DE1014330B - Process for the manufacture of a purified, arc-meltable titanium metal - Google Patents

Description

The invention relates to a method for removing impurities from raw titanium metal, in particular in the form of titanium metal sponge, and represents a further development of the process according to patent application N 7327 VIa / 40 a. By means of the method according to the invention, in particular such impurities are removed from the titanium metal either by themselves are present or formed during the presentation of the titanium metal; such impurities are for example magnesium metal and / or various water-soluble or acid-soluble compounds, such as magnesium chloride and the like.

When titanium metal is produced by a process in which titanium tetrachloride and an active reducing metal, for example magnesium, are reacted at elevated temperatures to form titanium metal and a chloride salt of the reducing metal, the titanium metal formed is usually due to the chloride salt of the reducing metal being present and often also by the reducing metal present itself contaminated. Before the titanium metal product can be further processed industrially for the most varied of suitable areas, these impurities must be separated from the titanium metal. The separation of the impurities from the metal can be done by leaching, using either water or a dilute acid solution as the leaching medium. When using pure water as the leaching agent, practically all of the water-soluble impurities, for example magnesium chloride, can be removed; if a dilute acid is used in the leaching process, it is also possible to separate out the metallic impurities, such as magnesium metal, and also the soluble, salt-like compounds. For economic reasons, it has hitherto been common practice to use an acidic solution, for example hydrochloric acid or sulfuric acid, in the leaching process. In the subsequent further processing and in particular in the melting of the leached titanium metal in an electric arc in order to cast the metal into molds suitable for industrial use, it has been shown that many undesirable difficulties arise and that to a certain extent the titanium metal product is not suitable for such a melting treatment in the Arc is suitable. The reasons for this are not clearly clear; however, it is quite possible that after the dilute acid leaching, the titanium metal will contain absorbed gas, such as hydrogen, and that this will be released during the subsequent arc melting treatment. This can cause loss of arc stability and spraying of the metal

for the production of a cleaned,

suitable for arc melting

Titanium metal

Addition to patent application N 7327 VI / 40 a
(Interpretation document 1 006 621)

Applicant:

Titangesellschaft mbH,
Leverkus en-B ayerwerk

'St y. JmtriKA. ret * it- & i%. itSiI

Dipl.-Ing. Robert Philip Lee, Plainfield, N.J "
and Dipl.-Ing. Harry Glenn Rodman,

Matawan, NJ (V. St. A.),
have been named as inventors

lead, whereby a satisfactory arc melting is made impossible.

The method according to the main patent avoids these disadvantages inherent in the known methods and allows satisfactory removal of the impurities from the raw titanium metal; the Titanium metal treated according to the process of the main patent is suitable for a subsequent arc melting. The process uses leaching and is easy and economical to use.

The method according to the invention represents a further development of the method according to the main patent and also relates to the treatment of an impure titanium metal to remove the impurities from it to remove and make the cleaned metal suitable for arc melting. the Invention is characterized in that the raw titanium metal product is in contact with an acidic solution is brought, which is a soluble oxidizing agent with an oxidation-reduction potential above that of the normal hydrogen electrode. Virtually any oxidizing agent has been found to be which is capable of converting hydrogen gas into hydrogen ions in a to oxidize acidic solution. To these oxidation

709 658/328

In addition to the ¹ nitrate compounds and acidic solutions of the ferric salts, agents include chromic acid, Na ₂ CrO ₄ , K ₂ Cr ₂ O ₇ , KMnO ₄ , H ₂ O ₂ , NaClO ₃ , NaClO, NaClO ₄ , KBrO ₃ , KIO ₃ , TiCl ₄ , MnO ₂ ,

clear that highly concentrated acids for economic reasons and because of their destructive effects are to be avoided. For example, when using concentrated sulfuric acid and salt ions is reduced and that its reduction products are not absorbed by the titanium metal or be included.

The leaching can be carried out within a relatively wide temperature range. To the Effective removal of the impurities, it is useful in most cases, the leaching practical initiate at room temperature. Normally

PbO ₂ , SnCl ₄ , CuSO ₄ and oxidizing gases such as 5 acidify the titanium metal itself easily through the acid chlorine gas, oxygen, ozone and bromine gas. attacked.

When carrying out the process according to the invention, the reason why the presence of an oxy-

Usually, the oxidizing agent is dissolved in the acidic alkali solution to form an acidic solution. Some of these agents, especially titanium metal products of higher quality with regard to the particular gases, such as oxygen and ozone, are in subsequent further processing, but are not fully, but only very slightly soluble. In these cases it comes clear; However, it can be assumed that the oxy is expedient to react the gases during the leaching as a bubble dating agent with hydrogen gas passing through the solution. It is clear that the specific substance can be released during the leaching, and the amount of the oxidizing agent to be used therefore prevents the absorption of such gaseous materials by the titanium metal in each individual case, depending on a large number of substances; but it can also be due to factors, such as the nature of the an- other, that the oxidizing agent is used before the water, the amount of impurities present, the physical
Shape of the titanium metal product to be cleaned and
from other procedural differences. In 20
some cases, for example when using
of Cu SO ₄ as an oxidizing agent, copper becomes on the titanium metal sponge during leaching
dejected; however, this copper can get through

a subsequent acid leaching before the arc 35 melts the leaching from the development of heat removed. be sliding, the resulting temperature rise

However, there does not appear to be any adverse effects when using chlorine gas and others Gases, the gas can have bubbles through the solution.

given or to a certain extent directly in The following examples serve for further information

of the solution itself. As some of the than 30 explanation of the invention. Oxidizing agents used salts only sparingly soluble. ^ ₁₁

in which, acid solution are, it is useful if example

Also not absolutely necessary, the addition of 70 parts of a titanium metal sample produced by reaction

to control the speed of either the oxidizing agent or between titanium tetrachloride and molten magnet of the acid content of the solution. In those cases where silicon metal is produced and in most cases where magnesium metal has been used, satisfactory results are obtained, and magnesium chloride has been contaminated if at least 0.5% of an oxidizing agent has been leached. As a caustic medium, based on the weight of the caustic solution, 1460 parts of an acidic solution were used, which becomes 44 parts. Percentages of the solution H ₂ SO ₄ and 292 parts of NaClO ₃ are preferably contained. This means between 0.5 and 20% is recommended. The distributions corresponded to a concentration of 3% H ₂ SO ₄ using an oxy- and 20% NaClO ₃ present in the caustic solution. The acid was slowly added during the dating agent leading to an improved titanium first half hour of the leach, metal product. The leaching itself was preferably carried out at temperatures between 24 and 47 ° for 4 hours at the temperature solution. After the leaching was completed with at least the greater proportion of the water, the titanium metal was made of substance to react, the _{acidic leach solution containing NaClO 3} would theoretically be released if the oxidizing agent was not taken in, washed with water and washed for 3 hours long caustic solution would be applied. A this dried at a temperature of about 150 °. By amount excess amount is recommended to have this surgery practically the entire magnitude to get better results. Any solution can remove 50 sium and magnesium chloride. After being used, which is acidic enough to attack, for example, removal of the impurities and drying of the wise magnesium metal. In particular, the titanium metal product was supplied to a facility, solutions of mineral acids, such as hydrochloric acid and for arc melting, and melted; Sulfuric acid, to be used as a lye; the molten titanium was then poured into but also organic acids, for example 55 ingot form. The titanium metal ingot possessed acetic acid, can be used. A Brinell hardness number of 220 that can be used
also have a sufficient acidic character,
to attack the metallic contaminants. 60

The concentration of the acidic solution used can vary considerably; the end Reasons of economy and convenience

As the arc melted, the arc was kept stable and there was no spraying of the titanium metal when melting.

Example 2

The same amount of impure titanium metal according to Example 1 of another caustic treatment was used subjected to the removal of the impurities

take advantage of the 65 magnesium metal and magnesium chloride in terms of their acid components. the

borrowed are thinned; for example caustic solutions are caustic solution of this example consisted of 1500 parts

with an acid content of 2 to about 10% HCl or H ₂ SO _{4 have been used} with success. When using

However, it is recommended to use solutions to

some oxidizing agents, however, have been found

Solution containing 150 parts of H ₂ SO ₄ and 150 parts of KMnO ₄ . The leaching was carried out for 4 hours at temperatures between 34 and 44 °

that other concentrations are more effective. It's 70 run. The leaching itself, the subsequent one

Melting in an electric arc and pouring the molten metal were carried out as in Example 1 performed. Again, there were no difficulties during the arc melting; the ingot had a Brinell hardness number of 140.

Example 3

Another part of the impure titanium metal according to Examples 1 and 2 was subjected to leaching in order to remove the impurities in the magnesium metal and magnesium chloride. In these examples, the caustic solution consisted of 1450 parts of solution containing 70 parts of H ₂ SO ₄ and 140 parts of H ₂ O ₂ . The obtained titanium metal product was then washed, dried and then subjected to arc melting. The cast titanium metal ingot had a Brinell hardness number of 210.

Example 4

20th

The procedure of Example 1 was repeated with the exception that 1500 parts of a solution containing 45 parts of HCl and 45 parts of K ₂ Cr ₂ O _{7 were used} as the caustic solution. Here, too, satisfactory results were achieved with the arc melting of the titanium metal.

Example 5

Another part of impure titanium metal was treated as in Example 1, with the exception that 1600 parts of a solution containing 180 parts of TiCl _{4 were used} as the leaching medium. The impurities were also removed and a satisfactory arc melting achieved; the cast ingot made of titanium metal had a Brinell hardness number of 140.

Example 6

The method of Example 1 was repeated, except that ¹ in 1400 parts of a solution with a content of 140 parts of H ₂ SO ₄ and 84 parts of KIO ₃ was used as the leaching medium. The results obtained corresponded to those of the previous examples; the Brinell hardness of the titanium metal ingot was 137.

Example 7

Another portion of the impure metal was treated according to Example 1; here: a solution of 1200 parts with a content of 36 parts of HCl and 180 parts of SnCl _{4 was} used as the leaching medium. The surface of the titanium metal was covered with a precipitate, which was then easily removed by leaching in dilute acid. The titanium metal was then satisfactorily arc melted.

Example 8

Another part of impure metal was added to 900 parts of water; through the solution Chlorine gas passed in the form of bubbles. The titanium metal thus treated then became more satisfactory in the arc Way melted.

Example 9

The same method was used as in Example 8, except that oxygen was turned on Bubble chlorine gas was bubbled through the solution and during the first half hour 28 parts of HCl were added to the solution to the leaching.

Results similar to those of the above examples were obtained using ozone, bromine and Na ₂ CrO ₄ , chromic acid, MnO ₂ , PbO ₂ , NaClO ₄ , NaClO, KBrO ₃ and CuSO ₄ .

The use of nitrates, nitric acid and ferric salts of mineral acids as oxidizing agents is the subject of the main patent, so that a discussion of these compounds in the context of the present Description unnecessary.

For comparison purposes and to illustrate the efficiency of the method according to the invention another part of the impure titanium metal product according to Example 1 was subjected to leaching, in which the same amount of sulfuric acid was used as in Example 1. However, no oxidizing agent was used applied. Albeit the impurities including magnesium metal and magnesium chloride were removed, the titanium metal product could not be subsequently melted in the Arc, as there was an extremely strong spray of the titanium metal and it was also impossible to maintain a stable arc during melting.

From the above examples and the description it is clear that when using the invention Process is possible to effectively remove impurities, such as magnesium metal and magnesium chloride, from titanium metal to be removed by leaching, in which acidic leaching solutions containing an oxidizing agent be used. The products resulting from such a leach are special suitable for subsequent arc melting. Furthermore, it was found in the case of the invention Process that the removal of the impurities by means of leaching is simple and economical and no additional equipment or large amounts of additional cleaning agents requirement.

Claims (2)

PA TE N TA N S P Γ. 0 C π E: 1. A method of making a purified arc-meltable titanium metal according to patent application N 7327 VIa / 40a, characterized in that the raw titanium metal with a acidic solution is leached, which is a soluble oxidant with an oxidation-reduction potential above that of the normal hydrogen electrode. 2. The method according to claim 1, characterized in that the oxidizing agent of chromic acid, NaCrO ₄ , K ₂ Cr ₂ O ₇ , KMnO ₄ , H ₂ O ,, NaClO ₃ , NaClO, NaClO ₄ , KBrO ₃ , KIO ₃ , TiCl ₄ , MnO ₂ , PbO ₂ , SnCl ₄ , CuSO ₄ , chlorine gas, oxygen, ozone or bromine gas. 1 709 658/328 8.