Volatilization Behavior of Fluorine in Fluoroborate Residue during Pyrolysis

摘要

Industrial hazardous waste from the fluorine chemical industry sometimes has a high content of fluorme, and incinerating it could be very poisonous if the flue gas is not property disposed. In this study fluoroborate residue is used to represent a typical waste from the fluorme chemical industry . Thenspgravimetric analysis coupled with Fourier transform infrared analysis (TG-FTIR analysis) was used to study the evolution characteristics of gaseous products during the pyrolysis of fluoroborate residue. The pyrolysis process of fluoroborate residue could be divided into three stages according to the TG analysis: moisture loss, fast decomposition, and charring. SiF_4 BF_3, and HF are, found as fluorine gas species evolved in the pyrotysis process. the evolution of SiF_4 finishes at 600 ℃ The evolution of BF_3 has two peaks and most of the emission happens before 600 ℃. The release of HF could be divided into two stages due to the different existence of F~-. In addition, the reforming condition of different fluorine-containing gaseous substances is verified in a thermodynamic equilibrium model and the results could explain the experiment phenomenon well.