The cell was a variation on the Partridge–Smith flotation cell [22], with air being bubbled through a frit at
the bottom of the column containing the mineral suspension. Fig. 1
shows the cell used, with a launder for the concentrate and a porous
frit at the base to allow the air to be dispersed.
55 ml of pH 9 aqueous solution (deionised water with the pH controlled
by addition of NaOH) was placed in the microflotation cell,
with 1 g of mineral sample (−75 μm size range; sieved from the original
sample). The air was introduced into the cell at a rate of 0.6 ml s−1
(36 ml min−1
) for 1 min and the concentrate was collected, filtered,
dried and weighed. The concentrate was filtered and dried to obtain
the mass of the floated mineral. This mass was used to calculate the
flotation recovery as a percentage