to any one of claims 1 to 4, characterized in that: The preparation method comprises: Step S1, weighing the main component according to a ratio to obtain a first raw material and putting the raw material into a ball mill to obtain a first mixed slurry through a first ball mill; Step S2, pre-calcining the first mixed slurry to obtain a pre-calcined material, wherein the pre-calcining temperature is 980-1035° C.; Step S3, weighing the pre-sintered material and the auxiliary component according to a ratio to obtain a second raw material, subjecting the second raw material to a second ball mill to obtain a second mixed slurry, and subjecting the second mixed slurry to spray granulation to obtain ferrite particles; Step S4, pressing the ferrite particles to obtain a blank, and sintering the blank to obtain the manganese-zinc ferrite material.

6. The preparation method according to claim 5, characterized in that: In the preparation method, the particle size of the powder in the first mixed slurry is 1.0 to 1.5 μm, and the particle size of the powder in the second mixed slurry is 1.0 to 1.5 μm.

7. The preparation method according to claim 5 or 6, characterized in that: The pre-burning step of step S2 is carried out in a rotary kiln, and the rotary kiln is fed by a spray gun device arranged thereon; preferably, the feeding speed is 400-500 kg / h.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The first ball milling in step S1 is wet ball milling, using steel balls as grinding media and water as dispersion medium, wherein the weight ratio of steel balls, the first raw material and water is (3-5):1:1; the second ball milling in step S2 is wet ball milling, using steel balls as grinding media and water as dispersion medium, wherein the weight ratio of steel balls, the second raw material and water is (3-5):1:

1.

9. The preparation method according to claim 8, characterized in that: The second ball milling step of step S3 further includes adding a binder and a dispersant; preferably, the binder is PVA, and the dispersant is citric acid; preferably, based on the total weight of the pre-sintered material, the binder is 7.5-12.5wt%, and the dispersant is 1-5wt%.

10. The preparation method according to any one of claims 5 to 9, characterized in that: The sintering step of step S4 is carried out in a nitrogen atmosphere with an oxygen content of 3 to 21 vol%, a sintering temperature of 1300 to 1400°C, and a sintering time of 4 to 10 hours; preferably, the oxygen content is 3 to 5 vol%, and the sintering time is 6 to 8 hours; preferably, the cooling stage of the sintering step is carried out under a balanced oxygen partial pressure.

Images