Development of Detoxifying Treatment and Regeneration Process of HFC-134a by Waste Materials

Abstract

This study proposed a new regeneration process of high-purity fluorite from C₂H₂F₄（HFC-134a） using chemical reaction with calcium compounds. Residual dross which is consisted of Ca（OH₂） and CaCO₃ in the manufacturing process of CaCO₃ was used as the reactant with HFC-134a. The HFC-134a decomposition showed high value more than 99.9％by using Residual dross. The calcium dross after reaction contained fluorite of 20.1％ and solid carbon. We try to purify the fluorite by calcination and dissolution/reprecipitation using HF-HCl waste acid. Then the calcium dross was dissolved in the waste acid, and the precipitation was recovered. This precipitation showed only peaks of fluorite without peaks of other calcium compounds. XRF measurement indicated the puerility of this sample is about 97 wt％. The recovery of fluorine in waste acid was 98.6％.