ASSISTANT MATERIAL FOR BUILDING MATERIAL COMPOSED OF WASTE WATER SLUDGE

摘要

PROBLEM TO BE SOLVED: To provide a porous assistant material for building material having uniform particle size, spherical form and high safety in use at a low cost by dehydrating a waste water sludge generated by the waste water treatment such as biochemical treatment and coagulating sedimentation treatment of domestic waste water and general industrial waste water and subjecting the dehydrated product to primary baking and secondary baking treatment. SOLUTION: Waste water sludge generated by the waste water treatment of domestic waste water and general industrial waste water is dehydrated to a water content of 60-80 wt.%, formed to prescribed shape and size, subjected to primary baking treatment at 300-800 deg.C to obtain a porous baked sludge granule having a number of fine pores to attain a specific gravity of about 0.24-0.7 and then subjected to secondary baking treatment in a rotary kiln maintained to 900-1100 deg.C while rotating the porous baked sludge granules. The composition components are fixed by the melting of silicon oxide to improve the infusibility and compression strength and the granules are formed to spherical form having uniform diameter.