Lightweight additive for building materials - produced from rubbish burning residue with addition of calcium ligninsulphonate plasticiser

摘要

Prodn. of additive for building materials by mixing dust from combustion installations with water and powdered calcium ligninsulphonate; granulating the mixt; preheating to 250 degrees C; sintering in a rotary kiln; and quenching, according to the Parent Patent is improved in that ground slag from a rubbish-burning installation (opt. with addition of fly-ash) is mixed with about 15% of water (5% of water can be opt. replaced by 5% of heavy oil/and about 5% of a calcium ligninsulphonate; the mixt. is granulated; the granules are preheated (pref. for 20 min); sintered at about 1100 degrees C (pref for 5-7, in) and quenched. Lightweight additive for building materials is produced in simple and inexpensive manner. The usually dumped combustion wastes are utilised. The granules have a porous inner structure, but a continuous outer layer. The heaping density can be 300 kg/m3.