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Magnesium Production from Calcined Dolomite via the Pidgeon Process
Published in Leszek A. Dobrzański, George E. Totten, Menachem Bamberger, Magnesium and Its Alloys, 2020
Mehmet Buğdayci, Ahmet Turan, Murat Alkan, Onuralp Yücel
The Pidgeon Process is a widely used vacuum silicothermic reduction process to produce primary magnesium (Mg) metal and, the process was developed by Lloyd Montgomery Pidgeon in the beginning of 1940s in Canada.1,2
Magnesium and Mineral Salts from Seawater: Exploration Study
Published in Hussein K. Abdel-Aal, Magnesium, 2019
As seen from the graph, Mg enjoys a favorable position to be extracted commercially. The cost of production of primary magnesium is influenced mainly by the source of energy used and by the method of production. China’s domination of the magnesium market is a typical example. The Pidgeon process that depends on using dolomite as the main ore, ferrosilicon is the reducing agent, and coal as the energy source represents the main production method in China. It involves lower capital costs, but it is less environment-friendly relative to the electrolytic processes favored in the west. Details are covered in the text in latter chapters.
Structural Materials
Published in C. K. Gupta, Materials in Nuclear Energy Applications, 1989
Thermic processes include (1) the Pidgeon process, (2) the Balzano process, and (3) the Magnetherm process. The Pidgeon process uses dolomite as the source for magnesium and ferrosilicon as the reductant. The two constituents are briquetted and heated externally to a temperature of about 1100°C in a retort kept under high vacuum. The process is being used in Canada and Japan. The Balzano process was derived from the Pidgeon process; the dimensions of the retorts are larger, and their electrical heating is internal. The by-product is a magnesia and lime silicate. The raw materials used in the Balzano process are the same as those of the Pidgeon process. However, the feeding system, the furnace shape, and the recovering operation of products and by-products are entirely different. Briquetts of mixed dolomite and ferrosilicon are introduced into an electrically heated furnace under vacuum. The magnesium is reduced and condensed in the solid form every day in a block of 2000 kg or more. This process has been developed and is operated by SAIM in Italy. The Magnetherm process consists of the reduction of calcined dolomite by ferrosilicon without any prior briquetting. The reduction is achieved in a light electrical furnace under reduced pressure at 1600°C, a temperature definitely higher than in the other two thermic processes. Through the addition of a fluidizing agent, alumina, a liquid slag is obtained. By-products are this slag, which is used in cement industries, and some low-grade ferrosilicon, used as thermic load in steel production. The process is used by SOFREM in France and its licensees in the U.S. and Yugoslavia. Figure 2 shows schematically the Magnetherm process flowchart.
Environmental Assessment of Global Magnesium Production
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Saeed Rahimpour Golroudbary, Iryna Makarava, Andrzej Kraslawski
Processing and primary production generate large amounts of greenhouse gas emissions, which may offset the potential advantage of using magnesium. Primary magnesium production from ores takes place using hydrometallurgical and pyrometallurgical methods. First step of extraction includes hydrometallurgical treatment followed by either thermal reduction (mainly the Pidgeon process) or molten-salt electrolysis. Both thermal and electrolytic processes produce large amounts of toxic emissions and consume a lot of energy as both alternatives operate at high temperatures, roughly from 1160°C for the Pidgeon Process and 700–800°C for electrolytic processes (Table 7) (Navarra et al. 2021).