5. Conclusions
The aim of the research was to identify the effect of two polymeric
depressants, namely the Stypress 504 modified guar and the Depramin
267 carboxymethyl-cellulose on the foaming properties of the Dowfroth
200 frother.
The study has shown that depressants indeed influence the foaming
and frothing properties of frothers in two and tree phase systems. Both
depressants enhanced froth formation, but the mechanism of action is
different. The Depramin 267 CMC depressant seems to act more through
increasing bulk viscosity, while the Stypress 504 guar has more
influence on the surface rheology.
The Depramin 267 significantly enhanced the frothability, defined
as the froth volume vs. the gas flow rate, due to increase in bulk
viscosity that resulted in slower drainage and inhibited coalescence.