Manganese Alloy Production
Total world production of manganese alloys dropped to 11.7 million metric tons (mt) in 2009, down 18% from the previous year. China continued to be the world's largest Mn alloy producing country having produced nearly 6.6 million mt. It accounted for almost 57% of global output. The global economic recession caused a major drop in the demand for steel, which led to the decline in alloy production. Ultimately, 2009 was a year of global de-stocking and lean production.
Global production of silico-manganese (SiMn) in 2009 was just under 7.4 million mt, which was greater than the combined production of high carbon ferro-manganese (HC FeMn) and refined ferromanganese (Ref FeMn), their respective totals being 3.3 million mt and 1.0 million mt. SiMn is commonly used in the production of steel long products, critical components in the construction industry. Continued investment in infrastructure and in new urban real estate in fast developing countries, such as India and China, continue to fuel greater use of long products.
In 2009, the global unit consumption of manganese ferro-alloys (gross weight) continued to be approximately 10 kg alloy per mt of steel produced. This figure varies significantly from region to region with the differences related to the steel production process, the quality of raw materials used, (such as iron ore grades) and types of steel products produced.
Manganese ore production
Mn ore (wet) production decreased by 22% in 2009, to 35 million mt. This amounted to 11 million mt in Mn units, a year on year decline of 23%.
China was the largest producer of Mn units (2.7 million mt), followed by South Africa (1.9 million mt), Australia (1.8 million mt), Brazil (1 million mt), Gabon (956K mt), India (845K mt) and Kazakhstan (377K mt). Other countries produced 1.4 million mt.
World demand for manganese depends directly on the needs of the steel industry. There are numerous grades of steel and each requires a different amount of manganese. Unit consumption is determined by calculating the average requirement of manganese per ton of steel. Some manganese which is to be converted into steel is present in the iron (hot metal) coming either from the iron ore charge or from the addition of manganese ore to the blast furnace. This manganese is only a small part of the total requirement and it is partly oxidized during the different processes that convert the hot metal into steel. Hence most of the manganese addition is made in the steel melting shop. The majority of it is in the form of manganese ferro-alloys, but there are some cases when it can be added in the form of ore.
Part of the manganese is lost in the steelmaking process through oxidation. In the 1960s and 70s, when the oxygen-blown process progressively replaced the open hearth, Bessemer and Thomas processes, the subsequent improved manganese yield caused a decline in unit consumption. In the 1980s further improvements in steelmaking (brought about by the development of combined blowing processes) meant even better manganese yields. Today, the average unit consumption for industrialized countries is a little over 7.5 kg of manganese per ton of steel. Changes in steel grade chemistry have had an effect on manganese requirements. For a constant unit consumption, manganese demand follows the growth in steel production. Manganese requirements for other metallurgical applications or for non-metallurgical uses do not represent a quantity large enough to significantly affect the evolution of the overall manganese demand as a direct function of steel production growth.
International manganese trade has long been closely linked with the demand of industrialized countries in Europe, North America, Japan and South East Asia. In the early 1980s, a slowdown in steel production combined with a decrease in manganese unit consumption resulted in a decrease in the demand for manganese. This was partly compensated by new demands from China and CIS, all wanting to upgrade their own resources. These trends, added to the decrease in demand for ferruginous ore, increased the share of high grade ore in world trade.
Out of a manganese ore production of over 35 million tons in 2009, 15 million tons were declared as imports. China alone accounted for over 60% of these global imports. A few producing countries, Australia, Brazil, Gabon and South Africa, accounted for around 74% of the world's seaborne supply in 2009.
Today, most of the manganese requirements of industrialized countries are supplied in the form of alloys. In Europe, countries such as France, Norway, Slovakia and Spain have continued to be large exporters of Mn ferro-alloys. Other major exporting countries are China, South Korea and Australia in the Asia-Oceania region; the Ukraine and Kazakhstan in the CIS, South Africa, as well as Brazil and Mexico in the Americas. Japan, Russia and the USA all produce ferro-alloys as well but these are used primarily in domestic consumption. Mn alloys are also produced in smaller amounts in other countries, where they are usually consumed in that countries (or close neighboring countries) domestic steel production.
Manganese and Manganese Alloy Production
With the exception of Japan, where steelmakers developed about ten years ago the direct use of manganese ores, most of the manganese ore used by the steel industry is processed into suitable metallic alloy forms.
Manganese metallurgy is very similar to iron metallurgy except that a higher temperature (over 1200°C) is required for the reduction of manganese oxide. Standard (or high carbon) ferromanganese, which is to manganese what pig iron is to iron, is a very commonly used alloy. It contains more than 76% of manganese and about 7% carbon, and can be produced either in the blast furnace or in the electric furnace. Production world-wide was about 3.3 million mt in 2009.
Another high tonnage alloy is silicomanganese, which was first produced at the beginning of the 20th century, when calcium carbide furnaces were reconverted to produce ferro-alloys. The standard grade contains 14-16% Si, 65-68% Mn, with about 2% carbon. Lower carbon levels result when the silicon content is increased. Special grades with up to 30% Si are produced for use in the manufacture of stainless steel. World production of SiMn was about 7.3 million mt in 2009.
The steel industry also requires manganese alloys with less carbon than that contained in standard ferromanganese. For a long time these alloys, medium-carbon and low-carbon ferromanganese were both produced by a silicothermic process involving the reaction of silicomanganese and manganese ore, the latter generally being reduced to near-MnO state by heating. At present, however, medium carbon grades (1% to 1.5% carbon) are produced either in the ladle or in the converter. For a lower carbon grade, silicomanganese must still be used in many cases. About 1.0 million mt of medium and low carbon grades were produced in 2009.
Manganese metal was first produced by an aluminothermic process in 1898. Some commercial production took place in the early 20th century. The development of electrolytic manganese began on a pilot scale in 1940 and the first commercial-sized plant was built fourteen years later in the USA. The manganese is produced through the electrolysis of a sulphate solution and sold as flakes (which are the stripped cathode deposits) or as powder. In 1966, electrothermic manganese, with a purity between 93 to 98% Mn, was first produced on a commercial scale in France. The process uses high-silicon silicomanganese to yield extremely low carbon levels. Approximately 1.2 million mt of electrolytic manganese metal was produced in 2009, with China accounting for over 95% of production.