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Asbestos Replacements

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 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.

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% 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.


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.

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 strength. 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.


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.

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.


Textiles

There is a bewildering array of textiles out there. Keramicalia has tested a vast range of them, and reduced the range to those that work really well in mouldings. We do not manufacture any of them, but stock all the best ones.

Fibreglass Scrim: Ours is alkali resistant, those which are not can yield terrible disasters with cementitious binders. Plain weaves unravel too easily, our twill is more stable. The hole size of 10mm is optimal for most ceramic and cementitious applications.

Fibreglass Mat: Normal mats have limited flexibility. Our stitched mat can do complex curves. (Curved along 2 axes).

Polypropylene scrim: for alkaline binders.

Alumina fibre: Amazing stuff, see Keraline


Woven Ceramic Fibre: keratex is a composite with stainless steel wire incorporated.

Aerogel fibre: Super insulation in flexible sheets.

Non-woven Text

Ceramic Fibre Blanket needs no introduction.

Skin Safe is an amazing new mineral wool, in blanket attached to diamond mesh, or boards.

IT DOES NOT ITCH!

Ceramic Fibre Paper: we stock 1mm and 3mm.

We also stock carriers for Keraforce, from 17g/m2 to 150g/m2

Miscellaneous:

SFK: “one side corrugated” cardboard used in pipe and cylindrical furnace manufacture.

Stiff plastic sheet: used over casting formers for very smooth surfaces.

Carbon fibre: sometimes in stock.

Carbon felt

Graphite paper

Expanded Metal: for anchoring abrasion resistant material to steel sheet.

Hexmetal: for anchoring abrasion resistant materials to steel sheet.


Ceramic Fibre Blanket:

Alumino Silicate Spun Fibre Needled Blanket 

Description and Application:
Flexible needled ceramic fibre blanket made of long and large-diameter spun fibre. Good thermal stability and thermal shock resistance, good chemical stability and tensile strength, low heat storage and thermal conductivity.

Packaging : in cartons with plastic liner

Storage : in dry and weather proof stores

Health and Safety : refer to MSDS.

Get Expert Help Today

Contact Heat Consult to Explore Tailored Solutions For Your Refractory Projects

Contact:

+27 82 808 4757

dave@heatconsult.co.za

Contact:

+27 82 808 4757

dave@heatconsult.co.za

Contact:

+27 82 808 4757

dave@heatconsult.co.za