Bank of Zambia (BoZ) governor Caleb Fundanga told a news conference that higher global metals prices had encouraged fresh investment in copper mines, pushing output higher.
Fundanga said Zambia exported 229 247 tons of copper to earn $1.4bn in the first six months of the year.
Last year's copper exports during the same period stood at 188 228 tons.
"The increase in copper production was mainly attributed to the rebound in production on account of an increase in investment and the realised copper prices," Fundanga said.
Robust metals prices had enabled the vast copper mines to recapitalise and to upgrade infrastructure, he added.
Fundanga said the Kansanshi Copper Mine, which is majority-owned by Canada's First Quantum Minerals, had contributed about 17.5% of total production.
"As new mines come on board, it is expected that minerals production will increase and its share is likely to increase," Fundanga said.
Fundanga said cobalt output at 2 426 tons in the first six months of the year was lower than 2 878 tons which was produced during the same period in 2005.
Fundanga gave no further details on cobalt output but a senior mining industry official told Reuters that most copper and cobalt mines have faced production problems at smelters.