Treatment of a complex ore

Many complex ores are found in the West, which contain zinc in large quantities together with lead, copper, gold, and silver in sufficient amounts to yield a good profit could they be separated from the zinc economically, If such an ore were sent to the smelter to be treated in a blast furnace for the recovery of lead, copper, gold, and silver the smelter would penalize the shipper for all zinc over ten percent. On the other hand if the ore were sent to a zinc smelter for direct treatment there would be a penalty for excess lead present, and the shipper would receive no pay for the copper, silver and gold which it contains. The problem then is to separate the zinc from the balance of the ore, making the residue suitable for treatment in the blast furnace, and putting the zinc in a marketable form --page 1