The whole melting process of Consteel electric furnace steelmaking can realize continuous feeding. Before the start of each heat and scrap charge to the furnace, it can continuously preheat the scrap steel, pig iron and other metal materials by reversely discharging hot flue gas. In order to reduce the emission of flue gas and improve the utilization rate of thermal energy, the smelting characteristics are that the hotel steel retains a certain amount (usually 25t ~ 30t), and the amount of retained steel can improve the hot start speed of the next heats. The temperature of the molten pool in the whole smelting process is always maintained in the proper temperature range (1550 ° C - 1590 ° C) to ensure that the steel slag is in a constant temperature and strong decarburization boiling state, the composition is very uniform. At the same time, the smelting process can spray a certain amount of foaming agent (carbon powder) through the 0/C supersonic oxygen lance during the oxygen smelting to form foam slag. The foam slag can stabilize the arc and bury the heat deeply, and the electricity utilization efficiency can be greatly increased. Increasing, the foamed slag also has the effect of avoiding the entry of harmful gases into the molten steel, thereby improving the quality of the molten steel.
Consteel electric furnace steelmaking has many advantages. Compared with traditional electric furnaces and DC arc furnaces, its equipment condition and refining process have the following advantages:
1) The plant and equipment have a small footprint and can save investment funds.
The process can reduce the production scale and investment ratio. The plane design of the plant is “S” type. The layout of the workshop is reasonable and compact, and the production process is easy to organize. Compared with the DC arc furnace, the transformer capacity can be reduced by 35-40%.
2) Production costs are greatly reduced.
Due to the use of continuous preheating steel scrap for the smelting process, the process uses the whole process of foam slag operation, the electrode, power consumption, and refractory consumption are greatly reduced. In the case of conditional upper furnace hole opening with 30% molten iron, power consumption Can be reduced by more than 40%;
3) The concentration of slag (FeO) is greatly reduced, and the metal yield is significantly improved.
In the process of foaming slag smelting, the carbon slag spraying amount of foam slag is increased to about 10kg/t, and the metal yield from scrap steel to molten steel can be increased by nearly 1% (because the molten pool temperature is 1550 ° C ~ 1590 ° C, molten steel stirring) Very strong, the [O] and C] reaction in the steel is almost close to equilibrium, and the content of (Fe0) in the slag is very low, generally only 10 to 15%);
4) The gas content in the steel is low and the quality of the molten steel is improved.
When the raw materials such as scrap steel enter the molten pool, the hydrocarbons in the scrap steel in the presteel preheating section are basically completely burned, which can eliminate the [H] and [N] sources in the steel, and the foam is used in the refining process. The slag operation, which reduces the gas content entering the molten pool, so that the contents of [H] and [N] in the steel can be kept at a very low level. At this time, it is also violently reacted by boiling in the furnace, which is beneficial to the floating of inclusions in the molten steel, and can ensure good de-S and P-release effects;
5) Adaptability to raw materials is very strong.
The equipment can be applied to scrap steel, pig iron, cold or hot-loaded direct reduced iron ore (DRI) and hot pellets (HBI), hot metal and Corex sponge iron. If molten iron is added to the furnace, the amount of molten iron can reach 20 to 60%.
6) The treatment of flue gas is more reasonable and simple.
Because it has a long Consteel preheating section, the exhaust gas has been basically burned in the preheating section of the length of 2/3 of the electric furnace, which basically controls the release of CO, VOC and NOx.