Investigation of Technological Parameters Influencing the Conversion of Magnesium Nitrates and Chlorides with Sodium Chlorate

Abstract

Aim: This study investigated the feasibility of directly producing chlorate defoliants from secondary mother liquors (SML) via interaction with sodium chlorate. Study Design: Laboratory investigation of the effects of the SML:NaClO₃ ratio and reaction duration on conversion and phase separation at a constant temperature of 120 °C. Methodology: The reaction duration was varied from 20 to 90 minutes. The reaction mixtures were subjected to hot filtration and subsequent cooling. The precipitates were characterised by X-ray diffraction, and the mother liquors were examined by ICP analysis and measurements of density and viscosity. Results: It was established that across the studied range of parameters, the liquid-to-solid (L:S) ratio of the system fluctuates between 3.76:1 and 32:1 in the hot state, and between 1.72:1 and 3.43:1 in the cold state. Depending on the selected conditions, the hot-state solid-phase yield ranged from 2.84 to 17.47 % for the experiments in which a solid phase was obtained. Upon cooling, the filtered liquid phase of almost all samples yielded 21.7–27.7 % solid precipitate. X-ray diffraction showed that the sodium chloride content of the hot-state precipitates varied within 77–100 %, while sodium chlorate (NaClO₃) was present in some hot-state samples. Conclusion: The results indicate the feasibility of directly processing secondary mother liquors with sodium chlorate and show that the conversion conditions influence the composition of the separated solid phases.