Magnesium Production by the Pidgeon Process Involving Dolomite Calcination and MgO Silicothermic Reduction:  Thermodynamic and Environmental Analyses

Abstract

Thermochemical equilibrium calculations indicate the possibility of considerable fuel savings and CO2 emission avoidance in the three steps of the Pidgeon process: (a) calcination of dolomite; (b) production of ferrosilicon from quartz sand, coal, and iron oxide; (c) silicothermic reduction of calcined dolomite by ferrosilicon to magnesium. All three steps should benefit from application of concentrated solar energy as the source of high-temperature process heat, while the first two steps may be adapted to the coproduction of syngas. For the production of ferrosilicon, an experimental study was carried out by thermogravimetry as a model for a solar-driven process. The net reaction at 1823 K was shown to be represented by Fe2O3 + 4SiO2 + 11C → 2FeSi(s) + 10CO(g) + SiC(s) + SiO(g), confirmed by gas chromatographic analysis of the evolved CO and by XRD identification of the solid products FeSi and SiC. This product mixture agrees with that predicted for the thermochemical equilibrium, but differs from that reported in the literature for the electric arc process.

Valuable Metals—Recovery Processes, Current Trends, and Recycling Strategies

“…TheP idgeon process proceeds according to Equations (19) and (20), and is today the most important . [5,26,132,[143][144][145] Thec alcium oxide fraction forms ab asic calcium silicate slag, whereas magnesium is discharged overhead as vapor and condensed in aw ater-cooled condenser outside the furnace. [142] In addition, the unwrought magnesium is often contaminated with Ni, Cu, and Si.…”

Efektivitas dolomit teraktivasi yang diperkaya dengan bakteri pelarut fosfat sebagai pengganti kiserit pada bibit kakao The effectiveness of activated dolomite enriched by phosphate solubilizing bacteria as kieserite substitute on cocoa seedling

“…Karakteristik tanah Ultisol yang digunakan sebagai media tumbuh bibit kakao. (Gunasekaran & Anbalagan, 2007;Halmann et al, 2008). Namun demikian, kelarutan MgO dalam air dari bahan dolomit hasil proses kalsinasi ini masih sangat rendah.…”

Laser-induced Mg production from magnesium oxide using Si-based agents and Si-based agents recycling

“…29 Such high temperature makes it difficult to find suitable material for the retort. 30 Notice that energy efficiency of laser process using silicon is 12.1 mg/kJ, 2.3 times that of the Pidgeon process. requirement can be excluded.…”

“…According to statistics of International Energy Agency in 2006, 80% of the world total primary energy was provided by fossil fuel, where coal, oil and gas supply 26%, 30.4%, and 20.5%, respectively. 1 Due to the massive fossil fuel consumption, the increasing CO 2 concentration seriously brings about the global warming, which leads directly to climate change and sea-level rise.…”