Ann: First copper shipment date set. Block 8 licence renewed., page-49

OK have found out where the 22% came from - Page 1 of that Project Update that I linked to a moment ago has the following table -

- Divide the "Total tonnes copper metal production" (79,297) by the 10.3 year mine life gives an average per year of 7698.7 tons of actual copper (in the concentrate)
- For simplicity round that to 7,700 tons of actual copper per year
- 7,700 tons is exactly 22% of the 35,000 tons given as the annual concentrate production - so that gives us an annual copper in concentrate percentage of 22%