At present, for the internal pouring of the iron runner, the aluminum SiC carbonaceous castable for the blast furnace casting house developed by our company is made of high-quality dense corundum, brown corundum, bauxite, silicon carbide and carbon materials, a variety of organic and inorganic binders and additives. When using, it is only necessary to add a certain amount of water and stir it in the mixer before pouring. This kind of castable has fast setting time, strong resistance to erosion and erosion of molten iron and slag, good thermal shock resistance, small bulk change in reheat, no slag iron, strong anti-oxidation ability, easy construction and long service life. The castables used in the iron slag of the blast furnace casting house are mainly divided into main iron runner castable, iron runner branch castable, slag runner castable, slag skimmer castable, swing downspouting castable.
The construction technology:
- 1. Preparation before construction
- 2. All kinds of bagged castables will be transported to the site in time before construction, stacked according to the grades, marked, and protected from rain, water and moisture.
- 3. Prepare the excavator (including bucket, gun, and quick connector), mold, mixer, automatic cloth trolley, plug-in vibrating rod, pneumatic pick and other construction tools and their connecting parts and accessories to be delivered to the site before construction. Connect the power supply and debug.
- 4. The construction personnel will conduct safety training one day in advance, familiarize themselves with the site situation and clarify their respective division of labor and responsibilities.
- 5. Removal of residual ditch.
- 6. Main runner: Demolition with a gun machine must be carried out by a special person with a laser light to control the amount of dismantling. In principle, the metamorphic layer and the loose material can be removed, and the local manual is repaired with the wind. After the dismantling is completed, the dismantled waste is cleaned to the outside of the ditch by the excavator, and the residual powdery or small granular waste in the ditch is blown out of the ditch by the high-pressure air pipe, so that the wastes removed in the ditch are all cleaned up.
Demolition standard: the residual iron and residue will be removed and cleaned at the bottom of the ditch; all the white and grayish metamorphic materials will be removed; the loose material of the ditch wall will be removed; especially the drop point must be removed and in place. Not sloppy.
- 1. Branch iron runner, slag runner: After the gun machine cleans the slag iron, it is manually removed in principle, and the standard is removed from the main ditch.
- 2. Swing chute: Manually dismantled, the standard is removed from the main ditch.
When removing the residual ditch, pay attention to safety and prevent burns.
- 1. Preparation before pouring
- 2. Clean and rinse the mixer, cloth trolley and all other construction tools before mixing, and connect the mixer and the automatic cloth truck.
- 3.Apply a proper amount of mold release oil to the side of the mold, insert the round steel pipe into the upper part of the mold to reserve the original hole, and then hang the abrasive piece separately, then splicing or splicing it, and then hoisting into the cleaned main groove or branch groove, or slag ditch, or in the swinging groove, the steel pipe and the steel plate at the upper edge of the steel shell are welded together with steel bars to ensure that the construction process is inactive or not floating.
- 4. After the grinding tool is spliced, the rail is placed on the grinding tool and fixed. The cleaned mixer is placed at one end of the track, and the automatic cloth truck is placed on the rail, and then the mixing and pouring can be performed.
- 5.Pouring operation method
- 6. New trenches for new blast furnaces, the debris in the trenches should be removed before casting, and the permanent lining bricks should be wetted with water.
- 7. Put the bagged iron gutter into the blender, dry it for 1-2 minutes, and then add clean tap water as required.
Product Model | adding water volume % |
Iron Falling Position Castable(XPTG-N1) | 5.0—6.0 |
Main Iron Runner Castable(XPTG-N2) | 5.5—6.0 |
Iron Branch and Slag Castable(XPTG-N3,N4) | 6.0—6.5 |
Swing Chute Castable(XPTG-N5) | 5.5—6.0 |
When used on site, it can be increased or decreased according to the actual situation, and it can be discharged after 4-5 minutes of wet mixing.
- 1. Judgment of water content: Take a stirring material and squeeze it into a tight pellet. The diameter is 7.5-10 cm. The pellet is thrown about 30 cm high and then caught by hand. If the pellet is deformed and not broken, it indicates water content. Just if the pellet is deformed and flows out of the hand gap, it means that the water content is too much; if the pellet is cracked and scattered, it means that the water content is too small. Because the water content (water-cement ratio) directly affects the quality of the castable, it is better to minimize the water consumption under the conditions of meeting the construction requirements.
- 2. The stirred castable is placed in a groove outside the mold for casting vibration. When using a vibrating rod, the thickness of the paving should not exceed 1.25 times the length of the vibrating rod. The vibrating rod should be slowly inserted into the castable. When the surface of the castable is in a flowing state, the vibrating rod is moved. The moving speed is 1 -2 m / min, the moving distance of the vibrating bar should not be greater than 1.5 times the radius of action (the radius of action is generally about 20 cm), the speed of the vibrating bar should be slow when pulled out, and should stay for a few seconds when the head is close to the surface, The surface is smoothed, and the vibration duration of the vibrating bar at each position should not be too long, otherwise it is easy to produce segregation, and it is generally suitable to control within 4-5 minutes.
- 3. The pouring construction must be carried out continuously, and the secondary layer castable should be poured before the former castable is condensed. In special cases, such as mixer failure or crane failure, the interval exceeds the setting time. The surface of the poured material should be squashed and covered with plastic film to keep it moist for the subsequent pouring.
- 4. After the castable is applied, it can be demolded in 2-4 hours, and it can be baked for 12-24 hours after natural curing. In special cases, when the red groove is poured, the film can be removed in about 30 minutes.
- 5. Care should be taken not to damage the edges and surfaces when removing the mold.
- 6. Baking is the key link for the use of refractory castables. Its main function is to eliminate the free water and chemically bound water of the castables. When baked properly, the service life of the iron trench castables can be improved. Otherwise, the moisture removal is not smooth, which can cause cracks, peeling and even bursting accidents in the castable body. Baking is generally carried out in two ways: firewood baking and gas pipe baking.
- 7. If you use a gas fire pipe during baking, the gas fire pipe (baker) uses a steel pipe with a diameter of Φ50 and a length of 6 m, and a sting-out hole Φ3 is drilled around it. When the roaster is placed in the bottom of the main ditch, it shall be padded with refractory bricks and shall not be placed directly at the bottom of the ditch. Start with a small fire like a light, bake for 24 hours, then use a large fire and compressed air directly sprayed with the gas pipe, the nozzle is lining red in front of the nozzle, so baked for 72 hours. Each construction site is subject to actual conditions.
- 8. Baking curve
Main runner, iron runner branch, slag runner Castables
Fire Pattern | Temperature Range(℃) | Time Needed(h) |
Small Fire | <300 | 24 |
Medium Fire | <600 | 36 |
Large Fire | >600 | 36 |
The above baking temperature curve is a new infrastructure. The iron inner of the production cycle depends on the user requirements and production rhythm.