In evaluating the separation of coal from slurries of fine solids by froth
flotation, it is necessary to work to a standard method to ensure that the
procedure, on the same sample, can be repeated by others and the same resul
ts obtained. In a number of countries the standard procedure is produced an
d distributed by the International Standards Organisation (ISO) working thr
ough its member countries. In the preparation of a froth flotation standard
, two different techniques from two countries (Australia and Great Britain)
have been proposed. These procedures, known as the 'tree' and 'release' an
alyses respectively, differ in the laboratory technique and presentation of
results. In order to assist in the debate of which of the procedures shoul
d be adopted as the basis for the International Standard, a short programme
of comparative work was undertaken to evaluate the different methods. Samp
les of coal slurries from Australia, Great Britain and South Africa were ev
aluated using the Australian and British procedures.
The work undertaken is described detailing the preparation of the samples,
test procedures and differences between the two techniques. The results sho
wed that the two techniques produced similar results with the 'Release Anal
ysis' giving more detail at the cleaner (low ash) end of the curve and the
'Tree Analysis' more data for the middle (medium ash-higher yield) part of
the curve. The results indicated that the technique chosen would be depende
nt upon the information required from the flotation analysis, i.e, the Brit
ish 'Release Analysis' for the cleaner coal data and the Australian 'Tree A
nalysis' for higher ash fractions. (C) 1999 Elsevier Science Ltd. All right
s reserved.