Breakdown characteristics of CO2 -Cores

Effects of sucrose, glycerol, nitrobenzene, silica flour, sodium chloride and calcium nitrate on the residual strength of silica-bonded and mixtures hardened by CO2 were studied to get an insight into the breakdown characteristics of such cores. The addition of glycerol, sucrose, silica flour and nitrobenzene and silica flour and nitrobenzene to CO2 hardened cores, impart collapsibility when the cores attain 600° c, nitrobenzene and silica flour impart collapsibility, the former being preferable. None of the additions were found satisfactory in the case where the cores attain a temperature of 1200°c. However it should be borne in mild that obnoxious fumes are evolved by nitrobenzene when specimens containing nitrobenzene are exposed to high temperatures.