Grind Size & Liberation for Optimum Flotation Recovery

Grind Size & Liberation for Optimum Flotation Recovery

Here is a trick for knowing if your flotation feed grind size is fine enough to achieve adequate mineral liberation without doing a full mineralogy study.

  • If your key mineral is sufficiently liberated, it should float and be recovered in the first few minutes in an initial %mass that stabilizes quickly
    = the green curve.
  • If, your valuable minerals are still badly locked, the longer you float, the more %mass you pull, the more your recovery increases
    = the red curve.

Sadly, I have seen unsavvy “metallurgist” do recovery VS flotation time tests only to falsely conclude they needed more flotation time to get a higher metal recovery. Selective flotation is allowed by a minimum liberation level in which you maximize metal recovery in a minimum mass. Recognizing the partners can save you much needless pain.

Now I do not advocate unnecessary grinding, but you need what you need.  I have seen some misguided mineral processing souls claim you could compensate grind (purposely under design the primary circuit) with more flotation time/capacity.

How to Improve Flotation Recovery