Waste water from wet scrubbers used in cupola melting

3 Waste water from wet scrubbers used in cupola melting 

Wet scrubbers are in use in melting shops to clean the cupola off-gas. Wet serubbers use water to remove dust particles (average loading 10-15 g/Nm ) and gases sueh as sulphur dioxide from cupola off-gas. In the settling tank, a large part of the solid partieles are captured and thereby almost completely removed from the scrubbing water. 

The partly acid gases washed out of the cupola off-gas, such as sulphur dioxide, accumulate in the scrubbing water, causing its salt concentration to increase (e.g. the formation of e.g. sodium sulphate) and its pH to decrease. This salt accumulation is supported by evaporation losses, so it is necessary to draw the water off from time to time. 

Waste water from wet dedusting systems in melting shops mainly contains  

4 Waste water from the casting, cooling and shake-out area and from mould production/sand preparation 

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