The slag tapping of the converter can effectively control the amount of slag under the ladle, reduce the return of phosphorus from the steel slag, reduce the consumption of deoxidized aluminum, reduce the cost of converter smelting, and achieve good metallurgical effects. After years of development, from the initial simple slag ball to the development The slag plug and the sliding nozzle automatically block the slag. specifically is:
1. Slag ball blocking slag
The slag ball slag is used to remove the slag ball above the taphole when the tapping is finished. The Metallurgy Slag Ball drops into the tap and blocks the slag from flowing into the ladle. The shape of the slag ball is spherical. The center of the slag ball is generally made of cast iron block, and the outer part is made of refractory mud. It can be made of high alumina castable or magnesium castable, and the density is generally 4.2-4.5g / cm3.
The slag ball is used to block the slag, the slag blocking efficiency is about 60%, the alloy yield is about 85%, and the ladle slag thickness is between 80-120mm.
2, pneumatic slag
The pneumatic slag is different from the radiation of the molten steel and the slag in the infrared frequency range. When the slag is present, an alarm is issued and the slag stopper is activated to perform the slag blocking operation. When the slag is blocked, the slag plug head mechanically closes the taphole, and the end part sprays high-pressure gas to prevent the slag from flowing out.
The pneumatic slag is used, the slag blocking efficiency is 60-70%, the alloy yield is about 90%, and the ladle slag thickness is between 70-100mm.
3, sliding nozzle slag
Slide Gate Ladle Nozzle is similar to the ladle sliding nozzle flow control system. The sliding nozzle slag blocking device is installed outside the converter tapping pipe body. It is automatically opened and closed by hydraulic drive system and automatic slag detection system control to achieve less slag and no slag. The purpose of tapping.
The sliding slag is used to block the slag, and the thickness of the slag under the ladle is less than 40mm, even up to 30mm.
4, slag plug slag
The shape of the Slag Stopping Plug is hemispherical, the reinforced bar passes vertically through the center, the lower outer refractory material acts as a guide bar, and the upper part is used for the holder to fix. In the later stage of tapping, the mechanical arm inserts the slag plug guide rod into the taphole, and the hemisphere is partially suspended at the interface between the molten steel and the slag. When the molten steel runs out, the hemispherical part blocks the taphole in time to prevent slag. Flow into the ladle. Because there is a diversion groove on the hemisphere, it can suppress the eddy current slag of the molten steel. When the slag plug body blocks the taphole, the residual steel can still flow to the ladle through the diversion trough, thus increasing the yield of molten steel.