the activated carbon used for the air purification.   specification unit HPZ-04 secondary PQR secondary CTC  adsorption % > 100% > 75% > 100% > 80% Benzene adsorption % > 50% > 35% > 50% > 35% Iodine adsorption Mg/g 1100 800 1000 800 Surface area m2/g 1400~2400 1000~1300 1400~2400 1100-1800 Bulk density g/ml 0.33~0.38 0.33~0.40 0.33~0.38 0.33~0.38 Ignition temperature ℃ 400~450 400~450 400~450 400~450 Hardness % > 95% > 95% 70~90 50~70 Ash % < 6 5-8 < 6 5~8 Moisture content % < 5 < 5 < 5 < 5 Particle size mesh 3, 4mm 3,4mm 6× 8 20× 40