The company announced results from its metallurgical test work program in September 2021. This was a major de-risking step for Cordero with all major rock types hosting sulphide ore returning excellent recoveries via conventional flotation processes to generate clean, highly saleable concentrates.
Highlights from the test work include:
Sulphide flotation test work
- Silver recoveries of 80-89%, lead recoveries of 83-91% and zinc recoveries of 81-90% from locked cycle tests.
- Test work completed on all major rock types at Cordero.
- Higher recoveries were achieved at coarser grind sizes.
- Saleable concentrate grades confirmed and levels of penalty elements for concentrates were insignificant.
Oxide & transition cyanidation test work
- Silver recoveries of 54-80% & gold recoveries of 61-75% at coarse crush / grind sizes from coarse bottle roll testing.
- Results represent the first indication that a heap leach on the oxide & transition material at Cordero may be economic.
- Follow-up column leach test work is currently underway
Further details can be found in our September 7, 2021 press release.