JPS60197830A - Production of boron alloy - Google Patents

Abstract

PURPOSE:To enable production of a low-carbon B alloy contg. Al and S at a smaller rate by subjecting the melt of Fe-B or Co-B produced from boric anhydride, etc. as a raw material by a thermit method to oxidation refining by a specific oxidizing agent. CONSTITUTION:A mixture 6 composed of boric anhydride, iron oxide (cobalt oxide) and calcined lime is placed in the bottom of a thermit furnace 1 and is heated to melt by a burner 7. The molten mixture is cooled to solidify. The thermit raw material obtd. by mixing boric anhydride, iron oxide (cobalt oxide) and Al which is a reducing agent at 105-130% of theoretical amt. respectively in the form of powder and mixing further calcined lime which is a slag forming agent and sodium chlorate which is combustion assistant is charged thereonto. The mixture is ignited to induce a thermit reaction and Fe-B(Co-B) is manufactured. The oxidizing agent in the furnace bottom is melted by the heat generated by said reaction and the Al and S in the molten metal is oxidized away while the molten oxidizing agent ascends in the molten Fe-B(Co-B). The molten metal is otherwise replaced several times into another vessel where de-Al and de-S reaction is thoroughly accelerated to produce a B alloy contg. Al and S at a smaller rate.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for producing boron alloys such as low aluminum-containing ferroboron and cobalt boron by the thermite process, which are used in amorphous alloys and sintered alloys. be.

[Prior art]

Generally, boron alloys such as ferroboron and cobalt boron are used as additives for steel. Among these boron alloys, 7 x cz borz, which is usually used as an additive for iron
7 is B14-26%, CN3.02%-g811.0
Ferrophoron, which is used for amorphous metals, has an Azo of 0! M
Below, Po, 0.2% or less, Mn 0.1% or less, so
, o1tIb or less is required.

These ferroboron production methods include an electric furnace method and a thermite method. The electric furnace method uses boric acid ()IsBOa) in the electric furnace.
In the thermite method, boric anhydride, borax (Nal
Boron compounds such as O, 2B*Os ), carbon-free reducing agents such as aluminum powder or aluminum-magnesium alloy powder, iron sources such as iron ore or mill scale, and some sodium chlorate or potassium chlorate, etc. A mixture of 7 lux, such as a combustion aid and burnt lime, is charged into a reaction vessel lined with a refractory and reacted.

In the former method, if the impurities contained in the raw materials are limited, it is possible to produce ferroboron with a fairly low content of impurities such as At+ Sip P) Mn.

However, this carbon reduction method using an electric furnace has the following problems.

1) High melting point boron carbide (
For example, BaC (with a melting point of 2,450° C.) is deposited, making continuous operation for a long period of time difficult due to poor tapping due to the rise of the hearth, making it unsuitable for mass production in large electric furnaces.

2) Cheap reducing agents such as coke and coal cannot be used because the AtzOa content in the ash is high, and expensive charcoal or the like must be used.

6) Since a carbonaceous reducing agent is used, the obtained boron alloy usually contains 0.2 to 0.4 carbon,
% or less requires special decarburization.

As mentioned above, there are various drawbacks in terms of cost and quality when producing boron alloys industrially by the step reduction method using an electric furnace. For this reason, in cases where the aluminum content is not an issue, such as in the case of ferroboron for steel, the latter method (#1), that is, the aluminum thermite method, has been industrially adopted. For example, when producing 7-eroboron using this method, B*Os in boric anhydride and 50 g of Fe in iron ore are reduced to aluminum, but the main reaction is as follows.

1■ 1■ Both of the above reactions are exothermic reactions, and theoretically,
Although it is not necessary to add thermal energy such as electricity from the outside, it is common to add a combustion aid such as sodium chlorate to compensate for the heat in order to completely separate the generated metal and slag.

Furthermore, since the produced slag has a high alumina content and a high melting point, measures such as adding Tonofranks, which is burnt lime, are used to improve the fluidity of the slag.

In this thermite method, aluminum with a very low carbon content is used, so the carbon content of the resulting ferroboron is less than 0.1%, usually 0.01 to 0.03%, using the carbon reduction method using an electric furnace. It is less than 1/10 of ferroboron. Also, compared to the carbon reduction method, it is easier to obtain products with lower contents of impurities such as phosphorus and sulfur;
This is because the sulfur content is low.

However, since the thermite method uses aluminum as a reducing agent, the resulting boron alloy contains several percent aluminum (usually about 1 to 10%).
. Due to this drawback, the raw material boron alloys used in recently developed amorphous metals and some steels that require a low aluminum content have a zero aluminum content.
．． 1% or less or 0.05% or less is desired, and it was considered impossible to manufacture such low-aluminum products using the thermite method.

Therefore, as low-aluminum boron raw materials, expensive metallic boron or high-carbon boron alloys produced by carbon reduction in an electric furnace are used. Therefore, it has been desired to develop a method for producing boron alloys that is low in cost and has a low content of impurities such as aluminum and carbon.

[Summary of the invention]

An object of the present invention is to provide a method for producing a boron alloy on an industrial scale, which has a sufficiently low content of impurities such as carbon, aluminum, and fibres, and is low in cost, by the thermite process.

In the present invention, when producing a boron alloy by the thermite method using an aluminum-based reducing agent such as aluminum or aluminum and magnesium alloy as a reducing agent,
First, a reducing agent of 105 to 160 liters, which is the theoretical amount required to reduce the metal oxide, is mixed and reacted to produce a boron alloy with a high At content. When the coated low-melting point oxidizing agent and desulfurizing agent are dissolved by the reaction heat and floated through the metal layer, de-aluminum is removed.
t S removal occurs and most of the A4 S in the metal is removed, but in order to further complete the removal, the molten metal is removed between the molten metal and an empty reaction vessel prepared separately.

This is a boron alloy manufacturing method that can easily produce a boron alloy of Azoyt- or less, So, 01% or less, and C001% or less by carrying out a slag emptying operation and removing At and S by forced stirring. .

Normally, when boron alloys are produced by the thermite method using boric anhydride as a raw material, the reducing agent used is silicon, which is almost impossible to fully advance the reduction reaction, and metal aluminum powder, aluminum, magnesium powder, etc. An alloy powder made of living aluminum is used. In this thermite method, as mentioned above, the carbon content is o, 1
Although it is possible to easily produce a low-carbon boron alloy with a carbon content of 1 to 10%, the At content of the resulting boron alloy is usually 1 to 10% because a portion of the reducing agent aluminum remains in the alloy. The reason for this is that in order to reduce manufacturing costs, it is necessary to improve the boron yield from boron oxide to boron alloy.
This is done by increasing the actual amount of a reducing agent such as aluminum or magnesium used to reduce the raw material boric anhydride and oxides such as iron ore beyond the theoretically required amount.

The more the amount of reducing agent added is increased beyond the theoretically required amount,
Since the reduction reaction is sufficiently completed, the boron yield is inevitably improved, or, on the other hand, the aluminum content in the resulting boron seam becomes higher.

In the present invention 8A, the above-mentioned reduction reaction is carried out in a thermite reaction vessel as shown in FIG. 1, with the amount of reducing agent blended at a theoretically required amount or more. Figure 1 is a schematic diagram of a thermite reaction vessel, in which the IIi reaction vessel is shown, 2 is an iron shell, and 6
4 is a refractory brick, and 4 is a magnesia stamp lining material. In this container 1, a boron alloy molten metal with high aluminum and magnesium content copper is once generated, and then AA*Mg contained in the boron alloy molten metal is efficiently oxidized and removed using an appropriate oxidizing agent while stirring the molten metal. be.

In this case, it is important to avoid using all nine strong oxidizing agents (eg, oxygen gas, etc.) because they not only oxidize AltMg but also reoxidize boron, reducing the boron yield.

As an oxidizing agent, it is possible to remove At and Mf without reoxidizing boron by using an oxide of a metal that has an affinity for oxygen that is stronger than Ate, Mg, or B, but it is possible to remove At and Mf without reoxidizing boron. It is difficult to find a suitable oxide, and steel acid anhydride (
BxOm) and anhydrous borax (Na*0.28g) are preferable. In addition, iron oxide can be used in Feropon, and cobalt oxide can be used in cobalt boron. Also, A due to oxidizing agent
In the 4-hour removal process, it has become clear from the examples described later that At and M2 can be removed more efficiently if the molten metal is stirred.

In addition, the amount of reducing agent is 10% of the theoretically required amount (stoichiometrically required amount).
If the Ul content is less than 055 g, which is limited to 5 to 130%, the B yield will decrease and the cost will increase.If the Ul content is less than 5.130 g, the amount of oxidizing agent will increase and it will be difficult to effectively remove At, which is undesirable.

Furthermore, the amount of oxidizing agent used must naturally be sufficient to sufficiently oxidize Alt in the produced high Aj boron alloy. It should be noted that it is difficult to remove P, Mn, and Si by the method of the present invention, so by selecting materials with low impurity content in the raw material, the content in the boron alloy can be reduced. .

Hereinafter, embodiments of the present invention will be described step by step along with conventional examples.

(Example) The present invention will be explained based on examples and compared with a conventional method.

First, the quality of the raw materials used in this example and comparative examples was as follows:
The materials shown in the table were used.

Comparative Example-1: Normal production example of low carbon ferroboron In a cylindrical reaction vessel 1 as shown in Fig. 1, the raw materials listed in Table 1 were prepared in the proportions shown in Table 2 below. The prepared mixture for ferroboron was charged and an ignition reaction was carried out to produce ferroboron. The results are shown in Table 2.

@2 Table Yield of produced ferroboron B 70.4chi As shown in Table 2, the At content #'i in the obtained ferroboron is 1.8%, which is a very high value. 'Comparative example-2
Low aluminum content reduction method by reducing the amount of reducing agent aluminum;
A blended mixture for ferroboron in which the amount of reducing agent blended was reduced by about 15 grams compared to Comparative Example-1 was charged into a cylindrical reaction vessel 1 as shown in FIG. 1, and ignited and reacted to produce ferroboron. It was as shown in Table 3.

Table 6 Yield of produced ferroboron B 51.796 As shown in Table 3, simply reducing the reducing agent aluminum only unnecessarily lowers the B yield, and the aluminum-containing lid also decreases to 0.25%. Although it was reduced to some extent, it did not become less than 0.1 inch, and it was found that such a method was completely unviable in terms of cost and quality.

Example t: Method of charging an oxidizing agent into the hearth of a reaction vessel Before charging the ferroboron preparation mixture into the cylindrical reaction vessel 1 as shown in FIG. An oxidizing agent mixture 6 consisting of anhydrous borax (Na 0.2 kOs), boric anhydride, iron ore, and burnt lime is charged into the bottom hearth 5, and the melting point of the anhydrous boric acid is Easily softens at 450°C and 400-500°C.

Thereafter, it was allowed to cool and solidify, and after the oxidizing agent mixture 6 had solidified, the blended mixture for ferroboron was charged, and the ignition reaction was carried out in the usual manner to obtain ferroboron, and the results are as shown in Table 4.

Table 4 B Yield 65.1 As shown in Table 4, the At content in the obtained ferroboron is 0.048%, which is much lower than that of normal ferroboron, and the At removal rate is over 95%. It became.

B: Although the yield has slightly decreased, it is clear that it will be possible to produce ferroboron with high added value at a slightly lower cost.

Thus, in this example, by charging the furnace preparation in the reaction vessel onto the oxidizer and causing an ignition reaction, a molten metal with a high At content is first produced by the reaction of the 7-stage roboron preparation, and then a molten metal with a high At content is produced. Because the temperature is high, when the oxidizing agent in the hearth melts and floats, it passes through the 17-eroboron molten layer with a high At content.

Here, oxidation of [mu]L in the molten metal progresses as in the above-mentioned formula 00.

In this way, in the same reaction vessel, type 0 A was used as the first stage.
It became possible to carry out the reduction reaction using t, and then, as a second step, remove the remaining At in the molten metal by oxidation using formula 0.

In addition, anhydrous borax (Na20.28*Os) is used as an oxidizing agent for fc, which improves the viscosity of the slag and removes At.
It was found that the sulfur content in the obtained 7-eroboron was significantly reduced, in addition to the improved yield. The reason for this is presumed to be that Nag O contained in anhydrous borax contributes to metal removal.

As described above, it was found that in this example, it was possible to produce ferroboron with an At content (LO of 5% or less).

Example 2 Next, in exactly the same manner as in Comparative Example 2, the bottom part 5 of the container was placed in a dollar-shaped reaction container 11 capable of rotating and tilting as shown in FIG.
The oxidizing agent mixture 6 was heated and softened, then allowed to cool and solidify.
Preparation 10 for engineered roboron was charged and an ignition reaction was caused.

After the reaction was completely completed, the reaction vessel was lifted up using a hook 8, and the metal and slag were replaced with another empty reaction vessel 12 of exactly the same shape. After this empty space was replaced six times, the slag 22 was removed, and the metal 21 was cast into the mold 13 and solidified.

The steps of Example 2 are shown in flowcharts in Figures 4 (a) to (
). That is, in FIG. 4, (a) indicates that a mixture 6 of borax, boric anhydride, iron ore powder, and burnt lime powder is charged into the bottom 5 of the reaction vessel (ladle) 11 as an oxidizing agent and a desulfurizing agent. , (b) shows that the mixture 6 is heated and softened by the gas burner 7, and then left to cool and solidify (not shown), and (c) shows that the mixture 10 is charged onto the solidified mixture 6. ) indicates that an ignition reaction is occurring.

9 is a guarantee ring. In (e), the contents of the reaction vessel 11 are emptied into another vessel 12, and this process is repeated six times. (fart)
The blank shows the step of casting the replaced boron alloy metal 21 into the cast bed 13.

Further, the results of Example 2 are shown in Table 5.

Table 5 B Yield: 66.3% In order to avoid difficulty in separating metal and slag due to temperature drop of the melt during air exchange, the amount of sodium chlorate in the formulation in ferroboron was increased, and as a result, the amount of sodium chlorate was increased. The air was replaceable and the metal sludder separation was good.

A/ contained in the resulting 7eroboroy.

The content decreased significantly, and it was demonstrated that the At removal reaction was promoted even if the containers were not emptied after the reaction.

With this method, compared to the conventional ferroboron of Comparative Example 1 described above, it was possible to achieve an At removal rate of 99 degrees or higher.

Although the above example deals with ferroboron, the present invention can also be applied to other boron alloys. Next, examples of cobalt-boron alloys will be shown.

Example 3. . . . The manufacturing process of the example of cobalt boron alloy is exactly the same as that of Example 2 above.

However, cobalt oxide powder was added to the substitute for iron ore powder.

The breakdown of the oxidizing agent in the bottom 5 of the mixing container used in this example and the chemical components of the obtained cobalt boron are shown in Table 6.

Table 1 Produced cobalt boron It was also found that the grade of cobalt oxide used (weight i%) was able to reduce the At content to α05 or less even in a cobalt boron alloy.

[Effects of the Invention] As described above, the boron alloy production method according to the present invention makes it possible to economically produce a low-aluminum boron alloy with excellent quality, which was previously considered impossible using the thermite method. It is a useful invention with enormous industrial value.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a thermite reaction vessel, Fig. 2 is a schematic diagram for explaining an embodiment of the present invention, Fig. 3 is a schematic diagram of a rotary tilting reaction vessel, and Fig. 4 is a schematic diagram of a rotary tilting reaction vessel. It is a figure for explaining the process in an Example. DESCRIPTION OF SYMBOLS 1... Reaction container, 4... Magnesia stamp lining, 5... Hearth part, 6... Oxidizing agent mixture 10.
...Preparation, 11...Rotary tilting reactor, 12...
Empty container, 15...Cast bed, 21...Metal, 22.
...Slag Note that the same symbols in the drawings indicate the same or equivalent parts. Agent Patent Attorney Sanro Kimura No. 1rI4 Fig. 2 5 6 ■, Matter 1' (Indication Patent Application 1982-51005 2. Name of the invention: Boron alloy manufacturing method? (h) (412) Nippon Kokan Co., Ltd. (Mr. ¥i) 4. Agent 6, “Claims” and [Details of the invention (2) of the oil field specification
), page 2, line 20 (DrAl~51~J)ir,s
~0.02%~, P~0.1:N1~" is additionally inserted. (3) Correct it to "Ferrophoron Jt?r Ferroboron" in the first line of page 3. (4) rMno on page 6, lines 2 to 6, 1% or less, S
0.01 or less" rco, i- or less, 80.00
Correct 2- or less and 1. (5) r on page 6, line 19 Al, Si, P, M
n J rAi. Correct as S, P, and J. (6) In the reaction formula on page 5, line 7, [2/3FtO8
Jr 2/3 Ft, o, J To T8 positive-f le. (7) Correct “normally 0.01 to 0.03 J” in the first line of page 6 to rnormal 0.005 to 0.02 J. (8) Correct “amorphous” in the 11th line of page 6 to “ Correct to amorphous j. (9) Correct "empty replacement" on page 7, line 20 and page 18, line 17 to "empty replacement". a* rMo of sth page tg1 line, is below, 80.01J
Correct rMD, 05% or less, So, 002J and '1. C11, page 8, lines 7-8, "aluminum/magnesium" is corrected to "aluminum-magnesium" and the supplementary "baked stone". α◆Second negative component.C column ro.o09J to rO.o06J.P column rO.014Jt-rO.008J KMn column rO
．． 047J to rO. 01clJ in the Ft column IO. 55J
rO. Corrected to 08J. (lI page 20 line 1 0 rB step '1J13.7%J
is corrected to rB yield 66, 7%1. Attached Patent Claims (after amendment) ``(1) When producing a boron alloy by the thermite method using an aluminum alloy or an aluminum alloy as a reducing agent, the amount of the reducing agent used is greater than the theoretically required amount. After reacting to produce a boron alloy with a high M content, the high M content boron alloy is reacted with a low melting point oxidizing agent and a desulfurizing agent that have been coated on the hearth of the sintering reaction vessel. , a boron alloy production method characterized in that M and S in a high M-containing boron alloy are removed to produce a boron alloy with a low impurity content. (2) The amount of the reducing agent used is 105% of the theoretically required amount. ~13
2. The method for producing a boron alloy according to claim 1, wherein the boron alloy is produced at 0°. A method for producing a boron alloy according to claim 1. (4) A method for producing a boron alloy, wherein the boron alloy is ferroboron. Ron alloy manufacturing method. A boron alloy manufacturing method according to claims 1 and 4. The boron alloy manufacturing method described. ”

Claims (1)

[Scope of Claims] +11 When producing a boron alloy by the thermite method using aluminum or an aluminum alloy as a reducing agent, the reaction is performed using the reducing agent in an amount greater than the theoretically required amount to produce a boron alloy with a high At content. After producing the above-mentioned high At content boron alloy, the high At content boron alloy is reacted with a low melting point oxidizing agent and a desulfurization agent coated on the hearth of the reaction vessel in advance to remove M and S in the high At content boron alloy. A boron alloy production method characterized by removing boron alloys and producing boron alloys with low impurity content. (2) The amount of the reducing agent used is the theoretically necessary amount of 105 to 1
30%. The method for producing a boron alloy according to claim 1, wherein the boron alloy is 30%. (3) The oxidizing agent and desulfurizing agent are boric anhydride, anhydrous borax,
The boron alloy manufacturing method according to claim 1, characterized in that iron ore powder or burnt lime powder is used. (4) When the low melting point oxidizing agent and desulfurizing agent are reacted with the boron alloy having a high At content to remove S from the boron alloy containing &ht, forced stirring is performed by changing 9. A method for producing a boron alloy according to claim 1. (5) The boron alloy manufacturing method according to claim 1, wherein the boron alloy is a ferroboron alloy or a cobalt boron alloy.