Sawdust

coal gangue and paper sludge were chosen as pore-forming agents of sintered shale brick. The pyrolysis behaviors of different forming agents were studied and the influences of the agents on bulk density

compressive strength

porosity

and water absorption properties of the shale brick were also investigated. It is shown that

with the increase of the dosage of sawdust

pore number of the sintered bricks and water-absorption increase

while the volume density and strength fall rapidly. Thus

the dosage of sawdust should be controlled within 6%. Because of poorer plasticity and lower ignition of coal gangue as well as low porosity rate of sintered bricks

the water-absorption of sintered bricks is poor

and decreases of density and strength are not obvious. In practical production

according to the requirements of brick-making heat and plasticity

a moderate amount of coal gangue can be added. The plasticity of the bricks improves as the dosage of paper sludge increases due to its good plasticity. However

excessive dosage of paper sludge will result in large shrinkage of sintered brick

low strength and high water absorption; therefore

the dosage should not exceed 7%.