Abstract: A method and apparatus for the removal of mold core material from metal castings and for fragmentation of municipal waste material, e.g., paper products, involves heating and hydrating the materials within a pressure vessel. Chemicals active on the material to be processed or the hydration water are added during hydration to soften the material to be removed or fragmented. Excess liquid in the vessel is drained and pressurized steam is added for a selected period of time. A suitable temperature and pressure are achieved such that the moisture or liquid carried by the processed material will rapidly turn to steam or vapor when the pressure in the vessel is rapidly reduced by quickly opening an unloading means at the bottom of the pressure vessel. The sudden release of the pressure in the vessel causes the moisture to change to steam and a certain portion of the liquid in the material to flash to vapor in accordance with thermodynamic laws.

Abstract: A method for the separation of components of solid waste which has been treated by thermal explosive decompression followed by biodegradation (also hereinafter referred to as composting) is presented. The explosive decompression and composting pretreatment before separation presents a granular and inoffensive finely-divided product mixed with less-fragmented non-biodegradable materials such as plastic, metals and other substances. The method first separates the finely-divided product from the waste to leave a first residue, then magnetically separates any magnetic components from the first residue to leave a second residue, and then separates by gravity flotation any plastic components from the second residue, each step being carried out successively without interruption for further treatment of the waste.A system is described which separates the biodegradable and fine residues first, followed by the separation of other, more valuable components from each other at later stages of separation.

Abstract: Certain solid waste, particularly that comprising trash, rubbish, refuse, garbage, animal and organic remains, and similar materials as is collected from municipalities, is heated and pressurized, preferably with the addition of moisture which saturates those components of the waste which will accepted it, to a suitable temperature and pressure in a pressure vessel. The suitable temperature and pressure are such that the moisture or liquid already in the waste will rapidly turn to steam or vapor at the temperature of the waste when the pressure in the vessel is rapidly reduced. Unloading means at the bottom of the pressure vessel then quickly open. The sudden release of the pressure in the vessel then causes the moisture to change to steam and a certain portion of the liquid in the waste material to flash to vapor in accordance with thermodynamic laws. The resulting rapid expansion within the waste material fragments the waste material.