The world’s biggest miner is turning to copper as iron ore demand wanes. It’s time to go for a mega takeover BHP has always shied away from: Going after the biggest copper mine of all. The world’s biggest miner is turning to copper as iron ore demand wanes. It’s time to go for a mega takeover BHP has always shied away from: Going after the biggest copper mine of all. Business / Companies Sydney Morning Herald – Latest News