Initial Exploration of Application of Open-Gradient Magnetic Separation of Coal to Beneficiation of Liquefaction Feeds

摘要

Finely divided multi-component solids can be separated into multiple fractions by Open-Gradient Magnetic Separation if differences in magnetic susceptibility exist among the components. This technique has now been applied to several crushed coals, in particular to the 30-100 mesh cut. Coal fractions have been characterized by petrographic, mineralogical, and analytical data. As one proceeds from the most diamagnetic to the most paramagnetic fractions, there is a progressive decrease in the content of the reactive vitrinite macerals and an increase in the content of the unreactive inertinite macerals, the pyrite, and the nonpyritic minerals. The fact that the inertinite macerals tend to report to the paramagnetic fractions apparently results from epigenetic pyrite cell inclusions. There is also a size discrimination for pyrite with the diamagnetic coal fractions tending to contain the smaller syngenetic fractions tending to contain the larger particles from cleat fill. One set of 9 fractions from the 30-100 mesh cut of a precleaned Kentucky No. 9 coal was subjected to liquefaction conditions in a Short Contact Time solvent for 5 min at 425 exp 0 C. Considerable discrimination was observed in the values of the maf conversion based on pyridine solubility. The conversion of the most diamagnetic fraction (43% of the feed coal; 89% conversion) exceeded that of the feed coal (79% conversion). Conversion levels of successive fractions gradually decreased to approx. 50% before an abrupt increase to 71% for the most paramagnetic fraction. These encouraging initial experimental observations suggest the need for further laboratory studies and for process considerations of the potential benefits. (ERA citation 08:013824)