(b)1 part by weight of vegetal carbon dust produced from beech wood with a particle size of 0-100 μm, | a4c0 | |
(b)1 part by weight of vegetal carbon dust |
a3c0 | |
(b)1 part by weight of vegetal carbon dust (beech wood) with a particle size of 0-100 μm, | a0c0 |