China plans to launch 100 new large-scale recycling "bases" by the end of next year, part of a campaign to make better use of its resources after extending a ban on foreign trash imports.

A long manufacturing boom has saddled China with millions of tonnes of waste, much of which is buried in sprawling landfill sites or dismantled by hand in polluting backstreet workshops. It has vowed to tackle the problem by creating fully industrialised recycling bases and cutting off foreign supplies.

"Large volumes of solid waste are already impacting and restricting the high-quality development of the industrial economy," the Ministry of Industry and Information Technology said in a policy document issued late last week.

It said 50 new "comprehensive utilisation" bases would deal with bulk solid waste and another 50 with industrial waste from sectors such as metals production, coal mining, construction, agriculture and forestry.

The bases will tackle waste with the biggest public impact, the ministry said, citing shared bicycles, packaging, batteries and solar panels as examples. They will also promote advanced technologies, products and recycling methods, it added.

Projects or companies approved to set up shop in one of these new bases can apply for special government funding, and China will also make use of new financing mechanisms, including green bonds, the document added.

China's recyclers have profited from waste shipped in from Europe and the United States, which is better sorted and therefore cheaper to treat than domestic material.

Imports reached 60 million tonnes a year at their peak, but the government has been steadily blocking shipments since 2017.

The initial 2017 ban on 24 types of imported waste, including plastic and paper, was extended at the end of 2018 to 16 new products, including scrap ships and automobile parts.

It said in December that it would also ban imports of more varieties of scrap steel, copper and aluminium from July, and another 16 products - including scrap stainless steel and titanium - will be blocked at the end of the year.

Total solid waste imports fell 48 percent on the year in 2018, and China eventually aims to block all imports that have readily available domestic replacements.

Many domestic recyclers have tried to move their facilities to Southeast Asia, despite tougher restrictions in Malaysia and elsewhere, and while some have started to switch to domestic feedstock, China still needs to do more to standardise and scale up the treatment of local waste.

"Some items just can't be imported anymore, including plastics ... but domestic waste and imports are handled by different people, and they are not part of the same system," said Wang Wang, secretary general of the China Scrap Plastic Association.