Waste water from core-making

In core-making shops, chemical scrubbers are in use. They use either acid (cold-box process) or basic (S02-process and Croning). The quantity of waste water discharged is dependent upon the accumulation of pollutants and salts in the circulating water. If pollution levels are too high, part of the polluted water must be drawn off. 

Scrubbing solutions from cold-box and hot-box core-making contain readily biodegradable amines and phenols. 

The treatment of amine-containing scrubbing solutions requires a nitrification/denitrification stage. These treatment steps can also be carried out in an external biological waste water treatment plant. An alternative to discharge is the recovery of the amines. 

Following oxidation, scrubbing solutions from the SO2 process mainly contain sodium sulphate. Since high sulphate concentrations ( 600 mg/1) can lead to damage to sewerage systems, a limit value is set by the respective competent authority according to local conditions (e g. the presence of sulphate-resistant piping and dilution with other waste water). 

In this section, techniques for environmental protection and energy saving measures are given for individual processing steps. The various techniques are structured into generic topics, which allows a thematic approach to be taken for assessing the various different foundry processes and steps. 

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