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Mining Industry

Case Study – Defoamer Project at Concentrate Thickener

Problem Statement

The client was struggling with foam at the concentrate thickener.

Solution

Watericon trialed a project to find the optimal dosage of defoamer at different parameters for the tough adherent foam at the thickener. Due to the fine grind, the nature of the foaming conditions as a result of reagents and dissolved air bubbles in the recycled water from the high-pressure filtration, the use of a defoamer alone may not be sufficient. The objective of this project was to;

  • Use defoamer to achieve complete foam knock-down or collapse
  • Use spray water to improve defoamer dispersion over the entire surface of the concentrate thickener
  • Use lime to improve settling rate of slow finer particles to achieve the desirable thickener overflow water clarity.
  • Assess the cost implication of adding lime to the thickener to improve clarity.

Innovation

Based on the measured suspended solids, there was a 90% relative overall improvement in thickener overflow clarity during the period on defoamer and lime.

Average O/F TSS was measured at 490mg/L for the OFF period and 50mg/L during the defoamer ON period.

  • The defoamer achieved a complete foam knock-down at 50g/t based on the milled tonnage.
  • The spray water improves the defoamer dispersion across the surface of the thickener
  • Lime acts as a coagulant and improves the settling rate of finer particles.
  • The addition of lime reduces the flocculant consumption.

 

This led to: 1.25T per month of Nickel concentrate losses ELIMINATED, leading to $27,000 additional revenue per month after costs. ROI = $324,000/yr.