DEFOAMER FOR SOLVING FROTH PERSISTENCE AND HANDLING ISSUES IN FLOTATION CIRCUITS

InterChem defoamers can assist sites with froth handling challenges

CASE STUDY – COMMERCIAL APPLICATION

The operators of a prominent Australian minerals processing plant sought technical assistance from InterChem to address long-standing issues relating to excessive persistent froth in several locations downstream of their flotation cells. Undesirable consequences of the excessive froth included (1) regular overflow events from the final concentrate hopper, which required hosing up to minimise losses of final concentrate, and (2) a thick layer of persistent froth permanently floating on top of the final concentrate thickener, which resulted in losses of contained valuable products by recirculation of the thickener overflow through the plant process water circuit.

Based on preliminary testing, two INTERFOAM^® products were found to be the most suitable for further evaluation in this circuit. Each defoamer product was tested in an on/off plant trial over several months. Each defoamer was dosed directly into the top of the final concentrate hopper, as well as into the final concentrate thickener feed well. Both defoamers performed well and were able to greatly reduce the presence of persistent froth throughout the circuit under normal operating conditions. However, INTERFOAM^® D 5900 was eventually selected as the preferred product by the customer as it demonstrated greater ability to handle process upsets and achieved better performance during periods with large variations in plant feed composition. Significant improvements resulted to overflow clarity in the final concentrate thickener from use of INTERFOAM^® D 5900. The product is now in regular use to overcome froth events in the circuit.