The briquette was prepared by the carbonation hardening method using waste filter aid and lime as raw materials. Carbonation of the briquette was completed in 6 to 12 hours, and the compressive strength of the briquette reached 25 MPa after 120 hours. The strength was increased not only by carbonation of lime, but also by crystallization of carbonated lime into calcite. The carbonation of the lime near the surface did not interfere with the carbonation inside the briquette, indicating that the carbonation progressed well into the interior of the briquette.
Toshifumi Ashida (Thu,) studied this question.