Harmfulness Assessment of Resins Used as Lustrous Carbon Carriers in Bentonite Moulding Sands

Abstract The assessment of harmfulness of two resins applied as a partial substitute of coal dust in moulding sands with bentonite - was performed in the paper. The emission value of compounds from the PAH and BTEX groups was assumed as the main harmfulness criterion. Also mixtures of the Kormix type prepared with additions of these resins were tested. Experiments were carried out in an argon atmosphere in a temperature range: 500-1300°. The obtained emission values of these substances were recalculated for 1% of lustrous carbon content in each carrier. It was assumed in the calculations, that the NW 1 and NW 2 carriers contain approximately 55% of lustrous carbon while the Kormix mixture approximately 15%. The critical temperature of forming compounds of the PAH group for the NW 1 carrier is 900°, while for the NW 2 carrier is 1100° (this is a temperature, at which the emission abruptly increases). In case of formation of compounds from the BTEX group the critical temperature for both lustrous carbon carriers is a temperature of 900°.