Medium frequency melting furnace production rate , melting period can be shortened to 35min left and right , to maximize the power of the furnace , must slag as fast as possible. Using slag skimmer or artificial , poor results, for a long time, poor working conditions. To this end , a method of pouring the slag back from the furnace is proposed , that is, the furnace body is tilted backward by 20-25 ° , and the slag is poured into the transport vehicle through the slot at the back of the top of the furnace body. This method is fast and convenient. After the intermediate frequency melting furnace is operated , it must be repaired. In order to shorten the furnace shutdown time of replacing the lining refractory , mechanized means must be adopted , and the vibration building machine and the lining machine are the main accessories of the large intermediate frequency melting furnace . The lining push-out machine pushes the lining refractory when it is not completely cooled , further shortening the furnace repair time and improving the working environment.