Gases from heated green sands and two core sands were ana- lyzed in this study. The measured gases included the volume percent of 0_2, C0_2, CO, H_2, CH_4 and C_n H_m. Molten gray irons and heated steel bars were used to heat the green sands and core sands. Gases were sucked into sampling burettes and collected during the period of gas evolution. The measured gases showed a marked decrease in 0_2 to as low as 8 vol/100 in the early two minutes after sands had heated, followed by a gradual increase to about 20 vol/100 in six minutes. Sand ingredients, mulling time and the order of adding clay and seacoal were found to be significant factors in determining the volume percent of measured gases.
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