The production process of ferromanganese can be broadly divided into two main methods: the blast furnace process and the electric furnace process. These two methods differ in terms of raw materials, equipment, and product types. Below is an introduction to both methods commonly used by ferromanganese manufacturers.
1. Blast Furnace Process
The blast furnace process is primarily used to produce high-carbon ferromanganese. Its working principle is similar to that of ironmaking in a blast furnace, using coke as both a reducing agent and a heat source. This method is suitable for large-scale, continuous production.
Raw Material Preparation:
The main raw materials include manganese ore (Mn content 30–50%), coke (fixed carbon ≥85%), and fluxes such as limestone and dolomite. The materials are crushed to appropriate sizes and proportionally mixed before charging.
Smelting in Blast Furnace:
The prepared charge is fed from the top of the blast furnace, while the hot blast stoves inject preheated air at 1000–1200°C. The combustion of coke generates high temperature and carbon monoxide (CO), which reduces manganese oxides in the ore. Simultaneously, the flux combines with gangue to form slag.
Product Separation and Tapping:
The molten ferromanganese and slag separate by density inside the furnace. The molten metal is tapped periodically, cooled, and crushed to obtain the high-carbon ferromanganese final product.
2. Electric Furnace Process
The electric furnace process uses electric energy as the main heat source. Depending on the carbon content of the product, it can be subdivided into the electro–carbon-thermal method and the electro–silico-thermal method. This process is mainly used to produce medium- and low-carbon ferromanganese, refined ferromanganese, and silicomanganese alloys.
(1) Electro–Carbon-Thermal Method
This method is similar in principle to the blast furnace process but uses an electric furnace instead of a blast furnace. It can produce high-carbon ferromanganese or silicomanganese alloys.
Key Features:
Utilizes closed or semi-closed electric furnaces.
Uses coke or anthracite as the reducing agent.
The electric arc between electrodes generates temperatures of 1600–1800°C, reducing manganese oxides in the ore.
Product Types:
Mainly produces high-carbon ferromanganese and silicomanganese alloys, offering greater flexibility compared to the blast furnace method.
(2) Electro–Silico-Thermal Method
This is the main process for producing medium- and low-carbon ferromanganese (carbon content 0.5%–2%) and refined ferromanganese (carbon content <0.1%). It uses silicon as the reducing agent to avoid introducing carbon into the alloy.
Raw Material Composition:
High-carbon ferromanganese (as the manganese source), ferrosilicon (as the reducing agent), and lime (as the flux).
Smelting Process:
Inside the electric furnace, silicon reacts preferentially with manganese oxides in the high-carbon ferromanganese, producing medium- or low-carbon ferromanganese and silico-manganese slag. The carbon content of the product can be precisely adjusted by controlling the amount of silicon added.
Key Advantages:
Enables precise control of carbon content.
Produces high-quality ferromanganese with low phosphorus and low sulfur levels.
Meets the stringent requirements of special steel grades.
The blast furnace process is suitable for large-scale production of high-carbon ferromanganese, while the electric furnace process offers better control and flexibility, especially for producing low-carbon and refined ferromanganese used in high-grade steelmaking.
DeDao Company is a professional manufacturer of ferroalloy products, specializing in metallurgical refractories such as ferrosilicon, ferromanganese, and silicomanganese. We offer stable supply and provide high-quality metallurgical products that meet your specifications. For inquiries or purchases, please email us at: wangwei@dedaoferrosilicon.com. We will respond promptly.
