This section is from the book "Leaching Gold and Silver Ores. The Plattner And Kiss Processes: A Practical Treatise", by Charles Howard Aaron. Also available from Amazon: Leaching Gold And Silver Ores.
208. This is a simple brick lined rotating cylinder, not differing essentially from those described. It is however made of large capacity, as much as seven tons of ore being treated at once. A good feature in the make-up of this furnace is that the charging hoppers, of which there are two, are supplied by the foundry already mounted on iron supports.