Investigation of the Carbochlorination Process for Conversion of Cerium and Neodymium Oxides into Their Chlorides

Abstract

This study focuses on evaluating the conversion of cerium oxide and neodymium oxide into their chlorides through the carbochlorination process. The experiments were completed inside a quartz reactor, and the % conversion was determined by performing a water leach to dissolve the soluble chloride phases present and leave behind the insoluble unreacted oxide and oxychloride phases. The process parameters chosen for this investigation were temperature, time, chlorine gas concentration, and carbon-to-rare earth oxide ratio. A rate curve was generated for both the cerium oxide and neodymium oxide carbochlorination processes. These curves showed that reactions had a significant dependence on time with 4 h being the optimal reaction time for both processes. Statistical modeling and optimization was also performed through the use of Stat-Ease Design-Expert 8® software. This analysis showed that temperature had the most significant effect on the degree of reaction achieved for both processes. The reaction products were also subjected to X-ray diffraction analysis to verify the degree of reaction determination method as well as to determine whether any intermediate phases occurred during the carbochlorination process.