Effects of electrolytic manganese residue (EMR) to co‐sintering mechanism of ceramic aggregate

Abstract

AbstractThe influences of co‐sintering temperature on the physical properties of EMR (electrolytic manganese residue) ceramic aggregate were investigated over the gradient of co‐sintering by EMR, CFA (coal fly ash), and P (perlite) that were used as raw materials. Seven EMR samples were prepared to sinter at different temperatures that were decided by the data of a thermal mass spectrometer, and four ceramic aggregate embryos were sintered at 1120, 1140, 1160, and 1180°C. The mechanisms of co‐sintering temperature action on performance were determined by means of X‐ray diffraction and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy. The optimal temperature of 1160°C and the temperature increment lead to an enhancement of cylinder compressive strength and a damping of 1‐h water absorption, softening coefficient, and grain shape coefficient was discovered. Gypsum of EMR dissolved and exhausted gas during co‐sintering resulted in CaO. The crystalline transformation of wollastonite and gehlenite produced anorthite, which boosts the strength of aggregate and the content of anorthite, was proportional to the co‐sintering temperature and the pressure strength of cylinder. The liquid phase of “overfiring”‐coated crystal contributed to the further improvement of strength, but the aggregate sphere deformation generated a reduction of comprehensive performance. The formation of bustamite calcian in co‐sintered ceramic aggregate realized the solidification of Mn, and the solidification rate of leaching toxicity test was 99.92%, and the absence of radioactivity was demonstrated.