Problem: How to remove 200,000m3 of 325 mesh goethite (pH 2.2 - 2.5 range; sulfuric acid) from a lined pond with dimensions of 120m x 253m. Since the material had settled and was resting on the pond bottom, dredging was selected as the appropriate removal method. No standard acid-resistant dredge was in production which would enable the the client to consistently feed a dewatering process down-line from the pond.
Solution: Crisafulli was selected based on Crisafulli's abiliby to desing and manufacture for specialized applications and experience in aggressive dredging environments, including caustic, corrosive and abrasive sites.
The Crisafulli 180P Rotomite Dredge was selected as the dredge of choice, capable of removing the customer's settled solids at a rate of 50 - 80 m3/hour. The dredge's hull and all wetted parts were fabricated of stainless to deal with extremely corrosive enviornment in which ot would work. Hig-grade acid resistant coatings were applied to all components above-deck which might be subject to incidental contact with the low pH material. The dredge's cutterhead was fitted with a protection system to prevent accidental penetrattion of the pond's liner.