Simple Solutions That Work! Issue 15

24 ALUMINUM METAL IS STILL MORE EXPENSIVE THAN ENERGY W ith energy prices scheduled to rise 30% in the next two years, foundries are looking for ways to reduce wasted energy and materials in their manufacturing process. Foundry managers are looking to the melt room as a place to recover costs. In the past, metal melt loss was a given. Now there’s potential for cost savings in the melt room by just controlling the aluminum content in your dross. This can be accomplished several different ways, with a focus on furnace design and auxiliary equipment that can help you recover some of that metal that used to be shipped out of your plant every month. FURNACE TYPE The furnace type is directly related to the amount of dross you create. Here are some known industry standards: 1. Electric wet bath reverberatory melters lose less than 1% in metal melt loss. 2. Natural gas-fired wet bath reverbs low headroom loses 2-4% 3. Gas-fired high headroom wet bath reverbs lose 4-5% 4. Gas-fired dry hearth furnaces lose 7-12% 5. Tower jet or stack melters lose 5-7% These results are dependent on what’s charged into them to melt and assumes the worst-case scenario. Lightweight scrap materials account for 60% of the load and 40% ingots, and melting all sows or T-bars will reduce metal melt loss. The driving factor for metal melt loss is the weight to density ratio of what you are melting. Lightweight scrap oxidizes faster and over a greater area than a dense 1,000 pound sow. Unfortunately, we can’t change the laws of physics. If you melt aluminum in a combustion-rich atmosphere, it will oxidize and you will lose more metal. RICHIE HUMPHREY National Sales Manager THE SCHAEFER GROUP ARTICLE TAKEAWAYS: • Controlling the aluminum content in your dross can lead to cost savings • Recover your own aluminum, reduce scrap, and keep your furnaces clean • Appoint a metal saving guru to manage the metal you melt By melting metal under the surface of the bath, you greatly reduce the oxidation process and limit it to only the surface metal in the bath. Batch melting creates more dross than even continuous charging because the metal is up out of the aluminum during the batch charge, so more