Always Remember This: Fine Grinding Does Not Preclude LIMShttps://www.researchgate.net/publication/229038171_Processing_of_Magnetite_Iron_Ores-Comparing_Grinding_Options In thew above paper, they would not consider grinding down to 30 microns (And in some other papers down to 23 micron), if this small particle size could subsequently not be captured by LIMS. WIth some magnetite ores, a small particle grind size is important to get a "clean" , high quality concentrate.
And if this same 30 micron ground ore was passed through a Davis Tube, the recovery would be slim to nil. Clearly then, we need to view LIMS recovery as being significantly different from Davis Tube recovery.