Apple...said a large chunk of its metal suppliers use conflict-free minerals, amid ethical concerns about how iPhones and other devices are produced...The use of conflict minerals raises concerns about the treatment of those sourcing the minerals, and the role of the tech industry in potentially funding local warlords...[A]pple said every smelter and refiner that provides tantalum metal to its suppliers had been designated conflict-free by a third-party auditor...Apple has had its hand forced under new US regulations, section 1502 of the Dodd-Frank Act...[refers to Intel]