Public domain
Anaconda smelter, Montana. Anaconda Copper Mining Company. Battery of Oliver filters. In these machines flotation concentrates are filtered from the liquid; from this operation the concentrates, which contain about twenty-six percent copper, go directly to the roasting furnace
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineAnaconda smelter, Montana. Anaconda Copper Mining Company. Battery of Oliver filters. In these machines flotation concentrates are filtered from the liquid; from this operation the concentrates, which. 1942-01-01. Lee, Russell. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.