DE2706432A1 - METAL ALLOYS, METAL MIXTURES OR ORES LEVELING PROCESS - Google Patents

Description

I I / ho

FRANKFURT (MAIN) ₁ 16th Harz 1977

Elkem-Spigerverket A / S, Middelthunsgate 27, Oslo 5, Norway.

Process for leaching metal alloys, metal mixtures or ores.

The invention relates to a method for leaching metal alloys, metal mixtures or ores. In industry, solutions of iron (III) chloride are used to leach iron and other metals such as aluminum or calcium. A well-known process of this type is the so-called Silgrain process. A pure silicon metal can be produced by leaching with iron (III) chloride solutions. The reaction takes place at about 110 ⁰ C. Iron, aluminum and calcium are then brought into solution. The divalent iron salt resulting from the reduction of the dissolved metals is oxidized with chlorine gas and used again for leaching. A solution of iron (III) chloride is also used in the extraction of zinc and / or copper by leaching corresponding ores. This also creates a solution of iron (II) chloride that has to be regenerated before it can be used again.

The regeneration of ferrous chloride solutions requires thus a reaction with chlorine gas. However, this method of oxidation has obvious drawbacks and exists in the industry there has long been a desire and need to replace this method with a simpler and less unpleasant method. The disadvantages of chlorine gas oxidation are that

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!, Large quantities of liquefied chlorine paste, sorted and stored v / need to ground. The transport and storage of chlorine is: ni +; strict safety regulations. Floodplains the oxidation by means of Chlorpas at elevated temperatures, generally at 9o to 1o5 ° C, can be carried out. This requires a special choice for the material in the oxidation device.

The method of the invention avoids those outlined above Np.chteil °.

The making of the invention; aur outlet; un. ^r j of he r; s, metal mixtures or ores by means of aqueous solutions of H'i.lo-'eni den of metals, the ions of which were in v ^ ssr ^ n-ei "solution in mei: ir as a stable valence stage, isI ; essentially characterized in that, in a manner known per se, the v / Hsnri ( ^r e solution of the halides of the metals in the higher valence stage is used for leaching, the aqueous solution; The anolyte and the catholyte are kept completely separated by a diaphragm, an electrolyte containing chlorine inside is used as the catholyte, and the solution oxidized in the anode area is led to further leakage separating Di can anhrstfma 'made of different materials, for example a glass fiber _aas. or a plastics fiber material What material for the ι Di Pr ¹ I ^ q ^ ^0- IUa rrew' is selected in such hnnrrt of the Temperature of the electrolyte. At low temperatures, such as room temperature _(Knnn Glasfaserraaterial, mid-range temperature, ^including: at ^C: O to 60 ⁰ C, a polyester fiber cloth and ^ aturen at high TeniDei such as '/' o to Ho ⁰ C, a PolytetraCluoräthylcn-, Diaphragm materials structured in this way are particularly suitable, which have a perineous permeability and allow about 5 liters of air / dm "to pass through at a pressure of 100 mm water column.

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ORIGINAL INSPECTED ^C0PY JH

-S- 2706A32

Purely in the case of reduction by means of iron (III) chloride, the Dianhrafjma prevents the maxsenic transport of iron chloride from one cell half to the other, while the current transport is not significantly hindered. One can therefore choose a catholyte which is not identical to the iron (II) chloride solution to be oxidized, which is the anolyte. The oxidation takes place in the anode compartment. A number of chloride-based electrolytes can be used in the cathode compartment, provided that the conductivity is sufficiently high. The chlorine requirement of the anolyte is covered by the diffusion of chlorine ions from the cathode compartment to the anode compartment.

It is not necessary to have only an iron (II) chloride solution in the anode compartment. It can also, and this is often cheaper, be a mixed solution of iron (II) and iron (III) chloride. In, each case, a VoIl- ■ oxidation z \ i of an iron (III) -chloridlösunf5 is possible.

An advantage of oxidizing a mixed solution is that a smaller and simpler apparatus is used for the oxidation can be.

The invention is illustrated schematically with reference to the enclosed

Drawing explained. In this the electrolysis cell is with 1, j the diaphragm dividing the cell in two halves with 2, the j denotes the anode with 4 and the cathode with 5. The anode can; a graphite anode or some other dimensionally stable anode be. The cathode can be made of graphite or another metal: that is more noble than hydrogen, e.g. copper.

The process of the invention can be carried out as follows: The solution of iron (II) chloride to be oxidized is on

Bottom in the electrolytic cell 1 through the pipe 6 into the! Anode compartment initiated while the oxidized solution through

the pipe 7 is led out. The catholyte is introduced by the \ pipe 8 at the bottom of the electrolysis cell and out through the tube. 9 The reaction temperature is im

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- • - ♦ ff-

generally held between 50 and 100 G, whereby it is expedient is to set the incoming liquids to the desired temperature in advance. It is also expedient adjust the speeds of the various electrolytes according to the chlorine requirement and by means of pumps and Strömunp: to regulate knives.

The invention is further illustrated by Examples 1 and 2 explained.

Example 1

.2+

Electrolytic oxidation of Fe ⁺ using; of 1 η UCl as catholyte

Anodi- Zeil- tempe- flow- test- energy- current- increase see voltage temperature and time out of Fe ^ ⁺ - current- consumption prey concentrate

density cm / kWh / kg tration

^{2 0} ^

tight
A / dm ²

min

min

Wh / Fe ^ +

g / l

6th 3.2 66 8th 1o 5.9 77 27) 13th 6.8 78 18th 15th 5.9 86 18th

79 1oo

93 1oo

12.4

15.4 15.4

! Example 2

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Current density

A / m ⁴

Cell voltage

Example 2 Catholyte A ¹ IS ¹ T ^

Flow. Together-1 pH together- *: flow together- '

l / h

ι setting of the inflow

settlement

l / h

settlement
of the inflow

Power cut-out loot

Energy consumption of oxidation kwh / leg

ο ¹²⁷ ° CO GO CO CO

O 12 K)

lloo

6.0

6.0

7.5

4.15

4.7o

18th

! 36%
! SaIz-
'acid
t 0 HCl I 36%
SaIz-
: acid and
: 29o g / l
NaCl 1.5 HCl and
NaCl 3oo g / l
NaCl 12, 5 NaCl
and
. NaOH

318

3oo

3 Io

FeCl ₃ : 2oo FeCl ₃ : 22 3 FeCl ₂ : 44 FeCl ₃ : 21

44 HCl

36

FeCl ₃ : 169 FeCl ₃ : 194 FeCl ₂ : 34 FeCl ₃ :

4o HCl

9 4o

FeCl ₃ : 166 FeCl ₃ : 191

FeCl-: 65 FeCl ₀ : 4o c 2 '

46 HCl

42

3.1

2.9

2.7

2706A32

The method of the invention is for the case of oxidation an iron (II) chloride solution or a mixture of iron (H) chloride and iron (III) chloride solutions have been described. But it can also be used for the oxidation of other metals, which in aqueous solution have ions with more than one have a stable valence level. Such metals can be most heavy metals, cerium, europium and thin actinides.

In the case of an oxidation of a copper (I) chloride solution or a Mixture of a copper (I) and a copper (II) chloride solution the method of the invention is equally applicable.

Are sulfuric acid salts used, which is basically possible the sulphate ions pass through the diaphragm. There are leaching processes in which polyvalent sulphate salts are used can be worked.

As the examples show, it is possible to send a 100 # to approach or to achieve anodic current yield.

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Claims (3)

Claims 1.) Process for leaching; of metal alloys, metal mixtures or ores by means of aqueous solutions of halides of metals, whose ions in aqueous solution in more than one stable valence stage, characterized in that in a manner known per se, the aqueous solution of the halides the metals in the higher valence stage are used for leaching, the aqueous solution is used for leaching Metal halides are subjected to anodic oxidation, the anolyte and the catholyte being completely through a diaphragm be kept separately, as a catholyte one different from anolyte s Electrolyte containing chlorine ions is used and the solution oxidized in the anode compartment for further leaching to be led. 2.) The method according to claim 1, characterized in that j Instead of an aqueous solution of halides, aqueous solutions of sulfates can be used. i 3.) The method according to claim 1 or 2, characterized in that i that an anolyte is subjected to oxidation, which is an ι Solution of salts of the same metal but different | Represents oxidation stages. 4.) Method according to one of the preceding claims, characterized in that that the anolyte and / or the catholyte to the temperature predetermined for carrying out the anodic oxidation is set. 709833/0726 ORIGINAL INSPECTED