Two Construction Methods of Refractory Castable

A good construction method can help to save refractories, but many many people don’t know how to do it exactly, here are the construction methods of castable for ladle bottom and ladle wall.

Casting of Backing Layer for Ladle Bottom (construction time: 1 day)

    Firstly, fix Refractory Permeable Brick and Well Block, and then plug the inner hole with some resilient staff.

    Secondly, weld some anchoring nails in the middle area of ladle bottom between one well block and another, the vertical and horizontal distances between every two anchoring nails are 25 mm and 30 mm.

    Thirdly, mix backing layer castable for ladle with about 5% of water, and then stir it for about 20 minutes till smooth.

    At last, pave the mixed backing layer refractory castable at the bottom of ladle, and then vibrate it to 100mm in thickness by flat vibrator.

Casting of Backing Layer for Refractory Ladle Wall (construction time: 1 day)

    After maintenance of bottom permanent layer, stick a layer of high alumina fiber mat which is 10 mm in thickness with the ladle shell. Then place the mould right in the middle, flat, no deviation. The mould surface should be clean, smooth and greased for easy demould.

    Lay the mould properly to ensure that the gaps between mould and sidewall are the same, then pour the mixed backing layer refractory castable into the gaps, vibrate it by vibration bar till no bubble emerges (If mould is unavailable, cast working layer first and then permanent backing layer). The bottom of permanent backing layer is 100 mm in height; vibrate 300-400 mm per time, and its 90-100 mm in thickness, then one circle by one circle till to the top.

    After vibration of permanent backing layer, lift the refractory ladle to an area at higher temperature, so that it is convenient for water evaporation and drying of cast body. The time of demould should be more than 12 hours, usually 24 hours, specific time depends on lining harden situation.

How to recycle refractories?

In a word: Recycle the refractory materials by decomposing them.

The type of refractory materials used in a furnace differs by the position. All kinds of used refractories mixed together make it hard to keep good quality, so it is necessary to classify refractories before reusing them. They can be classified by magnesia, alumina, carbon-based, non-carbon-based.

In addition, for the dissimilar materials or iron mixed in, we can use some ways to pick them out, such as the method of magnetic separation. First, the used refractory materials should be crushed to 200mm~ 400mm, and then reduce to smaller than 20mm after impacting, compression or snipping, so as to be easy used.

For the refractories mixed with iron, we can use the way of electromagnetic separation, on the effect of magnetic strength higher than 12000 GS, making the content of iron in the used refractories with the size of 5~10mm less than 2%. While reusing the slit after crushing and after removal of iron powder as raw materials, we should classify them by particle size. The classification is generally done by using some metal mesh sieves, put the large mesh screen in the above and the small mesh screen under the large ones, keep continuously screening. In the process of crushing, grinding and classification, we should notice that not let the dust spread, sealing the device and recycling refractories in duster. The left dust also can be added to raw materials of landscape bricks.