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Graphite for aluminium production |
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Aluminium can be produced by using anodes and cathodes in the aluminium smelter. The main components of anodes are petroleum coke, a product from the distillation of oil, and coal tar pitch, a distillation product extracted from the tar that is obtained in coking plants. A part of the anode material, the so-called anode butts, is returned by the aluminium smelters to be reused as raw material. Petroleum coke and anode butts are crushed, dried if necessary, graded, ground, heated and mixed with an exact amount of pitch and finally kneaded. An optimal composition is yet another prerequisite for good anode quality. Depending on the anode format the compound will be moulded to a 'green anode' either in a press or in a vibrating machine. After forming, the anodes are baked at approx. 1150°C to carbonize the pitch binder and eliminate the volatile parts of the pitch. After cleaning, inspecting and packaging, the anodes are ready for delivery. Anodes can be produced in allshapes and sizes. Anode production process steps involve 1) Petroleum coke storage 2) Butt storage 3) Liquid pitch storage 4) Sampling 5) Drying 6) Grading 7) Crushing 8) Grinding 9) Sifting 10) Intermediate storage 11) Metering 12) Preheating 13) Mixing and kneading 14) Homogenizing/cooling 15) Pressing 16) Vibrating 17) Baking 18) Inspecting 19) Packaging, storage 20) Dispatch    Cathodes/graphitized blocks made from carbon and graphite are applied for the production of primary aluminium in construction of electrolysis cells. Requirements to the cell lining which mean material should be •electrically conductive •high thermal conductivity •resistant against high temperature •low sodium expansion •low chemical reactive with bath components •no alloy-formation with liquid aluminium make CARBON/GRAPHITE the only candidate for manufacturing the cell parts. Aluminium production processis described in biref here |
