Both Shanghai and London copper futures fell as concerns about China's cooling economy continued to dominate bearish sentiment.

The most-traded copper contract on the Shanghai Futures Exchange (SHFE), for October delivery, closed at 38,250 yuan ($6,159) per ton on Friday, down 430 yuan from Thursday. The October contract rose 130 yuan for the week.

The benchmark three-month copper contract on the London Metal Exchange (LME) closed at $5,235.50 a ton on Friday, down from $5,264 a ton on Thursday.

A total of 283,054 lots changed hands on the SHFE on Friday, 17,300 fewer than on the previous trading day.

Base metal prices were weaker. Copper gave back some of its gains from earlier in the week as higher stockpile levels, according to a research note sent to the Global Times on Friday by ANZ Banking Group.

Miners' output costs have dropped more than expected due to lower energy prices and weak emerging market currencies, according to a report from Reuters on Saturday, citing figures from Societe Generale. The figures suggested metal prices still have a ways to fall before any companies are forced out of business. 

Societe Generale puts the copper price floor at $3,469 a ton, 15 percent ­lower than industry consensus of $4,500, and 34 percent higher than current prices. 

This shows a sharp deterioration from a cost floor of $4,300 estimated in April.

The report comes amid mounting bearish sentiment toward metals in light of China's cooling economy, according to the Reuters report.

For other base metals, "Tin is the only base metal that has registered monthly gains in July," the ANZ note said. "The price rally in tin has been supported by declining exports from Indonesia, as the world's largest supplier restricts shipments."