Online cleaning method for accumulated slag on furnace cover of LF (Ladle Furnace)

The invention discloses an online cleaning method for accumulated slag on a furnace cover of an LF refining furnace. The method comprises the following steps: tapping after converter smelting; performing LF furnace refining, and performing operation and control at the stage: descending a furnace cover of the LF furnace to a position which is less than or equal to 50mm away from a molten steel tank opening; molten steel is electrically heated under the protection of argon, specifically, when the molten steel is heated to the temperature not lower than 1580 DEG C, the argon flow is reduced to be not larger than 50 NL/min, and the arc current is reduced to be 24,000-28,000 A; when white light appears in the heating area, heating continues to be conducted for 2-6 min, and then heating is stopped; c, adjusting the position of the electrode; and performing the next process. According to the invention, the accumulated slag on the furnace cover of the LF refining furnace can be cleaned on line from four times of manu