Sydney-listed mining groups were taking a hit in Thursday trade as a drive to limit steel production in China during the winter continued to undermine demand for iron ore.

在悉尼上市的矿业集团的股价周四下跌，原因是中国在冬季限制钢铁产量的行动继续削弱对铁矿石的需求。

Shares in miner BHP Billiton were down as much as 1.7 per cent in morning trading, while rival Rio Tinto had dipped as much as 1.5 per cent. The materials segment of Sydney’s S&P/ASX 200 index was down 0.8 per cent while the broader index was flat.

矿业集团必和必拓(BHP Billiton)股价早盘下跌1.7%，而其竞争对手力拓(Rio Tinto)则下跌1.5%。悉尼S&P/ASX 200指数的材料类股板块下跌0.8%，指数整体表现平平。

Those falls came after futures contracts for key steel-making ingredient iron ore on China’s Dalian Commodity Exchange ended Wednesday down 1.3 per cent at Rmb434.5 ($65.93) per metric tonne, the lowest close in three and a half months. That was down 28.7 per cent from a peak of Rmb609.5 hit on August 22.

此前，炼钢关键原料铁矿石在中国大连商品交易所(Dalian Commodity Exchange)的期货合约周三收盘下跌1.3%，至每吨434.5元人民币(合65.93美元)，这是3个月以来最低的收盘价。这比8月22日达到的高点每吨609.5元人民币下降了28.7%。

Beijing has ordered heavily polluting industries that operate in the smog prone provinces of Hebei, Shanxi and Shandong to reduce output and curb emissions over the winter heating season, a period that runs from October to March.

北京严令河北、山西和山东等易受雾霾侵袭的省份，污染行业在冬季供暖季减少产出和控制排放。供暖季从头年10月持续到次年3月。

On Tuesday, benchmark Australian iron ore fines fell 4.1 per cent to a three-month low of $59.1 a tonne, according to a price assessment by The Steel Index, taking losses since the start of September to more than 20 per cent.

根据钢铁指数公司(The Steel Index)的价格评估，周二基准的澳大利亚铁精矿价格下跌4.1%，至每吨59.1美元的三月低点，自9月初以来其跌幅已超20%。