Method for preparing amorphous magnetic powder and magnetic powder core based on laterite-nickel ore

Abstract

The invention provides a method for preparing amorphous magnetic powder and a magnetic powder core based on laterite-nickel ore. According to the method, valuable elements such as Fe, Ni, Cr and Si in the laterite-nickel ore and a C element in a reducing agent are fully utilized, only a small amount of iron-boron and iron-phosphorus alloy needs to be added, alloying is conducted through physical heat of molten iron of the laterite-nickel ore, and the FeNiCrSiCBP amorphous magnetic powder is directly prepared through a short process. According to the novel short-flow process for the soft magnetic amorphous magnetic powder, the novel FeNiCrSiCBP amorphous magnetic powder can be produced by fully utilizing laterite nickel ore resources, and the production energy consumption and cost can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of amorphous magnetic powder preparation technology, specifically to methods and applications for preparing amorphous magnetic powder and magnetic powder cores based on laterite nickel ore. Background Technology

[0002] Amorphous magnetic powder cores are widely used as high-frequency magnetic components due to their high permeability, low coercivity, high DC bias performance, and excellent machinability at high frequencies. They are applied in new energy vehicle motor drives, 5G communication base stations, and high-efficiency power conversion devices. The preparation process of amorphous magnetic powder cores involves insulating and coating amorphous magnetic powder with resin, then pressing it into a magnetic ring to obtain the amorphous magnetic powder core. The key aspect is the preparation of the amorphous magnetic powder itself.

[0003] Currently, the most widely used commercially available amorphous magnetic powder is FeSiBCCr amorphous magnetic powder, which generally adopts the preparation process of "high-purity metal or alloy raw materials, remelting and alloying, and atomization powdering". This process is highly dependent on the purity of raw materials such as iron, chromium, silicon, iron boron, and iron carbon, resulting in high raw material costs; moreover, the preparation process requires remelting and alloying high-purity metal or alloy raw materials, leading to high energy consumption in production. Summary of the Invention

[0004] Therefore, it is necessary to provide methods and applications for preparing amorphous magnetic powder and magnetic powder cores based on laterite nickel ore.

[0005] The present invention adopts the following technical solution: This invention provides a method for preparing amorphous magnetic powder based on laterite nickel ore, comprising the following steps: obtaining laterite nickel ore; mixing the laterite nickel ore with a reducing agent until homogeneous, and then melting and reducing to obtain laterite nickel ore molten iron; alloying the laterite nickel ore molten iron with iron-boron alloy and iron-phosphorus alloy to obtain a mother liquor, wherein the mother liquor contains 84.72~86.75 wt.% Fe, 1.35~1.62 wt.% Ni, 3.33~4.00 wt.% Cr, 1.88~2.20 wt.% Si, 1.70~2.02 wt.% C, 0.91~3.64 wt.% B, and 1.27~3.80 wt.% P; and subjecting the mother liquor to water atomization to powder preparation and drying to obtain FeNiCrSiCBP amorphous magnetic powder.

[0006] In some embodiments, the reducing agent is one of coke, pulverized coal, or biomass powder. Laterite nickel ore and the reducing agent are mixed at a C / O ratio of 0.8 to 1.0, and laterite nickel ore molten iron is prepared using the RKEF molten reduction process.

[0007] In some embodiments, the laterite nickel ore contains 37.79 wt.% TFe, 1.05 wt.% TNi, 4.17 wt.% Cr₂O₃, 9.68 wt.% SiO₂, 4.57 wt.% MgO, 0.95 wt.% CaO, and 3.65 wt.% Al₂O₃. The iron-boron alloy contains 81.82 wt.% Fe and 17.28 wt.% B; the iron-phosphorus alloy contains 76.26 wt.% Fe and 23.61 wt.% P. The melting reduction temperature is 1550–1650 °C.

[0008] Preferably, the total content of iron-boron alloy and iron-phosphorus alloy in the mother liquor is 20%, with the iron-boron alloy accounting for 5-15% and the iron-phosphorus alloy accounting for 5-15%. The alloying temperature is 1400-1600℃.

[0009] In some embodiments, the water atomization powder production process is as follows: mother liquor temperature 1350~1450℃, water atomization pressure 80~100 kPa.

[0010] In some embodiments, the drying temperature is 50~70°C.

[0011] This invention provides FeNiCrSiCBP amorphous magnetic powder prepared by the above method.

[0012] This invention provides a method for preparing a magnetic powder core, comprising the following steps: preparing FeNiCrSiCBP amorphous magnetic powder according to the above method; coating the FeNiCrSiCBP amorphous magnetic powder with resin insulation; pressing it into a ring according to a preset size to obtain the magnetic powder core.

[0013] Preferably, the amount of epoxy resin added is 3% of the amount of FeNiCrSiCBP amorphous magnetic powder used, and the ring-forming pressure is 1000 MPa.

[0014] Compared with the prior art, the core advantage of this invention is: Lateritic nickel ore is a typical associated iron ore resource in my country, containing valuable elements such as Fe, Ni, Cr, and Si. This invention is the first to explore the preparation of molten iron from lateritic nickel ore, obtaining a novel short-process technology for amorphous magnetic powder based on lateritic nickel ore molten iron, and obtaining FeNiCrSiCBP amorphous magnetic powder that conforms to the compositional characteristics of lateritic nickel ore molten iron.

[0015] 1. Compared with commercial FeSiBCCr amorphous magnetic powder, the present invention is based on a short-process new process for amorphous magnetic powder from laterite nickel ore molten iron. It can make full use of beneficial elements such as Fe, Ni, Cr, Si, and C in the molten iron, reduce the external demand for expensive high-purity iron, nickel, chromium, silicon or iron-carbon alloys, and significantly reduce raw material costs. It can utilize the physical heat of molten iron for alloying, reduce additional heating and remelting energy consumption, achieve higher thermal energy utilization efficiency, and significantly reduce production energy consumption and emissions.

[0016] 2. Compared with commercial FeSiBCCr amorphous magnetic powder, the novel FeNiCrSiCBP amorphous magnetic powder of this invention, which conforms to the composition characteristics of laterite nickel ore molten iron, has a high amorphous forming ability, and the 75 μm magnetic powder is amorphous; the magnetic permeability of the magnetic ring pressed after epoxy resin insulation coating is higher, and it has better corrosion resistance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a short process for preparing amorphous magnetic powder based on laterite nickel ore molten iron according to the present invention.

[0018] Figure 2 The present invention designs a ternary phase diagram of molten iron, iron boron, and iron phosphorus for FeNiCrSiCBP amorphous magnetic powder.

[0019] Figure 3 This is a particle size distribution diagram of the magnetic powder prepared in Example 1.

[0020] Figure 4 The image shows the XRD pattern of the magnetic powder prepared in Example 1.

[0021] Figure 5 This is a SEM image of the magnetic powder prepared in Example 1.

[0022] Figure 6 This is a comparison chart of the magnetic permeability of the magnetic powder core (magnetic ring) prepared in Example 1 and the magnetic ring prepared in Comparative Example 1.

[0023] Figure 7 This is a comparison of the morphology of the magnetic powder core (magnetic ring) prepared in Example 1 and the magnetic ring prepared in Comparative Example 1 after 48 hours of salt spray corrosion. Detailed Implementation

[0024] The technical concept of this invention is to provide a new short-process technology for amorphous magnetic powder using laterite nickel ore molten iron, to obtain FeNiCrSiCBP amorphous magnetic powder that conforms to the composition characteristics of laterite nickel ore molten iron, and then to form a magnetic powder core by insulating and coating the amorphous magnetic powder.

[0025] For detailed process flow, please refer to [link / document / contact information]. Figure 1 The novel short-process amorphous magnetic powder manufacturing process of this invention includes the following steps: S1, obtain laterite nickel ore molten iron.

[0026] S2, the mother liquor is obtained by alloying laterite nickel ore molten iron with iron-boron alloy and iron-phosphorus alloy.

[0027] S3. The mother liquor is atomized into powder by water atomization and then dried to obtain FeNiCrSiCBP amorphous magnetic powder.

[0028] S4. The amorphous magnetic powder is insulated, pressed, and formed into a magnetic powder core.

[0029] The novel FeNiCrSiCBP amorphous magnetic powder produced in this invention exhibits high amorphous forming ability, and the resulting magnetic powder core has higher permeability and better corrosion resistance.

[0030] The present invention will be further described in detail below with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention. The following embodiments are only used to illustrate the present invention, and are not intended to limit the scope of the present invention. Based on the specific embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. In the embodiments of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the embodiments of the present invention, unless specifically specified, the technical means used are conventional means well known to those skilled in the art.

[0031] Explanation of the source of key materials: Laterite nickel ore, source: Guangxi Beigang New Materials Co., Ltd., main components: TFe 37.79 wt.%, TNi 1.05 wt.%, Cr2O3 4.17 wt.%, SiO2 9.68 wt.%, MgO 4.57 wt.%, CaO 0.95 wt.%, Al2O3 3.65 wt.%.

[0032] Laterite nickel ore molten iron, source: RKEF molten iron from Guangxi Beigang New Materials Co., Ltd., main components: Fe content 88.89 wt.%, Ni content 1.80 wt.%, Cr content 4.43 wt.%, Si content 2.35 wt.%, C content 2.23 wt.%.

[0033] Iron-boron alloy, source: Shanghai Shenyun Ferroalloy Co., Ltd., main components: Fe content 81.82 wt.%, B content 17.28 wt.%.

[0034] Iron-phosphorus alloy, source: Shanghai Shenyun Ferroalloy Co., Ltd., main components: Fe content 76.26 wt.%, P content 23.61 wt.%.

[0035] The following example illustrates this.

[0036] Example 1 This embodiment provides an FeNiCrSiCBP amorphous magnetic powder and a magnetic powder core, and the specific process route includes the following steps: S1, obtain laterite nickel ore molten iron.

[0037] In this step, lateritic nickel ore and reducing agent carbon powder are mixed at a C / O ratio of 0.8~1.0 and placed in an electric arc furnace for molten reduction at a temperature of 1600±50℃ to obtain lateritic nickel ore molten iron. The molten reduction adopts the RKEF process, namely rotary kiln-electric furnace reduction process. The lateritic nickel ore powder and reducing agent powder are thoroughly mixed and uniformly, then formed into agglomerates, pre-reduced in a rotary kiln, and then molten reduced in an electric arc furnace to obtain lateritic nickel ore molten iron.

[0038] S2, the molten laterite nickel ore is transferred to the ladle furnace. According to the ternary phase diagram of the molten laterite nickel ore with iron-boron and iron-phosphorus, see [reference needed]. Figure 2 The mass ratio of lateritic nickel ore molten iron to iron boron and iron phosphorus was determined to be 8:1:1; then 10% iron boron alloy and 10% iron phosphorus alloy were added to the lateritic nickel ore molten iron to carry out alloying at a temperature of 1500±50℃ to obtain alloy mother liquor.

[0039] S3. The mother liquor is atomized into powder using water atomization: the mother liquor temperature is controlled at 1350~1450℃, and it is transferred to a water atomization device for powder spraying. The nozzle diameter is selected as 5 mm, and the water atomization pressure is controlled at 80~100 kPa to obtain water-atomized powder. The powder is then dried at 60℃ for 60 min to obtain FeNiCrSiCBP amorphous magnetic powder.

[0040] S4. Insulate and encapsulate amorphous magnetic powder: Add 3% epoxy resin and press it into a magnetic ring with an outer diameter of 27 mm, an inner diameter of 14.5 mm, and a height of 8 mm under a pressure of 1000 MPa to form a magnetic powder core.

[0041] The amorphous magnetic powder and magnetic powder core prepared in this embodiment were tested: (1) The ternary phase diagram of laterite nickel ore (iron, boron, and phosphorus) was calculated using FactSage 8.1, and the results are as follows: Figure 2 As shown, it can be seen that when the mass ratio of laterite nickel ore molten iron, iron boron, and iron phosphorus is 8:1:1, the mother liquor has a low melting point (around 1200℃), which is beneficial for the preparation of amorphous magnetic powder.

[0042] (2) The particle size distribution of the amorphous magnetic powder product was tested using a laser particle size analyzer.

[0043] The results are as follows Figure 3 As shown, the particle size of the obtained water atomized powder exhibits a typical normal distribution. D 10 =2.32 μm,D 50 =6.52 μm, D 10 =18.33 μm.

[0044] (3) The structure of the amorphous magnetic powder product was tested using an X-ray diffractometer (XRD).

[0045] The results are as follows Figure 4 As shown, the XRD pattern of the obtained water atomized powder exhibits a broad diffuse scattering peak, indicating that it is amorphous.

[0046] (4) The morphology of the amorphous magnetic powder products was tested using a scanning electron microscope (SEM).

[0047] The results are as follows Figure 5 As shown, the obtained water atomized powder has good sphericity, with the particle size mainly concentrated around 6 μm, and some larger particles reaching 50 μm, which is consistent with the particle size detection results.

[0048] The product was identified as Fe after testing. 85.60 Ni 1.44 Cr 3.55 Si 2.04 C 1.81 B 1.82 P 2.54 (wt.%), particle size is D 10 = 2.32 μm, D 50 =6.52 μm, D 90 = 18.33 μm.

[0049] (5) The permeability of the amorphous magnetic powder core at different frequencies was tested using an impedance analyzer.

[0050] The results are as follows Figure 6 As shown, the magnetic permeability of the obtained FeNiCrSiCBP amorphous magnetic powder is approximately 24, and it remains stable within 3MHz.

[0051] (6) The magnetic ring was subjected to salt spray corrosion for 24 h at 35 °C and 5% NaCl solution in a salt spray test chamber.

[0052] The results are as follows Figure 7 As shown, it can be seen that the obtained FeNiCrSiCBP amorphous magnetic ring did not undergo significant corrosion after 24 h of salt spray corrosion.

[0053] Example 2 Referring to Example 1, this example investigated the effect of different compounding ratios of raw materials (latrine nickel ore molten iron, iron boron, and iron phosphorus) on the performance of the prepared powder: 5% iron boron alloy and 15% iron phosphorus alloy were added to the laterite nickel ore molten iron. This example successfully prepared water-atomized powder, but it was completely amorphous only below 30 μm, and its amorphous formation ability was slightly worse than in Example 1.

[0054] Example 3 Referring to Example 1, this example investigated the effect of different compounding ratios of raw materials (latite nickel ore molten iron, iron boron, and iron phosphorus) on the properties of the prepared powder: 15% iron boron alloy and 5% iron phosphorus alloy were added to the laterite nickel ore molten iron. This example successfully prepared water-atomized powder, which is completely amorphous below 75 μm, and its amorphous formation ability is comparable to that of Example 1.

[0055] Under the same test conditions, a salt spray corrosion test was conducted. After 24 hours of salt spray corrosion, a small number of rust spots appeared, and the corrosion resistance was slightly worse than that of Example 1.

[0056] Comparative Example 1 This comparative example provides a commercially available AMP-1 amorphous magnetic powder from Tianzhi Alloy Materials Technology Co., Ltd., specifically composed of Fe. 87.86 Cr 2.50 Si 6.60 C 0.50 B 2.50 (wt.%), particle size is D 10 = 2.17 μm, D 50 = 5.18 μm, D 90 = 11.05 μm.

[0057] This comparative example provides a method for preparing magnetic powder cores, which is the same as the magnetic powder core preparation step S4 in Example 1, and the resulting magnetic powder core size is also the same as that in Example 1.

[0058] Referring to Example 1, the magnetic permeability and salt spray tests were performed on the magnetic powder core of this comparative example. The results are shown in [link to example]. Figure 6 and Figure 7 .

[0059] The above comparison clearly shows that the FeNiCrSiCBP amorphous magnetic powder core of Example 1 has superior magnetic properties and corrosion resistance.

[0060] Comparative Example 2 Referring to Example 1, this comparative example investigated the powder properties prepared from laterite nickel ore molten iron with different ferroalloys: only 20% iron-phosphorus alloy was added to the laterite nickel ore molten iron. Although this comparative example successfully prepared water-atomized powder, the product was not amorphous.

[0061] Beyond the experimental examples mentioned above, the inventors' team discovered through extensive research that: A novel short-process technology for preparing molten laterite nickel ore using laterite nickel ore and a reducing agent at a specific C / O ratio, and then compounding the molten laterite nickel ore with iron-phosphorus and iron-boron alloys in a specific ratio to form amorphous magnetic powder, can obtain FeNiCrSiCBP amorphous magnetic powder that conforms to the compositional characteristics of laterite nickel ore molten iron. Furthermore, the amorphous magnetic powder is insulated and coated to form a magnetic powder core, resulting in lower production costs and energy consumption, and superior comprehensive performance such as magnetic permeability and corrosion resistance.

[0062] It should be noted that the above embodiments are only for further elaboration and explanation of the technical solution of the present invention, and are not intended to further limit the technical solution of the present invention. The method of the present invention is only a preferred embodiment and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing amorphous magnetic powder based on laterite nickel ore, characterized by, The method comprises the following steps: obtaining laterite nickel ore molten iron; alloying the laterite nickel ore molten iron with ferro-silicon alloy and ferro-phosphorus alloy to obtain a mother liquor, wherein the Fe content in the mother liquor is 84.72-86.75 wt.%, the Ni content is 1.35-1.62 wt.%, the Cr content is 3.33-4.00 wt.%, the Si content is 1.88-2.20 wt.%, the C content is 1.70-2.02 wt.%, the B content is 0.91-3.64 wt.%, and the P content is 1.27-3.80 wt.%; carrying out water atomization powdering on the mother liquor, and drying to obtain FeNiCrSiCBP amorphous magnetic powder.

2. The method for preparing amorphous magnetic powder based on nickel laterite ore according to claim 1, characterized in that, The laterite nickel ore molten iron is prepared by mixing laterite nickel ore and a reducing agent according to a C / O ratio of 0.8-1.0, and then performing RKEF melting reduction.

3. The method for preparing amorphous magnetic powder based on nickel laterite according to claim 2, characterized in that, The temperature of the melting reduction is 1550-1650 ℃.

4. The method for preparing amorphous magnetic powder based on nickel laterite according to any one of claims 1 to 3, characterized in that, The total content of the ferro-silicon alloy and the ferro-phosphorus alloy in the mother liquor is 20%, the content of the ferro-silicon alloy in the mother liquor is 5-15%, and the content of the ferro-phosphorus alloy in the mother liquor is 5-15%.

5. The method for preparing amorphous magnetic powder based on nickel laterite ore according to claim 4, characterized in that, The temperature of the alloying is 1400-1600 ℃.

6. The method for preparing amorphous magnetic powder based on nickel laterite according to any one of claims 1 to 3, characterized in that, The process flow of the water atomization powdering is that the temperature of the mother liquor is 1350-1450 ℃, and the water atomization pressure is 80-100 kPa.

7. The method for preparing amorphous magnetic powder based on nickel laterite according to any one of claims 1 to 3, characterized in that, The drying temperature is 50-70 ℃.

8. FeNiCrSiCBP amorphous magnetic powder prepared by the method according to any one of claims 1-7.

9. A method of producing a magnetic powder core, characterized by, The method comprises the following steps: preparing FeNiCrSiCBP amorphous magnetic powder according to the method of any one of claims 1-7; coating the FeNiCrSiCBP amorphous magnetic powder with epoxy resin; pressing the FeNiCrSiCBP amorphous magnetic powder into a ring according to a preset size to obtain a magnetic powder core.

10. The method of producing a magnetic powder core according to claim 9, wherein The addition amount of the epoxy resin is 3% of the amount of the FeNiCrSiCBP amorphous magnetic powder; The pressure for pressing the FeNiCrSiCBP amorphous magnetic powder into a ring is 1000 MPa.

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