Systematically Identifying and Investigating Key Active Component and Its Transformation Mechanism in the Process of Purifying TiCl4 with Organic Reagents

TL;DR

This study identifies 1-dodecene as an effective organic reagent for removing vanadium impurities from TiCl4 and explains its transformation mechanism during purification.

Contribution

The study systematically identifies 1-dodecene as a key active component and reveals its transformation mechanism in vanadium removal from TiCl4.

Findings

1-dodecene achieves 93.35% VOCl3 removal efficiency.

1-dodecene transforms through cyclization, aromatization, and carbonization during the purification process.

VOCl3 interacts with both incompletely carbonized organic precursors and alkenes.

Abstract

The purity of titanium sponge is crucial for determining the performance of final titanium alloys, underscoring the importance of impurity control in its precursor, TiCl4. Among these impurities, VOCl3 is particularly challenging to remove due to its similar boiling point and complete miscibility with TiCl4. Although organic reagents are widely employed for vanadium removal, their complex compositions complicate the identification of key active components. This study systematically compares the vanadium removal efficiency of six organic compounds bearing different functional groups. Results demonstrate that 1-dodecene exhibits superior performance, achieving a VOCl3 removal efficiency of 93.35%. Mechanistic studies reveal that 1-dodecene initially undergoes cyclization to form cyclododecane, followed by aromatization and subsequent carbonization through stacking, dehydrogenation, and coking, ultimately yielding partially graphitized amorphous carbon. In this process, VOCl3 interacts not only with the incompletely carbonized organic precursor but also directly with the alkenes. These findings elucidate the reaction pathway and central role of linear α-alkenes in vanadium removal, providing a theoretical foundation for developing efficient and stable vanadium removal agents.

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