Capital Refractories Induction Furnace Linings, Crucibles, Gas Diffusers and Nozzles

Selection and quotation of Capital Refractories products: Coral dry linings for induction furnaces, crucibles, Caperdiff gas diffusers, Unibore and RCN nozzles.

Coral Dry Spinel-Forming Linings for Coreless Induction Furnaces

Coral dry ramming mixes form spinel and build the working lining of coreless induction furnaces. Coral SP7 is designed for large steel plants, while Coral SP7 Cr4 adds chrome for aggressive slags. Coral GR9 and Coral CXL cover a wide range of steels and high alloyed metals.

Coral SP1, SP7 and SP7 Cr4 dry mixes for large steel plant furnaces
Coral GR9 and CXL mixes for steels and high alloyed, non-ferrous metals
Topping and spout materials compatible with Capital dry linings
Mica slip plane material and mica mesh for early penetration warning

Isopressed Crucibles and One-Shot Liners

Alumina, chrome alumina and magnesia crucibles are pressed, vibration-formed and fired at the Capital plant in the Czech Republic. Isostatically pressed crucibles range from 2 kg to 75 kg capacity. The One-Shot system pairs a single-use fused silica or alumina liner with a multi-use outer crucible.

Alumina crucible grades AL97I and AL88I
Chrome alumina grades CA93I and CA84I for arduous slags
Magnesia grades MG88I and MG95I for basic slags
One-Shot liner grades FS70S and AL68S

Caperdiff and Caprax Gas Diffusers (Porous Plugs)

Capital gas diffusers treat melts to remove inclusions, reduce gas content and homogenise temperature. Induction furnace plugs made of Caperdiff 94AL in stainless steel cans are designed to last the life of the lining. Caprax ASF DP with directional porosity serves ladles with aggressive slag.

Caperdiff 94AL apparent porosity 17.7 %
Caperdiff 94AL cold crushing strength 120 MPa
IF 3 and IF 5 sizes matched to lining thickness
Caprax ASF DP plugs for ladles with aggressive slag

Unibore Nozzles and RCN Rotary Control Nozzles

Unibore combines a re-usable outer nozzle with a replaceable inner nozzle offering bores from 25 to 100 mm. Its Autopour version suits the small gap between tundish and mould. The RCN rotary control nozzle for 5 to 25 ton ladles was tested by more than 3,000 heats without gate failure.

Unibore inner nozzle bores from 25 to 100 mm
Unibore version for Autopour pouring units
RCN rotary nozzle for 5 to 25 ton ladles
Foundry nozzle materials Pm600, Pm700 and Pm850

MetCon G Molten Metal Filters and AtomiZIR Atomising Nozzles

MetCon G filters made of carbon bonded ceramic clean steel and modify flow in the running system. They suit steels with a carbon content of 0.18% or more and offer fully customisable porosity. AtomiZIR zirconia and zircon nozzles serve water and gas atomisation of ferrous and non-ferrous metals.

MetCon G filters for steels with 0.18% carbon or more
Carbon bonded ceramic with customisable porosity
AtomiZIR nozzles in zirconia and zircon
Water and gas atomisation of ferrous and non-ferrous metals

Monolithic Refractories and Channel Furnace Linings

Capital makes Caprax, Capflow and Pencrete LC low cement monolithics and PBond phosphate bonded products with no curing. Capram 60, 70 and 90 are used in iron and steel plants for patching, toppings and spouts. Channel furnace inductors are lined with Capcor 96S or basic Capmag SP.

Caprax, Capflow and Pencrete LC low cement ranges
PBond phosphate bonded products with rapid dry out
Capram 60, 70 and 90 for patching and spouts
Capcor 96S inductor mix rated to 1650 °C

Selecting a Coral Lining by Alloy and Slag

Coral selection depends on the alloy, furnace size and slag chemistry. Coral SP1 and SP7 are designed for large steel plants, Coral SP7 Cr4 adds chrome for aggressive slags, and Coral GR9 or the general purpose Coral CXL cover a wide range of steels and high alloyed metals.

Compatible topping and spout materials, a hydraulic coil screed and a mica slip plane complete the lining system. Mica mesh with a metal layer is used in systems that give early warning of metal penetration through a lining.

Sizing an Induction Furnace Gas Diffuser

Induction furnace diffusers are named IF followed by the nominal size in inches. The size follows lining thickness: IF 3 (drawing 7206) for 100–150 mm and IF 5 (drawing 7217) for 200–250 mm. Capital recommends quoting the drawing number on every order to avoid confusion.

The standard range uses high alumina Caperdiff 94AL with stainless steel cans.

Choosing a Crucible Grade by Slag Chemistry

Alumina crucibles AL97I and AL88I are the general purpose choice for a wide range of alloys and stainless steels. Chrome alumina grades CA93I and CA84I are preferred to alumina in more arduous applications. Magnesia grades MG88I and MG95I resist basic slags.

For investment foundries the One-Shot system uses a single-use liner, so there is no risk of cross-contamination of alloys.

Choosing the Bore of a Unibore Ladle Nozzle

The Unibore inner nozzle is changed after each pour, so the bore can match the planned job without stripping the ladle. Because Unibore reduces drag, a smaller diameter inner nozzle is usually employed for a similar flow rate.

In the Autopour version the outer nozzle is changed around once a week and the inner nozzle daily. Standard reverse taper nozzles come with 25, 29, 32, 38, 44, 57, 64 and 76 mm bores.

Capital Refractories and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Capital Refractories and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.