Slide Nozzle and Slide Plate Description
Slide gate nozzle is the equipment installed at the bottom of steel ladle( or tundish) to control the flowing of liquid steel. Slide nozzle composes top and bottom nozzle bricks and top and bottom slide plates. Slide plate is the key component of slide gate nozzle. Slide nozzle has the advantages of easy and safe operation, reliable and accurate flow control, fast turnover of steel ladles, decreasing the consumption of refractory material. Slide nozzle has replaced traditional combined sleeve bricks, blockage bricks and nozzle bricks consisted flow control system and is the indispensible technique for steel liquid secondary refinery in ladle and tundish.
As steel liquid flowing control equipment, slide nozzle are divided into rotary and reciprocating type by structure, and it can also be divided into double layers and three layers slide plates with holes, the matched refractory materials are top and bottom nozzle bricks and pocket bricks.
Alumina carbon and alumina zirconia carbon slide plate
Slide nozzle is key equipment for continuous steel casting, and slide plate is the core component of slide nozzle, its working condition is harsh, so the technical requirements such as performance index, dimension, processing accuracy and quality stability of slide plate is very high. Material property and composition is the fundamental factors which will affect sliding plate’s performance and using effect. Sliding plate should endure steel liquid scouring, slag corrosion, thermal impaction, sliding abrasion and so on, so slide plate should have good high temperature strength, abrasion resistance, slag corrosion resistance, spall resistance.
Alumina carbon slide plates include sintered and unburned types. Unburned alumina carbon sliding plates is usually produced with small size. Sintered alumina carbon slide plates has excellent performance and can be used to make large size sliding plates. Alumina carbon slide plates have far better thermal shock resistance, spall resistance and corrosion resistance than high alumina sliding plates, especially for small size electric furnace, tundish alumina carbon slide plates have significantly longer service life.
Alumina Zirconia Carbon Slide Plates Properties
Alumina zirconia carbon slide plates use low expansion coefficient zircon mullite aggregate to improve thermal shock resistance and corrosion resistance. Moreover, fused zirconia corundum or zirconia can be added into the raw material to further improve slide plates’ performance, but the cost and price will be higher correspondingly.
Slide Plate Physiochemical Index
| Item | High alumina | Unburned Alumina Carbon | Sintered Alumina Carbon | Sintered Al2O3-ZrO2-C sliding plate |
| Al2O3 | 80 | 60-70 | 60-70 | 70-80 |
| ZrO2 | — | — | — | 5-9 |
| C | — | 5-6 | 6-12 | 6-12 |
| Apparent porosity % | 16-18 | 8-12 | 5-10 | 5-9 |
| Bulk Density g/cm3 | 2.7-2.8 | 2.8-2.9 | 2.8-3.0 | 3.0-3.2 |
| Compression Strength/Mpa | 60-100 | 40-90 | 80-120 | 90-160 |
| High temperature rupture strength/Mpa | 2-3 | 5-8 | 12-16 | 14-20 |
Slide Plates Applications
Unburned alumina carbon sliding plates are mainly used in small size steel ladles, and the service life is only one time. Sintered alumina carbon sliding plates are mainly used in middle and large size ladles, the service life is about 1-3 times. Sintered alumina zirconia carbon sliding plates are mainly used in large scale steel ladles and tundishes, the service life for large scale ladles is 3-6 times, the service life for tundish is about 4-8 times.
