Electrolytic manganese metal: a strategic functional material for steel strengthening and new energy batteries

I. Core Definition of Electrolytic Manganese Metal Electrolytic manganese metal (element symbol Mn) is high-purity metallic manganese produced through electrolysis. Industrial-grade products have a purity ≥99.7%, with high-purity grades reaching over 99.99%. It has a density of 7.43 g/cm³, a melting point of 1244℃, and a boiling point of 2097℃. Its core value lies in its "strong alloying ability + excellent electrochemical performance." It can serve as a key alloying element in the steel industry, significantly improving the strength, toughness, and corrosion resistance of steel. It can also be used as a positive electrode material component in new energy batteries, optimizing battery cycle stability and energy density. Therefore, it is a strategic functional metal connecting traditional metallurgy and the new energy industry. II. Development History The industrial production of electrolytic manganese metal began in the early 20th century. In 1913, the United States first achieved large-scale production of manganese from manganese sulfate solution through electrolysis, initially mainly used in the smelting of special steels for military applications. From the 1950s to the 1970s, the expansion of the global steel industry drove the growth in demand for electrolytic manganese. Production processes were upgraded from flat-plate electrode electrolysis to vertical electrolytic cells, significantly increasing capacity and product purity. Leveraging its abundant manganese resources (accounting for 18% of global reserves and 65% of global production), China achieved large-scale production in the 1980s, gradually becoming the world's largest producer of electrolytic manganese. Since the 21st century, the "dual-carbon" strategy and the rise of the new energy vehicle industry have driven industry transformation. Research and development of high-purity electrolytic manganese (≥99.99%) and low-selenium electrolytic manganese has accelerated, and its applications in power batteries and energy storage batteries have continued to expand. Its strategic position has upgraded from "auxiliary raw material for steelmaking" to "core material for new energy." III. Core Characteristics Analysis

(I) Core Functional Characteristics
The core advantages of electrolytic manganese metal lie in its dual value of "alloy strengthening + electrochemical activity": As an alloying element, manganese can form a solid solution with iron, refining the steel grains and increasing the yield strength of steel by 20%~40%, while improving the weldability and corrosion resistance of steel, achieving a balance between "strength and toughness"; as an electrochemical material, manganese has multiple valence states (Mn²⁺/Mn³⁺/Mn⁴⁺), making it a key component of cathode materials for lithium batteries and sodium-ion batteries, improving battery capacity and cycle life, and its cost is only 1/10~1/5 of cobalt and nickel, combining performance and cost-effectiveness advantages.

(II) Physical and Chemical Characteristics
Pure electrolytic manganese appears as a silvery-gray metallic block, with a light brown oxide film (MnO) formed on the surface due to oxidation. It is relatively hard and brittle, and can be crushed into powder or processed into flakes or granules. It has moderate electrical and thermal conductivity (thermal conductivity 7.81 W/(m·K)), slightly lower than iron and aluminum. It is chemically reactive, easily oxidized at room temperature, and reacts with oxygen, sulfur, nitrogen, and other elements at high temperatures to form stable compounds; it can react with dilute acids to release hydrogen gas, making it suitable for electrochemical synthesis and battery reaction scenarios; it needs to be stored in a moisture-proof, sealed environment to prevent oxidation and deterioration. (III) Process Adaptability Characteristics Electrolytic manganese can be applied in various ways in metallurgy and materials manufacturing: in steel smelting, it can be directly added to molten steel in block or powder form, with uniform dissolution speed, suitable for converters, electric furnaces, and other processes; in alloy manufacturing, it can form multi-element alloys (such as aluminum-manganese alloys, zinc-manganese alloys) with metals such as aluminum, zinc, and magnesium, optimizing material performance through composition control; in battery material production, high-purity electrolytic manganese can be pulverized and calcined to convert into manganese oxides (such as MnO₂, Mn₂O₃), suitable for cathode material sintering and coating processes, exhibiting strong compatibility. IV. Mainstream Production Processes

(I) Manganese Sulfate Electrolysis (Mainstream Process)
This is currently the core process for global electrolytic manganese production, accounting for over 98% of global capacity. It uses manganese carbonate or manganese oxide ore as raw material and involves a four-step process: leaching, purification, electrolysis, and refining.
1) Acid leaching and dissolution: The manganese ore is crushed and reacted with sulfuric acid to generate a manganese sulfate (MnSO₄) aqueous solution.
2) Purification and impurity removal: Through neutralization, oxidation, and sulfidation processes, impurities such as iron, aluminum, and heavy metals are removed (impurity content is reduced to below 10 ppm) to obtain a pure manganese sulfate electrolyte.
3) Electrolytic deposition: The electrolyte is fed into an electrolytic cell, using a lead-silver alloy as the anode and stainless steel as the cathode, at 25~35℃ and a current density of 300~500 A/m². Under certain conditions, electrolysis produces manganese ions that deposit at the cathode to form metallic manganese plates; 4) Refining process: The electrolytic manganese plates are peeled off, washed, dried, and then crushed or sliced ​​to obtain the finished product. The purity of industrial-grade products is ≥99.7%, and high-purity products require additional vacuum distillation to ≥99.99%. This process is technologically mature and the raw materials are readily available, but the traditional process consumes a large amount of water (100~150 m³ of water per ton of manganese), resulting in significant wastewater treatment pressure. (II) Technological Upgrading Directions With the upgrading of environmental protection and "dual carbon" requirements, the industry is accelerating technological innovation: First, green smelting technology, developing a "membrane separation purification + closed-loop circulation" process, reducing water consumption per ton of manganese to below 30m³, and achieving a wastewater reuse rate of 95%; Second, green electricity coupling production, with enterprises in Hunan, Guangxi, Guizhou and other places introducing hydropower and wind and solar green electricity to drive electrolytic cells, reducing carbon emissions per ton of manganese by more than 60% and saving 400-600 yuan in electricity costs; Third, high purification technology, adopting a "deep impurity removal + vacuum distillation" composite process to produce ultra-high purity electrolytic manganese (purity ≥99.999%), suitable for semiconductor and high-end battery needs; Fourth, resource recycling, recovering manganese resources from manganese battery waste and steel smelting dust, developing an integrated "waste regeneration-electrolysis" process to reduce dependence on primary ore. (III) Exploration of Alternative Processes Currently, processes in the laboratory or pilot-scale stages include: 1) Manganese chloride electrolysis: using manganese chloride solution as the electrolyte, it has higher electrolysis efficiency, but the risk of equipment corrosion is high; 2) Direct oxide electrolysis: using MnO as raw material, skipping the leaching process, reducing energy consumption by 15%~20%, but still needing to overcome the bottleneck of raw material preparation; 3) Bioleaching: utilizing microorganisms to decompose manganese ore, suitable for low-grade ore, with significant environmental advantages, but the production cycle is long and it has not yet been applied on a large scale. V. Core Application Areas (I) Steel Industry (Traditional Core Area) More than 70% of electrolytic manganese worldwide is used in steel production, and it is a key alloying element for carbon steel, high-strength steel, and stainless steel. In high-strength rebar for construction, adding 0.8%~1.2% manganese can increase the yield strength of the steel to over 400MPa, reduce the amount of precious metals such as vanadium and niobium, and lower production costs by 5%~8%. In automotive steel (such as hot-formed steel and cold-rolled steel sheets), manganese works synergistically with iron and carbon to achieve a steel strength of over 1500MPa while maintaining good stamping formability. In stainless steel production, manganese can replace some nickel (1 ton of manganese replaces approximately 0.3 tons of nickel), reducing costs while improving the corrosion resistance of the steel, and is widely used in household appliances, chemical equipment, and other applications. (II) New Energy Battery Field (Emerging Growth Pole) High-purity electrolytic manganese is a core raw material for the cathode materials of lithium batteries and sodium-ion batteries, accounting for 25% of the demand in the battery field and continuing to grow rapidly. In lithium-ion batteries, manganese is used to produce ternary cathode materials (NCM) and lithium manganese iron phosphate (LFP) materials. Adding manganese can increase battery energy density by 10% to 15% and extend cycle life by more than 20%, making it suitable for power batteries and energy storage batteries for new energy vehicles. In sodium-ion batteries, manganese-based cathode materials (such as NaMnO₂) have become one of the mainstream technologies due to their low cost and high safety, driving the expansion of electrolytic manganese applications in the energy storage field. In 2024, the global demand for electrolytic manganese in the new energy battery field reached 180,000 tons, and it is expected to exceed 500,000 tons in 2029. (III) Other High-End Fields (Supplementary Scenarios) In the field of non-ferrous metal alloys, electrolytic manganese is used to produce aluminum-manganese alloys (such as 3003 aluminum alloy), improving the alloy's corrosion resistance and processing performance, and is widely used in aerospace sheet materials and food packaging materials; in the field of electronic information, high-purity electrolytic manganese is used to manufacture magnetic materials (such as manganese-zinc ferrite), suitable for electronic components such as transformers and inductors; in the chemical industry, manganese powder is used as a catalyst for organic synthesis reactions, and is used to produce products such as coatings and dyes; in the military industry, it is used to manufacture special steels such as armor steel and shell steel, improving the impact resistance of materials. VI. Market Development Trends (I) Rapid Demand Growth and Significant High-End Gap In 2024, China's electrolytic manganese production capacity was approximately 2.3 million tons, accounting for 65% of the global total, with a market size exceeding 20 billion yuan. It is expected that the average annual compound growth rate will remain at 12%~15% over the next five years, ranking among the top in the metal materials industry. Among them, the demand for high-purity electrolytic manganese (≥99.99%) is growing the fastest, with its share increasing from 15% in 2024 to over 35% in 2029. Currently, the domestic supply and demand gap for ultra-high purity electrolytic manganese (≥99.999%) is 30,000 tons, with an import dependency of about 38%, mainly relying on imports from Japan and South Korea. New energy vehicle power batteries and energy storage batteries are the core driving forces for demand. (II) Optimization of production capacity structure and restructuring of regional layout Global electrolytic manganese production capacity is mainly concentrated in China (Hunan, Guangxi, Guizhou, Chongqing), South Africa, Australia and other countries. Domestic production capacity is affected by environmental protection policies (such as the "Manganese Triangle" region rectification) and energy consumption control. Traditional high-pollution production capacity is gradually being phased out. Hunan, Guangxi and other places retain high-quality production capacity through technological transformation and upgrading, while Guizhou and Yunnan take over incremental production capacity with their advantages in hydropower resources, forming a coordinated layout of "resource production area + green power base". Industry concentration continues to increase, with the top ten companies accounting for 55.8% of the total capacity. Leading companies such as Hunan Yuneng, Guangxi Zhongxin Dameng, and Guizhou Hongxing Development have built competitive barriers through the integration of the "manganese ore - electrolysis - battery materials" industrial chain, while small and medium-sized enterprises focus on industrial-grade electrolytic manganese or niche alloy fields. (III) Green and low-carbon driven, technological innovation becomes the core barrier. The "dual-carbon" strategy and environmental protection policies are forcing the industry to transform, with green smelting and zero wastewater discharge becoming the bottom line for enterprises' survival. The policy requires that all production capacity that does not meet the energy efficiency benchmark (comprehensive energy consumption per ton of manganese ≤ 5800 kWh) and environmental standards be phased out by 2025, forcing enterprises to increase investment in technological transformation. The popularization rate of membrane separation purification, green electrolysis, and resource recycling technologies is expected to increase from 40% in 2024 to 75% in 2027. In the medium to long term, the research and industrial application of high-purity electrolytic manganese preparation technology, battery-grade manganese oxide synthesis technology, and waste-free processes will reshape the industry landscape, with the integration of "mineral resources - electrolytic production - battery materials" becoming the core competitive model. (IV) Price Fluctuations and Strategic Layout Electrolytic manganese prices are affected by multiple factors: fluctuations in upstream manganese ore (average price in 2024 was RMB 1350/ton, an increase of 18%), sulfuric acid, and energy prices directly affect production costs (manganese ore accounts for 40%~45% of total costs); downstream steel industry operating rates, new energy vehicle production, and energy storage policy guidance influence demand; environmental protection, green electricity policies, and export controls (China introduced a high-purity electrolytic manganese export quota policy in 2024 to ensure the supply of the domestic new energy industry chain) affect supply elasticity. Due to its irreplaceable role in the new energy battery and high-end steel industry chains, electrolytic manganese has been included in the key mineral lists of many countries, including China, the United States, and Europe. Enterprises are strengthening their manganese ore reserves (China's dependence on imported manganese ore is approximately 70%, mainly from South Africa and Australia) and aligning their operations with green energy, while simultaneously increasing investment in the research and development of high-purity products to overcome technological bottlenecks in ultra-high purity electrolytic manganese and battery-grade manganese materials, thereby enhancing their influence in the industry chain.