The most important factor is to have sufficiently high capacity for the specific waste stream to allow the allocation of essentially fixed labor and capital costs. This is illustrated in the estimated costs for an MSW vitrification facility summarized in figure 7. Note the accelerating rate of cost per ton as the daily processing rate decreases. This general trend is also true for other waste streams. Vitrification costs are also very dependent upon the physical form of the waste.
Contaminated soils requires the largest amount of energy to melt.
A major part of these costs are for energy. This highlights the need to include wastes containing energy with soils. This can significantly reduce processing costs.