| Description |
3 leaves, 1 plate : illustrations ; 28 cm |
| Summary |
"In the Joplin region are enormous piles of tailings, that for waste material, run very high in blende. This is due mainly to the temporary character of the mills which are built with more regard to low first cost than to receiving a high percentage of extraction. As a result we have some piles of tailings containing from 200,000 to 300,000 tons of materials that will average from about 2 to 3% zinc, and all crushed so as to pass through about #2 mesh"--Leaf [1]. |
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