The Pidgeon process is a practical method for smelting magnesium. The most common method involves the raw material, dolomite being fed into an externally heated reduction tank and then thermally reduced to metallic magnesium using 75% ferrosilicon as a reducing agent in a vacuum.[1] Overall the processes in magnesium smelting via the Pidgeon process involve dolomite calcination, grinding and pelleting, and vacuum thermal reduction.[1]
Besides the Pidgeon process, electrolysis of magnesium chloride for commercial production of magnesium is also used, especially for magnesite ores,[2] which at one point in time accounted for 75% of the world's magnesium production.[3]
With year 2000 technology, it took between 17 and 20 kilowatt-hours per kilo of magnesium produced by the Pidgeon process.[2] The Pidgeon processes in Canada in the year 2000 all used SF6 to cover the reaction so as not to introduce stray oxygen to it. Research to replace SF6 with boron trifluoride was underway in 2000.[2] By 2011 magnesium production had departed under the Kyoto Protocol from Canada.[4] Wu, Han and Liu bragged that "China is the world’s largest producer of primary magnesium and has a magnesium smelting industry that is mainly based on the Pidgeon process" in an era in which China had obtained an 80% market share of production of magnesium metal.[1]
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