Fluorine Vaporization and Leaching from Mg Slag Treated at High Temperature

Abstract:

Pidgeon process is used by more than 300 plants in China to produce magnesium (Mg) metal. Fluorite, ranging 2-3%, is often mixed in raw materials to catalyze the Mg production. The Mg slag from the production then contains F of several mass percent. When the Mg slag is used in construction or treated for recycling, possible F pollutions are of concerns. The present study used slag samples containing F of 0.98-2.15% from an Mg factory in northwest China. Both treatments at 1000-1400°C and leaching tests before and after the treatments were conducted for the slag samples. The study results show influences of the treatments on mineral compositions of the samples, which controlled F contents in both the slag samples and leachates. The results are reported and discussed. Some suggestions are also presented to minimize fluorine pollutions and to improve environmental performances of the Pidgeon process.

• Periodical: Advanced Materials Research (Volumes 726-731)
• Pages: 2898-2907
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.726-731.2898
• Online since: August 2013
• Authors: Feng Lan Han, La Ner Wu, Qi Xing Yang, Chun Du
• Keywords: FactSage, Fluorine, Leaching, Mg, Pidgeon Process, Pollution, Slag, Vaporization

References

[1] Editorial Column, The yearbook of nonferrous metals industry of China 2005 [M]. Beijing, China Nonferrous Metals Industry Association (2005), p.503 (in Chinese).

[2] Hongxiang LIU et al.: Light Metals, 11, (2010), p.43 (in Chinese).

[3] China Magnesium industry report, 2011, on www.researchinchina.com.

[4] Jindan Du et al.: Journal of Cleaner Production, 18, (2010), P. 112.

[5] Pidgeon LM, Alexander WA: in New York Meeting: reduction and refining of non-ferrous metals, Trans Am Inst Mining Mater Eng 159 (1944), p.315.

[6] Toguri JM, Pidgeon LM: Can J Chem., 40 (1962), p.1769.

[7] RAMAKRISHNAN S et al.: [J]. Resources Conservation & Recycling, 24, (2004), p.49.

[8] Feng GAO, Zuo-ren NIE et al: Trans. Nonferrous Met. Soc. China 18 (2008), p.749.

[9] Feng GAO, Zuo-ren NIE et al: Int J Life Cycle Assess (2009) 14, p.480.

[10] Laner Wu et al.: in Proceedings of International Conference on Solid Waste Technology and Management, Mar. 11-14, 2012, Philadelphia, USA

[11] Congyun Huang et al.: Cement Guide for New Epoch, No. 5 (2005) p.27 (in Chinese)

[12] Fenglan Han et al.: Advanced Materials Research Vols. 418-420 (2012) p.1657, Trans Tech Publications, Switzerland

[13] Fenglan Han et al.: Advanced Materials Research; Nr 581–582 (2012) p.1044, Trans Tech Publications, Switzerland

[14] PRC test standard HJ/T299-2007, Solid waste-Extraction procedure for leaching toxicity- Sulphuric acid and nitric acid method, (2007) (in Chinese)

[15] PRC standards GB 5749-2006 for drinking water quality, (2006) (in Chinese)

[16] Final draft prEN 12457-2, Characterization of waste-Leaching-Compliance test of leaching of granular waste material and sludges -Part 2: One stage batch test at a liquid to solid ratio of 10 l/kg for materials with particle size below 4 mm (with or without particle reduction)

DOI: 10.3403/02667193

[17] C.W. Bale et al.: CALPHAD 33 (2009), p.295

[18] Official Journal of the European Communities, 2003: Council Decision of 19 December 2002, establishing criteria and procedures for acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC, 16.1.(2003)

[19] Yuuki Nagaike et al.: ISIJ International, Vol. 51, No. 3, (2011), p.508

[20] Ryo Inoue et al.: ISIJ International, Vol. 42, No. 7, (2002), p.785

[21] Hongye He et al.: ISIJ International, Vol. 42, No. 7, (2002), p.794