Precast, non-wetting ceramic linings and shapes for melting and holding non-ferrous metals.
Aluminum, zinc and copper alloys do not just melt refractory.
They wet it, soak into it and grow through its joints.
Refractory works in molten aluminum, copper and zinc when the metal does not wet it and it survives constant thermal cycling: non-wetting oxide and nitride bonded silicon carbide (OXYTRON, NITRON), aluminum titanate and ultra high alumina are the materials Blasch uses for these metals. They come as precast parts, among them CeraLoop channel furnace linings for copper, brass, zinc and aluminum, ALRAM ultra high alumina backup ram for induction furnaces, and holders and supports for heating elements. Fewer joints and a fired hot face leave the metal fewer ways into the lining.
Wetting and buildup: molten aluminum sticks to many refractories. Oxide and corundum grow on the surface, narrow channels and have to be broken out.
Penetration: metal and zinc vapor move into pores and joints. In a channel furnace for leaded brass, zinc vapor had cut inductor life by up to 90%, and several castables and dry vibes did not change that.
Erosion and cracking: flowing metal in the channel of an inductor erodes the lining, and thermal cycling at every start opens cracks.
A refractory for these metals has to deal with all three at once, which is why the hot face matters more than the bulk of the lining.
Three products for the furnace itself, from the inductor to the coil to the roof.
A fired ceramic channel that goes into the inductor box, with no burnout and no wash heat.
Ultra high alumina ramming mixes that pack tight behind induction furnace crucibles.
Net shape holders, supports and hangers for the elements of electrically heated furnaces.
Non-ferrous metals get into a lining through its pores and its joints, so a lining with a fired, non-wetting hot face and fewer joints simply gives the metal fewer ways in.
| Material | Metals | Why |
|---|---|---|
| OXYTRON oxide bonded SiC | Aluminum, zinc | Non-wetting in molten aluminum, thermal shock |
| NITRON nitride bonded SiC | Aluminum, copper alloys | Non-wetting, thermal shock |
| Aluminum titanate | Aluminum | Not wetted, gas tight, very low expansion |
| Ultra high alumina | Brass, copper, zinc, aluminum | Dense fired hot face in channel linings |
Blasch casts linings for non-ferrous metals from a single 9 in brick shape up to interlocking assemblies, and makes tap blocks, troughs and runners and pump components in the same materials. Parts in contact with the melt in a die casting cell, such as ladles, riser tubes, heater tubes and degassing parts, are grouped under degassing and die casting products.
How CeraLoop performed in a zinc alloy channel furnace is described in the CeraLoop case study for aluminum zinc alloys.
The composition of the ceramic and its bond. Blasch OXYTRON and NITRON silicon carbides and aluminum titanate are formulated so molten aluminum does not wet the surface, without any applied layer.
Often yes. NITRON and OXYTRON resist copper alloys, zinc and galvalume, and CeraLoop linings are used for copper, brass, zinc and aluminum. The grade is chosen per alloy.
CeraLoop is made by Blasch and distributed exclusively by Allied Mineral Products, which also supplies the backup materials around the loop.
Tell us the metal, the furnace type and how long the current lining lasts. A Blasch engineer proposes the material and the shape.
