Volatilization of Potentially Harmful Trace Elements in Coal Pyrite during Heat Treatment in a Tube Furnace at 573-1473 K

Some potentially harmful trace elements,such as Sb, As, and Hg,are usually associated with pyrite in coals and can be threats tothe environment and human health. In this study, the release of 12selected elements generally associated with pyrite was investigatedduring heat treatment in a tube furnace to access their behavior duringcombustion. FactSage has been used to calculate their behavior withthe increase in temperature. Nickel, Cu, Zn, Cr, and Cd are more enrichedin the samples containing syngenetic pyrite than in other samples.Other elements are generally more enriched in the samples containingepigenetic pyrite than in other samples. The volatilization of elementswith a very high volatility, such as Hg and As, was complete at hightemperatures in most samples. For other most elements in this study,the volatilization of a specific element in different samples is generallydifferent. During heat treatment, the selected elements, accordingto their volatilization, can be classified into three groups: low,medium, or high volatility. At the conditions of this study, the volatilizationof trace elements is influenced strongly by their inherent volatility,moderately by their modes of occurrence, and weakly by the pyritetypes. The volatility-based behavior of the selected trace elementsin FactSage calculation is generally consistent with their classificationduring heat treatment.

Automated summary

The behavior of 12 trace elements associated with pyrite during heat treatment was investigated. Nickel, Cu, Zn, Cr, and Cd were found to be enriched in samples containing syngenetic pyrite, while other elements were more enriched in samples containing epigenetic pyrite. The volatilization of highly volatile elements like Hg and As was complete at high temperatures, while other elements showed different levels of volatilization in different samples. The elements were classified into low, medium, or high volatility groups based on their volatilization behavior.