The Central Mining Institute under the State Academy of Sciences succeeded in recycling fly ash piled at thermal power plants, thus paving a way to make use of slag as raw materials for fuel, building materials and fertilizer. And the Construction and Building-materials Branch under the Academy finished the research for making cement with fly ash and slag.

The City Management Research Institute put the production of a new kind of heat-insulating material on an industrial basis with scraps of polystyrene foamed plastic. The material was already applied to the reconstruction projects of the Pyongyang Grand Theatre and the Taedongmun Cinema House.

The Environmental Protection Institute under the Ministry of Land and Environment Protection invented a reasonable process of producing organic fertilizer with sludge in Pothong River.

Recycling wastes is regarded as one of important works at local industrial establishments.