The most-traded January iron-ore on the Dalian Commodity Exchange ended daytime trading 0.3% lower at 732.50 yuan ($113.66) a tonne. It touched 717.50 yuan a tonne on Thursday, the weakest since February 4.
The steelmaking ingredient's October contract on the Singapore Exchange shed 0.4% to $129.15/t by 0703 GMT.
Spot iron-ore tumbled to a nine-month low of $131.50/t on Thursday, SteelHome consultancy data showed.
"iron-ore prices have had a volatile couple of months but as August closed, it was clear there had been a quantum shift in the market leading us to revise down our year–end forecast from $175/t to $125/t," said Westpac senior economist Justin Smirk.
China has vowed to limit crude steel output this year at no higher than its 2020 production to curb industrial pollution. But news of possible further restrictions rattled the market.
In Jiangsu, China's second-largest steel-producing province, a campaign to monitor energy consumption among industrial enterprises including steelmakers raised fears of further disruption in blast furnace operations, Mysteel consultancy reported.
Prices of metallurgical or coking coal, another steelmaking input, and its processed form - coke - retreated from a record-setting rally.
Dalian coking coal slumped 4.9% but was up nearly 13% this week. Coke tumbled 6% after a 20% jump in a nine-session advance.
"With the market closed to Australian coal, China has to source met coal from other producers and pay a massive premium to do so," Smirk said.
Rebar on the Shanghai Futures Exchange rose 1.3%, while hot-rolled coil advanced 0.4%. Stainless steel gained 0.2%.
