| 摘要 |
1,152,407. Sorting ores by reflectance. SPHERE INVESTMENTS Ltd. Feb.2, 1968, No.5527/68. Heading G1A. In a method and apparatus for sorting irregularly shaped objects such as ores in which the objects are moved through a sorting zone which is scanned repeatedly across the zone to detect light reflected from discrete areas of the objects and zone, a series of at least three parameters are derived from the reflected light, a plurality of them are selected for comparison in a predetermined manner, and the result of the comparison is used to effect acceptance or rejection of an object . The ores are fed from a hopper to a belt conveyer passing through the sorting station by way of two vibrating conveyers and a shoot, the last named accelerating the lumps to approach the speed of the test conveyer which is faster than the others, to achieve separation of the pieces. The test conveyer may be black or white to provide a desirable background for the rock being sorted and the sorting is by blasts of compressed air from one of a number of apertures corresponding to the identified position across the belt of the object. The light source, which may be a laser, and the detector are repeatedly scanned across the belt, by a mirror drum, the detector including a polarizer to receive the reflected laser light and reject specular reflection. Photo-cells determine the lateral limits of each scan and a reflecting standard is included in the scanned path for calibration purposes. A draught of air and screens may be provided to keep dust from settling on the optical apparatus. The apparatus is described for sorting gold ore and in this case the following parameters are selected by preset switches for determination. The number of white areas per unit of area. The area of a piece of rock. The black area of the piece of rock. |
