Treatment of Hydrogen Fluoride Generated from the F-gases Decomposition Processes

Abstract

The objective of this study is to obtain the optimal conditions to remove hydrogen fluoride (HF) generated from a variety of F-gas treatment processes. First, we selected Ca(OH)2 and CaCO3 as a reactant among the various alkali salts which have a high removal efficiency and a competitive price by forming a calcium fluoride precipitate. Additionally, various factors were investigated to improve the removal efficiency of HF. The conditions such as the settling time, agitating time and intensity, reaction temperature, and pH were considered as main factors. As a result, in the treatment process to remove HF through Ca-based alkali salts, the optimal conditions were a 120 min settling time, 30 min of agitation at 100 rpm, a pH of 4-8, and a reaction temperature of 40°C.

Keywords

• hydrogen fluoride
• fluoride removal
• calcium hydroxide
• calcium precipitation
• alkali salts