Keramicalia

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

Pourables

By "pourable materials" we mean materials which flow by themselves after mixing, until they reach a level surface.

  • Kerapour is a viscous insulation material which can be coaxed into highly inaccessible places.
  • The Kerapump range is often installed by pouring. Kerapump 1 is a high strength, very fast setting material.
  • Kerapump 2 is a very soft injectable material, mainly used in compensators, which can be poured.
  • Kerapump 3 is a general purpose insulation material. It is also used in moulding, for its good machinability.
  • Kerapump 6 is a dense andalusite pourable material.
  • Kerapump 7 is a very user-friendly injectable insulation.
  • Keratab Ultrafine is an alumina material used for very difficult castings, potting, and high temperature components.
  • Electricast is a zircon based pourable material for intricate electrical components.
  • Kerasic is a pourable silicon carbide material with extreme strength and abrasion resistance. Used for sintering trays, thermocouple sheaths, wire drawing sleeves and wear parts.
  • Keratab Fine Special high strength tabular alumina pourable with good thermal shock resistance.

Electricast

Description; A fine, creamy, self levelling hydraulic bonded, rapid setting castable. It is largely composed of zircon, a zirconium silicate mineral with exceptionally high electrical resistivity. Its main application is the manufacture of electrical components and "potting" applications. After casting it is quite soft and very readily machinable. Nornally it is prefired to 1200ºC, to give very high strength, but it can be used after firing to 400ºC. Strengths of up to 140 MPa have been recorded, using it in putty form with +6% water. Shrinkage on firing to 1200ºC is approximately 1% (With +9% water) Fired colour is buff to beige, unfired it is grey.

Maximum service temperature; 1300ºC.

Chemical analysis;

Al2 O3        21%
Fe2 O3          
0.1%
SiO2          
27.6%
MgO             
0.1%
ZrO             
46.7%
CaO            
4.2%
Na2 O         
0.1%
K2 O          
0.01%
P2 O5         
0.1%
Total
100.1%

Mixing; Add plus 9% water for pouring.

Applications; Element supports, leadouts, cuplocks, candle components, bobbins, nozzles, cloning of electrical components.

Packaging; 25kg plastic bags.

 

Kerapour

Description; Kerapour is a cellular insulation material. It has an exceptionally high strength to density ratio and can be used as a structural member rather than just a filler. It has very low thermal conductivity due to its very fine structure. Kerapour has very low permeability due to its closed porosity. Kerapour is very easily mixed to a pourable consistency with +32% water, and flows right into the furthest corners, self-leveling.

Temperature C.C.S Density Porosity P.L.C Conductivity
110oC 11.2MPa 1.1 50% 0%  
400oC 11.9MPa 1.02 -0.38% 0.28Wmk  
800oC 11.7MPa 0.99 -0.38% 0.34Wmk  
1000oC 12.7Mpa 1.06 61% -0.90%  
1300oC 18.0Mpa 1.07 58% -3%  

Note; From the above data it is clear that Kerapour is exceptionally stable.

Particle size distribution; Very fine; 90% -0,85mm

Chemistry; Aluminosilicate.

Installation; Use 1,1tons per cubic metre. Mix with +32% water and pour it. Mixing can be done by hand in a bucket.

Applications;: All insulation applications, especially where structural strength is an advantage, or installation is difficult or impermeability is desirable.

ISCOR pilot plant code; QJO

KERAPOUR DEMONSTRATION

1. FLOW

Mix 500g Kerapour with 160g water to give a highly viscous ball, which flows slowly but continuously, self-levelling. At this very viscous consistency the flow is most impressive. On a real installation, it can can be made wetter, to flow faster. After doing the demo. once, no need to weigh out the quantities.

2. THERMAL SHOCK RESISTANCE AND INSULATION

Take two crucibles. Put one upside down on a clearing at least 4m diameter, with no combustible materials nearby. Place the other crucible on top of it, upright. The lower crucible is to keep the demo. one away from splashes, which could burn you or make it difficult to pick up the crucible after the reaction. The splashes also heat the outside of the crucible if it is on the ground. If you only have one crucible, substitute a brick or something.Pour thermit powder into the crucible, about half full. Make a depression in the thermit powder and place in it either about a teaspoonful of ignition powder or push in a starlighter. Over this, place about half a teaspoon of fuse powder. Light the fuse powder with a match and move up-wind of it.The fuse powder gives off a lot of smoke, and lights the ignition powder/starlighter. The ignition powder generates intense heat and ignites the thermit powder. The thermit powder splashes sparks up to 1m away. It reaches a temperature of over 2000°C. Once the sparks have stopped for at least 6 seconds, pick up the crucible in your hands. The outside will still be cold, and remain so for at least half a minute. You can now pour out some molten steel, if there is a completely dry surface available. Give the crucible to the customer to hold.

The purpose of the demonstration is;

1. To impress the hell out of the customer.
2. To show that Kerapour can withstand a thermal shock of ambient to 2000°C in seconds without cracking.
3. To show how good cellular insulation is.
4. To prove that Kerapour can withstand super hot molten metal in a breakout situation.

Kerapour demo. crucibles are prefired to 400°C.

In the event of a burn from a spark, apply Bactrazine Flammazine ointment to the burn. (It has never happened yet in about 50 demonstrations.)

The demonstration is very impressive and frequently misleads the customer into considering Kerapour for high continuous temperature applications. Most of the applications which the customer now thinks of can be satisfied by Kerapour, Hollocast castable, Keratuff/Keratuff 2 plaster, or Kerapump 1 to 5.

Now that you have the customer's attention and interest, you will find him very communicative.

Kerapump

Pumpable materials can be installed into inaccessible places, or can be mixed far from the site of installation and pumped, usually a high vertical distance to their point of application.

All very fine materials can be pumped, but only carefully designed ones keep their volume after drying, without shrinking. Pumpable materials are not necessarily self-flowing materials.

The most versatile pumping materials are self levelling, insensitive to water addition, do not seggregate, and do not shrink. They may be strong or soft, dense or insulating.

The Kerapump range contains a variety of materials, mostly cellular insulation.

kerapump 1 is a high strength, very fast setting material.

Kerapump 2 is a very soft injectable material, mainly used in compensators, which can be poured.

Kerapump 4 is a medium strength cellular insulation material.

Kerapump 5 is a very light precision casting material for components traditionally made from Marinite or calcium silicate.

Kerapump 6  is a dense andalusite pourable material.

Kerapump 10  is a very user-friendly injectable insulation.

Kerapump 10

DESCRIPTION: A pourable or pumpable insulation refractory. It is extremely fine and can be used for precision cast and detailed components. It can also be machined.


MAXIMUM SERVICES TEMPERATURE: 1150°C
CCS: 110°C: 7-12Mpa
400°C: 10-15MPa
1000°C: 6-10MPa
1200°C: 15-25MPa


DENSITY: 1,15g/cm³


THERMAL CONDUCTIVITY: About 0,4W/mK at 600°C


Chemistry: Aluminosilicate cellular insulation.


WATER ADDITION: + 40% by weight.


APPLICATIONS:
Coke ovens pumping behind flashplates.
Blocking gas tracking.
Synthetic coals for gas fireplaces.

CHEMICAL ANALYSIS:

Al2O3 34%
Fe2 O3 1.0%
Cr2O3 0.04%
SiO2 37%
TiO2 1.5%
Ca2O3 16%
MgO 0.5%
Na2O 0.6%
K2O 1.3%
MgO 0.5%
P2O5 1%
   

PACKAGING: 10kg plastic bags

Kerasic

Description; Kerasic is alumina bonded silicon carbide. The main problem with silicon carbide is that it oxidises to silica. The alumina bond reacts with the silica to form a mineral called mullite, which has a needle like structure and imparts high strength, and has a melting point of 1850ºC. Kerasic is not as electrically conductive as other silicon carbide materials. Kerasic is a very fine grained material which can be poured like thick cream. Very detailed castings can be made with wall thicknesses down to 2mm. Plates have been made 300mm x 300mm x 5mm thick. The surface texture is very smooth, and the abrasion resistance of fired parts is excellent. The strength increases with repeated firing.

Cold crushing strength; 50 - 120 MPa

Chemical analysis;
Al2 O3      34.0%
SiO2           2.0%
SiC           58.0%
CaO           6.0%

Packaging; 25kg plastic bags.

Water addition for pouring; +12% vibration casting; +9%

Keratab Fine Special

Description; A self flowing self de-airing, fine tabular alumina pourable hydraulic setting ceramic.

Applications; Pipes, thin walled tubes, lead-outs, crucibles funnels, complex shapes, burner quarls.

Maximum service temperature; 1800°C

Maximum particle size; 0,5mm

Density; 2,85g/cm³

Strength;

Air dry;          35MPa

Fired 1200°C; 80MPa

Mixing; Add +9% water, mix for 2 minutes and pour. Pot life 12 minutesChemical analysis;


Al2O3
97%
CaO 3%

Al2O3   
97%
CaO      3%
SiO2        0.01%
B2O3         0.008%
Fe2O3      0.01%
Na2O        0.25%



Keratab Ultrafine

Keratab is range of refractory materials mainly for electrical applications, where it is in contact with elements. Keratab can be supplied tailor made for the exact application, between an ultrafine creamy pourable material for delicate components and a coarse robust castable. A plasticised material, "Induction Coil Coating" is also part of the range. All formulations are essentially based on aluminium oxide and contain over 90% Al2 O3 . The iron content is less than 0,1% and sodium oxide less than 0,3%. The usual operating temperature is around 1300ºC to 1400ºC, but it could be used safely at 1700ºC. The colour is white and the texture is fine with a smooth surface.

Thermal shock resistance; A slab can be heated with an oxyacetylene flame until it melts locally, without the slab cracking.

Applications; Element holders, element holding bricks, kiln muffles, tubes, electrical connectors etc. For small production runs of intricate components, a sample can be cloned in Keratab by the Multimould system.

Test results on Keratab Ultrafine:

CCS


Dried
40-60MPa
400oC 35-57MPa

1050oC
60-70MPa
1200oC 65-75MPa

(At +16% water addition; creamy fluid)