The Copper Mark extends its responsible mining assessment already covering a fifth of global copper production, to molybdenum, nickel and zinc with the launch of a pilot program.
China buys about half of Codelco's production and also accounts for about half of global copper consumption, which analysts estimate will be around 25 million tonnes this year.
The Chilean state-owned company recently signed some contracts for three to five years with customers in Europe, in contrast to the more standard annual deals.