Manganese is an element essential for the sovereignty of modern societies, irreplaceable and consumed in large quantities by all industrialized and developing nations. Manganese has no substitute in its major applications. Of importance is that few nations produce relevant amounts of manganese – resources are large but irregularly distributed, with South Africa accounting for about 74% of the world’s identified manganese resources and Ukraine accounting for another 10%. Currently, the largest global manganese producers are South Africa, Australia, Gabon, and China.
An abundant and stable long-term supply of manganese is critical to the United States. U.S. resources of manganese are very low grade with high extraction costs, causing the United States to be totally reliant on imports. Unfortunately, there is no government stockpile of manganese. Additionally, U.S. manganese consumption increased by 20% in 2018 over 2017.
The combination of total import reliance, essential use in our industrialized society, lack of substitutes, limited sources of primary manganese ore, and the potential impact of supply disruptions has obligated the U.S. Department of Defense to declare manganese to be a Critical Mineral Resource. It cannot be disputed that trade wars and geopolitical tensions could limit the ability of the U.S. to secure necessary manganese resources in the future.
Beyond the basics above, what else should we know about manganese? Check out the 25 interesting facts below!
- Manganese compounds have been used since ancient times – the first utilization of manganese can be dated back to the Stone Age. Manganese dioxide was used as a pigment for cave paintings during the upper paleolithic period 17,000 years ago.
- The ancient Egyptians used manganese compounds to add color to glass.
- The presence of manganese in the iron ore used by the Spartans is a likely explanation as to why their steel weapons were superior to those of their enemies.
- In the first century AD, Pliny the Elder, the Roman author, described how black powder (manganese dioxide) was used to manufacture colorless glass.
- The first recognition of manganese’s existence as a distinct element was in 1740, when the German chemist Johann Heinrich Pott stated that pyrolusite (manganese dioxide) contained a new earth metal. Until then pyrolusite was believed to have been a compound of iron.
- Details of the first isolation of metallic manganese were published in 1770 by Ignatius Gottfried Kaim in a dissertation under the supervision of the chemist Jakab Jozsef Winterl. These were impure samples, however.
- At the beginning of the 19th century, both British and French scientists started to consider the use of manganese in steelmaking, with patents granted in the U.K. in 1799 and 1808.
- In 1826, Prieger in Germany produced a ferromanganese containing 80% manganese in a crucible.
- J.M. Heath produced metallic manganese in England in 1840.
- In 1841, Pourcel began industrial-scale production of spiegeleisen, a pig-iron containing a high percentage of manganese, and in 1875 he started the commercial production of ferromanganese with 65% manganese content.
- The major breakthrough in the use of manganese occurred in 1860. At that time, Sir Henry Bessemer was trying to develop the steelmaking process which was to bear his name. But he experienced difficulty with an excess of residual oxygen and sulphur in the steel. Robert Mushet suggested adding spiegeleisen after the blow to introduce both manganese and carbon and remove oxygen. This procedure made the Bessemer process possible, and thus paved the way for the modern steel industry.
- In 1866, Sir William Siemens patented the use of ferro-manganese in steelmaking so as to control the levels of phosphorus and sulphur. The demand for manganese dioxide increased because of the invention of the Leclanché cell in 1866 and the subsequent improvement of batteries containing manganese dioxide as a cathodic depolarizer.
- In 1912, manganese phosphating electrochemical conversion coatings for protecting firearms against rust and corrosion were patented in the United States, and have seen widespread use ever since.
- Manganese ore containing 20% or more manganese has not been produced domestically since 1970.
- The U.S. imports manganese primarily in three forms: manganese ore, ferromanganese, and silicomanganese. Major U.S. import sources of manganese ore from 2014 to 2017 were: Gabon, 74%; South Africa, 13%; and Australia, 8%. Imports sources of ferromanganese from 2014 to 2017 were: South Africa, 41%; Australia, 18%; and Norway, 14%. Imports sources of silicomanganese from 2014 to 2017 were: Georgia, 29%; South Africa, 26%; and Australia, 18%.
- In May 2018, the U.S. Department of the Interior, in coordination with other executive branch agencies, published a list of 35 critical minerals (83 FR 23295), including manganese. This list was developed to serve as an initial focus, pursuant to Executive Order 13817, ‘‘A Federal Strategy to Ensure Secure and Reliable Supplies of Critical Minerals” (82 FR 60835).
- Manganese is a metal with an atomic number of 25, an atomic weight of 54.94, a density of 7.3 grams per cubic centimeter, an ionization energy of 7.434 eV, and is located in period 4, group 7 of the periodic table.
- There are for different temperature dependant allotropes of manganese designated as alpha, beta, gamma and delta. The transformations occur at 700°C (973K, 1292°F), 1088°C (1361K, 1990°F) and 1139°C (1412K, 2082°F).
- Manganese melts at 1246°C (1519 K, 2275°F) and boils at 2061°C (2334 K, 3742°F).
- Manganese has 21 isotopes whose half-lives are known, with mass numbers 46 to 66. Naturally occurring manganese consists of its one stable isotope, 55Mn.
- From a chemical standpoint manganese is similar to iron.
- Manganese is the twelfth most abundant element in the Earth’s crust at 0.1% by weight. Manganese abundance in our solar system is at 10 parts per million by weight.
- Manganese is an essential trace element for all life on earth and important in photosynthesis. Without manganese, there would be no free oxygen on earth.
- Manganese is essential to iron and steel production for its sulfur-fixing, deoxidizing, and alloying properties. Although manganese is too brittle for structural use on its own, alloyed to iron manganese produces a steel with improved rolling and forging qualities, strength, toughness, stiffness, wear resistance, hardness and hardening ability. It also helps remove sulphur and oxygen contaminants from molten steel.
- Steelmaking, including its ironmaking component, accounts for most U.S. manganese demand, at approximately 85% to 90% of the total, with construction, transportation, and machinery end uses accounting for about 34%, 12%, and 11%, respectively, of manganese consumption on a manganese-content basis.