Brazilian mining giant Vale's production increased 12.6% year-on-year in the second quarter to 79.448Mt of iron ore, its best Q2 output ever, the company said.

"The good operational performance was supported by better weather conditions and the ramp-ups of the Plant 2 in Carajás and the new Conceição Itabiritos plant in the Southeastern System," Vale said in its 2Q14 production report.

Pellet production reached 9.951Mt, a 2.4% increase from 2Q13 on an increase in Samarco's attributable production. Samarco is a 50:50 JV between Vale and BHP Billiton.

Copper production reached 81,000t, down 11.3% year-on-year. "A planned maintenance shutdown in Ontario was the main driver for the reduction," Vale said.

Nickel production decreased 5.2% to 61,700t from 65,200t. "Vale New Caledonia is resuming its ramp-up following the leakage of acidic solution in May, which resulted in a discharge into the environment and a shutdown of the complex," the firm said.