A method for optimising a mineral recovery process. A slurry 10 is fed to a conditioning step 20. The condition slurry 30 is then provided to a flotation circuit 40 to recover a concentrate 50. The remainder of the slurry is then rejected as tail 60 or passed for further processing. The present invention provides apparatus for analysing a sample stream 100 of the slurry. A sample stream 100 is provided to an analysis device 200 which treats the sample with an oxidising gas similar to the oxidative treatment 20. Several parameters are measured before and/or after the oxidative treatment of the slurry. The flotability characteristic of the slurry is then determined as a function of the measured parameter(s). The result is used to optimise mineral recovery. This apparatus can be used intermittently or continuously to provide on-going optimisation of the mineral recovery circuit.