摘要

In the production of metallurgical grade silicon (MG-Si), fugitive emissions are a serious concern due to the health risks associated with the fumes formed in different parts of the production. The fumes are also a potential environmental hazard. Yet, the chemical composition of the fumes from most process steps in the silicon plant, such as oxidative refining ladle, remains unknown. This in turn constitutes a problem with respect to the correct assessment of the environmental impact and working conditions. A comprehensive industrial measurement campaign was performed at the Elkem Salten MG-Si production plant in Norway. Samples of the ingoing and outgoing mass flows were analyzed by high-resolution inductively coupled plasma mass spectrometry, with respect to 62 elements. In every step of the sampling and sample treatment processes, possible sources of error have been identified and quantified, including process variation, mass measurement accuracy, and contamination risk. Total measurement errors for all elements in all phases are established. The method is applied to estimate the order of magnitude of the elemental emissions via the fumes from the tapping and refining processes, with respect to production mass and year. The elements with higher concentrations in the fume than slag and refined silicon include Ag, Bi, Cd, Cu, In, K, Mg, Na, Pb, Rb, Se, Sn, Tl, and Zn: all being present in the ppm range. This work constitutes new and vital information to enable the correct assessment of the environmental impact and working conditions at an MG-Si plant.

  • 出版日期2013-8

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