Electrolytic metal manganese is a simple metal obtained by acid leaching of manganese ore and then sent to the electrolytic cell for electrical analysis. The appearance is like iron, irregular flake, hard and brittle, one side is bright, the other side is rough, silvery white to brown, silvery gray after processing into powder; It is easy to oxidize in the air. In case of dilute acid, it will dissolve and replace hydrogen. When it is slightly higher than room temperature, it can decompose water and release hydrogen.
Electrolytic manganese (customs tariff No.: 81110010 unwrought manganese, manganese scrap and powder). The refining methods of metal manganese mainly include thermal method (fire method) and electrolytic method (wet method). The purity of thermal method (metal manganese) is not more than 95 ~ 98%, while pure metal manganese is prepared by electrolytic method (electrolytic metal manganese), and its purity can reach more than 99.7 ~ 99.9%. Now, electrolytic production has become the main way of manganese production.
Mn + H2O (heat) = Mn (OH) 2 + H2 ↑
Manganese is located before hydrogen in the electric sequence, so it is easily soluble in acid. Even acetic acid can dissolve it to release hydrogen and generate Mn2 + ions at the same time.
Mn + H2SO4 (dilute) = Mn SO4 + H2 ↑
3MN + 8hno3 (dilute) = 3MN (NO3) 2 + 2No ↑ + 4H2O
The purity of electrolytic manganese is very high. Its function is to increase the hardness of alloy metal materials. Manganese copper alloy, manganese aluminum alloy and 200 series stainless steel are applied. Manganese can improve the strength, toughness, wear resistance and corrosion resistance of these alloys.
Manganese and manganese alloys are one of the indispensable and important raw materials for iron and steel industry, aluminum alloy industry, magnetic material industry, chemical industry and so on.
Manganese is an indispensable additive in the smelting industry. Electrolytic manganese is the main raw material for the production of manganese trioxide after being processed into powder. The original magnetic material widely used in the electronic industry is produced with manganese trioxide. Electrolytic metal manganese is needed in the electronic industry, metallurgical industry and aerospace industry. With the continuous development of science and technology and the continuous improvement of productivity level, electrolytic manganese has been successfully and widely used in iron and steel smelting, non-ferrous metallurgy, electronic technology, chemical industry, environmental protection, food hygiene, welding electrode industry, aerospace industry and other fields because of its high purity and low impurity characteristics.
Main production areas of electrolytic manganese in China
In China's electrolytic manganese industry, the manganese triangle at the junction of Hunan, Guizhou and Chongqing is the concentration place,
Due to the early development and rapid development, manganese ore is in short supply in Xiushan and Songtao. In addition, the local government repeatedly collects resource compensation fees and charges dozens of yuan / ton out of the county. The ore price accounts for 1 / 3 of the cost of electrolytic manganese. The mines in Chongqing, Songtao and Western Hunan all have the phenomenon of indiscriminate mining and excavation. At present, only half of the reserves of tens of thousands of tons are left, and the resource recovery rate is very low, only about 50%. The phenomenon of mining rich and abandoning poor is serious, and the ore grade is reduced from 19% to 16%. However, Guangxi is rich in ore supply, and Daxin has 100 million tons of reserves, which is enough for decades.
Main influencing factors of price
The price of electrolytic manganese is mainly affected by the relationship between supply and demand, electricity and raw materials. Since the electrolytic manganese manufacturers are generally concentrated in the south, which usually rely on water conservancy for power generation, the wet season and dry season have a great impact on power, which is also closely related to the production of electrolytic manganese. Generally, there is sufficient rain from April to October every year, the power situation is good, and the production is normal. In other months, due to the power shortage caused by lower rainfall, the output of the factory will be reduced accordingly.
At present, the production of electrolytic manganese in China is mainly 99.7% of the products (now most manufacturers have actually reached more than 99.8%), and only a few manufacturers produce 99.9% of the products (because the market demand for 99.9% of the products is small, but many enterprises claim to produce 99.9% of the products when making the feasibility study report), The main raw materials manganese ore are manganese oxide ore and manganese carbonate ore. except that the liquid preparation methods in the previous process are different, the electrolytic production process is basically the same.
Manganese carbonate ore directly uses sulfuric acid and manganese carbonate to prepare manganese sulfate solution, and then prepares it as electrolyte through a series of processes such as neutralization, purification and filtration. After adding additives such as selenium dioxide and ammonium sulfite, it can enter the electrolytic cell for electrolysis; The process of producing electrolytic manganese by using manganese dioxide is different from that by using manganese carbonate. The main reason is that manganese dioxide does not react with sulfuric acid under normal conditions. It must be treated into divalent manganese and then react with sulfuric acid to prepare manganese sulfate solution. The treatment method is generally roasting method, which is to mix manganese dioxide with reducing substances (generally coal) and heat it in a closed manner, At a certain temperature, C reduces tetravalent manganese to divalent manganese and reacts with sulfuric acid after crushing. This method is called roasting method; Another method is called two ore method, that is, manganese sulfate is prepared by oxidation-reduction reaction between manganese dioxide ore powder and pyrite under the action of sulfuric acid. However, due to the high cost of these two methods, they are basically not used in the industry. Among them, the roasting method is more common than the two ore method. However, because the roasting furnaces used in many roasting production plants are simple and easy to manufacture but have high energy consumption and great pollution, the National Development and Reform Commission has explicitly banned the use of reverberators in the production of electrolytic manganese a few years ago.
Electrolytic manganese and stainless steel
In steelmaking production, electrolytic manganese is especially suitable for smelting "special, fine and high" alloy steels such as stainless steel, heat-resistant steel, precision steel, high-temperature steel and corrosion-resistant steel containing more than 10% of the total alloying elements, pure steels with low impurities and low harmful elements (∑ P, s, O, n, H ≤ 100ppm), purified steels (∑ P, s, O, N, H ≤ 200ppm). According to the output and consumption level of electrolytic manganese of special steel such as stainless steel, high alloy steel and high-quality steel in China, the smelting consumption of excellent special steel such as stainless steel in China was about 160000 tons in 2004; The consumption of chromium manganese stainless steel is about 80000 tons, and the excessive and abnormal consumption of chromium manganese stainless steel is 20000-30000 tons; The consumption of chromium nickel stainless steel, chromium stainless steel, heat-resistant stainless steel, precision alloy steel, high-temperature alloy steel, corrosion-resistant alloy steel and other excellent and special steels is about 50000 tons.
According to the macro development trend of China's national economy and iron and steel industry, in 2005 and even in the future, the stainless steel and other high-quality and special steel industries are in a rising time, the domestic stainless steel industry, production capacity, output and market demand are developing at a high speed, and the demand for electrolytic manganese in the smelting of high-quality and special steel products such as stainless steel remains strong on the whole. At the same time, as iron and steel enterprises further increase the structural adjustment, optimization and upgrading of steel varieties, the output of high-quality steel with high added value and high-tech content such as stainless steel and Youte steel will increase significantly in the future. There is no doubt that the consumption of electrolytic manganese in the smelting of high-quality steel will also have relatively large incremental space.
To grasp the development of electrolytic manganese industry, the situation of downstream manufacturers is naturally closely related. In addition to 200 stainless steel, electrolytic manganese is also used to produce special steel and high-quality steel, in which special steel can also use manganese ingot or cheaper high-carbon ferromanganese. The global production of special steel needs 70000-80000 tons of electrolytic manganese, about 10000-20000 tons of manganese for manganese aluminum alloy, about 50000-60000 tons of manganese for Mn3O4 and other magnetic materials every year. The global total demand is about 450000-500000 tons, and the domestic demand is about 150000-200000 tons.