Hall–Héroult process

<p>The Hall–Héroult process is the major <a href="/facts/Industrial_process/etguaagU">industrial process</a> for <a href="/facts/Aluminium_smelting/x11apsra">smelting aluminium</a>. It involves dissolving <a href="/facts/Aluminium_oxide/wXM9P6pI">aluminium oxide (alumina)</a> (obtained most often from <a href="/facts/Bauxite/CJ10QPc6">bauxite</a>, <a href="/facts/Aluminium/7wmR8jYE">aluminium</a>'s chief ore, through the <a href="/facts/Bayer_process/HH5NoTvu">Bayer process</a>) in molten <a href="/facts/Cryolite/AFPScQqQ">cryolite</a> and <a href="/facts/Electrolysis/pU75nCDI">electrolyzing</a> the molten salt bath, typically in a purpose-built cell. The process conducted at an industrial scale, happens at 940–980 °C (1700 to 1800°F) and produces <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> with a purity of 99.5-99.8%. <a href="/facts/Aluminium_recycling/eenL8s8V">Recycling aluminum</a>, which does not require electrolysis, is thus not treated using this method.
</p><p>The Hall–Héroult process consumes substantial electrical energy, and its electrolysis stage can produce significant amounts of <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a> if the electricity is generated from high-emission sources. Furthermore, the process generates <a href="/facts/Fluorocarbon/jA9N6aoT">fluorocarbon compounds</a> as <a href="/facts/Byproduct/qDosnqoD">byproducts</a>, contributing to both <a href="/facts/Air_pollution/zmk9Dy7S">air pollution</a> and <a href="/facts/Climate_change/rEN4BDE7">climate change</a>.
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Hall–Héroult process open-in-new

Hall–Héroult process