MIBC (Methyl Isobutyl Carbinol), 100% laboratory grade, and
fresh Caltex diesel were used as frother and collector, respectively.
Commercial lignosulfonate D748 was supplied by Borregaard–
Lignotech USA and used in this study. The chemical properties of
the lignosulfonate was well characterized by Ma and Pawlik [19].
It was reported that the average molecular weight of the lignosulfonate is 45 kDa and the proportion of Na, total sulphur, sulfonate
sulphur, HPLC sugars, and Carboxylic groups in lignosulfonate is
7.0%, 6.5%, 6.2%, 1.0%, and 3.1% respectively. Fresh stock solutions
of lignosulfonate were prepared at a concentration of 1 g/L daily.