STRUCTURE AND PROPERTIES OF A MOLDED CARBON DERIVED FROM RICE HULL

Rice hull was moulded into a tube (outer diameter: 54 mm; inner diamet er: 17 mm, length: c. 170 mm) by use of an extruder and then carbonize d in nitrogen atmosphere below 1000 degrees C. Ash content of the hull was 16 wt%, of which c. 94 and 4 wt% were SiO2 and K2O, respectively. Carbon yield and shrinkage of the mould after carbonization at 1000 d egrees C were 42 wt%, and 43 vol%, respectively. The bulk density incr eased with rising of carbonization temperature to reach to 0.93 g ml(- 1) at 1000 degrees C via 0.82 g ml(-1) at 500 degrees C. The largest c ompressive strength of 3.6 MPa was obtained after carbonization at 100 0 degrees C. No micropore was developed after carbonization, and the t otal pore volume measured by a mercury porosimeter was 0.25-0.31 ml g( -1) after carbonization. These data were compared with those of charco al.