Surface-active bio-oil (SABO) solutions, prepared from vacuum pyrolysis bio-oil with a phenol-to-levoglucosan mass ratio of 4.8, was compared to pine-oil (PO) as foaming agent in the process of flotation of sulfured copper minerals. With the aid of 2³ factorial designs, regression models were obtained for % Cu in flotation concentrate (L Cu) and % Cu recovery (R), as functions of foaming agent-to-Cu mineral, collector-to-Cu mineral mass ratio and liquid-to-solid ratio (v/w). Experimental designs composed of a <IMG SRC="/img/revistas/bjce/v22n1/a01img01.gif">saturated design in its first half and a fold over <IMG SRC="/img/revistas/bjce/v22n1/a01img01.gif">design in its second half allowed to study the influence of flotation conditions on L Cu and R when SABO was the foaming agent. The factors selected were: particle size; pulp pH; flotation time; initial Cu content in the mineral (mineral type); liquid-to-solid ratio and finally SABO-to-mineral and collector-to-mineral mass ratio. Within the chosen experimental region only pulp pH affected significantly both responses. It is shown that high pulp pH, in the presence of minerals rich in Cu content leads to a significant increase in L Cu and R. Although SABO to mineral mass ratio is high compared to PO, it is considered that an optimization study on pulp pH should reduce this difference making SABO an attractive alternative to PO and a way to widen the field of applications of pyrolysis products.
Pyrolysis phenols; Bio oil
