It had warned last week up to 800,000 tonnes of iron ore sales could be impacted this quarter if it had to halt the Teluk Rubiah Maritime Terminal to comply with restrictions designed to stop the spread of COVID-19.
It then said TRMT could remain open, following discussions with authorities, but has now announced a stoppage until at least March 31.
Vale said the impact on first quarter sales was now expected to be about 500,000t and there was no expected impact on full-year production and sales volume.
Vale has previously put 2020 iron ore fines production guidance at 340-355 million tonnes and March quarter guidance at 63-68Mt.
Vessels headed to TRMT would be redirected and redistributed among Vale's blending facilities in China, the company said.
"An immaterial cost increase is expected due to additional logistics," Vale said.
The facility had handled 23.7Mt in 2019.
The Metal Bulletin iron ore 62% fines price is down about 2.7% to US$88/t, with most commodity prices lower as the impact of the coronavirus spreads.
Vale closed down 3.1% yesterday, near the lower end of a one-year range, and is capitalised at BRL180.2 billion (US$35 billion).