The study considered the use of three powder samples of LS: two of them were commercial samples of lignosulfonates obtained from Sigma Aldrich (St. Louis, MO, USA), i.e., a sugared sodium lignosulfonate (NaLS) and a calcium lignosulfonate (CaLS); the third sample, a KLS, was prepared through sulphomethylation of kraft lignin and further precipitation from black liquor of a cellulose pulp plant that processed radiata pine. The procedure for precipitation of the KLS sample is explained elsewhere [3 (link)].
Distilled water with electrical conductivity of 20 μS/cm was used in all the experiments and pH was adjusted using sodium hydroxide (NaOH) obtained from Merck (Kenilworth, NJ, USA). Methyl isobutyl carbinol (MIBC) obtained from Merck was used as a frother in some experiments.
Distilled water with electrical conductivity of 20 μS/cm was used in all the experiments and pH was adjusted using sodium hydroxide (NaOH) obtained from Merck (Kenilworth, NJ, USA). Methyl isobutyl carbinol (MIBC) obtained from Merck was used as a frother in some experiments.