Low Carbon Ferro Manganese Production from High Carbon Ferro Manganese Slag

According to the carbon content, the ferromanganese can be divided into high carbon ferro manganese(C:7%approx), medium carbon ferromanganese(C:1.0-2.0%approx), and low carbon ferro manganese (C:1.0%max).

Low carbon ferro manganese is widely used in the steelmaking industry, foundry industry, and other industries. Compared with medium carbon ferromanganese and high carbon ferromanganese, it has higher economic added value.

The manufacturer uses the electro-silicon thermal method to produce low-carbon ferromanganese. The carbon content in the raw material ferrosilicon manganese reduces product quality and increases production costs.

In order to solve the problem, we explore a new way to produce low-carbon ferromanganese. Smelting high carbon ferromanganese by shaking ladle with ferrosilicon powder.

High Carbon Ferro Manganese Slag

The raw material HC ferromanganese slag is the by-product of carbon ferromanganese.

Shown in the table above:

• The high content of manganese oxide is conducive to its reaction in the shaking ladle.
• The alkalinity of the slag is conducive to its reaction in the shaking ladle.
• The shortcoming of the molten slag is that the temperature is lower about 1100℃.

Principle & Process of Low Carbon Ferro Manganese Production by Shaking ladle

Production Principle

The molten high carbon ferromanganese act with ferrosilicon powder in a 5m³ of shaking ladle.

2(MnO)+[Si]=2[Mn](SiO₂)

The application of the shaking ladle

• Expand the raw material reaction interface.
• Speed up the diffusion of ions.
• Thoroughly stir the high carbon ferromanganese slag and ferrosilicon alloy.

With the help of the sensible heat of high carbon ferromanganese slag and the heat of desiliconization, the reaction in the shaking ladle can last 8-10 minutes without heating, which reduce the power consumption and smelting time. Furthermore, this manufacturing process can produce low carbon ferrosilicon manganese with carbon content below 0.2% (Mn 65%-67%, Si 18%-20%).

Manufacturing Process

1. Pour the prepared molten high carbon ferromanganese slag into a shaking ladle, then add 1 ton of ferrosilicon powder (FeSi75%), turn on the shaking ladle and start the shaking process ( shaking speed 200-300 rpm).
2. As the reaction in the ladle intensifies, continue to pour a small amount of high-carbon ferromanganese slag into the ladle. (The liquid does not exceed two-thirds of the volume of the shaker, and the alkalinity is 0.9-1.0), increase the speed of the shaking ladle.
3. The shaking process last 5-20minutes, let stand for 2-3minutes. The alloy is poured into the electric refining furnace for smelting, and the slag is water quenched. At the same time, the molten silicon manganese is prepared in another shaking ladle, the manufacturing process is the same as the high carbon ferromanganese slag.
4. The silicon manganese alloy is poured into the electric refining furnace. Low carbon ferro manganese smelting completed.

To produce low carbon ferromanganese from high carbon ferromanganese slag, the following points should be paid attention to.

• Temperature: The temperature of the molten high carbon ferromanganese slag is one of the key points for smelting. In the absence of heating conditions, the thermal insulation of high-carbon manganese slag is very important. Firstly, cover the molten high carbon ferromanganese slag to avoid heat loss. Secondly, the submerged arc furnace and the refining furnace are released at the same time to ensure that the temperature does not decrease.
• Raw material: The molten high carbon ferromanganese slag should be more than 6tons in a 5m3 of shaking ladle. The addition ratio of ferrosilicon powder and high carbon ferromanganese slag is 1:8. The slag alkalinity is 0.8-1.2. The content of MnO in the slag is not less than 30%.
• Rotating speed: Slowly increase the speed in the early stage of the reaction. Adjust to the maximum speed immediately after the response is stable. Reduce the speed at the time of the shaking ladle to make a noise.
• Time: The action in the shaking ladle last 5-7 minutes. When the flame at the mouth of the ladle is dim, the amount of reaction gas decreases sharply, and there is small molten iron popping out of the ladle, the Perrin production process is finished.

The electric furnace high carbon ferromanganese slag has the features of a high ratio of manganese to iron, and low impurity content. It can be used as an electric furnace raw material of ferrosilicon manganese alloy.

Producing the low carbon ferromanganese from the high carbon ferromanganese slag, making full use of high carbon ferromanganese slag, improves the quality of low carbon ferromanganese, and reduce the production cost.