Method And Apparatus For Determining Particle Parameter And Processor Performance In A Coal And Mineral Processing System

Abstract

An image ( 100 ) of particulate material, such as an X-ray image of coal, is captured and processed to determine a parameter of the material, such as particle density or particle size distribution. The performance or efficiency of a processing system, such as a dense medium separator, can be evaluated by determining parameters of the material before entry to and after exit from the processing system. The parameter is determined by comparing image characteristics (relating to statistical features), to a predetermined set of image characteristics. If the image ( 100 ) is obtained by transmission of radiation through the material, accuracy can be improved by measuring the thickness of the material.

1 - 39 . (canceled) 
   
   
       40 . A method of determining a parameter of particulate material, comprising:
 capturing an image of radiation after the radiation has passed through a sample of the particulate material, and which radiation has been altered by the particulate material;   generating local image windows within which only one particle or a group of overlapped particles presents by identifying boundaries of individual particles or groups of overlapped particles;   measuring the thickness of each particle;   determining a set of image characteristics relating to statistical features, textures features, Gabor features and features based wavelet transforms; and   determining the parameter from the set of images characteristics and thickness of particles using a predictive mathematical model.   
   
   
       41 . The method of  claim 40  wherein the parameter is the density of the particulate material. 
   
   
       42 . The method of  claim 40  wherein the radiation is x-ray radiation. 
   
   
       43 . The method of  claim 40  wherein the alteration of the radiation is the attenuation of the radiation. 
   
   
       44 . The method of  claim 40  wherein the radiation is captured by the sensor by illuminating the particulate material with a source of radiation so that the radiation passes through the particulate material to the sensor. 
   
   
       45 . The method of  claim 40  wherein the particulate material is inherently self-radiating or made self-radiating by including radiation producing material within the particulate material. 
   
   
       46 . The method of  claim 40  wherein the captured image is made up of a number of pixels, each of which has an intensity level depending on the degree to which the radiation has been attenuated by the particle through which the radiation passes. 
   
   
       47 . The method of  claim 46  wherein the parameter is determined by generating local image windows within which only one particle or a group of overlapped particles presents by identifying boundaries of individual particles or groups of overlapped particles, determining a set of image characteristics relating to statistical features, textures features, Gabor features and features based wavelet transforms, and determining the parameter from the set of image characteristics and thickness of each particle using a predictive mathematical model. 
   
   
       48 . The method of  claim 47  wherein the set of characteristics are selected from the group consisting of two or more of a plurality of characteristics including total number of pixels, mean, median, standard deviation, kurtosis, skew, entropy, contrast, correlation, energy, local homogeneity, maximum probability, sum entropy, difference entropy and features based on Gabor filters and wavelet transforms. 
   
   
       49 . The method of  claim 48  wherein the determination of the parameter is performed by intelligent data analysis of image characteristics extracted from the captured image. 
   
   
       50 . The method of  claim 48  further comprising the characteristic of a material thickness measure for providing a measure of the thickness of the material. 
   
   
       51 . The method of  claim 40  wherein an X-ray image of calibration sample material is captured in which the parameter is known and determining a set of image characteristics relating to that parameter of the calibration material. 
   
   
       52 . The method of  claim 48  wherein the image characteristics are selected based on those image characteristics which most accurately relate to the known parameter of the calibration material. 
   
   
       53 . The method of  claim 52  wherein the number of characteristics in the set of image characteristics is as low as possible to provide the required degree of accuracy and level of confidence in the determined parameter. 
   
   
       54 . An apparatus for determining the parameter of a particle, comprising:
 a sensor for capturing an image of radiation after the radiation has passed through a sample of the particulate material, and which radiation has been altered by the particulate material; and   a data processor for generating local image windows within which only one particle or a group of overlapped particles presents by identifying boundaries of individual particles or groups of overlapped particles, and determining a set of image characteristics relating to statistical features, textures features, Gabor features and features based wavelet transforms, comparing the set of image characteristics with a predetermined set of image characteristics relating to the particulate material, and determining the parameter from the comparison.   
   
   
       55 . The apparatus of  claim 54  wherein the radiation is captured by the sensor by illuminating the particulate material with a source of radiation so that the radiation passes through the particulate material to the sensor. 
   
   
       56 . The device of  claim 54  wherein the device also includes a source of radiation for producing radiation for irradiating the particulate material, so the radiation can pass through the particulate material. 
   
   
       57 . The device of  claim 56  wherein the sensor and the source of radiation are provided in a housing and a conveyor is provided for conveying the particulate material passed between the source of radiation and the sensor, so the radiation can pass through the particulate material, and so the respective images can be captured by the particulate material. 
   
   
       58 . The apparatus of  claim 54  wherein the particulate material is placed on a stationary flat plate between the source of radiation and the sensor, so the radiation can pass through the particulate material, and so the respective images can be captured by the sensor. 
   
   
       59 . The apparatus of  claim 56  wherein the sensor is an X-ray linear array detector based various detecting techniques, such as scintillator and photoconductors, or a CCD X-ray detector having a plurality of pixels for creating the images. 
   
   
       60 . The apparatus of  claim 54  further comprising a device for measuring the thickness of the material for providing a thickness measure for improving the accuracy of the determination of the parameter. 
   
   
       61 . (canceled) 
   
   
       62 . (canceled)