ABSTRACT
Procedures have been developed to determine the volume, rate and composition (particularly BTEX: benzene, toluene,
ethylbenzene and xylenes and PAHs (polycyclic aromatic hydrocarbons)) of gas evolution from moulds and
cores prepared with various binders as a means of harmfulness of moulding sands. The rate of gas evolution from
green sands with four dif erent lustrous carbon carrier and BTEX content were determined. The gas evolution rates
are highest in the range of about 20 to 30 s after contact with molten metal. In practice during the i rst 200-250 s the total emission of gases generated in investigated samples occurred. The main emitted component from the BTEX
group was benzene.
INTRODUCTION
The assessment of harmfulness of moulding sand sapplied for casting moulds and cores concerns two basic problems:
• emission of harmful gases during the sands preparation, moulding, pouring, cooling and shakeout of moulds;
• leaching of dangerous substances into the environment from spent foundry sands e.g. during their storage or waste management.
Therefore, when assessing the infl uence of the given sand on the environment, these two problems should be taken into account. Only such investigations can provide the total assessment of the moulding sand harmfulness.
It is expected that the development of binding agents appliedfor moulding and core sands will be more of the
evolutional than revolutionary character. Changes will be mainly caused by more and more demanding requirements
within the environment protection domain.
http://www.pfa.org.pk/wp-content/uploads/2017/04/Harmfulness_of_moulding_sands_with_bento-1.pdf
