Manganese (Mn) is a brittle metal with silvery white color, which is an element arranged in subgroup VIIB of the periodical table of elements. Its atomic number is 25 and the atomic weight 54.938. It has II-, III-, IV- and VII-valence states in nature, of which II- and IV-valence states are more common.
Up to date, over 150 Mn-bearing minerals have been discovered. Among them, the following minerals are of industrial value and commonly seen in nature: pyrolusite (MnO2), psilomelane (mMnO?MnO2?H2O), manganite (MnO2?H2O), hausmannite (Mn3O4), braunite (Mn2O3), rhodochrosite (MnCO3) and alabandite (MnS).
Manganese and its compounts are employed in diversified fields of the national economy. The iron and steel industry is the major user, which consumes 90%~95% of the total Mn resources. The rest 5%~10% are used for other purposes, such as chemical, light, building materials, national defense and electronics industries, environment protection and agriculture and livestock husbandry. All in all, manganese is an important strategic metal in the national economy.
The Whitefield Mine in Tennessee, the US, is the earliest manganese mine in the world, which was first mined in 1837. India started its manganese mining as early as 1892 and the export of manganese ore ranked first in the world before World War I. This place, however, was taken by the former Soviet Union after 1928. Other countries such as Brazil, Ghana, Australia, South Africa and Gabon also have a fairly long history of manganese mining.jaw crusher supplier:http://www.hxjq-crusher.com/1.html
In China, the earliest Mn mine is the Yangxin Mine in Hubei Province. It was first exploited in 1890, but shut down shortly afterwards due to poor ore quality. The Xiangtan Manganese Mine in Hunan Province was mined in 1914 and then the Mugui Mn deposit in Guangxi, Hehua deposit in Jiangxi, Wafangzi deposit in Liaoning and Qixia deposit in Jiangsu were found and mined. According to incomplete statistics, during a period of 33 year from 1912 to 1945, 1.4 million tons of Mn ores were mined in total and the average annual output was 42,000 tons with the highest of 74,300 tons in 1927.
Large-scale geological prospecting and mining were launched after 1949 when the People's Republic of China was founded. Statistics show that totally 109 million tons of ores had been mined from 1949 to the end of 1997 and the highest annual output was 7.66 million tons (1996). The cumulative explored reserves were 664 million tons.