34 34 34 60 98 1 slurry dried 34 34 34 60 95 to 20 h sub 2 o 3 34 34 34 34 60 85 5 34 34 34 34 60 80 __________________________________________________________________________ indicates quantity not measured refers to sample of identical number as described in table 1 as can be seen from examination of tables 2 and 3 the desulfurization level shows a maximum as a function of elasped irradiation time while the exact reason for this phenomenon is not known it is believed that prolonged treatment beyond an optimum time produces polysulfides or elemental sulfur within the coal which are insoluble in water and consequently not removed during the washing operation thus effectively reducing the effectiveness of the treatment it is for this reason that a multiple treatment approach is preferred over long irradiation times where a high degree of sulfur removal is required tables 2 and 3 also show the measured loss in heating value for several of the various types of coal samples treated in accordance with the method of this invention as can be seen from examination of these tables large percentages of sulfur may be removed using the process of this invention with relatively small heating value loss referring to fig2 therein is shown a graph illustrating the energy requirements for the process of this invention this graph plots the percentage of residual sulfur as a function of the electromagnetic energy used and the measured calorific value for several coal samples processed as shown in tables 2 and 3 this graph illustrates that the process of this invention can be used to reduce the sulfur content of coals containing pyritic and or.