Keramicalia

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

Asbestos

Keramicalia started with asbestos replacements in the 1980’s. A vast number of people and organizations have worked on this problem, and most of them spent a fortune and got no direct reward. Keramicalia had many successes, but the spinoffs from everyone’s work gave more than ample reward. I am not sure that going to the moon justified the cost, but certainly the technology spinoffs justified the cost. The first one was;

LAGGING: Insulag was developed to replace asbestos lagging. Mineral wool with galvanized cladding was the main competitor. Insulag wins when it comes to valves and joints and any irregularities or complications, mineral wool is cheaper for straight pipe sections.

ASBESTOS CEMENT: Keratuff 1 is the answer. It has the extreme strength, can be made into boards and pipes, is weatherproof and tough. It beats asbestos cement by having excellent thermal insulation. It can also be easily and safely cut with an angle grinder. It can also be plastered.

ARC CHUTES: We have done a lot of work on this flash heating application. Our work continues in partnership with an established asbestos cement board manufacturer. We have not yet reached the desired electrical insulation properties with board. However, we did try another approach with zirconium silicate, making complex arc chutes easily and cheaply. If an arc chute fails, you get an immediate result. If it works, it gets lost in the system and nobody can find it. We have some “Electricast ” arc chutes lost in systems, where they are hopefully still working.

SINDANYO BOARD: We cannot make this yet, but we still have some stock of 20mm thick square metre boards. Still made with asbestos. Our cement board is a substitute.

FABRIC: We have sold cloth under the name keratex for many years. The first ones were very poor. The present Keratex is good, 2mm thick with stainless steel wire interwoven for strength.

TAPES, SEALS and PACKINGS: We do not stock these, as the variety of products is enormous, and they are continually being improved. We can recommend and source them.

FINISHING PLASTERS: We supply Insulag indoors and Keratuff 2 outdoors.

CLADDING BOARDS: We can make a variety. We are still trying to make a true replacement for dense asbestos cement board.

No other fibres perform the same as asbestos but we supply several fibres which are adequate in different applications. They are:

Granulated ceramic fibre

Blown bulk ceramic fibre

Cardboard dust

Water dispersible fibre

Polypropylene fibre

RFT fibre.

Sometimes we use Textiles to get the reinforcing effect.

Keratex

Keratex is a woven aluminosilicate cloth, reinforced with fine nickel-chrome wires. Conventional refractory fibre blankets are either asbestos based or have organic material woven in. Keratex is completely asbestos free. Keratex contains less than 2% organic matter. It is very strong, flexible and light. Keratex can withstand 980°C. It is normally used as a screen for radiant heat from temperature sources much higher than 980°C, but the textile itself seldom reaches its temperature limit.

Keratex remains flexible at high temperature. It only breaks down slowly by abrasion. It does not shrink. It has very good chemical resistance. It is only attacked by hydrofluoric acid, phosphoric acid and strong alkalies. It is not affected by water and steam. Screens are not impervious, but stop most of the air flow through them.

Applications: Curtains to limit convection air flow at furnace doors. Curtains to separate different heat zones of furnaces or ovens. Screens to shield operators from radiant heat. Temporary screens for operators during gunning and hot repair. Protection of hot floors during gunning or other repair. Entrance and exit barriers in continuous heat treatment processes.

 Width: 980mm.   Roll length: 42m.

Strips can be stitched with thin element wire.

Keratuff 2

DESCRIPTION: Keratuff 2 is a structural insulating refractory. Insulation materials are normally only usable as a backing or with some kind of structural support.Keratuff 2 has sufficient strength to be a free standing structure. It has low permeability and is easily machined or cut when dried or fired.

APPLICATIONS: Electric kiln walls and element holders, crucible furnace lids, heat shields, masonry protection in charcoal ovens, aluminium launders, burner shields, machined components.

THERMAL CONDUCTIVITY:

200°C 0,2W/ mK
4000C 0, 2W/'mK
6000C 0,231W/!mK
800°C 0,28mK


MAXIMUM SERVICE TEMPERATURE: 1230°C. Shrinkage at 1200°C is 1,91.

DENSITY: 0,8 g/cm3 dry.

STRENGTH: 6 MPa at 110°C, 6 MPa fired 1200°c.

COMPOSITION: Contains Litefill and Hollofill synthetic aggregates and zirconia containing ceramic fibres.

PREPARATION: Add +40-5O1 water to the powder, mix well and apply it.

It can be vibration cast at +40% water. Water content is not critical and need not be measured.

Extensive mixing and trowelling improves the fibre dispersion and improves strergth. All particles are less than 1mm diameter. Setting time is about one hour.

COLOUR: Grey. Yellow when fired 1200°C.

PACKAGING: 10Kg in thick polythene bags.

PILOT PLANT CODE PGK.

Keratuff 1

DESCRIPTION:        Keratuff is a structural refractory insulation. Insulation materials are normally only usable as a backing or with some kind of structural support.       Keratuff has sufficient strength to be a free standing structure.

APPLICATIONS:      Precast pizza oven roofs, crucible furnace lids, heat shields, splash boards, aluminium launders, burner shields.

THERMAL CONDUCTIVITY:

200°C 0,19W/mK
4000C 0,23W/mK
6000C 0,25W/mK
8000C 0,28W/mK
1000°C 0,31W/mK


MAXIMUM SERVICE TEMPERATURE:  1200°C.           Keratuff melts between 1200°C

and 1300°C.    Shrinkage at 1200°C is 1,7%.

DENSITY:      1,0 dry, 0,85 fired.

STRENGTH:  23MPa at 110°C,        6MPa fired 1200°c.

COMPOSITION:       Contains Litefill and Hollofill synthetic aggregates, and

zirconia containing ceramic fibres.      53/o alumina.

PREPARATION:       Add +40 to +50% water to the powder, mix well and apply it. It can be vibration cast at +40% water, +50% is easier to apply by trowelling.   Water content is not critical and need not be measured. Extensive mixing and trowelling improves the fibre dispersion and improves strength.   All particles are less than 1mm diameter. Setting time is about one hour.

PACKAGING:           10Kg in thick polythene bags.

PILOT PLANT CODE:         OEV.

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.

 

Insulag

Insulag is a range of very light insulation materials. They are all asbestos free.

Insulag 2 is a white powder, which is mixed with water and trowelled or plastered.

It can be used up to 600°C continuous temperature, or as fire protection. Its thermal decomposition is highly endothermic, giving it very superior fire resistance.

Density is around 0.6g/cm³, depending on water addition.

Thermal conductivity is very low, about 0.2W/mK.

Setting time is around 20minutes.

Insulag 2 has no shrinkage below 600°C

After setting the material is easily cut, machined or sanded.

It will deteriorate if exposed to rain for long periods.

When used as pipe lagging or boiler plaster, no cladding is required.

Mix by hand in small quantities to desired consistency. It will stiffen as the plasticizer dissolves.  Add water as you work, but finish working it within 10 minutes of mixing.

Insulag 1 is the pourable version, for precasting.

Insulag 3 is an ultralight material used in composites.

Insulag 4 is a hard wearing insulation for flooring.

Insulag 5 is very easily removed can be re-mixed with water and re-used.    Used where insulation has to be regularly removed for inspection.

Insulag 6 is for cold/ cryogenic insulation. It contains expanded polystyrene in a non-flammable composition.

Insulag 7 is rapid setting insulation.

Insualag 8 is injectable insulation.

Insulag 9 is weather resistant insulation.

Insulag 10 is acid resistant insulation.