When constructing refractory bricks for steelmaking electric furnaces, the construction work should be carried out in accordance with the following specifications:
The furnace bottom should be staggered and dry-laid, and the fire brick joints should be filled with corresponding refractory powder. The longitudinal long seams of the upper and lower bricks should be staggered 30°~60°. The top bricks of the furnace bottom should be laid vertically.
The furnace bottom of the DC arc furnace should not have horizontal and vertical expansion joints. Other parts should have expansion joints as required.
The installation of the strip electrode at the furnace bottom should be vertical, and the vertical allowable deviation of its full height should be 0~1mm.
The thickness of the brick seam of the outer shielding brick of the strip electrode should not exceed 0.5mm. The adhesive between the two layers of shielding bricks should be evenly applied, and the upper and lower shielding bricks should be tightly combined.
The shielding bricks should be tightly combined with the strip electrode.
The cathode ramming of the furnace bottom should be supported by a mold. The contact part with the strip electrode shielding brick should be finely constructed, and the refractory ramming material in the groove part of the shielding brick should be dense and the joint should be tight. The construction of refractory ramming materials shall be carried out in accordance with the provisions of Section 4.5 of GB 50211-2014.
The refractory bricks of the slag hole shall be laid synchronously with the slag hole collar. A gap shall be left between the slag hole bricks and the collar bricks according to the design requirements. After the ramming of the furnace bottom working layer is completed, the gap shall be filled and compacted with refractory ramming materials.
The inner wall of the slag hole shall be kept flat, and the thickness of the annular seam shall not exceed 1mm.
The dry material of the furnace bottom working layer shall be rammed in layers, and the thickness of each paving shall not exceed 200mm. The furnace shape shall be controlled by a template during the ramming process.
The steel outlet shall be carefully laid and rammed, and shall meet the design angle.
When laying the furnace cover, the furnace cover ring shall be laid flat. The furnace cover bricks shall be laid with staggered seams, and the refractory bricks around shall be close to the furnace cover ring.
When refractory castable prefabricated parts are used on the furnace roof, the stacking, lifting, hoisting and masonry of the prefabricated parts shall be carried out in accordance with the provisions of Articles 4.3.14 to 4.3.18 of GB 50211-2014.
The masonry around the electrode port and its surroundings shall be carefully processed and masonry, and the diameter of the electrode port brick ring shall comply with the design requirements. The allowable deviation of the distance between the centers of each electrode port shall be ±5mm0
The furnace wall door bricks shall be laid within 1m to 2m on both sides of the slag port, and the upper and lower layer door bricks shall be staggered by 4 to 5 bricks. The width of the processed door bricks shall not be less than 2/3 of the original brick width.
When using dry materials as the furnace bottom working layer, a 1mm to 2mm thick steel plate shall be used for covering and protection after ramming.
