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We manufacture specialised refractories and ceramics.

Hollocast 1

Description; Hollocast is a refractory castable with a high insulation value yet high strength and resistance to thermal cycling.

Composition; Hollocast has a very fine microstructure and low permeability, yet the total porosity is 40%. The porosity is largely in the form of minute hollow alumino-silicate spheres of "Hollofill."

Physical properties; Hollocast mixed with +18 to 21% water gives the following properties after firing to 1300°C.:

C.C.S;: 20MPa.

Bulk density: 1,6g/cm³ (S.G. 2,75)

Total porosity 40%

Permanent linear change: -0,8%

Thermal conductivity:
200°C      0,49W/mK
400°C      0,5 W/mK
600°C      0,52W/mK
800°C      0,55W/mK

Applictions; Replaces all traditional "semi-insulation" materials; Hot face linings for ladles to reduce sculling. Soaking pit roofs, especially where Detrick bricks are used as anchors. Any roofs where a weight saving can reduce the structural support system. Brick kiln roofs. Insulation applications which are subjected to mild abrasion. Heat treatment bogeys. Intricate kiln furniture. Places where access is limited or difficult. High thermal shock applications. Aluminium launders, ladles and holding furnaces.

Installation; Mix with about +19% water to +23% water and place by pouring

DO NOT VIBRATE, it will cause segregation and failure.

Pilot plant codes: OTO OZW and PGJ



Hollocast 1 Incinerator lining after 2 years of installation


Clean out ladle completely. Fit well block and purge cone seating block with mortar. Cover sides of well block and seating block with cardboard and wrap with buff tape to leave gap for ramming. Cover top of well block and seating block with cardboard or a lid of some sort. Make mark on a trowel or stick to measure required floor thickness. Place a pan mixer next to the top of the ladle and make a discharge chute to pour directly into the ladle. Remove the ladder from the ladle. Weigh out or measure in buckets, 32 litres of water. Place 8 x 20kg bags of Hollocast in the mixer. Start the mixer and dump all of the water rapidly into it. Mix for about 20 seconds and then add a further 4 litres of water to bring the mix to a very fluid consistency. (+22,5% water). Open mixer gate and discharge the whole mix directly into the ladle. Place the ladder back in the ladle, go down and check the thickness of Hollocast next to the purge plug seating block is approximately correct, using your prepared measure. Sweep material towards the edges of the ladle floor if it is flowing too slowly. Get out and remove the ladder. Clean out the residue from the mixer into an empty bag, to monitor setting time. The Hollocast will stop flowing after about 10 minutes. Once the setting sample in the bag is hard and warm, you may fit the former. (About an hour.) Repeat procedure for sidewalls.

Drying; Place ladle under the preheater and heat to 150°C for 3 hours. Raise temperature to 400°C and hold for 3 hours. Allow to cool and continue bricking the side up.

Hollocast 1 user references

* Armitage Shanks: 012 316 2571 Hennie van der Bank. Use it for sanitaryware kiln furniture, cycling through 1120°C daily. They find that its abrasion resistance is better than that of dense castable in their application.
* Aztek Furnace Services; 016 22 3414 Billy Wolmarans. Heat treatment furnace floors.
* Bohler Steel; 011 974 2781 Frank. Large heat treatment furnace floor.
* Custom Furnaces; 016 365 5723 John Lee Use it for all furnace floors, even forges.
* Fibreline; 016 54 020 John and Phillip Havenga. Used around 4 tons per month.
* Iscor Pilot Plant; 012 318 7785 Paul Hloben. Tested on project codes OTO, OXW, and PGJ.
* Pressure Die Casting; 0331 72327 Colin Belsham. Aluminium furnaces. Good resistance to thermit reaction.
* S.A.A.: 011 978 6298 Isaac van Rensburg Relined Wild-Barfield furnace with complex element bricks made from Hollocast. Also a large very flat heat treatment furnace floor.
* Darton: 011 432 0086 Darryl & Alan. Various furnaces.
* Microsteel: Insulation on floors of dolomite lined ladles.
* LTL Abrasives; 011 412 2920 Mike Reid. Furnace floors.
* Zimalco; Aluminium ladle linings. Kim Garner, 011 914 4300
* S.A. Metals; Ladle and tundish backlinings. Peter Lumley, 021 590 3943