A method of disposing of combustible materials. The method includes the steps of: providing a heating space; providing a first source to generate heat to a first predetermined level at a first location in the heating space sufficient to reconstitute the combustible materials to a molten slag at the first location and so that heat generated by the first source elevates the temperature at a second location within the heating space to a second predetermined heat level that is below the predetermined heat level and high enough to cause combustion of the combustible materials; directing combustible materials to the second location at which the combustible materials are combusted to produce ash; and causing the ash to be directed to the first location to be reconstituted as molten slag.