The drop to 64.057 million tonnes came as several major operations remained fully or partially shut down in the second quarter following a deadly dam burst at the Corrego do Feijão mine.
The pullback followed an increase in transaction fees for all iron ore futures contracts on the Dalian Commodity Exchange and a rise in iron ore shipments to China.
Nearly 25 asset management firms and some pension funds are seeking compensation for losses derived from Vale's plummeting share price since the disaster.