CN102978424A - Method for preparing bismuth-ferromanganese alloy by water cooling process - Google Patents

Abstract

The invention belongs to the preparation method of water-cooling and homogenization treatment of bismuth-manganese-ferromanganese additives for bismuth-alloying treatment of free-cutting alloy steel. The bismuth-manganese-ferro solid-liquid mixture is poured into warm water within a certain range to realize water cooling solidification and homogenization treatment to obtain bismuth-manganese-ferroalloy additives suitable for alloying treatment of free-cutting steel. The bismuth-manganese ferroalloy additives obtained by this preparation method When ferroalloy is added to molten steel, the yield of bismuth is higher, which belongs to alloy production technology.

Description

Method for preparing bismuth manganese iron alloy by water cooling

technical field

The invention belongs to the preparation method of water-cooling and homogenization treatment of bismuth-manganese-ferromanganese additives for bismuth-alloying treatment of free-cutting alloy steel. The bismuth-manganese-ferro solid-liquid mixture is poured into warm water within a certain range to realize water cooling solidification and homogenization treatment to obtain bismuth-manganese-ferroalloy additives suitable for alloying treatment of free-cutting steel. The bismuth-manganese ferroalloy additives obtained by this preparation method When ferroalloy is added to molten steel, the yield of bismuth is higher, which belongs to alloy production technology.

Background technique

Bismuth metal is silvery white, has a strong metallic luster, is brittle, and belongs to the orthorhombic crystal system. The reserves of bismuth in my country rank first in the world, accounting for about 73% of the global reserves; because bismuth is non-toxic and has similar properties to lead in many aspects such as low melting point and high flexibility, it can be widely used as a substitute for lead. Bismuth is added to cast iron, steel and aluminum alloys to improve their cutting performance. At present, bismuth-containing free-cutting steel has become a raw material urgently needed by modern manufacturing industries.

Due to the low melting point of bismuth (271.3°C), it has caused great difficulties in the alloying treatment of bismuth free-cutting steel; , but due to the low melting point of bismuth-manganese alloy (only 446 ° C), it is still very difficult to use it as an alloy additive; and the results of Chinese patent retrieval and literature search show that alloying treatment is feasible and can be used for free-cutting steel Except for the invention patent "Bismuth Manganese Ferroalloy", the bismuth alloy additive with higher yield of alloying treatment has not been reported yet; however, there are still some deficiencies in the alloy preparation method described in the patent "Bismuth Manganese Ferroalloy", such as The bismuth-manganese-ferroalloy is prepared by two-step method. Since the melting points of manganese and iron are high, it must be heated to a high temperature of 1300°C~1500°C in each step of smelting, which wastes energy and increases the burning loss of bismuth. Therefore, Finding a preparation process for bismuth-manganese ferromanganese with lower smelting temperature has practical application value and is also the expectation of the rapid development of modern metallurgical industry. It is of far-reaching significance to enhance the product quality and international competitiveness of China's free-cutting steel.

Contents of the invention

The purpose of the present invention is to propose a method for high-temperature smelting, rapid solidification and homogenization in warm water, to prepare bismuth-manganese-ferroalloy additives for bismuth alloying of free-cutting alloy steels, so that the alloy is suitable for bismuth alloying of free-cutting steels, And the yield of bismuth is high.

One of the technical schemes of the present invention is that the components and the atomic percentages of each component of the described a kind of bismuth manganese ferroalloy are: bismuth: 40~49%, manganese: 39~48%, iron: 8~ 9%, carbon: 0~2%, unavoidable impurities: 0~1%; converted to mass percentage: bismuth: 72.3~80%, manganese: 17~23.3%, iron: 3~4.4%, carbon : 0~0.2%, other unavoidable impurities: 0~0.1%.

A typical technical scheme of the present invention is: described a kind of bismuth-manganese ferroalloy its component and the atomic percent content of each component are: bismuth: 40～45%, manganese: 44～48%, iron: 8~9%, carbon: 0~2%, unavoidable impurities: 0~1%; converted to mass percentage: bismuth: 72.3~76%, manganese: 20~23.3%, iron: 3.7~4.4% , Carbon: 0~0.2%, other unavoidable impurities: 0~0.1%.

The bismuth-manganese-ferroalloy that above-mentioned technical scheme obtains is because the bismuth-manganese mass percentage content is higher than 70%, and its specific gravity ≥ the specific gravity of iron, so it is feasible and convenient to adopt the present invention for pre-furnace alloying treatment, because the bismuth-manganese The melting point of the iron alloy is relatively high, so the yield of bismuth is high, thereby realizing the purpose of the present invention.

The second technical solution of the present invention is a water-cooled preparation method of a bismuth-manganese-ferroalloy additive treated with bismuth alloying of free-cutting alloy steel:

A. Put the low-carbon ferromanganese master alloy on the bottom of the corundum crucible, put pure bismuth on the top, cover the surface with a salt covering agent to prevent oxidation, and put the corundum crucible in a box furnace;

B. Raise the temperature of the box-type furnace to 1100°C~1300°C, and start smelting. The smelting holding time is controlled at 1h. During the smelting process, the bismuth-manganese-ferroalloy is in a solid-liquid mixed melting state. During the holding process, the metal liquid is stirred in the box-type electric furnace for 2 ~3 times to make the solid-liquid mixed melt uniform, cover the surface of the melt with a salt covering agent after each stirring, and leave it in the furnace for 3 to 5 minutes after the last stirring;

C. Take the smelted melt out of the box furnace and quickly pour it into warm water in the range of 30~75°C to realize water cooling and solidification, and prepare ferrobismuth manganese with a thickness in the range of 0.5~15 mm and a width in the range of 0.5~100 mm The intermediate alloy block can be broken into 0.5~10mm granular alloy according to the need;

D. Dry the alloy obtained by the above water cooling and put it into a graphite crucible, perform homogenization treatment in an electric furnace at 400°C for 8 hours, and then air-cool, pay attention to completely covering the alloy with a salt covering agent, and prepare the bismuth-manganese-iron alloy additive.

The salt covering agent in the steps A, B and D is a dehydrated mass fraction of 50% KCl and 50% NaCl homogeneously mixed powder, used to prevent oxidation of the melt, reduce the burning loss of alloying elements and Purify the melt.

Both the pure bismuth and the ferromanganese master alloy in the step A are block-shaped, and the ferromanganese master alloy is a low-carbon ferromanganese alloy, and the mass percentage of Mn is 83-84wt.%.

The method for preparing a bismuth-manganese-ferroalloy is characterized in that: the bismuth-manganese-ferroalloy is block-shaped, with a thickness in the range of 0.5-15 mm and a width in the range of 0.5-100 mm; or granular, with a particle size in the range of 0.5-100 mm. In the range of 10 mm, the unavoidable impurities mainly refer to sulfur, phosphorus, and silicon, wherein the mass percentages of sulfur and phosphorus are both ≤0.1%.

The salt covering agent used in the A, B and D steps is a homogeneous mixture of analytically pure chemical reagents KCl and NaCl, which is baked at 300°C for 5 hours to remove crystal water before use, and then the mass ratio is 1:1 Mix evenly and store in a constant temperature drying oven at 100°C for use.

Put the ferromanganese master alloy at the bottom of the crucible, and put the pure bismuth on the upper part to make the bismuth manganese master alloy melt mix as evenly as possible, because the specific gravity of bismuth is much larger than that of the manganese ferroalloy, so that the specific gravity of pure bismuth is placed on top When melting, the pure bismuth that melts first will gradually infiltrate between the ferromanganese master alloy blocks, and react with it to form bismuth manganese compounds; the purpose of proper stirring during the smelting temperature holding process is to make the unmelted ferromanganese alloy dissolve into the ferromanganese as much as possible. Or make it evenly distributed in the alloy liquid, and add salt covering agent to cover after stirring, which can reduce the oxidation of the melt, reduce the burning loss of alloy elements and purify the melt; the longer the smelting time, the burning loss of bismuth element It will also be increased, so the smelting time should not be too long, generally controlled to 1h; in addition, due to the high melting point of pure manganese, pure iron and manganese-ferroalloy, in order to reduce the burning loss of bismuth element, the smelting temperature of bismuth-manganese-ferroalloy is controlled at slightly Lower than the melting point of ferromanganese alloy: that is, it is controlled within the range of 1100 ° C ~ 1300 ° C, and it is in a solid-liquid mixed state at this time; the water at room temperature is only a dozen degrees, and the smelted high-temperature melt is directly poured into water at room temperature If the water is cooled and solidified in the water, due to the low water temperature, the melt will explode instantly in the water, making a particularly loud noise, and the obtained products are all small, porous and fine products, which are easily oxidized quickly when taken out in the air. In actual production The value in the application is not too great, but the water cooling in warm water makes the sound very small, and many of the obtained pieces are massive flakes. In all aspects, the effect of warm water is better, so the water temperature of water cooling is determined to be 30~75°C, due to the water cooling The cooling rate is very fast, and the obtained alloy has better effect after homogenization treatment.

The invention has the advantages that: in the bismuth-manganese-ferroalloy prepared by water cooling, the bismuth element can fully react with manganese to form a BiMn phase, and the remaining ferromanganese phase is dispersed between the pure bismuth and the BiMn phase, thereby increasing the melting point of the alloy. The bismuth-manganese ferroalloy prepared by the invention has the characteristic of high bismuth yield in the bismuth alloying process of free-cutting steel, and is suitable for being used as an additive in the alloying treatment of free-cutting steel.

Description of drawings

Fig. 1 (a), 1 (b), 1 (c) and 1 (d) show respectively that when said atomic percentage only contains bismuth and manganese, it is Bi:Mn=50:50, if the three elements are carried out atomic percentage The comparison of the content is the SEM photo of the bismuth-manganese-iron alloy obtained after the composition of Bi:Mn:Fe=45.7:45.7:8.6 is smelted at 1100°C and then solidified by water cooling at 30, 45, 60, and 75°C; The comparison of the weight percentages converted into the three elements is: Bi:Mn:Fe=76.20:19.75:4.01, if the weight percentages converted into weighing objects are: pure bismuth: ferromanganese alloy=76.2:23.8 , Figure 1(e) shows that when the atomic percentage only contains bismuth and manganese elements, it is Bi:Mn=45:55. If the atomic percentage content of the three elements is compared, it is Bi:Mn:Fe=40.8:49.9:9.3 , the weight percent comparison is Bi:Mn:Fe=72.30:23.00:4.65, if converted into the weight percent comparison of the weighed object: pure bismuth: ferromanganese alloy=72.3:27.7 with the assigned composition at 1100 SEM photo of the bismuth-manganese-iron alloy obtained after smelting at 45°C and solidified by water cooling at 45°C; Figure 1(f) shows that when the atomic percentage only contains bismuth and manganese elements, it is Bi:Mn=55:45, if the three elements are atomically The comparison of percentage content is Bi:Mn:Fe=50.7:41.5:7.8, the comparison of weight percentage content is Bi:Mn:Fe=79.60:17.14:3.22, if it is converted into the comparison of weight percentage content of weighed objects It is: the SEM photo of the bismuth-manganese-iron alloy obtained after the composition of pure bismuth: ferromanganese alloy = 79.6:20.4 is smelted at 1100°C and then solidified by water cooling at 45°C.

(a) Melting at 1100°C + water cooling at 30°C (Example 1); (b) Melting at 1100°C + water cooling at 45°C (Example 2);

(c) Melting at 1100°C + water cooling at 60°C (Example 3); (d) Melting at 1100°C + water cooling at 75°C (Example 4);

(e) Melting at 1100°C + water cooling at 45°C (Example 5); (f) Melting at 1100°C + water cooling at 45°C (Example 6).

Figures 2(a), 2(b), 2(c), and 2(d) are the alloys of Figures 1(a), 1(b), 1(c) and 1(d), respectively, at 400°C for 8h SEM photographs of bismuth-manganese-iron alloy obtained by chemical treatment.

(a) 30°C; (b) 45°C; (c) 60°C; (d) 75°C

Figure 3(a), 3(b), 3(c), 3(d), 3(e), and 3(f) are Figure 1(a), 1(b), 1(c), 1( d), Macroscopic photographs of Bi-Mn-Fe alloys of 1(e) and 1(f).

(a) 30°C (Example 1); (b) 45°C (Example 2); (c) 60°C (Example 3);

(d) 75°C (Example 4); (e) 45°C (Example 5); (f) 45°C (Example 6).

Detailed ways

Embodiment one: the proportioning of each raw material of the bismuth-manganese-ferroalloy in the present embodiment is set to be: pure bismuth is 76.2wt.%, and low-carbon ferromanganese alloy is 23.8wt.%. That is, the chemical composition of bismuth-manganese-ferroalloy is: Bi:Mn : Fe: C (wt.%)=76.20:19.75:4.01:0.04; According to the preparation method of technical scheme two of the present invention, the bismuth-manganese-iron alloy solid-liquid mixture that will be smelted in 1100 ℃ of box-type electric furnaces and kept warm for 1h is poured into 30 ℃ in warm water for water cooling and solidification to obtain granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 10 mm; dry the alloy obtained by water cooling and put it into a graphite crucible, perform homogenization treatment in an electric furnace at 400 °C for 8 hours, and then air-cool. The alloy must be completely covered with a salt covering agent to prepare the bismuth-manganese-ferroalloy additive for subsequent treatment; as shown in Figure 1(a), it is the microstructure photo of the structure of the bismuth-manganese-ferroalloy obtained by cooling and solidifying in warm water at 30°C , it can be seen that the dark gray long dendritic and agglomerated BiMn phases are very small and disorderly distributed in the dark white base Bi, and the distribution is uneven, and the area of the dark white base Bi phase is larger than that of the BiMn phase. The black Mn(Fe) phase has a large number, a large size, and a relatively uniform distribution.

Figure 2(a) shows the microstructure photo of the alloy after water cooling at 30°C and then air cooling at 400°C for 8 hours after homogenization treatment. It can be seen that compared with the structure without homogenization treatment, the dark gray long The dendritic BiMn phase grows up and distributes evenly, the dark white Bi phase decreases, the black Mn(Fe) phase distributes evenly, the number decreases obviously, and the particles are fine.

As shown in Figure 3(a), it is a macroscopic photo of bismuth-manganese-iron alloy particles obtained by water cooling and solidification at 30°C. It can be seen that most of the obtained alloys are small particles with a particle size in the range of 0.5-10 mm. The formation is due to the rapid solidification of the high-temperature melt when it meets water, and then it is broken and dispersed, and it is accompanied by relatively loud noises during the preparation process.

Embodiment two: the proportioning of each raw material of bismuth-manganese-ferroalloy in the present embodiment is set: pure bismuth is 76.2wt.%, and low-carbon ferromanganese alloy is 23.8wt.%. That is, the chemical composition of bismuth-manganese-ferroalloy is: Bi:Mn : Fe: C (wt.%)=76.20:19.75:4.01:0.04; According to the preparation method of the technical scheme two of the present invention, the bismuth-manganese-iron alloy solid-liquid mixture melted and kept warm for 1h in a 1200°C box furnace is poured into 45 Water-cooling and solidification in warm water at ℃ to obtain massive or granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 15 mm; dry the alloy obtained by water cooling and put it into a graphite crucible, perform homogenization treatment in an electric furnace at 400 °C for 8 hours, and then air-cool , note that the alloy must be completely covered with a salt covering agent to prepare the bismuth-manganese-ferroalloy additive for subsequent treatment; Figure 1(b) shows the microstructure of the bismuth-manganese-ferroalloy obtained by cooling and solidifying in warm water at 45°C From the microstructure photos, it can be seen that the dark gray BiMn phase is in the form of short strips and clusters, which are very uniformly and densely distributed in the base Bi phase. Compared with the structure of the alloy obtained by water cooling and solidification at 30 °C, the BiMn phase is thicker and the number is increased. The black Mn(Fe) phase particles are fine and uniformly distributed in the BiMn phase and the base Bi phase.

Figure 2(b) shows the microstructure photo of the air-cooled structure after drying the alloy obtained by water cooling at 45°C and putting it into an electric furnace at 400°C for 8h homogenization treatment. It can be seen that compared with the alloy without homogenization treatment In the structure, the dark gray BiMn phase grows obviously, very dense and connected into one piece, the Bi phase is distributed in it, and the black Mn(Fe) phase particles become smaller and the number decreases.

Figure 3(b) shows the macroscopic photo of the structure of the bismuth-manganese-iron alloy obtained by water cooling and solidification at 45°C. It can be seen that the obtained alloy is basically a block, with a thickness ranging from 0.5 to 15 mm and a width ranging from 0.5 to 100 mm. In the range of millimeters, some of them are granular, with a particle size in the range of 0.5 to 10 millimeters, accompanied by relatively small noises during the formation process. The surface of the alloy block is relatively dense, and there are no pores and so on.

Embodiment three: the proportioning of each raw material of bismuth-manganese-ferroalloy in the setting present embodiment is: pure bismuth is 76.2wt.%, and low-carbon ferromanganese alloy is 23.8wt.%. That is, the chemical composition of bismuth-manganese-ferroalloy is: Bi:Mn : Fe: C (wt.%)=76.20:19.75:4.01:0.04; According to the preparation method of technical scheme two of the present invention, the bismuth-manganese-iron alloy solid-liquid mixture that will be smelted in 1100 ℃ of box-type electric furnaces and kept warm for 1h is poured into 60 Water-cooling and solidification in warm water at ℃ to obtain massive or granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 15 mm; dry the alloy obtained by water cooling and put it into a graphite crucible, perform homogenization treatment in an electric furnace at 400 °C for 8 hours, and then air-cool , note that the alloy must be completely covered with a salt covering agent to prepare the bismuth-manganese-ferroalloy additive for subsequent treatment; Figure 1(c) shows the microstructure of the bismuth-manganese-ferroalloy obtained by cooling and solidifying in warm water at 60°C Microstructure photos, it can be seen that the dark gray BiMn phase is in the form of agglomerates or coarse particles, the BiMn phase is evenly distributed in the base Bi phase, and the number of dark white Bi phases is larger than that of the BiMn phase. In addition, the black Mn(Fe ) phases are more numerous and coarser.

Figure 2(c) shows the microstructure photo of the alloy obtained by water cooling at 60 °C after being dried in an electric furnace at 400 °C for 8 hours after homogenization treatment. It can be seen that compared with the structure without homogenization treatment, The dark gray BiMn phase grows obviously, and the coarse BiMn phase is almost connected into one piece, and the Bi phase is distributed among them. In addition, the amount of black Mn(Fe) phase decreases obviously after heat treatment.

As shown in Figure 3(c), it is a macroscopic photo of the structure of the bismuth-manganese-iron alloy obtained by water cooling and solidification at 60°C. It can be seen that the obtained alloy is basically a block, with a thickness in the range of 0.5~15 mm and a width of 0.5~ In the range of 100 mm, some particles have a particle size in the range of 0.5 to 10 mm; during the alloy preparation process, accompanied by relatively small noises, the liquid surface emits smoke and the water surface turns black, the alloy surface layer is black, and many pores appear .

Embodiment four : the proportioning of each raw material of bismuth-manganese-ferroalloy in the present embodiment is set: pure bismuth is 76.2wt.%, and low-carbon ferromanganese alloy is 23.8wt.%, namely the chemical composition of bismuth-manganese-ferroalloy is: Bi:Mn : Fe: C (wt.%)=76.20:19.75:4.01:0.04; According to the preparation method of technical scheme two of the present invention, the bismuth-manganese-iron alloy solid-liquid mixture that will be smelted in 1100 ℃ of box-type furnaces and kept warm for 1h is poured into 75 Water-cooling and solidification in warm water at ℃ to obtain massive or granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 15 mm; dry the alloy obtained by water cooling and put it into a graphite crucible, perform homogenization treatment in an electric furnace at 400 °C for 8 hours, and then air-cool , note that the alloy must be completely covered with a salt covering agent to prepare the bismuth-manganese-ferroalloy additive for subsequent treatment; Figure 1(d) shows the microstructure of the bismuth-manganese-ferroalloy obtained by cooling and solidifying in warm water at 75°C Microstructure photo, it can be seen that the dark gray BiMn phase is in the form of small clusters, the BiMn phase is sparsely distributed in the base Bi phase, the number of the dark white base Bi phase is much larger than that of the BiMn phase, and the black Mn(Fe) phase The quantity and phase size are relatively large and distributed in a disorderly manner.

Figure 2(d) shows the microstructure photo of the alloy obtained by water cooling at 75 °C after drying and then placed in an electric furnace at 400 °C for 8 hours of homogenization treatment and air cooling. It can be seen that compared with the structure without homogenization treatment, The dark gray BiMn phase is obvious and connected into one piece, the Bi phase is evenly distributed between the BiMn phases, the number of black Mn(Fe) phases becomes smaller, and the particles become smaller.

Figure 3(d) shows the macroscopic photo of the structure of the bismuth-manganese-iron alloy obtained by water cooling and solidification at 75°C. It can be seen that the obtained alloy is basically a block, with a thickness ranging from 0.5 to 15 mm and a width ranging from 0.5 to 100 mm. In the range of millimeters, some particles have a particle size in the range of 0.5 to 10 millimeters; during the preparation of the alloy, accompanied by relatively small noises, the liquid surface emits smoke and the water surface turns black, and there is a layer of black metal oxide on the surface of the alloy. The alloy oxide color is darker than that of Example 3.

Embodiment five : the proportioning of the bismuth-manganese-ferroalloy raw material in the present embodiment is set to be: pure bismuth is 72.3wt.%, and low-carbon ferromanganese alloy is 27.7wt.%. That is, the chemical composition of bismuth-manganese-ferroalloy is: Bi: Mn: Fe: C (wt.%)=72.30:23.00:4.65:0.05; according to the preparation method of the second technical scheme of the present invention, the bismuth-manganese-iron alloy solid-liquid mixture smelted in a box furnace at 1100°C and kept for 1h is poured into 45°C Water-cooled solidification in warm water to obtain massive or granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 15 mm; Figure 1(e) shows the microstructure photo of the bismuth-manganese-iron alloy obtained by water cooling and solidification in warm water at 45 °C. It can be seen that the dark gray BiMn phase is long and agglomerated, and is evenly and densely distributed in the Bi phase. Compared with Example 2, the BiMn phase is coarser, and the black Mn(Fe) phase particles are coarse and the number More, but more evenly distributed.

Figure 3(e) shows the macroscopic photo of the structure of the bismuth-manganese-iron alloy obtained by water cooling and solidification at 75°C. It can be seen that the obtained alloy is basically a lump, and the block degree is not uniform, and the thickness is in the range of 0.5 to 15 mm. , the width is in the range of 0.5-100 mm, and the particle size of some granular materials is in the range of 0.5-10 mm.

Embodiment six : the proportioning of the bismuth-manganese-ferroalloy raw material in the present embodiment is set to be: pure bismuth is 79.6wt.%, and low-carbon ferromanganese alloy is 20.4wt.%. That is, the chemical composition of bismuth-manganese-ferroalloy is: Bi: Mn: Fe: C (wt.%)=79.60:17.14:3.22:0.04; according to the preparation method of the second technical scheme of the present invention, the bismuth-manganese-iron alloy liquid melted and kept for 1 hour in a box furnace at 1100°C is poured into warm water at 45°C Perform water cooling and solidification to obtain block or granular bismuth-manganese-iron alloys with a thickness in the range of 0.5 to 15 mm; as shown in Figure 1(f), it is a microstructure photo of the bismuth-manganese-iron alloy obtained by water cooling and solidification in warm water at 45 °C. It can be seen that the dark gray BiMn phase is in the shape of short strips and clusters, and is evenly and densely distributed in the Bi phase. Compared with the alloy structure obtained in Example 2, the number of BiMn phases is slightly less, and the number of small black Mn(Fe) phase particles are more evenly distributed in the alloy structure.

Figure 3(f) shows the macrophotograph of the structure of the bismuth-manganese-iron alloy obtained by water cooling and solidification at 45°C. It can be seen that the obtained alloy is basically a block with a relatively uniform block size and a thickness in the range of 0.5 to 15 mm. The width is in the range of 0.5-100 mm, and the particle size of some granular materials is in the range of 0.5-10 mm.

Claims (7)

1. utilize water-cooled to prepare the method for bismuth manganese iron alloy, it is characterized in that comprising the steps:

A, the low carbon ferromanganese master alloy is put in corundum crucible bottom, pure bismuth is put in top, adds the salt insulating covering agent on its surface and covers with anti-oxidation, and corundum crucible is placed box-type furnace;

B, box-type furnace is warming up to 1100 ℃ ~ 1300 ℃, the beginning melting, the melting soaking time is controlled at 1h, bismuth manganese iron alloy is solid-liquid mixed melting state in the fusion process, stirring makes the solid-liquid blend melt even 2 ~ 3 times to molten metal in cabinet-type electric furnace in the insulating process, all add the salt insulating covering agent at bath surface after each the stirring and cover, in stove, leave standstill after last the stirring and came out of the stove in 3 ~ 5 minutes;

C, the melt after the melting is taken out box-type furnace pour into fast in the warm water in 30 ~ 75 ℃ of scopes, the realization water-cooled is solidified, be prepared into thickness at 0.5 ~ 15 millimeter scope, the width bismuth ferromanganese master alloy piece 0.5 ~ 100 millimeter scope, can be broken into as required 0.5 ~ 10 millimeter particulate state alloy;

Put into plumbago crucible after D, the alloy drying that above water-cooled is obtained, in 400 ℃ electric furnace, carry out the 8h homogenizing process after air cooling, notice that alloy adopts the salt insulating covering agent to cover fully, prepares bismuth manganese iron alloy.

2. the method for utilizing water-cooled to prepare bismuth manganese iron alloy as claimed in claim 1 is characterized in that: described bismuth manganese iron alloy, and the atomic percentage conc of its component and each component is: bismuth: 40 ~ 49%, manganese: 39 ~ 48%, iron: 8 ~ 9%, carbon: 0 ~ 2%, inevitable impurity: 0 ~ 1%; Being converted into the quality percentage composition is: bismuth: 72.3 ~ 80%, and manganese: 17 ~ 23.3%, iron: 3 ~ 4.4%, carbon: 0 ~ 0.2%, other inevitable impurity: 0 ~ 0.1%.

3. the method for utilizing water-cooled to prepare bismuth manganese iron alloy as claimed in claim 2, it is characterized in that: the atomic percentage conc of its component of described bismuth manganese iron alloy and each component is: bismuth: 40 ~ 45%, and manganese: 44 ~ 48%, iron: 8 ~ 9%, carbon: 0 ~ 2%, inevitable impurity: 0 ~ 1%; Being converted into the quality percentage composition is: bismuth: 72.3 ~ 76%, and manganese: 20 ~ 23.3%, iron: 3.7 ~ 4.4%, carbon: 0 ~ 0.2%, other inevitable impurity: 0 ~ 0.1%.

4. the method for utilizing water-cooled to prepare bismuth manganese iron alloy as claimed in claim 1, it is characterized in that: the salt insulating covering agent in described A, B and the D step is for being respectively 50% KCl and 50% the even mixed powder of NaCl through the massfraction of processed, be used for preventing melt oxidation, reduce the scaling loss of alloying element and purify melt.

5. the method for utilizing water-cooled to prepare bismuth manganese iron alloy as claimed in claim 1, it is characterized in that: pure bismuth and ferromanganese master alloy in the described A step are bulk, and the ferromanganese master alloy is the low carbon ferromanganese alloy, and the mass percent that contains Mn is 83 ~ 84wt.%.

6. utilize as claimed in claim 2 or claim 3 water-cooled to prepare the method for bismuth manganese iron alloy, it is characterized in that: described bismuth manganese iron alloy is block, and its thickness is in 0.5 ~ 15mm scope, and width is in 0.5 ~ 100mm scope; Perhaps in pelletized form, its particle diameter is in 0.5 ~ 10mm scope, and described inevitable impurity mainly refers to sulphur, phosphorus and silicon, and wherein the quality percentage composition of sulphur and phosphorus all≤0.1%.

7. the method for utilizing water-cooled to prepare bismuth manganese iron alloy as claimed in claim 1, it is characterized in that: used salt insulating covering agent is the uniform mixture of analytical pure chemical reagent KCl and NaCl in described A, B and the D step, before using it was removed crystal water in 5 hours 300 ℃ of lower bakings, then 1:1 evenly mixes in mass ratio, is stored in 100 ℃ of thermostatic drying chambers in order to using.

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