CN1040061A

CN1040061A - Reduction-fusion process for preparation of rare-earth Fe-Mn alloy

Info

Publication number: CN1040061A
Application number: CN 88106962
Authority: CN
Inventors: 孙光飞; 陈菊芳; 呼琴; 周寿增
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 1988-10-07
Filing date: 1988-10-07
Publication date: 1990-02-28
Also published as: CN1005919B

Abstract

A kind of technology of reduction-fusion process for preparation of rare-earth Fe-Mn alloy, this method is low with fusing point, low-cost rare earth chloride or oxychloride are raw material, be equipped with an amount of iron, boron (or ferro-boron, boron oxide compound) adding is as the calcium metal or hydrolith (or the sodium Metal 99.5 of reductive agent, potassium), the mixture of required composition proportion is carried out reduction reaction at 700-880 ℃, then at 1050-1400 ℃, in inert gas atmosphere or in reducing atmosphere or the vacuum, melt, thereby by reduction of rare earth muriate and rare earth that is reduced out and iron, the fusion of boronation component element makes rare-earth iron-boron alloy with calcium metal with separating of calcium chloride.

Description

Reduction-fusion process for preparation of rare-earth Fe-Mn alloy

The present invention relates to a kind of preparation method of rare-earth iron-boron permanent magnet alloy of high-performance cheapness, mainly be that the employing rare earth chloride is that raw material is equipped with suitable iron powder, boron powder, and add reductive agent calcium or hydrolith, by reduction fusion method synthesizing rare-earth ferroboron.

Rare-earth iron-boron is that permanent magnetism is the superpower magnet of a class, is one of very important electron material of using in wide spectrum.At present, the production method of rare-earth iron-boron permanent magnet alloy mainly contains smelting process, quick quenching technique and reduction-diffusion process.Smelting process is that the employing pure rare-earth metals is that raw material is equipped with suitable iron and boron is smelted into rare-earth iron-boron alloy in vacuum induction furnace, makes the rare-earth iron-boron magnet through sintering again through fragmentation, abrasive dust, magnetic field orientating, compression moulding then.Reduction-diffusion process is that employing rare earth oxide (seeing disclosed patent application GK-CN 85 100860) or rare earth chloride are raw material, be equipped with an amount of iron and boron, diffusion by calciothermic reduction and required alloy ingredient forms the rare-earth iron-boron alloy powder, through reactants separate, fine grinding powder, magnetic field orientating, compression moulding, sintering form the rare-earth iron-boron permanent magnet then.

Smelting process adopts pure rare-earth metals, and require impure few purity height, thereby raw materials cost height, but this method prepare the cycle of rare-earth iron-boron magnet short, efficient is high, it is raw material that reduction-diffusion process adopts rare earth oxide or muriate, raw materials cost is lower, will grow but this method prepares the period ratio smelting process of rare-earth iron-boron magnet.The purpose of this invention is to provide a kind of improved processing method-reduction fusion method, this method synthesis the advantage of smelting process and reduction-diffusion process.

The rare earth chloride that the used starting material of the present invention obtain when being low, the low-cost mishmetal extraction separation of fusing point, do not need to be converted into again oxide compound or fluorochemical, also can adopt rare earth oxychloride or with the composition of rare earth chloride, also can adopt the composition of rare earth oxide and rare earth chloride.Rare earth is at least a in the rare earth element, based on light rare earthss such as Nd, Pr, Ce, also can also can contain the composition of mixed rare earth chlorides such as other heavy rare earth Gd, Tb, Dy, Ho, Er, Tm, Yb or oxide compound with the mishmetal that contains other rare earth of Nd, Pr enrichment.

The proportioning of alloy major ingredient (in atomic percent)

Ree content 10-25%

Boron content 4-15%

Iron level 70-85%

The element boron of wherein allocating into can be used ferro-boron, and wherein boron content is 12-30 weight %, also can use the oxide compound of boron.For the temperature stability of improving the rare-earth iron-boron based permanent magnet and the erosion resistance that improves the alloy coercive force and improve alloy can be allocated an amount of magnesium-yttrium-transition metal Co, Al, Mo, Ti, Cr, Ni, V, Nb, Mn, Sn, Ta, Zr, Hf, Ge, Bi, Ga, W etc. or its muriate, oxide compound into.As replace Fe 5-30%(atomic percent with Co) or Al replacement Fe 2-8%(atomic percent), magnet temperature stability and coercive force can be improved.The alloy compositions powder mean particle sizes that requirement is allocated into is 5-50 μ m, reductive agent is calcium or hydrolith also available metal sodium, potassium, its granularity is less than 5mm, the amount of allocating into is 1.1-2.5 a times of the required chemical dose of reduction of rare earth muriate, adopt rare earth chloride, oxychloride or its composition, or when being raw material with the composition of rare earth oxide and rare earth chloride, reductive agent is with calcium or hydrolith.If rare earth chloride is 120-360 ℃ through the decompression dehydration pretreatment condition, dehydration furnace pressure is lower than 2.66 * 10 ⁴Pa(200mmHg), and the dehydration rare earth chloride that obtains is a raw material, reductive agent available ca, hydrolith, sodium, potassium or its composition.

After the composition batching in accordance with regulations, mix in efficient blender in inert atmosphere, mixed powder carries out briquetting, merges technology with reduction then and produces rare-earth iron-boron alloy.Its technology is, under vacuum or inert atmosphere, reducing atmosphere, carry out reduction reaction, temperature be 700-880 ℃, the reaction the time be all 2-30 minute, be warming up to 1050 ℃-1400 ℃ subsequently, time is 2-20 minute, and the rare earth metal and iron, the boron that are reduced out are merged and the formation rare-earth iron-boron alloy.Forms owing to the by product calcium chloride of reaction is different with the proportion of rare-earth iron-boron alloy and to be easy to separately and the free of contamination discrete slag phase of rare-earth iron-boron alloy layer.This process is finished under inert atmosphere.Because fusing point, the boiling point of the by product of reaction and rare-earth iron-boron alloy are different, can adopt decompression to remove Ca and CaCl in addition ₂, condition is under the 1050-1400 ℃ of temperature, pressure 1.33 * 10 ^-1Pa～1.33 * 10Pa(1 * 10 ^-3～10mmHg) obtain highly purified rare-earth iron-boron alloy.The powder sintered rare-earth iron-boron magnet performance that adopts the rare-earth iron-boron alloy preparation that present method obtains is excellent and stablize.Adopt this technology can prepare the rare-earth iron-boron series product of different size types such as high magnetic energy, high-coercive force and low-temperature coefficient.

Advantage of the present invention is to have reduced material cost to have shortened manufacturing the cycle of rare-earth iron-boron alloy again, this be because:

The rare earth chloride that obtains when (1) adopting by the rare earth extraction separation is not only than pure rare-earth metals but also more cheap than rare earth oxide, fluorochemical.

(2) the rare earth chloride fusing point is low, and reduction-fusion temperature is low, the time is short.

(3) reductive agent metachemistry dosage can reduce significantly.

(4) saved the cleaning separation circuit of the necessary reaction by product of reduction-diffusion process.

(5) alloy ingredient is easy to control, and purity improves, and recovery rate is higher than 94%.

(6) adopt magnet performance that this technology makes than reduction-diffusion process height, with smelting process quite or be better than.

Embodiment

With A material in efficient blender mixing, briquetting, put into reduction and merge stove, vacuum tightness is 10 ^-2MmHg, applying argon gas protection, in 820 ℃ of insulations be warming up in 0.5 hour 1300 ℃ 0.1 hour, cooling, scarfing cinder, fragmentation, magnetic field orientating, compacting, sintering, gained magnet performance are (BH) _m=38-42MGO _e

The B material is warming up to 1200 ℃ 850 ℃ of insulations 0.2 hour, and 0.2 hour, the gained magnet performance was (BH) _m=36-38MGO _e

The C material is warming up to 1150 ℃ 860 ℃ of insulations 0.2 hour, and 0.2 hour, the gained magnet performance was (BH) _m=32-34MGOe.

Claims

1, a kind ofly produce the method that rare-earth iron-boron is an alloy, it is characterized in that:

A) adopting the reduction fusion method to produce rare-earth iron-boron is alloy, promptly under vacuum or inert atmosphere or reducing atmosphere, carry out reduction reaction, temperature 700-880 ℃, reaction times is 2-30 minute, be warming up to 1050 ℃-1400 ℃ subsequently, time is 2-20 minute, makes and is reduced out metal and iron, boron merges and forms rare-earth iron-boron alloy, also can adopt vacuum to remove Ca, CaCl ₂, condition is 1050-1400 ℃, pressure remains on 1.33 * 10 ^-1～1.33 * 10 ³Pa (1 * 10 ^-3～10mmHg),

B) adopt rare earth oxide, oxychloride or its composition, also can adopt rare earth chloride and muriatic composition, at least comprise a kind of in the rare earth element in the rare earth, based on light rare earthss such as Nb, Pr, Ce, can contain heavy rare earths such as Gd, Tb, Dy, Ho, Er, Tm, Yb, its composition ratio is: rare earth element is 10-25%, and iron is 70-85%, boron is 4-15% (being atomic percent)

C) reductive agent is calcium or hydrolith, sodium, potassium or its composition, and the 1.1-2.5 that allocates dosage into and be the reduction of rare earth required dosage doubly.

2, the method for producing rare-earth iron-boron alloy according to claim 1 is characterized in that, Neodymium trichloride that used Neodymium trichloride or rare earth chloride obtain when being the mishmetal extraction separation or rare earth chloride.

3, according to claim 1, the 2 described methods of producing rare-earth iron-boron alloy, it is characterized in that used Neodymium trichloride or rare earth chloride can carry out the decompression dehydration pre-treatment, condition is 120-360 ℃, pressure is lower than 2.66 * 10 ⁴Pa(200mmHg).

4, it is characterized in that according to the described rare-earth iron-boron alloy method of producing of claim 1, add Elements C o, Al, Mo, Ti, Cr, Ni, V, Nb, Mn, Sn, Ta, Zr, Hf, Ge, Bi, Ga, W etc., or its muriate, oxide compound.

5, the method for producing rare-earth iron-boron alloy according to claim 1 is characterized in that, the reductive agent of dehydration rare earth chloride is with Ca or CaH ₂, also available Na, K or its mixture.

6, the method for producing rare-earth iron-boron alloy according to claim 3, the reductive agent of the rare earth chloride that it is characterized in that dewatering is with Ca or CaH ₂, also available Na, K or its mixture.

7, the method for producing rare-earth iron-boron alloy according to claim 1 is characterized in that with the composition reductive agent of rare earth chloride, rare earth oxychloride or its composition or rare earth oxide, rare earth chloride with Ca or CaH ₂