Evidence for trace element forms of titanium and manganese in coal liquefaction extract solutions

Abstract

The trace element contents of the insoluble portions of a filtered coal extract solution treated with pentane, toluene and THF were determined using atomic absorption spectroscopy (a.a.s.) and atomic emission spectroscopy (a.e.s.). In all cases a large proportion of the trace elements were found in the insoluble portion, but there were no significant differences between the individual trace elements. Further experiments were carried out in which TiO 2, MnCO 3 and low temperature ash were added to normal digestions of coal in hydrogenated anthracene oil (HAO), and were also digested in HAO only. The filter cakes produced in the latter experiments were redigested in fresh HAO a second and third time. The results strongly indicate that Ti passes through the filtration stage of the liquefaction process as finely-divided mineral matter. Mn, however, undergoes some change during the process which enables it to pass through the filtration stage.