Process for recovering non-ferrous metals from industrial mineral residues

Patent metadata

Field	Value
Publication number	US-2021292869-A1
Application number	US-201917254750-A
Country	US
Kind code	A1
Filing date	Jun 28, 2019
Priority date	Jun 29, 2018
Publication date	Sep 23, 2021
Grant date	—

Abstract

A process is described for recovering a non-ferrous metal from a first solid residue comprising iron. In this process, the first solid residue is mixed with a second solid residue including sulphur, thereby obtaining a particulate mixture. The particulate mixture is subjected to a roasting step at a temperature of at least 650° C. to obtain a roasted mixture, and the roasted mixture is subjected to leaching in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.

First claim

1 . A process for recovering a non-ferrous metal from a first solid residue comprising iron, the process comprising:
mixing the first solid residue with a second solid residue comprising sulphur thereby obtaining a particulate mixture, roasting the particulate mixture at a temperature of at least 650° C. to obtain a roasted mixture, and leaching the roasted mixture in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.

2 . The process of claim 1 , wherein the first solid residue comprises at least 15% iron (Fe) by weight.

3 . The process of claim 1 , wherein the non-ferrous metal is present in the first solid residue as an iron spinel of the non-ferrous metal for at least 20% by weight.

4 . The process of claim 1 , wherein the non-ferrous metal is zinc.

5 . The process of claim 4 , wherein the first solid residue comprises at least 20% by weight zinc ferrite.

6 . The process of claim 1 , wherein the first solid residue is one or a combination of the following:
goethite residue from metallurgical processing of zinc, Basic Oxygen Furnace dust, and Electric Arc Furnace dust.

7 . The process of claim 1 , wherein the second solid residue comprises at least 15% by weight sulphate mineral.

8 . The process of claim 1 , wherein the second solid residue is a jarosite residue from metallurgical processing of zinc.

9 . The process of claim 1 , wherein the second solid residue comprises the non-ferrous metal.

10 . The process of claim 1 , wherein the particulate mixture comprises a ratio of sulphur to the non-ferrous metal of at least 6:1.

11 . The process of claim 1 , wherein the first solid residue and the second solid residue are mixed in proportions such that the particulate mixture comprises an amount of sulphur at least equal to a stoichiometric amount of the non-ferrous metal in the particulate mixture.

12 . The process of claim 1 , wherein one or more of the first solid residue, the second solid residue, and the particulate mixture has a particle size distribution with 50 percentile diameter (d 50 ) equal to or smaller than 100 μm.

13 . The process of claim 1 , wherein the roasting is performed at a temperature between 675° C. and 800° C.

14 . The process of claim 1 , wherein the leaching is performed in water at a temperature between 10° C. and 90° C., wherein a weight ratio of the water to the roasted mixture is at least 1:1.

15 . The process of claim 14 , wherein a weight ratio of water to roasted mixture is between 5:1 and 15:1.

16 . The process of claim 1 , wherein the leaching is performed at a temperature between 15° C. and 50° C.

17 . The process of claim 1 , wherein the non-ferrous metal is zinc and the first solid residue comprises at least 30% by weight zinc ferrite, wherein the second solid residue comprises at least 15% by weight sulphate mineral, wherein the roasting is performed at a temperature between 675° C. and 800° C., and wherein the leaching is performed in water at a liquid to solid ratio of at least 5:1 and at a temperature between 15° C. and 50° C.

18 . The process of claim 17 , wherein the second solid residue is jarosite.

19 . The process of claim 7 , wherein the second solid residue is jarosite.

20 . The process of claim 1 , wherein the first solid residue and the second solid residue comprise the non-ferrous metal.

Assignees

• Vito Nv

Inventors

• Kukurugya Frantisek
• Horckmans Liesbeth
• Spooren Jeroen

Classifications

• Y02P10/20

  Recycling · CPC title

• C22B1/02 Primary

  Roasting processes (C22B1/16 takes precedence) · CPC title

• C22B19/30

  from metallic residues or scraps · CPC title

• C22B3/06

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• C22B7/006

  Wet processes · CPC title