The olivine sand of the molten outlet duct of the electric arc furnace is formed as a result of the rotation of the slag furnace by 10-12 degrees, and at the final stage, the taphole valve returns, and when the filling sand is discharged, the molten discharge is carried out. If the filling sand does not come out, the oxygen blow is used to open the filling sand, which greatly affects the life of the taphole refractories and poses life risks for the operator, and the use of the oxygen lance is tried to be minimized. To measure the level of satisfaction with EBT sand, the opening percentage is defined. Considering that EBT sand is one-time use and is thrown away after each use, so about 2 tons of EBT sand sample is checked to check the level of satisfaction. In each use, depending on the size of the furnace, the volume of the tap hole chamber will be different, and usually between 15 and 25 kg of EBT sand are used in each step of filling the tap hole. Self-opening happens when the melt starts to drain from the furnace into the crucible as soon as the valves are opened. Depending on how many times the sand does not come out by itself after 100 melt discharges from the furnace and requires an oxygen lance, the opening percentage is determined.

after 100 melt discharges from the furnace and requires an oxygen lance, the opening percentage is determined.The self-opening of the electric arc furnace duct is determined by the correct efficiency of the filling sand of the discharge duct. One of the most important parameters affecting self-opening is surface sinterability of sand and reduction of wettability of sand by molten steel, and in case of no self-opening, oxygen blowing is used, which on the one hand reduces the life of refractories in the chamber and reduces the quality of the steel product, and on the other hand, it causes life and injury risks. It may enter to the operator. Alvin sand produced by Atlas Seram company, this defect has been minimized.