This document is available in the Adobe Acrobat PDF Format. In the Sulchem Process, contaminated soil is mixed with elemental sulfur and treated at elevated temperatures in an externally-heated solids reactor with an inert atmosphere. Organic hydrocarbons react with sulfur to form an inert fine solid of carbon and sulfur, hydrogen sulfide, and modest amounts of carbon disulfide.
Heavy metals react to form less soluble sulfides or sulfide-coated particles.
Desorbed organic vapors are further treated with sulfur in a vapor-phase reactor. The acid gases are scrubbed and condensable byproducts are treated in an off-gas handling system. Elemental sulfur is recovered and the treated soild is prepared for site disposal in an auxiliary process unit.