Ann: Triple C Research Report, page-97

(Source: Manganese.org)
In the United States, there has not been any manganese mining activity since 1970. There are a few areas where it is possible to find manganese-enriched rocks (Maine and Minnesota), but the grades are substantially lower than what is available around the globe, so mining manganese in the United States does not make economic sense. As a result, the U.S. imports all of its manganese.
61% of the United States’ manganese imports come from **on. Australia is the second-largest provider of manganese to the U.S., with 21% of the total. South Africa (7%) and Brazil (5%) are the third and the fourth largest manganese exporters to the United States.
China, meanwhile, is the world’s number two producer of manganese and also one of its largest consumers. Demand for imported manganese ore in China more than doubled between 2006 and 2016. As of 2016, almost two-thirds (62%) of manganese ore in China was imported. The gulf between manganese production and consumption in China has been widening since 2001.