At the same time, portside iron ore inventory in China shrank to 126.75 million tonnes as of Dec. 31, down 4.1% from last year's peak of 132.15 million tonnes recorded on Nov. 13, SteelHome data showed.
Brazilian iron ore miner Vale SA said on Wednesday its Samarco joint venture with BHP had begun the gradual restart of operations, after a deadly dam failure in 2015.
The exchange already tightened single-day open positions on its most traded iron ore contract twice since the start of December to 5,000 lots as prices soared beyond market expectations.
Mysteel consultancy's latest survey showed iron ore dispatched from Australia and Brazil fell for the second week over Dec. 7-13 by another 1 million tonnes from the prior week.
China, the world's biggest steel producer, churned out 87.66 million tonnes of crude steel last month, down from 92.2 million tonnes in October but up from 80.29 million tonnes in November 2019.