Evaluation of the Standard Procedure to Assess the Sphericity and Size of Pellets Using Image Processing Techniques

Abstract

Through Pelletization iron ore fines produced spheres of typically 9––16 mm diameter which can be used as the raw material to the blast furnace. In the process of pelletizing the pellets may be produced of different sizes. Since the permeability of the blast furnace depends on the shape and size of the pellet it is desirable to produce nearly spherical pellets with a diameter range of 9–16 mm. There are many physical methods such as using a scale or caliper and solid displacement method to measure the size of the pellet. The shape and size of the pellet can be changed during measurement since they are wet. However, without physically handling them it is very difficult to measure the shape and size. This paper describes digital image processing techniques that are used to extract sphericity and size information from the 2D image of iron ore pellets. The techniques are simple but very useful for industrial applications. Online image processing method is also presented for calculating the sphericity and the size of a single/multiple pellets by software and its toolboxes. The technique can suitably derive the size distribution of a number of pellets. The technique is validated by conducting a number of experiments.