These lagging materials are being used by institutions and enterprises in Pyongyang and Rason cities and various local areas and rural villages.

Marlstone is their main raw material.

Neither power nor equipment, except for additives, is required for producing those materials.

If institutions and enterprises introduce the lagging materials to their boilers and furnaces, they can lift the burning rate 97 percent while cutting down the coal consumption 30 percent as compared with that in the past.

If households in the countryside update firebox structures by use of those lagging materials, they can use peat as fuel for heating and cooking and produce quality compost.

The new kind of lagging materials is environmentally friendly as it helps reduce the emission of carbon monoxide.