PURPOSE: To utilize industrial wastes as heat insulating material and slopping prevention material, etc., by drying ligneous chip dust, mixing powdery slag dust and then compressing.

CONSTITUTION: The chip dust, which is one kind or mixture selected among wood wastes, chip, chip dust, paper wastes, paper sludge, chaff, etc., is dried to ≤ 14% water content. Further, the slag dust contains blast furnace slag, electric furnace slag and also dust of electric dust collector in steel making plant, or its residual powder may be used after recovering iron and zinc therein. And the slag dust is effectively utilized to obtain high characteristic as the slopping prevention material and rise the specific gravity of the product at the prescribed value or more by mixing with the chip dust, and this slag dust is dried to ≤ 14% water content. After this slag dust is mixed with chip dust, they are compressed to make the pellet-like solid 1.