Copper output in Democratic Republic of Congo rose 7.9 percent year-on-year in the first half of 2018 to 597,249 tonnes and cobalt production jumped 37.6 percent to 52,491 tonnes, the central bank said on Thursday. Congo is Africa's top copper producer and the world's leading miner of cobalt, which is a key component in electric vehicles and other electronic products. Gold production rose 15.8 percent over the same period to 17,948 kg, central bank data showed.