Keramicalia

Tel: +27 (0)11 412 3261 or +27 074 587 2728 Fax: +27 (0)11 692 1232
We manufacture specialised refractories and ceramics.

Ramming

Ramming materials are not particularly user friendly, but we do make a few varieties.

Zircon ramming is an extremely dense material used mainly in the glass industry.

Permeable materials are very difficult to work with, and are mainly supplied as pre-built "porous plugs" or fluidised bed tiles.

Some of the Keraplas range of phosphate bonded chrome alumina materials are supplied in ramming consistencies.

Pyromould is pyrotechnic-refractory concoction that can be rammed in wet, ignited, and it burns dry in a few minutes, allowing metal to be tapped over it immediately afterwards.

Feranode

An alumina – carbon ramming material for use in D.C. arc furnacesmelting steel. Anodes for DC arc furnaces normally made of carbon ramming material , which is soluble in molten steel. Feranode contains 50% of tabular alumina part coarse, up to 10mm particles, and part fines, down to 20 micron.

The carbon is enriched with top quality natural flake graphite for enhanced electrical conductivity. The binder is chemically setting.

The rammed/ spiked density is 2,16g/cm²

Working time ; 45 minutes

Setting time; 90minutes

Heating can start immediately after ramming.  It does not soften when heated.  It gives less fumes than normal carbon ramming.

Shelf life: to be determined

Development No: 143903

Keraplas

KERAPLAS

Description Keraplas is a range of phosphate bonded Chrome alumina plastic materials. Compared to conventional phosphate bonded chrome-aluminas, the Keraplas range has appreciably lower shrinkage, which results in superior structural integrity.

Applications:

* Induction furnace repairs
* Metal splash shields
* Abrasion resistant linings.
* Sliding gate maintenance. Grades: "Patching" A fine (95% - 1mm) Highly plastic material for patching by hand, metal splash protection and abrasion resistant linings. "Capping" A coarse but highly plastic material for induction furnace capping. (95% - 8mm). "Ramming" or "Ladle" A dryish yet plastic ramming material for ladles, pouring boxes and sliding gate nozzles. (95% - 8mm)

Composition: The aggregate is tabular alumina: a high purity synthetic alpha alumina polycrystalline aggregate with good thermal shock resistance and excellent bonding properties. The matrix is alumina and chrome oxide, which sinter in a solid state reaction which results in ruby solid solution with negligible volume change. The binder is largely aluminium ortho-phosphate solution, which develops high strength at 100ºC. A complex series of dehydration reactions follow, culminating in a very strong anhydrous bond at 400ºC. The ceramic bond develops from 1000ºC, and rapidly above 1200ºC. Before the phosphate becomes pyroplastic, the chrome - alumina bond is well developed. Consequently Keraplas has very high strength over the whole temperature range from 200ºC to 1800ºC. Chrome oxide also imparts non-wetting properties.

Metal Protection: A sheet of expanded metal, heavy duty, such as Mentex 72, is bent and tacked onto the steel substrate such that it is positioned 10 to 15mm above the surface. Keraplas patching is then pressed into this continuous anchorage and hammered tight. The thickness is typically 25mm. This system is used in the following applications:

* The outsides of steel shells or structures which sometimes come into contact with pouring steel or ferroalloys. Eg.: Launder casings, especially upper edges. AOD hoods. Ladles with hoods. Bases of steel structures especially where silicon spillage is possible. Spincaster cover ends.
* Where occasional metal flow is expected yet there is insufficient space to apply conventional refractories: Eg.: Tundish overflows. Continuous caster emergency launders. Teapot ladle spouts. Handheld purging lances.
* Abrasion resistant linings where geometry is too complex for tiles. Eg.: nozzles.
* Abrasion resistant linings where the temperature fluctuation destroys tiles, Eg.: burner quarls, coke discharge chutes. See also: Keramor chrome alumina mortars Refractory paint, green.

Reinforcing
Keraplas can be made into pipes, by setting expanded metal; Mentex 72, about 10mm off theI surface. Keraplas Patching is pushed through the mesh and over it. It is prefired to 400ºC. It will develop cracks.

Zircon Ramming

Description; A fine zircon ramming refractory. It requires intensive ramming with a sharp pointed instrument, but gives very high density.

Chemical analysis;

Al2 O3 2.0%
Fe2 O3 0.2%
SiO2 32.0%
ZrO 61.0%
TiO <0.1%
CaO <0.1%
MgO <0.1%
Na2 O <0.1%
K2 O <0.1%
P2 O5 1.8%


Density; 3,7g/cm³.

Note; The standard sand rammer test will give a density of about 3,34g/cm³. To achieve full density, ram 400g 20 + 20 blows, repeated 3 times, to get a density of 3,7g/cm³ plus.

Packaging; 20kg plastic buckets.

Pyromould

Description: Pyromould is a mixture of refractory and pyrotechnic materials. It can be rammed into place, ignited, and it will be completely dry and hard within minutes.

Applications:

1. All applications where very rapid repair is required on refractories exposed to molten metal or slag.
2. Where pre-drying is difficult, eg. behind a brick lining of a ladle.
3. Ingot baseplate striker pads, where pre-drying is hampered by the mass of steel surrounding the striker pad. (Especially important for rimming steels). Installation; Pyromould is supplied damp, at a ramming consistency. It is rammed into place and ignited. It does not ignite easily; a spot of ignition powder is placed on the surface then fuse powder, which in turn can be lit with a match. Sulphurous fumes are emitted during combustion, and the area should be well ventilated.