DE2318262A1 - PROCESS FOR THE EXTRACTION OF METALS FROM HALOGENIDES USING REDUCING METALS - Google Patents

Description

St. 2468

Halomet AG, Basel / Switzerland

Process for the extraction of metals from halides by means of Reduktions.metallen

The invention relates to a process for the extraction of metals, starting from a halide of these metals, using reducing metals.

Under "reducing metals" are in the invention Process to understand metals and metal mixtures, as a result of their affinity for the halogens, metal halides able to reduce at least to subhalides.

According to known processes, metal halides with reducing metals are always down to the elemental metals reduced. These known methods have the following disadvantages in particular:

1. The reducing metals are highly volatile in almost all cases Alkali or alkaline earth metals, the residues of which remain in the recovered metal due to evaporation can be removed from the extracted metals. However, the regeneration of their halides is very expensive.

2. If low-volatility reducing metals are used, such as Mn, Sn ₉ Pb, etc., the halides of which are easy to regenerate, a residue of such a reducing metal always dissolves in the metal obtained. Apart from that, such reducing metals in technical quality contain residues of reducing agents, e.g. carbon, which * also dissolve in the recovered metal. As a result, you can

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pure metals cannot technically be extracted in this way. On the other hand, subsequent cleaning is economical not portable.

The invention is therefore based on the object, while avoiding these deficiencies, to develop a method which it allows pure metals (or alloys) to be used for reduction using less volatile reducing metals to win the halides.

According to the invention, this object is achieved in that the saturated halide of the metal to be obtained is in a first step at a reaction pressure below the pressure at the selected reaction temperature the metal to be extracted is formed in elementary form, almost completely to one by means of the reduction metal or more subhalides is reduced and these subhalides then in a second step in the absence of the reducing metal to the elemental metal and its saturated halide are disproportionated.

The invention is explained in more detail using the following examples:

example 1

In the reduction of AlCl according to the invention, by means of Manganese (that without impairing the purity of the aluminum to be extracted, for example with iron or carbon can be contaminated) the following reactions take place at a temperature of lÄSwC (which - like the thermodynamic Calculation shows - take place at each pressure below 50 at, without the reduction up to the elementary Al goes):

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AlCl (g) + Mn (fO = AlCl (g) + MnCl ₂ (fl) AlCl ₃ Cg) + | Mn (fl) = AlCl ₂ Cg) + | MnCl ₂ (fl)

(g) ... gaseous. (f) .... solid (fl) .. liquid

A gaseous mixture of the subchlorides of aluminum (AlCl and AlClp) with a residue of saturated aluminum chloride (AlCl-,) on the one hand and of molten manganese chloride (MnCl ₂ ) on the other hand is obtained. Then passing the Al-Subchloridgemisch from manganese away and cools it while maintaining a reaction pressure of more than 1, ¹ I at from ⁰ to 700 C, so disproportionate to subchlorides as follows:

3 AlCl (g) = 2 Al (it or fl) + AlCl, (g) 3 AlCl ₂ (g) = Al (f6 or fl) + 2 AlCl ₃ Cg)

The aluminum obtained according to the invention is pure.

If the pressure falls below 1.4 at, the MnCl ^ vapor carried along with the subchlorides can chemically react with the Al which is deposited in elemental form and contaminate the Al with Mn. For ■ connecting the two reaction spaces, namely the reduction chamber and the Disproportionierungsraumes, the whole system in this example, may operate under a single pressure at between 1, ¹ and J is 50 at. This means that compression and / or expansion units, which are problematic at these temperatures, are not required.

The manganese chloride can be burned in a known manner with air or oxygen to form manganese oxide and free manganese the manganese oxide is reduced with carbon to metallic manganese and reused as reducing metal.

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llloroei Int uses a residual carbon content in manganese for the purity of the »aluminum ?! without Hedeutunr,

Dir Zelch.iunf. Zeint a Prlnr.lpnchemn the way of working bein l «'? i game 1.

Example 2

Kb is pure elemental Ti in powder form from TlKr ₁₄ rlttrls vanadium as a reducton metal.

The reduction to r.ubhalop.enlden in the first procedural step takes place at a temperature of 173O ° C and a Pressure below 1 * 1.6 at, as it works at one pressure above 1.6 nt a reduction to Ti would result.

The disproportionation in the second process step takes place at a temperature of 1230 ° C. Here dirf ein! '»• trl ^ bndrurk from Γ, ^Γ > nt not overridden w« »rdrn, veil r-cnat - Ui" rr <n (] ynT ".lr.ch bodlnrt - the one with the :' u \ bronld ^ n from ότ ΠΉιιν t it> i: r "t uf> r.tarr.onde VUr_-Dampf ru cirrr Verutiflnlrunr. ''""f''>> · τ; Γ! 'Μΐ' * η Ti with Vanadium

would lead. , ^

For technical applications. inventedunf; sp; emüP> en Procedure int it beneficial to reduce and disproportionate one after the other continuler] I through7.ufniir <. 'n and then at the disproportional lrrunr prbildete pesSttl p; te .Halopenia dos to newlnnonden Metnllor. continuously to Reduction attributable to where en increase with fresh Halor.enide is reduced again to r.ubhalor; enides will.

0 9 8 A UI 0 / ♦ U 2

BATH ORIGINAL

If an alloy of several metals is to be obtained directly from their halides, then according to the invention one proceeds from a mixture of several halides.

For example, one starts from a mixture of AlBr, - and SiBr ^ vapor, reduced with manganese to AlBr, AlBr ₂ , SiBr ₂ and SiBr, and disproportionates this subbromide mixture, with an alloy of Al-Si e * and a gaseous mixture of AlBr, and SiBrj, are formed.

Depending on the temperature at which the reduction is carried out, the subhalide mixture produced (e.g. SiCl ₂ , SiCl,) contains a smaller or larger proportion of reducing _{metal halide (e.g. MnCl 2} ) and unreduced saturated halide of the metal to be recovered (e.g.

The greater the subchloride content, i.e. the smaller the saturated halide content of the metal to be extracted is, the greater the metal yield in the disproportionation, based on that supplied to the reduction Amount of saturated metal chloride. With regard to the proportion of the reducing metal halide in the subhalide mixture there is the possibility in the disproportionation that the metal formed (e.g. Si) with the reducing metal halide (e.g. MnCl ") reacts and through the reduction metal (e.g. Mn) is contaminated to a small extent.

Both the proportion of the saturated metal halide and the proportion of the reducing metal halide in the Subhalide mixture can be regulated by maintaining the pressure and temperature conditions during the reduction. Also a possible reaction between the one to be won

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Metal and the reducing metal halide in the disproportionation is pressure and temperature dependent. As a result, according to the invention in order to achieve maximum yields and pure metals to maintain optimal pressure and temperature conditions.

These pressure and temperature conditions can be determined for each individual case, taking into account the properties of each determine the reactants used in a known manner by means of thermodynamic calculations. Generally it is known that the formation of sub-halogenides by increasing and decreasing temperature and by disproportionation be favored by sub-halogenids by lowering the temperature and increasing the pressure.

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Claims (1)

Claims Process for the extraction of metals, starting from a halide of these metals, using Induction metals, characterized in that daft dan nes.ittlnte halide des metal to be recovered in a first step at a reaction pressure below the pressure at which Lei of the reaction temperature chosen is that to be obtained Metal is formed in elemental form, by means of the reduction metal almost completely to one ode »* rhreren Subhalorenlden is reduced and this Subhalides are then absent in a second step of the Reductlonsrretalles to elementary metal and his rer.JKt lrten Hnlorenld disproportionate will. Γ. Process according to Claim 1, by means of which the components and the f.ispri-rticriations are carried out continuously one after the other and that the largest halide of the metal to be recovered formed during the disproportionation is continuously returned to the reduction. 3. The method according to claim 1 or 2, characterized in that that for the purpose of obtaining an alloy from a mixture several halides is assumed. ¹ J. The method according to any one of claims 1 to 3 »characterized in that optimal pressure and temperature conditions are maintained for the recovery of pure metals in maximum yield. 409844/0 /. BAD ORfGINAL Blank page