Patent ID: 7513371

Claim:
An apparatus for the on-line sorting of waste according to its chemical composition and directing said waste into one of two or more channels according to predetermined criterion prior to the introduction of said waste into a waste processing plant or apparatus, wherein said apparatus comprises: a loading unit, adapted to accept said waste from one or more external sources; a weighing unit, adapted for accepting said waste from said loading unit in batches and determining the weight of each of said batches; a detector module, adapted for accepting one of said batches from said weighing unit and determining the presence and amount of one or more specified chemical elements in said batch; a diverter gate, adapted to accept said batch of material from said detector module and to direct said batch into one of said two or more channels; and a controller, adapted to control the activation and the timing of the activation of the elements of said apparatus and to perform calculations and store data necessary for the operation of said apparatus; characterized in that: said waste is not presorted prior to entering said loading unit; said detector module comprises elements for performing a neutron activation analysis technique to determine the presence and amount of said one or more specified chemical elements in said batch; that the results of said determination is used to decide into which of said channels said batch is to be directed; and said predetermined criteria, is whether the amount of said specified chemical is less than or greater than a predetermined threshold value; wherein said detector module comprises: a neutron moderator casing, made from a suitable hydrogenous material, said casing having an upper and a lower opening that can be selectively opened or sealed by doors; an inner chamber whose shape and dimensions are defined by the inner walls of said casing and said upper and lower openings; a suitable neutron generator for emitting neutrons to irradiate a batch of waste in said inner chamber; and a suitable spectrometric gamma detector for detecting gamma quanta; wherein, said emitted neutrons interact with different nuclei within said material thus producing excited nuclei, said excited nuclei decay emitting gamma quanta of different energies that are characteristic of said nuclei, and said detector detects said gamma quanta emitted by said nuclei and measures their intensity as a function of their energy.