CN115231916A - Magnesium aluminate spinel forming crucible and manufacturing method thereof - Google Patents
Magnesium aluminate spinel forming crucible and manufacturing method thereof Download PDFInfo
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Abstract
The invention relates to the technical field of neodymium iron boron permanent magnet materials, in particular to the technical field of neodymium iron boron smelting, and discloses a magnesium aluminate spinel forming crucible and a manufacturing method thereof; is prepared by constructing a furnace, baking and sintering a crucible blank; the crucible blank is formed based on a crucible core after the furnace building material and boric acid solution are uniformly stirred; the building material is prepared by uniformly mixing an adhesive and a high-strength refractory material; after the building materials are sintered, lanthanum oxide powder reacts with magnesia-alumina spinel sand/powder, and a replacement reaction protective layer is generated on the inner surface of the magnesia-alumina spinel forming crucible; the boric acid solution is 5-7% by mass; the mass of the boric acid solution is 5-7% of the mass of the building material. The magnesium aluminate spinel forming crucible can avoid the replacement reaction of the permanent magnet material and the crucible in smelting, and has the advantages of high strength and long service life.
Description
Technical Field
The invention belongs to the technical field of neodymium iron boron permanent magnet materials, relates to the technical field of neodymium iron boron smelting, and particularly relates to a magnesium aluminate spinel forming crucible and a manufacturing method thereof.
Background
The sintered Nd-Fe-B permanent magnetic material belongs to the third generation rare earth permanent magnetic material, and compared with other types of permanent magnetic materials, the sintered Nd-Fe-B permanent magnetic material has the outstanding advantages of high magnetic performance, low price and the like, so that the development and application of the sintered Nd-Fe-B permanent magnetic material are developed beyond the conventional way. At present, the comprehensive magnetic performance of the magnetic material reaches a higher level, the application of the magnetic material relates to various fields of national economy, and the magnetic material has wide application in the industries of computers, information, automobiles, nuclear magnetic resonance imaging, CD-ROM, DVF and the like.
Smelting is particularly important as the first step of sintered neodymium iron boron production, most of the crucibles for smelting at present adopt alumina forming crucibles, the service life of the alumina crucibles is generally 30-50 furnaces, the alumina crucibles are easy to corrode by neodymium iron boron molten steel to influence the discharging rate, the neodymium iron boron molten steel and the alumina crucibles can generate displacement reaction of different degrees, and the loss of rare earth in neodymium iron boron is large.
Disclosure of Invention
The invention aims to provide a magnesia-alumina spinel forming crucible and a manufacturing method thereof, and the crucible can prevent permanent magnet materials from generating replacement reaction with the crucible in smelting.
The invention is realized by the following technical scheme:
a magnesia-alumina spinel forming crucible is made by a crucible blank through furnace building, baking and sintering;
the crucible blank is formed on the basis of a crucible core after the furnace building material and boric acid solution are uniformly stirred;
the building material is prepared by uniformly mixing an adhesive and a high-strength refractory material; 6-9 parts of refractory cement as a binder in parts by mass; the high-strength refractory material is formed by mixing 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder;
after the building materials are sintered, lanthanum oxide powder reacts with magnesia-alumina spinel sand/powder, and a replacement reaction protective layer is generated on the inner surface of the magnesia-alumina spinel forming crucible;
the boric acid solution is 5-7% by mass; the mass of the boric acid solution is 5-7% of the mass of the building material.
Further, when the neodymium iron boron is smelted, the displacement reaction protective layer and the neodymium iron boron and lanthanum oxide powder generate MgO-ReO (Al, fe) 2 O 3 And (4) compounding layers.
Further, the magnalium spinel sand/powder consists of, by mass, 5-8 parts of magnalium spinel powder with the particle size of 40-60 microns, 20-25 parts of magnalium spinel sand with the particle size of 0-1mm, 20-25 parts of magnalium spinel sand with the particle size of 1-3mm and 11-15 parts of magnalium spinel sand with the particle size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle diameters of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
Further, the boric acid solution is a boric acid solution with the mass percentage concentration of 5.7%; the mass of the boric acid solution is 5.3 percent of the mass of the charging material, the mass of the boric acid is 0.3 percent of the mass of the charging material, and the mass of the water is 5 percent of the mass of the charging material.
A manufacturing method of a magnesia-alumina spinel forming crucible comprises the following steps by mass:
s1, uniformly stirring 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder to prepare a high-strength refractory material;
s2, adding 6-9 parts of refractory cement into a high-strength refractory material, and uniformly stirring to prepare a charging material;
s3, weighing a boric acid solution with the mass percentage concentration of 5-7% according to 5-7% of the mass of the building burden material;
s4, adding the boric acid solution into the building material, and stirring uniformly;
s5, placing the insulating layer in an induction coil of a vacuum induction furnace;
s6, paving 10-20mm thick building materials on the insulating layer at the bottom of the induction coil for 3-5 times, and tamping layer by layer;
s7, fixing the crucible mold core at the center of the furnace building material at the bottom of the induction coil, and adjusting the position of the crucible mold core to enable the upper plane of the crucible mold core to be flush with the upper part of the induction coil;
s8, adding the furnace building materials into a gap between the crucible mold core and the induction coil for 5-8 times, wherein the thickness of the furnace building materials added each time is 30-50mm, tamping, taking out the crucible mold core after 1-2 hours, and shaping the crucible blank to complete furnace building;
s9, airing the crucible blank for 60-84h in a natural state, and spraying and maintaining the crucible blank by using pure water;
s10, placing the resistance furnace into a crucible blank, baking and dehydrating for 20-28h in an open furnace;
s11, adjusting the vacuum degree in the vacuum induction furnace to 600-1200Pa, controlling the vacuum induction furnace to bake and dehydrate the crucible blank under 60KW of heating power, wherein the baking time is 20-28h, and finishing primary baking of the crucible blank;
s12, adjusting the vacuum degree in the vacuum induction furnace to 100-600Pa, baking and dehydrating the crucible blank for 4-6h under 50KW heating power, and then finishing secondary baking of the crucible blank;
adjusting the vacuum degree in the vacuum induction furnace to 3-100Pa, and baking the sintering crucible blank for 8-12h under the heating power of 100-200 KW; and simultaneously, an infrared temperature measuring gun is used for measuring the temperature of the inner surface of the crucible, and after the temperature of the inner surface of the crucible blank reaches 1800 ℃, the temperature is preserved for 2-3 hours by a vacuum induction furnace to prepare the magnesia-alumina spinel forming crucible.
Further, in S1, the magnesium aluminate spinel sand/powder consists of 5-8 parts of magnesium aluminate spinel powder with the particle size of 40-60 microns, 20-25 parts of magnesium aluminate spinel sand with the particle size of 0-1mm, 20-25 parts of magnesium aluminate spinel sand with the particle size of 1-3mm and 11-15 parts of magnesium aluminate spinel sand with the particle size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle sizes of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
Further, in S5, the insulating layer is an asbestos layer or glass cloth.
Further, in S7, the position between the crucible core and the induction coil is fixed by a plurality of wood wedges.
Further, in the S6 and the S8, the material building materials are tamped through steel chisels.
Further, in the step S11, 80-120kg of iron rods with the same depth as the crucible are filled into the crucible blank, the iron rods are heated through an induction coil of the vacuum induction furnace, and the crucible blank is primarily baked through the iron rods;
and S12, placing a core rod made of high-purity graphite which has the same shape as the inner cavity of the crucible blank and is 3-6mm smaller than the inner cavity into the crucible blank, heating the core rod through an induction coil of the vacuum induction furnace, and carrying out secondary baking on the crucible blank through the core rod.
Compared with the prior art, the invention has the following beneficial technical effects:
1. the magnesia-alumina spinel forming crucible prepared by the technical scheme of the invention replaces an alumina forming crucible which is commonly used in neodymium iron boron production; compared with aluminum oxide, the magnesium aluminate spinel added in the invention has a higher melting point (2135 ℃), lanthanum oxide powder is also added in the invention, and lanthanum is more active than elements in neodymium iron boron, so that in the crucible sintering process, the magnesium aluminate spinel and the lanthanum oxide powder react to generate a replacement reaction protective layer which can prevent neodymium iron boron and a crucible from generating a replacement reaction; in the process of smelting neodymium iron boron by using the crucible, the replacement reaction protective layer on the surface of the magnesia-alumina spinel forming crucible reacts with the neodymium iron boron to generate MgO-ReO- (Al, fe) 2 O 3 The composite layer inhibits the formation of rare earth slag and reduces the loss of rare earth oxide; zirconia powder is added, the zirconia is a cubic phase, the melting point is 2690 ℃, the bending strength is good, the zirconia dispersed on the inner surface of the crucible is beneficial to improving the high-temperature strength of the crucible, the crucible is not easy to crack, and the service life of the crucible is prolonged; furthermore, the magnesia-alumina spinel crucible is prevented from being corroded by neodymium iron boron molten steel, and does not have a displacement reaction with neodymium iron boron while having high-temperature strength.
2. According to the invention, the refractory cement is used for replacing water glass as a low-temperature adhesive, and boric acid and pure water are added, so that the boric acid can reduce the consumption of the pure water in the adhesive, ensure that the adhesive has better fluidity after preparation is completed, reduce the sintering temperature of a crucible blank, reduce the probability of holes in the crucible blank during sintering, and improve the strength and the refractoriness of the crucible.
Drawings
FIG. 1 is a graph showing the distribution of the substances on the inner surface of a magnesium aluminate spinel forming crucible prepared according to the formulation of example 1;
FIG. 2 is a graph showing the distribution of the material on the inner surface of a magnesia alumina spinel crucible made according to the formulation of example 2;
FIG. 3 is a graph showing the distribution of the materials on the inner surface of a magnesium aluminate spinel forming crucible made according to the formulation of example 3 in the present invention.
Detailed Description
The present invention will now be described in further detail, with the understanding that the present invention is to be considered as illustrative and not restrictive.
The invention discloses a magnesia-alumina spinel molding crucible, which is prepared by building a furnace, baking and sintering a crucible blank;
the crucible blank is formed based on a crucible core after the furnace building material and boric acid solution are uniformly stirred;
the building material is prepared by uniformly mixing an adhesive and a high-strength refractory material; 6-9 parts of refractory cement as a binder in parts by mass; the high-strength refractory material is formed by mixing 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder;
after the building materials are sintered, lanthanum oxide powder reacts with magnesia-alumina spinel sand/powder, and a replacement reaction protective layer is generated on the inner surface of the magnesia-alumina spinel forming crucible;
the boric acid solution is 5-7% by mass; the mass of the boric acid solution is 5-7% of the mass of the building material.
When the neodymium iron boron is smelted, the replacement reaction protective layer, the neodymium iron boron and lanthanum oxide powder generate MgO, reO (Al, fe) 2 O 3 And (4) compounding layers.
The magnesium-aluminum spinel sand/powder consists of, by mass, 5-8 parts of magnesium-aluminum spinel powder with the particle size of 40-60 mu m, 20-25 parts of magnesium-aluminum spinel sand with the particle size of 0-1mm, 20-25 parts of magnesium-aluminum spinel sand with the particle size of 1-3mm and 11-15 parts of magnesium-aluminum spinel sand with the particle size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle sizes of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
The boric acid solution is 5.7% by mass; the mass of the boric acid solution is 5.3 percent of the mass of the charging material, the mass of the boric acid is 0.3 percent of the mass of the charging material, and the mass of the water is 5 percent of the mass of the charging material.
The invention also discloses a manufacturing method of the magnesia-alumina spinel forming crucible, which comprises the following steps in parts by mass:
s1, uniformly stirring 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder to prepare a high-strength refractory material;
s2, adding 6-9 parts of refractory cement into a high-strength refractory material, and uniformly stirring to prepare a charging material;
s3, weighing a boric acid solution with the mass percentage concentration of 5-7% according to 5-7% of the mass of the building burden material;
s4, adding the boric acid solution into the building material, and stirring uniformly;
s5, placing the insulating layer in an induction coil of a vacuum induction furnace;
s6, paving 10-20mm thick building materials on the insulating layer at the bottom of the induction coil for 3-5 times, and tamping layer by layer;
s7, fixing the crucible mold core at the central position of the furnace building material at the bottom of the induction coil, and adjusting the position of the crucible mold core to enable the upper plane of the crucible mold core to be flush with the upper part of the induction coil;
s8, adding the furnace building materials into a gap between the crucible mold core and the induction coil for 5-8 times, wherein the thickness of the furnace building materials added each time is 30-50mm, tamping, taking out the crucible mold core after 1-2 hours, and shaping the crucible blank to complete furnace building;
s9, airing the crucible blank for 60-84 hours in a natural state, and spraying and maintaining by using pure water in the airing period;
s10, placing the resistance furnace into a crucible blank, baking and dehydrating for 20-28h in an open furnace;
s11, adjusting the vacuum degree in the vacuum induction furnace to 600-1200Pa, controlling the vacuum induction furnace to bake and dehydrate the crucible blank under 60KW of heating power, wherein the baking time is 20-28h, and finishing primary baking of the crucible blank;
s12, adjusting the vacuum degree in the vacuum induction furnace to 100-600Pa, baking and dehydrating the crucible blank for 4-6h under 50KW heating power, and then finishing secondary baking of the crucible blank;
adjusting the vacuum degree in the vacuum induction furnace to 3-100Pa, and baking the sintered crucible blank for 8-12h under the heating power of 100-200 KW; and simultaneously, testing the inner surface temperature of the crucible by using an infrared temperature measuring gun, and after the inner surface temperature of a crucible blank reaches 1800 ℃, preserving heat for 2-3 hours by using a vacuum induction furnace to prepare the magnesia-alumina spinel formed crucible.
In the S1, the magnesium aluminate spinel sand/powder consists of 5-8 parts of magnesium aluminate spinel powder with the particle size of 40-60 mu m, 20-25 parts of magnesium aluminate spinel sand with the particle size of 0-1mm, 20-25 parts of magnesium aluminate spinel sand with the particle size of 1-3mm and 11-15 parts of magnesium aluminate spinel sand with the particle size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle sizes of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
In S5, the insulating layer is an asbestos layer or glass cloth.
And in the S7, fixing the position between the crucible mold core and the induction coil through a plurality of wood wedges.
And in the S6 and the S8, tamping the building materials through steel chisels.
In the S11, 80-120kg of iron rods with the same depth as the crucible are filled into the crucible blank, the iron rods are heated through an induction coil of the vacuum induction furnace, and the crucible blank is primarily baked through the iron rods;
and S12, placing a core rod made of high-purity graphite which has the same shape as the inner cavity of the crucible blank and is 3-6mm smaller than the inner cavity into the crucible blank, heating the core rod through an induction coil of the vacuum induction furnace, and carrying out secondary baking on the crucible blank through the core rod.
Specific examples are given below.
Example 1: preparing a building material according to the following mass parts:
refractory materials: 66 parts of magnesium aluminate spinel sand/powder (11 parts of magnesium aluminate spinel sand with the particle size of 3-5mm, 22 parts of magnesium aluminate spinel sand with the particle size of 1-3mm, 25 parts of magnesium aluminate spinel sand with the particle size of 0-1mm and 8 parts of magnesium aluminate spinel powder with the particle size of 40-60 mu m); 20 parts of corundum sand/powder (wherein 11 parts of corundum sand with the particle size of 1-3mm, 2 parts of corundum sand with the particle size of 0-1mm and 7 parts of corundum powder with the particle size of 40-60 mu m); 3 parts of magnesia powder, 1 part of lanthanum oxide powder and 1 part of zirconia powder;
adhesive: 9 parts of refractory cement.
The preparation method comprises the following steps of:
s1, uniformly stirring 66 parts of magnesium-aluminum spinel sand/powder, 20 parts of corundum sand/powder, 3 parts of magnesia powder, 1 part of zirconia powder and 1 part of lanthanum oxide powder to prepare a high-strength refractory material;
s2, adding 9 parts of refractory cement into a high-strength refractory material, and uniformly stirring to prepare a furnace building material;
s3, weighing pure water according to 5% of the mass of the building burden, and weighing boric acid according to 0.3% of the mass of the building burden; heating pure water to 100 ℃, adding boric acid, and stirring until the boric acid is completely dissolved to obtain a boric acid solution with the mass percent concentration of 5.7%;
s4, adding the boric acid solution into the building material, and stirring uniformly;
s5, placing the insulating layer in an induction coil of a vacuum induction furnace;
s6, uniformly paving the building materials with the thickness of 15mm on the insulating layer at the bottom of the induction coil for 4 times, and tamping layer by layer;
s7, fixing the crucible mold core at the center of the furnace building material at the bottom of the induction coil, and adjusting the position of the crucible mold core to enable the upper plane of the crucible mold core to be flush with the upper part of the induction coil;
s8, adding the furnace building materials into a gap between the crucible mold core and the induction coil for 6 times, wherein the thickness of the furnace building materials added each time is 40mm, tamping, taking out the crucible mold core after 2 hours, and shaping the crucible blank to complete furnace building;
s9, airing the crucible blank for 72 hours in a natural state, and spraying and maintaining by using pure water;
s10, placing the resistance furnace into a crucible blank, baking and dehydrating for 24 hours in an open furnace;
s11, adjusting the vacuum degree in the vacuum induction furnace to 800Pa, controlling the vacuum induction furnace to bake and dehydrate the crucible blank under 60KW of heating power, wherein the baking time is 24 hours, and finishing primary baking of the crucible blank;
s12, adjusting the vacuum degree in the vacuum induction furnace to 400Pa, baking and dehydrating the crucible blank for 5 hours under 50KW heating power, and then finishing secondary baking of the crucible blank; adjusting the vacuum degree in the vacuum induction furnace to 50Pa, and baking and sintering the crucible blank for 12 hours under the heating power of 150 KW; and simultaneously, an infrared temperature measuring gun is used for measuring the temperature of the inner surface of the crucible, and after the temperature of the inner surface of the crucible blank reaches 1800 ℃, the temperature is preserved for 2.5 hours by a vacuum induction furnace to prepare the magnesia-alumina spinel forming crucible.
The distribution of the substances on the inner surface of the magnesia alumina spinel crucible prepared according to the formula is shown in figure 1, after 165 furnaces before continuous use, no cracks with the depth of more than 1mm and the length of 1mm exist on the inner surface of the crucible, the final service life of the crucible is 362 furnaces, and the average discharge rate is 99.13%.
Example 2:
the operation steps for preparing the magnesia alumina spinel crucible are the same as those of example 1; the difference is that:
preparing a building material according to the following mass parts: refractory materials: 67 parts of magnesium aluminate spinel sand/powder (13 parts of magnesium aluminate spinel sand with the particle size of 3-5mm, 24 parts of magnesium aluminate spinel sand with the particle size of 1-3mm, 23 parts of magnesium aluminate spinel sand with the particle size of 0-1mm and 7 parts of magnesium aluminate spinel powder with the particle size of 40-60 mu m); 23 parts of corundum sand/powder (wherein, 12 parts of corundum sand with the grain diameter of 1-3mm, 3 parts of corundum sand with the grain diameter of 0-1mm and 8 parts of corundum powder with the grain diameter of 40-60 mu m); 2 parts of magnesia powder, 1.5 parts of lanthanum oxide powder and 0.5 part of zirconia powder;
adhesive: 6 parts of refractory cement.
The distribution of the substances on the inner surface of the magnesia alumina spinel crucible prepared according to the formula is shown in figure 2, after 226 furnaces before continuous use, no cracks with the depth of more than 1mm and the length of 1mm exist on the inner surface of the crucible, the final service life of the crucible is 415 furnaces, and the average discharge rate is 99.24%.
Example 3: the operation steps for preparing the magnesia alumina spinel crucible are the same as those of example 1; the difference is that:
preparing a building material according to the following mass parts: refractory materials: 64 parts of magnesia-alumina spinel sand/powder (wherein, 14.5 parts of magnesia-alumina spinel sand with the grain diameter of 3-5mm, 25 parts of magnesia-alumina spinel sand with the grain diameter of 1-3mm, 17 parts of magnesia-alumina spinel sand with the grain diameter of 0-1mm and 7.5 parts of magnesia-alumina spinel powder with the grain diameter of 40-60 mu m); 25 parts of corundum sand/powder (wherein, 15 parts of corundum sand with the grain diameter of 1-3mm, 4 parts of corundum sand with the grain diameter of 0-1mm and 6 parts of corundum powder with the grain diameter of 40-60 mu m); 2.5 parts of magnesia powder, 0.5 part of lanthanum oxide powder and 1.5 parts of zirconia powder;
adhesive: 7 parts of refractory cement.
The distribution of the substances on the inner surface of the magnesia alumina spinel crucible prepared according to the formula is shown in figure 3, after the crucible is continuously used in a 185 furnace, no crack with the depth of more than 1mm and the length of 1mm exists on the inner surface of the crucible, the final service life of the crucible is 402 furnace, and the average discharge rate is 99.07 percent.
The magnesium aluminate spinel forming crucible prepared according to the examples 1-3 has the shortest service life of 462 furnaces and the lowest average discharge rate of 99.07%; the service life of the alumina forming crucible is 30-50 furnaces, and the average discharge rate is 98%; therefore, the technical scheme of the invention obviously prolongs the service life and the discharge rate of the neodymium iron boron crucible for smelting and reduces the loss of rare earth oxide when the neodymium iron boron is smelted.
The embodiments given above are preferable examples for implementing the present invention, and the present invention is not limited to the above-described embodiments. Any non-essential addition and replacement made by the technical characteristics of the technical scheme of the invention by a person skilled in the art belong to the protection scope of the invention.
Claims (10)
1. A magnesia-alumina spinel forming crucible is characterized in that the crucible is made by building a furnace, baking and sintering a crucible blank;
the crucible blank is formed based on a crucible core after the furnace building material and boric acid solution are uniformly stirred;
the building material is prepared by uniformly mixing an adhesive and a high-strength refractory material; 6-9 parts of refractory cement as the adhesive in parts by mass; the high-strength refractory material is formed by mixing 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder;
after the building materials are sintered, lanthanum oxide powder reacts with magnesia-alumina spinel sand/powder, and a replacement reaction protective layer is generated on the inner surface of the magnesia-alumina spinel forming crucible;
the boric acid solution is 5-7% by mass; the mass of the boric acid solution is 5-7% of the mass of the building material.
2. The forming crucible of claim 1, wherein the protective layer of the displacement reaction generates MgO-ReO (Al, fe) with the Nd-Fe-B and La oxide powder when smelting Nd-Fe-B 2 O 3 And (4) compounding layers.
3. The forming crucible of magnesium aluminate spinel as claimed in claim 1, wherein the magnesium aluminate spinel sand/powder is composed of, by mass, 5-8 parts of magnesium aluminate spinel powder with a particle size of 40-60 μm, 20-25 parts of magnesium aluminate spinel sand with a particle size of 0-1mm, 20-25 parts of magnesium aluminate spinel sand with a particle size of 1-3mm, and 11-15 parts of magnesium aluminate spinel sand with a particle size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle sizes of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
4. The magnesium aluminate spinel forming crucible according to claim 1, wherein the boric acid solution is a 5.7% boric acid solution by mass; the mass of the boric acid solution is 5.3 percent of the mass of the charging material, the mass of the boric acid is 0.3 percent of the mass of the charging material, and the mass of the water is 5 percent of the mass of the charging material.
5. The manufacturing method of the magnesia-alumina spinel forming crucible is characterized by comprising the following steps of:
s1, uniformly stirring 63-67 parts of magnesia-alumina spinel sand/powder, 20-25 parts of corundum sand/powder, 2-3 parts of magnesia powder, 0.5-1.5 parts of zirconia powder and 0.5-1.5 parts of lanthanum oxide powder to prepare a high-strength refractory material;
s2, adding 6-9 parts of refractory cement into a high-strength refractory material, and uniformly stirring to prepare a furnace building material;
s3, weighing a boric acid solution with the mass percentage concentration of 5-7% according to 5-7% of the mass of the building burden material;
s4, adding the boric acid solution into the building material, and stirring uniformly;
s5, placing the insulating layer in an induction coil of a vacuum induction furnace;
s6, paving 10-20mm thick building materials on the insulating layer at the bottom of the induction coil for 3-5 times, and tamping layer by layer;
s7, fixing the crucible mold core at the center of the furnace building material at the bottom of the induction coil, and adjusting the position of the crucible mold core to enable the upper plane of the crucible mold core to be flush with the upper part of the induction coil;
s8, adding the furnace building materials into a gap between the crucible mold core and the induction coil for 5-8 times, wherein the thickness of the furnace building materials added each time is 30-50mm, tamping, taking out the crucible mold core after 1-2 hours, and shaping the crucible blank to complete furnace building;
s9, airing the crucible blank for 60-84 hours in a natural state, and spraying and maintaining by using pure water in the airing period;
s10, placing the resistance furnace into a crucible blank, baking and dehydrating for 20-28h in an open furnace;
s11, adjusting the vacuum degree in the vacuum induction furnace to 600-1200Pa, controlling the vacuum induction furnace to bake and dehydrate the crucible blank under 60KW of heating power, wherein the baking time is 20-28h, and finishing primary baking of the crucible blank;
s12, adjusting the vacuum degree in the vacuum induction furnace to 100-600Pa, baking and dehydrating the crucible blank for 4-6h under 50KW of heating power, and then finishing secondary baking of the crucible blank;
adjusting the vacuum degree in the vacuum induction furnace to 3-100Pa, and baking the sintering crucible blank for 8-12h under the heating power of 100-200 KW; and simultaneously, an infrared temperature measuring gun is used for measuring the temperature of the inner surface of the crucible, and after the temperature of the inner surface of the crucible blank reaches 1800 ℃, the temperature is preserved for 2-3 hours by a vacuum induction furnace to prepare the magnesia-alumina spinel forming crucible.
6. The method for manufacturing the magnesia alumina spinel forming crucible according to claim 5, wherein in S1, the magnesia alumina spinel sand/powder is composed of 5-8 parts of magnesia alumina spinel powder with the grain size of 40-60 μm, 20-25 parts of magnesia alumina spinel sand with the grain size of 0-1mm, 20-25 parts of magnesia alumina spinel sand with the grain size of 1-3mm, and 11-15 parts of magnesia alumina spinel sand with the grain size of 3-5 mm;
the corundum sand/powder consists of 5-8 parts of corundum powder with the grain diameter of 40-60 mu m, 2-4 parts of corundum sand with the grain diameter of 0-1mm and 11-15 parts of corundum sand with the grain diameter of 3-5 mm;
the particle sizes of the magnesia powder, the zirconia powder and the lanthanum oxide powder are all 40-60 mu m.
7. The method as claimed in claim 5, wherein in the step S5, the insulating layer is an asbestos layer or glass cloth.
8. The method as claimed in claim 5, wherein in step S7, the position between the crucible core and the induction coil is fixed by a plurality of wood wedges.
9. The method of claim 5, wherein in S6 and S8, the material is tamped by a drill steel.
10. The method of claim 5, wherein in step S11, 80 to 120kg of iron rod having the same depth as the crucible is charged into the crucible blank, the iron rod is heated by an induction coil of a vacuum induction furnace, and the crucible blank is primarily baked by the iron rod;
and S12, placing a core rod made of high-purity graphite which has the same shape as the inner cavity of the crucible blank and is 3-6mm smaller than the inner cavity into the crucible blank, heating the core rod through an induction coil of the vacuum induction furnace, and carrying out secondary baking on the crucible blank through the core rod.
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Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50147418A (en) * | 1974-05-17 | 1975-11-26 | ||
| JPH06213572A (en) * | 1993-01-12 | 1994-08-02 | Arishiumu:Kk | Crucible type induction furnace |
| JP2000128624A (en) * | 1998-10-30 | 2000-05-09 | Kurosaki Refract Co Ltd | Basic refractory |
| JP2003156288A (en) * | 2001-11-16 | 2003-05-30 | Shin Etsu Chem Co Ltd | Crucible for melting of rare earth alloy and rare earth alloy |
| JP2003185346A (en) * | 2001-12-21 | 2003-07-03 | Sumitomo Metal Ind Ltd | Crucible for melting rare earth alloy |
| KR20080097138A (en) * | 2007-04-30 | 2008-11-04 | 제너럴 일렉트릭 캄파니 | Crucibles for melting titanium alloys |
| JP2009243723A (en) * | 2008-03-28 | 2009-10-22 | Mitsubishi Heavy Ind Ltd | Crucible for melting metal and its manufacturing method |
| CN102531645A (en) * | 2011-11-22 | 2012-07-04 | 中山市华山特种陶瓷有限公司 | Corundum Calcium Magnesium Aluminum Spinel Crucible |
| CN102786313A (en) * | 2012-08-22 | 2012-11-21 | 武汉钢铁(集团)公司 | Dry-type preparation method of self-sintering magnesium oxide crucible of vacuum induction furnace |
| WO2012176655A1 (en) * | 2011-06-21 | 2012-12-27 | 株式会社日立製作所 | Sintered magnet |
| CN104016669A (en) * | 2014-05-04 | 2014-09-03 | 中国东方电气集团有限公司 | Magnesium ceramic crucible for sintering and preparation method thereof |
| WO2015019513A1 (en) * | 2013-08-09 | 2015-02-12 | Jx日鉱日石金属株式会社 | Process for manufacturing neodymium-iron-boron-based rare earth powder or sputtering target, neodymium-iron-boron-based rare earth powder or sputtering target, and neodymium-iron-boron-based thin film for rare earth magnet or manufacturing process therefor |
| CN104748548A (en) * | 2013-12-30 | 2015-07-01 | 比亚迪股份有限公司 | High-temperature smelting pot and processing method and application thereof |
| WO2017209063A1 (en) * | 2016-05-31 | 2017-12-07 | デンカ株式会社 | Boron nitride nozzle and boron nitride crucible for production of neodymium alloy, and neodymium alloy production method using nozzle or crucible |
| CN109776100A (en) * | 2019-02-25 | 2019-05-21 | 包头稀土研究院 | Vacuum induction melting coating |
| CN111254369A (en) * | 2020-01-15 | 2020-06-09 | 株洲宜安新材料研发有限公司 | Method for refining yttrium-containing zirconium-based amorphous alloy material |
| CN114671668A (en) * | 2022-03-11 | 2022-06-28 | 钢铁研究总院有限公司 | Steel ladle refractory material for smelting rare earth steel and manufacturing method thereof |
-
2022
- 2022-07-13 CN CN202210820693.3A patent/CN115231916B/en active Active
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50147418A (en) * | 1974-05-17 | 1975-11-26 | ||
| JPH06213572A (en) * | 1993-01-12 | 1994-08-02 | Arishiumu:Kk | Crucible type induction furnace |
| JP2000128624A (en) * | 1998-10-30 | 2000-05-09 | Kurosaki Refract Co Ltd | Basic refractory |
| JP2003156288A (en) * | 2001-11-16 | 2003-05-30 | Shin Etsu Chem Co Ltd | Crucible for melting of rare earth alloy and rare earth alloy |
| JP2003185346A (en) * | 2001-12-21 | 2003-07-03 | Sumitomo Metal Ind Ltd | Crucible for melting rare earth alloy |
| KR20080097138A (en) * | 2007-04-30 | 2008-11-04 | 제너럴 일렉트릭 캄파니 | Crucibles for melting titanium alloys |
| JP2009243723A (en) * | 2008-03-28 | 2009-10-22 | Mitsubishi Heavy Ind Ltd | Crucible for melting metal and its manufacturing method |
| WO2012176655A1 (en) * | 2011-06-21 | 2012-12-27 | 株式会社日立製作所 | Sintered magnet |
| CN102531645A (en) * | 2011-11-22 | 2012-07-04 | 中山市华山特种陶瓷有限公司 | Corundum Calcium Magnesium Aluminum Spinel Crucible |
| CN102786313A (en) * | 2012-08-22 | 2012-11-21 | 武汉钢铁(集团)公司 | Dry-type preparation method of self-sintering magnesium oxide crucible of vacuum induction furnace |
| WO2015019513A1 (en) * | 2013-08-09 | 2015-02-12 | Jx日鉱日石金属株式会社 | Process for manufacturing neodymium-iron-boron-based rare earth powder or sputtering target, neodymium-iron-boron-based rare earth powder or sputtering target, and neodymium-iron-boron-based thin film for rare earth magnet or manufacturing process therefor |
| CN104748548A (en) * | 2013-12-30 | 2015-07-01 | 比亚迪股份有限公司 | High-temperature smelting pot and processing method and application thereof |
| CN104016669A (en) * | 2014-05-04 | 2014-09-03 | 中国东方电气集团有限公司 | Magnesium ceramic crucible for sintering and preparation method thereof |
| WO2017209063A1 (en) * | 2016-05-31 | 2017-12-07 | デンカ株式会社 | Boron nitride nozzle and boron nitride crucible for production of neodymium alloy, and neodymium alloy production method using nozzle or crucible |
| CN109776100A (en) * | 2019-02-25 | 2019-05-21 | 包头稀土研究院 | Vacuum induction melting coating |
| CN111254369A (en) * | 2020-01-15 | 2020-06-09 | 株洲宜安新材料研发有限公司 | Method for refining yttrium-containing zirconium-based amorphous alloy material |
| CN114671668A (en) * | 2022-03-11 | 2022-06-28 | 钢铁研究总院有限公司 | Steel ladle refractory material for smelting rare earth steel and manufacturing method thereof |
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