Since July, only firms with import quotas have been allowed to bring in scrap copper from overseas, part of a broader curb on waste imports into China linked to environmental concerns.

Beijing's ultimate goal is to reduce imports of solid waste to zero by end-2020. With scrap metal accounting for around 10% of China's total copper consumption last year, the restrictions have led to fears of a shortage.

The metals association's recycling branch says the industry will submit new standards for high-grade recycled copper and aluminium - which would see scrap metal meeting them no longer classed as waste - to the Chinese government for approval this month.

It says they will be implemented as early as Jan. 1 and by the second quarter of 2020 at the latest.

"But actually there are still some technical obstacles," Antaike said in a note. "Whether or not (they) can actually be implemented is still unknown."

It is unclear to what extent the new standards will be accepted by China's customs and environment ministry and how soon, Antaike said.

With the current quota system for scrap imports set to continue into next year, two parallel import mechanisms could be in place for a time.

Material that does not meet the new standards will still require an import quota.

China has issued quotas for around 550,000 tonnes of scrap copper imports since late June and Antaike expects the allocations to gradually decrease from the second quarter of 2020.

Meanwhile, the volume of overseas scrap copper melted into ingots and imported into China has risen two- or threefold year-on-year in 2019, said Antaike.

It expects this growth to continue into 2020, with Africa, South America and Pakistan the main sources.

(Reporting by Tom Daly; Editing by Jan Harvey)