High speed materials sorting using x-ray fluorescence

Abstract

A system and process for classifying a piece of material of unknown composition at high speeds, where the system connected to a power supply. The piece is irradiated with first x-rays from an x-ray source, causing the piece to fluoresce x-rays. The fluoresced x-rays are detected with an x-ray detector, and the piece of material is classified from the detected fluoresced x-rays. Detecting and classifying may be cumulatively performed in less than one second. An x-ray fluorescence spectrum of the piece of material may be determined from the detected fluoresced x-rays, and the detection of the fluoresced x-rays may be conditioned such that accurate determination of the x-ray fluorescence spectrum is not significantly compromised, slowed or complicated by extraneous x-rays. The piece of material may be classified by recognizing the spectral pattern of the determined x-ray fluorescence spectrum. The piece of material may be flattened prior to irradiation and detection. The x-ray source may irradiate the first x-rays at a high intensity, and the x-ray source may be an x-ray tube.

Description

FIELD OF THE INVENTION This invention relates to a system and process for sorting pieces of materials (by composition) in a stream of materials moving along a conveyor belt. Particularly, this invention relates to a system and process for classifying pieces of materials of unknown composition based on the x-ray fluorescence spectrum of each respective piece so as to permit very high speed sorting of the unknown materials. BACKGROUND OF THE INVENTION Current worldwide environmental concerns have fueled an increase in efforts to recycle used equipment and articles containing materials that can be reused. Such efforts have produced new and improved processes for sorting materials such as plastics, glass, metals, and metal alloys. As used herein, a “material” may be a chemical element, a compound or mixture of chemical elements, or a compound or mixture of a compound or mixture of chemical elements, wherein the complexity of a compound or mixture may range from being simple to comple...

AI Technical Summary

Benefits of technology

"The patent describes a system and process for classifying materials based on the x-ray fluorescence of the material. The system uses a high-speed x-ray source, such as an x-ray tube, to irradiate the material and detect the fluorescing x-rays. The process is faster and more accurate than previous systems, as it uses a high-intensity x-ray source. The system can also analyze the fluorescence of a broad range of elements in the material, and the detection is performed by a detector that is not affected by extraneous x-rays. The system can also use a conveyor to move the material through the detection area, and an ejector to eject the material from the conveyor. The system can also be used to identify and classify materials based on the x-ray fluorescence spectrum of the material. Overall, the system provides a faster and more accurate way to classify materials based on their x-ray fluorescence."

Problems solved by technology

Although use of an x-ray tube has been mentioned as a possible alternative x-ray source for a material sorting system, a high intensity x-ray source has not been implemented by others in such systems, and there are major problems in doing so that have not previously been resolved.

Consequently, there previously has not been shown a system that enables use of a high intensity x-ray source in such a system.

Another problem with many known material sorting systems that classify pieces of material based on the x-ray fluorescence of the material is that such systems are limited to analyzing only the fluorescence of specific, predetermined elements of interest in the piece of material.

Analyzing only select fluorescence limits the accuracy of the identification and the range of materials that can be identified.

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