Response of Properties and Chemicals to Preparation Parameters in the Oxidation Processing of Refined Montan Wax

Abstract

Refined montan wax (RMW) is a lignite-based chemical product with wide application and high added value. However, research on its processing and performance is very limited. Currently, four parameters in the key preparation procedure for the oxidation bleaching of RMW, including the concentration of two oxidants (H2SO4 (P1) and CrO3 (P2)), oxidation time (P3), and the mass ratio of CrO3 used in two oxidation steps (P4), were systematically evaluated in regard to their impact on the properties and chemistry of RMW. The results showed that the four tested parameters visibly affected RMW, and each parameter had a different impact on the properties of RMW by range analysis, of which P1 showed a greater influence on its acid value; P2 influenced its friability, specific surface area, and aperture; P3 affected its color, initial melting point, and saponification value; and P4 had a higher impact on its final melting point, melting range, and hardness. Gas chromatography with flame ionization detection–mass spectrometry analysis revealed that the compounds found in RMW samples (RMWs) under different oxidation conditions differed significantly, with major differences in the content and amount of these components. Among the compounds in RMWs, 16 different compounds (variable importance of projection > 1) were found by the orthogonal projections to latent structures discriminant analysis method, nine of which have a strong relationship to the different performances of RMWs. This work provided a basis for the development of performance-oriented preparation processing technology for RMW.