PRECIPITATION OF HEMATITE AND RECOVERY OF HYDROCHLORIC ACID FROM CONCENTRATED IRON CHLORIDE SOLUTIONS BY A NOVEL HYDROLYTIC DECOMPOSITION PROCESS

摘要

Regeneration of HC1 from chloride solutions is commercially practiced by high temperature (800-900 °C) pyrohydrolysis associated with high energy consumption and capital cost. As an alternative to pyrohydrolysis a novel low temperature (<200 °C) non-autoclave hydrolytic process has been studied in this research work, which comprises two steps. In the first step, ferrous chloride is oxidized by oxygen at T≤150 °C, followed by hydrolytic decomposition of ferric chloride to coarse hematite particles and superazeotropic hydrochloric acid (8-9M) operated at approximately 180 °C. This paper provides a summary of the laboratory results related to both oxidation and hydrolysis and presents a newly designed conceptual process flowsheet.