1. Boliden Group
2. DOWA HOLDINGS Co. Ltd
3. ENIRO-HUB HOLDINGS LTD.
4. Glencore
5. JXTG Holdings Inc.
6. LS-Nikko Copper Inc.
7. Mitsubishi Materials U.S.A. Corporation.
8. MITSUI & CO. LTD.
9. Outotec
10. Ultromex Limited