When Iron is Mixed with Gold

In a few placer operations with fine gold, where the black iron also carries free gold values, a different sheet has to be set up. Jigs are used to save this iron. The “hutch” product from the jig is set over concentrating tables to clean the iron. In a place like this a rag plant in front of the jigs and concentrating tables will scalp off 80 to 90 % of the free gold improved, with a very small quantity of iron and gangue saved on the carpet. This product from the carpet is washed on a small concentrating table. The table products are dried and put above the magnetic divider.

The jig table concentrate is ground and usually cyanided if the tonnage is large enough, or is fused if it is a small quantity. A different rag plant is used to keep the tails pending from both the tables and the jigs. The rag would not have to be cleaned as frequently as the rag plant ahead of the jigs, because most of the gold value has been scalped off. The product from this rag plant is handling the same way as the rag plant in front of the operation. On page 29 the word “insul” is used. This is a long refine term well understood by mining and milling men, but maybe needing more explanation. It maybe should be insol for insoluble. Gangue or pollution is another synonym.