Carbon Additive's Instructions

In-furnace injection method

Carburizer is suitable for use in induction furnace smelting, but the specific use varies according to process requirements.
(1) Carburizer is used in medium frequency electric furnace smelting. It can be added to the middle and lower parts of the electric furnace according to the ratio or carbon equivalent requirements. The recovery rate can reach more than 95%;
(2) If the carbon content is insufficient, adjust the carbon content. First, clean the slag in the furnace, then add carburizer. By heating the molten iron, electromagnetic stirring or manual stirring, the carbon is dissolved and absorbed. The recovery rate can be about 90%. If a low-temperature carburization process is used, that is, only a part of the charge is melted, and the temperature of the molten iron is relatively low, all the carburizer is added to the molten iron at one time, and at the same time, it is pressed into the molten iron with solid charge to prevent it from being exposed on the surface of the molten iron. This method can increase the carbon content of the molten iron by more than 1.0%.

Out-of-furnace carburization

(1) Spraying graphite powder in the bag
Graphite powder is selected as a carburizer, and the injection amount is 40kg/t. It is expected that the carbon content of the molten iron can be increased from 2% to 3%. As the carbon content of the molten iron gradually increases, the carbon utilization rate decreases. The temperature of the molten iron before carburization is 1600℃, and the average temperature after carburization is 1299℃. Graphite powder is generally used as a carrier for carburization, but under industrial production conditions, it is more convenient to use compressed air. The oxygen in the compressed air burns to produce CO. The heat of the chemical reaction can compensate for part of the temperature drop, and the reducing atmosphere of CO is conducive to improving the carburization effect.
(2) Use a carburizer when tapping
A 100-300 mesh graphite powder carburizer can be placed in a bag, or flushed into the tapping trough. After the molten iron is tapped, stir it thoroughly to dissolve and absorb the carbon as much as possible. The carbon recovery rate is about 50%.