Material is QT450
calcination
Heating furnace: take down the pressing iron put it back into the furnace waste. Switch on, slow temperature rise, heat insulation at 700-800 ℃ for a proper time, so that the crystal water in the raw materials for furnace building will completely disappear (about 6-8 hours).
Calcination: increase the output power to melt the waste in the furnace, then feed until it is full; then increase the output power to make the temperature of metal material liquid reach 1700 ℃ up down, then reduce the output power of high-quality marine castings for heat insulation heat preservation for about 1h to calcine. Then carry out slagging, deamination pouring for metal material liquid
Repair of charge
In the price manufacturing of silica sol casting, the furnace charge shall be inspected repaired continuously regularly: when the actual operation is continuous, before the cold furnace ignition, the rotary kiln, wall bottom shall be inspected in detail to see whether they need to be repaired. When the actual operation is continuous, the furnace condition shall be inspected every time when it is published; the service life of the furnace charge is generally 80-150 times up down (determined according to the smelting temperature materials)
Repair of furnace wall: generally, the cracks below 3mm need be repaired, the cracks above 3mm need to be repaired. First, remove the cracks neatly, then use the furnace building raw materials stained with sodium silicate to press smooth the surface.
Repair of tap hole furnace collar: vulnerable parts here need to be repaired before starting work. They are also repaired while smelting. The same refractory thermal insulation materials are used.
(Note: do use coarse magnesia for repair)