Precipitate Flotation II. Separation of palladium from platinum, gold, silver, iron, cobalt and nickel

Palladium is completely removed from 5 × 10−5 M‐PdCl2 solutions using the new technique of precipitate flotation of the second kind, in which no surfactant is used to float precipitates. Recoveries were best at pH 1–2 and were not markedly dependent on temperature. Increase in ionic strength had no deleterious effect, unlike conventional precipitate flotation. Palladium can be completely separated from a 400‐fold excess of nickel, a 100‐fold excess of platinum, iron and cobalt, a 10‐fold excess of gold but not from silver in the presence of chloride ions. Equimolar amounts of palladium, nickel and platinum were completely separated from each other by successive flotations. Photographs taken of the bubbles during flotation showed that, at a flow‐rate of 3.1 litre/hour, a mean surface area of 2.07 metre2 passed through the cell per minute.