Process for the recovery of metals from oxidic ores

Patent metadata

Field	Value
Publication number	US-12215407-B2
Application number	US-202017633342-A
Country	US
Kind code	B2
Filing date	Jul 27, 2020
Priority date	Aug 9, 2019
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

A process is disclosed for the recovery of valuable metals from oxidic ores, in particular from polymetallic nodules. The process is suitable for the recovery of Cu, Co, Ni, Fe, and Mn, which are the main metals of interest in such polymetallic nodules. The present process is, among others, characterized by the handling of Fe, which is dissolved and kept in solution until the step of crystallization rather than removed at an earlier stage. A mixed Mn—Fe residue is obtained, which, after thermal treatment, provides a Mn—Fe oxide that is suitable for the steel or for the manganese industry. Excellent Cu, Co and Ni yields are obtained, while Fe is leached and valorized together with Mn.

First claim

The invention claimed is:

1. A process for the recovery of Cu, Co, Ni, Fe and Mn from oxidic ores, comprising the steps of:
dissolving the oxidic ores (P1) in acidic conditions using H 2 SO 4 and SO 2 , thereby obtaining a Cu, Co, Ni, Fe, and Mn-bearing first solution (S1) and a first residue (R1);
Solid/Liquid (S/L) separation of the first solution and of the first residue;
recovering Cu (P2) by:
precipitation as a sulfide by addition of a sulfide-bearing compound, or as a metal by addition of a metal more easily oxidized than Cu, thereby obtaining a Co, Ni, Fe, and Mn-bearing acidic second solution (S2) and a Cu-bearing second residue (R2) and S/L separation of the second solution and of the second residue;
or by:
extraction by electrowinning or solvent extraction (SX), thereby obtaining a Co, Ni, Fe, and Mn-bearing acidic second solution (S2) and a Cu-bearing stream;

neutralizing (P3) the second solution (S2) to pH 2 to 5 by addition of first acid-consuming compounds, thereby obtaining a Co, Ni, Fe, and Mn-bearing neutralized third solution (S3);
precipitating Co and Ni (P4) by adding a sulfide-bearing compound to the third solution, thereby obtaining an Fe and Mn-bearing fourth solution (S4) and a Co and Ni-bearing fourth residue (R4);
S/L separation of the fourth solution and of the fourth residue;
crystallizing Mn and Fe (P5) as sulfates from the fourth solution, thereby obtaining a fifth solution containing a minor part of the Mn (S5), and a fifth residue containing the major part of the Mn and of the Fe (R5); and
S/L separation of the fifth solution and of the fifth residue.

2. The process according to claim 1 , wherein, in the neutralization step, the first acid-consuming compound contains calcium, thereby obtaining a third residue (R3), and further comprising the additional step of S/L separation of the third solution and of the third residue.

3. The process according to claim 1 , further comprising the steps of:
splitting the fifth solution (S5) into a first fraction (S5a) and second fraction (S5b);
recirculating the first fraction of the fifth solution to the step of dissolving (P1);
precipitating Mn and Fe (P7) as carbonates or hydroxides by addition of second acid-consuming compounds to the second fraction of the fifth solution, thereby obtaining a sixth solution depleted in Mn and Fe (S6), and a sixth residue rich in Mn and Fe (R6);
S/L separation of the sixth solution and of the sixth residue; and
recirculating the sixth residue to the step of neutralization (P3), as at least part of the first acid-consuming compounds.

4. The process according to claim 1 , comprising the steps of:
thermal decomposition (P6) of the fifth residue, thereby obtaining an oxidic Mn-bearing seventh residue (R7) and SO 2 ;
separating the SO 2 ; and
recirculating the SO 2 to the step of dissolving the ores (P1).

5. The process according to claim 1 , comprising the steps of:
reverse osmosis (P8) of the sixth solution, thereby obtaining water (S7) and concentrated salt solution (S8); and,
recirculating the water to the step of dissolving the ores (P1).

6. The process according to claim 1 , wherein the ores are deep sea nodules.

7. The process according to claim 1 , wherein Cu is recovered from the first solution (S1).

Assignees

• Umicore Nv

Inventors

• Daniels Michel
• Scoyer Jean
• Baltes Michael
• Neven Margot
• Leyssen Jan

Classifications

• C22B23/0484

  in acidic type solutions · CPC title

• C22B23/043

  Sulfurated acids or salts thereof · CPC title

• C22B15/0071 Primary

  containing sulfur · CPC title

• C22B3/08 Primary

  Sulfuric acid {, other sulfurated acids or salts thereof} · CPC title

• C22B47/0081

  Treatment or purification of solutions, e.g. obtained by leaching (C22B47/0054 takes precedence) · CPC title