Refer to the input text as context and select the correct relationship between 'Codelco' and 'copper' from the available options.
Options: product/material produced, industry, legal form, creator

SANTIAGO, July 28 World no.1 copper miner Codelco halted operations Tuesday at its key Chuquicamata mine as a week-long contract workers' strike intensified, chief executive Nelson Pizarro said.
product/material produced