Process and arrangement for extracting a metal from slag a containing said metal

Patent metadata

Field	Value
Publication number	US-9733016-B2
Application number	US-92188506-A
Country	US
Kind code	B2
Filing date	Jun 8, 2006
Priority date	Jun 8, 2005
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The invention is directed to a process for extracting a metal from a slag containing said metal, wherein the liquefied metal-containing slag is heated in at least one electric arc furnace ( 1, 2 ). In order provide an improved method for recovering especially copper from slags, the invention provides that the metal-containing slag is heated in a first furnace ( 1 ) constructed as an AC electric furnace or a DC electric furnace, and the melt is introduced from the first furnace ( 1 ) into a second furnace ( 2 ) which is constructed as a DC electric furnace. Further, the invention is directed to an arrangement for extracting a metal from a slag containing said metal.

First claim

The invention claimed is:

1. A process of extracting a metal from a slag containing said metal, comprising the steps of:
heating the metal-containing slag in a first furnace designed as an alternating current electrical furnace, and carrying out pre-reduction of slag and precipitation of metal matte in the first furnace;
conveying the metal matte into the second furnace designed as a direct current electrical channel furnace, and carrying out a thorough slag reduction and removal of inclusion in the second furnace, with separating the to-be-extracted metal by electrolytic precipitation accompanied by an electromagnetic stirring of the melt.

2. A method according to claim 1 , wherein the to-be-extracted metal is copper contained in the metal-containing slag.

3. A method according to claim 1 , wherein the to-be-extracted metal is lead, zinc, platinum, or nickel contained in the slag.

4. A method according to claim 1 , wherein at least one electromagnet acts on the melt in the second furnace in order to generate the electromagnetic stirring.

5. A method according to claim 4 , wherein the at least one electromagnet generates a magnetic field between 50 and 1000 Gauss, and in that the magnetic field covers at least a portion of a cross section of the melt and of an area of electrodes in the second furnace.

6. A method according to claim 1 , wherein at least one permanent magnet acts on the melt in the second furnace in order to generate the electromagnetic stirring.

7. A method according to claim 1 , comprising the step of introducing a reducing agent into the first furnace during heating.

8. A method according to claim 7 , wherein the reducing agent is coke.

9. A method according to claim 1 , comprising the step of adding carbon-containing material to the surface of the melt in the second furnace in such a way that a horizontally extending layer of the carbon-containing material is formed with a substantially constant thickness and forms a horizontally extending anode layer in contact with an electric connection.

10. A method according to claim 9 , comprising the step of maintaining a horizontally extending layer of the metal matte with a substantially constant thickness in the second furnace in the bottom area below the melt, and the layer, acting as a cathode, makes contact with an electric connection.

Assignees

• Kunze Jürgen
• Degel Rolf
• Borgwardt Dieter
• Warczok Andrzej
• Riveros Urzua Gabriel Angel
• Sms Group Gmbh

Inventors

• Kunze Jürgen
• Degel Rolf
• Borgwardt Dieter
• Warczok Andrzej
• Riveros Urzua Gabriel Angel

Classifications

• F27B3/04 Primary

  of multiple-hearth type; of multiple-chamber type; Combinations of hearth-type furnaces · CPC title

• F27D2099/0023

  DC arc heating · CPC title

• F27B3/085

  Arc furnaces · CPC title

• C22B7/04

  Working-up slag · CPC title

• C22B15/0054

  Slag, slime, speiss, or dross treating · CPC title