COATINGS FILTRATION FEEDING SYSTEMS MELT SHOP REFRACTORIES METALLURGICAL AND POURING CONTROL BINDERS CRUCIBLES LINING SYSTEMS High performance lining technology for aluminium foundries Aluminium foundry linings The aluminium foundry melting plant was once even better corundum resistance across a wider dominated by crucibles, however, bulk melting by temperature band whilst Foseco’s dry-vibratable coreless induction and tower melting furnaces is lining KELLUNDITE* is ideally suited to coreless increasingly important. Consequently monolithics induction melting. now play a significant role in modern aluminium The products listed in this brochure represent foundries. Foseco’s ALUGARD* low-cement the best-in-class products for typical foundry castables and TRIAD no-cement castable now applications. Foseco offers an extensive portfolio of contain a new aluminium resistant additive giving monolithic and precast refractory solutions to meet your specific needs. Please contact your local Foseco team for more information. Typical aluminium foundry layout Coreless induction Tower & reverberatory furnace melting furnace Casting furnace Transfer & treatment ladles Crucible melting & casting furnace 2 Melting furnaces in aluminium foundries Tower melting furnaces This leaves a clean refractory furnace lining, Tower melting furnaces are commonly used in optimising the client’s furnace service life. aluminium foundries. They consist of a vertical melting shaft with a connecting holding bath. The ALUGARD CE-S high alumina low-cement castable solid ingot is charged into the top of the tower, with offer excellent aluminium resistance. This is the pre-heating in the stack followed by melting in the perfect general purpose product, with good strength Tower melting furnace melt chamber hearth. and all round performance. The melt then flows naturally into the holding ALUGARD HS85 high alumina, super tough chamber. Here the metal resides until it is tapped aluminium resistant castable has been specially into a ladle, treated and then delivered to the developed to combat aggressive erosion and casting furnaces. These furnaces are complex in their mechanical damage around charge areas. geometry and most customers look for a full supply and installation maintenance package. QUICK FIX ALUGARD EXP 2-part phosphate bonded system contains a non-wetting additive and is ideal Reverberatory melting furnaces for patch repairing furnaces. This material can also Unlike tower melters, reverberatory furnaces are be used for thin veneer repairs due to the fact usually single chambered furnaces. The solid ingot that it sticks very well to existing, used and new is charged into the furnace through the charge door refractories. Cup test of ALUGARD CE-S opening, then melted within the furnace bath. The melt is then charged into the holding furnace. TRIAD* TRIAD AL high alumina cement-free castable offers ALUGARD exceptional resistance to aluminium wetting and ALUGARD aluminium resistant castables are used penetration. It has all the characteristics of normal to line these types of furnaces. There are a variety TRIAD castables: of grades, specifically developed for different + Easy to mix applications and conditions found in aluminium + Easy to install handling and containment. ALUGARD materials are + Reduced bake-out time. termed “non-wetting” due to their ability to “repel” molten aluminium, resulting in no reaction between The product is suitable for all metal contact areas; Sample of ALUGARD the metal and the refractory. including bath, lower sidewall, ramp and sill. CE with ARA (right) and without ARA (left) 3 Melting furnaces in aluminium foundries Coreless induction melting Ancillary products Coreless induction furnaces are the ideal foundry KELLUNDITE 707 dry topping prevents crack tools for batch melting scrap. propagation and ensures a seamless transition from the furnace body to capping area. Coreless induction furnace linings for aluminium melting are required to exhibit excellent non- Coil Protection wetting properties and operate successfully over COILCOTE high alumina grouts provide a protective a range of melting and casting temperatures for semi-permanent refractory sc reed to the power aluminium alloys. coil. KELLUNDITE 703 high alumina dry-vibration Spout Materials refractories are used for induction furnaces melting + BLU-RAM* HS and BLU-RAM HSW granular aluminium. phosphate bonded material with good installation properties They include the addition of a special aluminium + ALUGARD CE-S precast refractory resistant agent to provide a clean furnace lining with minimum dross build-up and sticking, enabling easy and non-aggressive cleaning. Lid Materials + CERCAST 1500AL castable with good volume KELLUNDITE 703 linings are based upon andalusite, stability and non wetting additives which is expansile through the aluminium alloy melting temperature ranges and therefore reduces the risk of metal penetration. Crucibles The most widely used method of melting aluminium in foundries is with crucible furnaces. Foseco offer a wide range of crucibles for all types of furnaces. 4 Casting furnaces in aluminium foundries There are three main types of casting furnaces Dosing furnaces found in aluminium foundries, each using different Refractory lined dosing furnaces have traditionally furnace technology: low moisture rammed linings. However these furnaces are usually small and can be cast in a + low pressure furnaces single pour. This is so that there are no construction + dosing furnaces joints below metal level that could allow aluminium TRIAD 70 AL cup test + bale-out furnaces penetration during the pressurised casting operation. Low pressure furnaces The bath linings can be cast in TRIAD 45AL castable, Refractory lined low pressure furnaces have TRIAD 70AL castable and precast INSURAL* traditionally cast linings. These furnaces are usually refractory. small and the cast furnace bath is done in a single pour. This is so that there are no construction joints Bale-out furnaces below metal level that could allow aluminium Most bale-out furnaces are crucible furnaces penetration during the pressurised casting operation. and are either electric resistance, gas or oil fired. The bath linings can be cast in one of the following Lifetimes can be many months, depending upon materials: the application and metal treatment conditions. Foseco offer a wide range of crucibles for all types Low pressure furnace with + TRIAD 70AL castable of furnaces. accessories + ALUGARD CE-S castable + ALUGARD A95 castable Many furnaces use crucibles to hold aluminium. The main advantage is that the crucible can be easily changed and casting can commence immediately, without the need for prolonged drying of the furnace linings and reducing the risk of hydrogen pick-up. Crucibles also ensure that the aluminium is uniformly heated through the crucible wall by electric resistance heating. Foseco offer a wide range of crucibles for all types of furnaces. Dosing furnace with accessories 5 INSURAL* Furnace Lining System Insulating shaped refractories for aluminium applications The target: Fast turnaround Preheating 800 750 700 The solution: Dry installation of INSURAL precast, insulat- The table shows a typical preheating curve for a tradi- 700 700 700 ing shapes. tional 650 kg capacity furnace lining against an INSURAL 600 500 500 lining. Unlike traditional refractory linings which have to 500 The benefits: be brought up to temperature gradually for up to 7 days, 400 350 350 + No sintering required an INSURAL lining can be heated to working tempera- 300 250 250 + Significant energy savings ture straight away. We recommend 48 hours holding 200 120 120 + Extremly low corundum growth time. 100 + 0 Improved melt quality in °C Temperature 0 6 31 36 48 64 70 98 104 134 140 166 + Reduced hydrogen level after commissioning Dentity index Time in hours + Reduction of energy peaks With an INSURAL installation, the desired density index + Can be installed on or off-site of the melt can be achieved much sooner. The advantage Traditional Lining + Minimised downtime is a faster integration of the furnace into the produc- INSURAL + Immediate achievement of a constant density tion process. Also, high quality castings can be produced + much sooner than with conventional linings. Restrictions Easy to clean 18 on production capacity are avoided or at least signifi- 16,2 16 15,9 cantly reduced. 14 12,9 12,4 12 12,1 11,2 Energy consumption 10 9,3 The insulating properties of INSURAL are very high and in 8 6 6,2 addition, a highly insulating backing material is used. The 6 thermal output stays at a low level for 98% of the service 4 4,1 3,5 time. This preserve the lining, the environment and saves 2 Density index in % 0 costs. Compared to monolithic lining systems, up to 17% 0 24 48 72 96 120 144 168 169 170 energy savings can be achieved. Time in hours Traditional Lining INSURAL 6 Ladles and launders in aluminium foundries Ladles in aluminium foundries are used to tranfer INSURAL ATL ladle linings are precast and supplied the metal from the melting unit to the casting fully fired. The non-wetting properties ensure that unit, therefore minimum temperature loss is very aluminium skull formation is reduced and simple to important. remove, preventing cross contamination between metal transfers. Oxide build-up is avoided, reducing The following products can be used: the risk of hard inclusions in the melt. TRIAD 45AL low density no-cement castable has Furthermore, traditional linings frequently require exceptional