marked enhancement in foaming. At the high concentrations of frother
(50 ppm), and depressant (1000 ppm) the volume of the foam was
more than twice the volume of that when only frother is present. (Note
that the y-scales on Figs. 1, 2 and 3 are different). The structure of the
foam was far more homogeneous and no Polyederschaum type foam
was present in the column. The standard deviation of the results with
this carboxymethyl-cellulose depressant was also much smaller than in
the case of guar.