(1) It is applicable to all grades of metal;
(2) It permits of either high or low current-density
being employed;
(3) It permits the use of cheaper lead-lined wooden
tanks for working;
(4) Anode plates may be used without previous refining,
if so desired.
It is, however, general to carry out this preliminary refining, which
yields sounder anodes, keeps the electrolyte purer, and promotes the
more regular working of the electrodes and electrolyte—although some
smelters still cast the anodes direct from converter metal.