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Pages in category "Manganese mines in the United States" The following 5 pages are in this category, out of 5 total. This list may not reflect recent changes .
The Chamberlain Manganese Deposits are located in north-central United States near Chamberlain, South Dakota. The Chamberlain Deposits represent one of the largest manganese reserves in the United States having estimated reserves of 2 billion tons of manganese ore grading 0.6% manganese metal. Although plentiful, the grade is so low in ...
The Maple Mountain mine is a mine located in the north-east of the United States in Maine. Maple Mountain represents one of the largest manganese reserve in the United States, having estimated reserves of 341 million tonnes of manganese ore grading 9% manganese metal. [1]
In 1917, three men—B.R. Jefferson, B. Edwards, and J. Marrs—discovered a manganese deposit with a high concentration of 20% to 40%. [6] Coinciding with World War I, open-pit mining operations began at the mine the same year, supplying the United States military with manganese for military equipment such as steel combat helmets.
Manganese exposure in United States is regulated by the Occupational Safety and Health Administration (OSHA). [116] People can be exposed to manganese in the workplace by breathing it in or swallowing it. OSHA has set the legal limit (permissible exposure limit) for manganese exposure in the workplace as 5 mg/m 3 over an 8-hour workday.
The mineral manganese was used in the production of steel. Mining at Crimora continued intermittently under a series of owners until March 1946. The Crimora deposit is about 500 feet wide, 200 feet deep, and half a mile long and consists of clay with scattered lumps of manganese ore.
This list of mines in the United States is subsidiary to the list of mines article and lists working, defunct and future mines in the country and is organised by the primary mineral output. For practical purposes stone, marble and other quarries may be included in this list.
The Milford Mine produced high manganese-content iron ore [2] in Wolford Township, Minnesota, United States.On February 5, 1924, it was the site of the Milford Mine Disaster, the worst mining accident in Minnesota history, when it was flooded by water from a nearby lake, killing 41 miners.