Zambia’s decision to drop a proposed import duty for semi-processed copper materials will help stabilize smelters in Africa’s second-biggest producer of the metal, the Chamber of Mines said. Finance Minister Felix Mutati’s announcement that the government will abandon plans to charge a 7.5 percent levy on copper concentrates from Jan. 1 is “reassuring,” said Talent Ng’andwe, the acting chief executive officer at the industry body.