Manganese production technology

Manganese production methods have Pyrogenic process and wet method. Pyrogenic process including silicon thermal power with thermo reduction, wet smelting is mainly the electrolytic route.

Pyrogenic process smelting, in the early stages of manganese production, once used silicon, aluminum or carbon reduction pyrogenic process, continuing to the present there are still applying. Silicon thermal method used widely, need to use electricity as supplementary heat source, its advantage is low production costs. Silicon thermal power can only obtain manganese metal that contains 95 ~ 98% of Mn. Thermite method can only obtain low-grade manganese metal that contains 85 ~ 92% of Mn.

Wet process smelting, which is manganese metal produced by electrolytic route called electrolytic manganese metal. It can be said that the current world produce manganese metal are mainly used electrolytic route, and pyrometallurgical method reduced the secondary. Electrolytic manganese metal is a costly method, the cost is always higher than pyrogenic process. Mainly due to: manganese is a high electronegative metal, the current efficiency is not high, modern production can only reach 60 to 68%; due to the high negative charge of manganese, it must use diaphragm electrolysis, cell voltage up to 5 volts; must be used MnSO4- (NH4) 2SO4-H2O system pure electrolytic solution, ammonia consumption is high, cleanup costs is high.

However, the following two important reasons which prompted this high-cost production of electrolytic manganese remains sustainable development: `Electrolytic manganese metal is the important raw materials used for preparing stainless steel, tool steel, alloy steel and non-ferrous alloys;a the low grade manganese ore of manganese carbonate or pyrolusite can be used as the raw materials of manganese production. The advantages of wet refining manganese are: high purity (99.8% in grade), also used for making special alloys.

Silicon thermal power was widely used, metal powder supplier in the USA, Japan, the Soviet Union were more using this method. China in the condition of lacking high-quality manganese, using three-step smelting method, the first step used manganese ore smelting low phosphorus low iron manganese-rich slag; the two step used manganese-rich slag smelting high manganese silicon alloy; Third step used manganese-rich slag as raw materials, high manganese silicon alloy as a reducing agent and lime as a flux to refine manganese metal. Advantages of this method in the smelting process, can remove a large number of iron, carbon, silicon, phosphorus, sulfur and other impurities, thus allow using poor grade ore. Products are containing up to 93 ~ 96% of manganese.

Because of electrolytic manganese metal with high purity, low impurity and low carbon content, mainly used in steel industry. The role of manganese in steel mainly in improving steel’s strength, hardness, elastic limit, wear and corrosion resistance, etc., mainly used for special steel and non-ferrous alloy elements, such as used for deoxidizer, aluminum manganese alloys and copper-manganese alloys in low carbon stainless steel smelting. Alloys due to the different manganese content make it with various characteristics, such as have high resistance and low temperature coefficient copper-manganese-nickel alloy (Mn11 ~ 12%, Ni3 ~ 4%, others are the Cu) and with high thermal expansion coefficient manganese-copper-nickel alloy (Cu18%, Ni10%, others are the Mn) and so on. Manganese is also used in chemical machinery, welding materials, high purity manganese salts, pharmaceutical, food packaging and newly developed vibration damping alloys and permanent magnet alloy elements. In recent years, electrolytic manganese metal in Japan is mainly for the aluminum industry and stainless steel.

Since jet metallurgical technology is developing rapidly, resulting in the application of powdered electrolytic manganese metal increasingly widespread. Producing 1 to 1.5% manganese aluminum-manganese alloy, in the 720 ~ 750 molten aluminum, can be directly injected manganese powder, replacing aluminum-manganese powder, replacing aluminum-manganese ball group, savings 60% cost. Produce special alloys such as jet engines, nuclear power industries super alloy, are required to use manganese powder injection smelting. The former Soviet Union in the development of particle metallurgy crashing the metal powder particles into less than 200¼m, it can be made metal parts which more dense than powder metallurgy.

Source:http://www.mhcmp.com