Furnace treatment is an important step during molten aluminium
production by which the dissolved hydrogen and solid impurity
particles are removed. Conventionally, a chlorine/inert gas
mixture is used for this purpose injected into the molten metal via
a simple lance. In order to meet new requirements for furnace
emissions and improve efficiency, mechanical agitation through
an impeller is becoming more widely used. In this research, the
homogenization behaviour of both lance bubbling and mechanical
agitation by impeller has been investigated experimentally and
numerically. It can be concluded that under the same mean
specific energy dissipation rates, the velocity magnitude for
mechanical agitation process is about ten times bigger than that
for the lance bubbling process, and the mixing time for the
mechanical agitation process are much lower than that for the
lance bubbling process, so better cleaning or fluxing would be
expected
