Petersen, Max S.2007-01-032022-02-032007-01-032022-02-03https://hdl.handle.net/11124/6250Date scanned: 2002-6-12.USBM #61646; Dorrco Sizer, lower section - treating fine iron ore. M. A. Hanna Company, Crosby, Minnesota. - M. S. Petersen - September 1945.Held in the Russell L. and Lyn Wood Mining History Archive, Arthur Lakes Library, Colorado School of Mines.Donor: United States Bureau of Mines.A sizer classifies rock materials and ore by particle size. The M. A. Hanna Company was one of the large mining companies that moved into the iron areas of the Lake Superior region in the early 1900s, consolidating smaller properties and engaging in exploration for other economic deposits. The Company was dissolved in 1965, then resurrected in 1985.Rights management statement available at: http://library.mines.edu/digital/rights.htmlM. A. Hanna CompanyIron mines and miningMineral processingScenes, interiorStillImage