Abstract
When 10-20 mass% of asbestos (chrysotile: Mg3Si2O5(OH)4)-containing cement board of 5 mm thickness was heated at 600°C for 2 h, the asbestos lost the crystal structure due to its dehydration reaction in the cement board, changing to an amorphous phase. Further, the heated cement board could be easily ground to grains with several μm size using a mortar. Then the asbestos seemed to be ground to below the size at the same time, because the fiber shape of original asbestos was not found in the sample.
