Stamp Mill 911 Metallurgist
The depth of the charge was from 20 to 30 inches, and vacuum leaching was used. A depth of three feet of ungraded pulp was found to be unmanageable, and no attempts were made to separate the slimes. According to James, the cost at the Waihi Mill was stated to be per ton less for dry stamping than for wet stamping on the same ores.