Shanghai steel futures jumped on Monday after key steelmaking cities in Northern China issued pollution alerts to arrest the deteriorating air quality in the region.
Top steelmaking city Tangshan launched a second-level pollution alert earlier in the day, following Shanxi and Shandong provinces which started the alerts over the weekend.
The alerts disrupted production at mills, boosting steel futures in China even as demand cools in winter due to slowing construction activity.
Construction steel rebar on the Shanghai Futures Exchange , for May 2020 delivery, closed up 0.7% at 3,538 yuan ($504.62) per tonne.
Steel futures were also supported by Beijing's move to stimulate imports and shore up a slowing economy amid a trade war with the United States.
The finance ministry said next year China would implement temporary import tariffs, which are lower than the most-favoured-nation tariffs, on some products ranging from avocados to frozen pork.
Meanwhile, the cabinet on Sunday pledged to support private firms in oil and gas exploration and said it would widen market access in areas such as infrastructure and financial services.
Hot-rolled coil, used in cars and home appliances, rose 0.9% to 3,572 yuan per tonne. It jumped as much as 1.3% earlier in the session.
Shanghai stainless steel futures, for February 2020 delivery, gained 0.4% to 14,440 yuan per tonne.
Prices for spot cargoes of iron ore with 62% iron content for delivery to China fell by $1.5 to $93 per tonne on Friday.
The most-actively traded iron ore futures on the Dalian Commodity Exchange slipped 0.1% to 639 yuan per tonne.
Dalian coking coal futures fell 1.1% to 1,169 yuan per tonne, after customs data showed coking coal imports rose 16% to 6.18 million tonnes in November.
Dalian coke dropped 0.7% to 1,863 yuan per tonne.
The Ministry of Industry and Information Technology said on Monday China's industrial output is expected to grow around 5.6% in 2019.
Brazil's Vale SA said on Friday it was buying back a 36.4% stake in its MBR production and transport unit from asset manager Bradesco BBI for 3.3 billion reais ($804.41 million), more than four years after selling it.