Carbothermic Reduction of Phosphoric Acid Extracted from Dephosphorization Slags to Produce Yellow Phosphorus
Phosphorous is an important element for agriculture and industry and is a non-renewable resource. Especially, yellow phosphorus is an essential material in advanced industrial technology, but phosphorus resources were not produced in Japan at all, and all depend on imports. It has been suggested, however, that the remaining accessible reserves of phosphate ore will be depleted within 50 years. Therefore, alternative resources for phosphate ore must be found. In this research, we have developed a process that enables the production of high-purity yellow phosphorus from domestic unused phosphorus resources such as steelmaking slags. The process consists of two parts: (1) the production of crude phosphoric acid from wastes such as steelmaking slag; (2) producing high-purity yellow phosphorus by low-temperature carbothermic reduction of phosphoric acid (H3PO4). The details of the carbothermic reduction of phosphoric acid are presented in this paper. Yellow phosphorus is commercially produced by carbothermic reduction of phosphate ore in an electric arc furnace at more than 1673K. In the newly developed system, gaseous P4O10 evaporated from H3PO4 is successfully reduced to yellow phosphorus by using carbon packed bed at less than 1273K. To meet the depletion of phosphate ore, the proposed process in this study to produce yellow phosphorus by carbothermic reduction of H3PO4 that are extracted from dephosphorization slags will be one of the effective and economical solutions.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3566431Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 450
 T. Nakakubo, A. Tokai, and K, Ohno, “Comparative assessment of technological systems for recycling sludge and food waste aimed at greenhouse gas emission s reduction and phosphorus recovery”, vol. 32, pp. 157-172, 2012.
 D. Cordell, J-O. Drangert, and S. White, “The story of phosphorus: Global food security and food for thought,” Global Environmental Change, vol.19, pp. 15–64, 2009.
 C-M. Du, X. Gao, S. Ueda, and S. Kitamura, “Distribution of P2O5 and Na2O between solid solution and liquid phase in the CaO-SiO2-Fe2O3- P2O5-Na2O slag system with high P2O5 content”, Metall. Mater. Trans. B, vol. 49B, pp. 181-187. 2018.
 C-M. Du, X. Gao, S. Ueda, and S. Kitamura, “Recovery of phosphorus from modified steelmaking slag with high P2O5 content via leaching and precipitation”, ISIJ Inter., vol.58, pp. 833–841,2018.
 C-M. Du, X. Gao, S. Ueda, and S. Kitamura, “Optimum conditions for phosphorus recovery from steelmaking slag with high P2O5 content by selective leaching”, ISIJ Inter., vol.58, pp. 860–868, 2018.
 C-M. Du, X. Gao, S. Ueda, and S. Kitamura, “Effect of Fe2+/T.Fe ratio on the dissolution behavior of P from steelmaking slag with high P2O5 content”, J. Sustain. Metall., vol.4, pp. 434–454, 2018.
 T. Iwama, C-M. Du, X. Gao, S-J. Kim, S. Ueda, and S. Kitamura, “Extraction of phosphorus from steelmaking slag by selective leaching using citric acid”, ISIJ Inter., vol.58. pp. 1351–1360, 2018.
 K. Yokoyama, H. Kubo, K. Mori, H. Okada, S. Takeuchi and T. Nagasaka, “Separation and Recovery of Phosphorus from Steelmaking Slags with the Aid of Strong Magnetic Field”, Tetsu-to-Hagane, Vol.9, pp.683-689, 2006
 H. Kubo, K. Matsubae and T. Nagasaka, “Magnetic Separation of Phosphorus Enriched Phase from Multiphase Dephosphorization Slag”, Tetsu-to-Hagane, Vol.95, pp.300-305, 2009.
 K. Matsubae-Yokoyama, H. Kubo, K. Nakajima and T. Nagasaka, “A Material Flow Analysis of Phosphorus in Japan - The Iron and Steel Industry as a Major Source”, Journal of Industrial Ecology, Vol.13, pp.687-705, 2009.
 K. Matsubae, J. Kajiyama, T. Hiraki and T. Nagasaka, “Virtual Phosphorus Ore Requirement of Japanese Economy”, Chemosphere, Vol.84, pp. 767–772, 2011.
 R. Li, W. Teng, Y. Li, W. Wang, R. Cui, and T. Yang, “Potential recovery of phosphorus during the fluidized bed incineration of sewage sludge”, J. Clean Production, vol.140, pp. 964-970, 2017.
 L. Egle, H. Rechberger, and M. Zessner, “Overview and description of technology for recovering phosphorus from municipal waste water”, Resour, conserv. Recy., vol.105, pp. 325-346.
 E. H. Brown and C. D. White, “Vapor pressure of phosphoric acids”, Ind. Eng. Chem., vol.44, pp. 615-618, 1952.
 H. G. M. Edwards, “Vibrational Raman spectroscopy and force constants of phosphorus P4”, J. Mol. Struct., vol. 295, pp. 95-1900, 1993.