The major chemical factors are reagent type and
pH[1]. In practice, experienced human operators usually
maintain pH value at a moderate level in circuit cells to
improve separation efficiencies. They sample the pulp on
hourly basis to check pH value, in which frequent
adjustments are needed for the commonly utilized
reagents like collector, and depressant[10] which are
usually kept at a constant speed during stable period,
except when the fed ore type is changed. While other
operational parameters, such as the impeller speed and
aeration rate, are generally fixed for the stability of
industry process.