Africa’s largest copper producing nation saw output fall back over the first four months of 2011, compared with a year ago. Cobalt output and exports rose though. A complete article on the Zambian Copperbelt will be published in the July issue of International Mining. Copper output dropped to 242,284 t, from 266,373 t during the first four months of 2010, the Bank of Zambia (BoZ) said last Thursday.Copper exports also declined to 260,631 t between January and April 2011 from 268,541 tonnes last year, the BOZ said. Cobalt production in the first four months of 2011 rose to 3,186 t from 2,666 t last year and exports rose to 3,221 t this year from 2,639 t last year, it said.