The blast furnace material is a dry type material composed of corundum, micro powder, and chromium oxide green. The construction site of the furnace material varies, and the construction method also varies slightly.
When tying the furnace bottom with furnace material, the thickness of the furnace bottom should be 280mm, and it should be filled and flushed in four times. When manually tying, uneven density should be avoided at all places. Therefore, the feeding thickness of the furnace material must be strictly controlled. Generally, the thickness of each time the furnace material is tied should not exceed 100mm, and the thickness of the furnace wall should be controlled within 60mm. The furnace material should be slowly rotated and shifted around the furnace, with even force.
When the furnace material is tied to the required height at the bottom of the furnace, it needs to be scraped flat before placing the crucible mold. The crucible mold is concentric with the induction ring, vertically adjusted up and down to closely connect with the built furnace bottom, and then the peripheral clearance is adjusted to be equal, and then clamped with a wooden wedge, and the weight is lifted in the middle to press on it, so as to avoid the displacement of dry materials when the furnace materials are knotted on the furnace wall.
When tying the furnace wall with furnace material, the thickness of the furnace material should be 110-120mm. The furnace material should be added in batches with uniform distribution, and the thickness of each addition of furnace material should not exceed 60mm until it is flush with the upper edge of the induction ring. After tying, the crucible mold does not need to be removed, allowing the furnace material to play an induction heating role during drying and sintering.
The baking and sintering process is roughly divided into two stages, which make the lining of the furnace material more dense and structurally stronger.
The first stage of baking the furnace material: heating at a rate of 50 ℃/h to 100 ℃, holding for 2 hours, heating at a rate of 100 ℃/h to 300 ℃, holding for 2 hours, with the aim of completely removing moisture from the furnace lining.
The second stage of sintering of the furnace material: heating at 200 ℃/h to 900 ℃, holding for 2 hours, heating at 100 ℃/h to 1200 ℃, holding for 2 hours, the first furnace of molten steel at 1400-1650 ℃, holding for 1 hour, controlling the heating rate to prevent cracks from occurring.
