Considering the action of frothers under degrading water quality

Abstract

The stability of the froth is known to strongly affect flotation performance. Literature shows that both frothers and ions reduce bubble coalescence, and stabilise the bubbles that form, resulting in greater froth stability. Considering both variables act on the froth in a similar manner, it is becoming increasingly important to understand how frothers behave under conditions of increased ionic strength. Increasing the frother dosage stabilised the froth and increased the recovery of water and solids but had no impact on the recovery of copper and only a slightly positive influence on the recovery of nickel, with a simultaneous decrease in the grades of both copper and nickel. Increasing the ionic strength also stabilised the froth which increased the recovery of water and solids, but both the recoveries and grades of copper and nickel were unaffected. Examining both variables simultaneously revealed that ionic strength was more influential than frother dosage in the recovery of water with the opposite being true for the solids recoveries. This means that a simultaneous increase in ionic strength and decrease in frother dosage by the same amount will increase the water recoveries and decrease the solids recoveries. Such an increase will also slightly decrease the nickel recoveries while having no effect on the copper recoveries. Overall, managing the frother dosage under conditions of increased ionic strength, while still maintaining flotation performance, is possible. However, depending on the water quality, the frother dosage can be managed, this needs to be tailored to suit the requirements of the plant. Therefore, this study investigates the interrelationship between frother dosage and ionic strength within the context of flotation.