A mine moves from development to production when:
1) A high percentage of planned production
2) Copper is produced for sale at a consistent rate.
3) Stockpiles are maintained at key points in the
production process to permit continuous production.
4) Downtime related to start-up of new operations is minimized.
5) Costs remain relatively stable within each process.
Production may last from 3 to 50 years, depending on the size and ore grade of the orebody, as well as on mining costs and price of the copper.