Influence of the processing factors on deresination rate and the residual resin on properties of deresined montan wax

Crude montan wax (CMW) is a natural wax extracted directly from lignite by organic solvents that can be prepared into deresined montan wax (DMW) by the deresination process and then bleached into refined montan wax (RMW) by an oxidation process. Based on the different requirements for the DMW properties in different applications, a study on effects of the different factors on the deresination rate in CMW and the residual montan resin (MR) content on basic properties of DMW was carried out in this work. It was found that ethyl acetate displays an improved deresination effect, and that time and temperature are the two key factors that affect the CMW deresination rate (ǀ r ǀ > 0.9). With the increase in the residual MR contents in DMWs, the melting point of DMW decreased while its melting range widened, and its friability, acidity and saponification values increased. Gas chromatography-mass spectrometry analysis revealed that DMWs are rich in fatty esters and acids. It is concluded that the differences in their properties are related to the changes in the amount and content of the acids and esters.