A Comparative Experimental Analysis of the Effect of Spiral Geometry on the Separation of Fine Chromite Particles. Part 2: Image Analysis Application in a High-Capacity Spiral

The beneficiation of fine particles using spiral concentrators is challenging, although finding the appropriate spiral geometry for specific feed conditions is crucial for a successful concentration or pre-concentration of particles. A previous study (Izerdem, 2024) described a series of spiral separation processes applied to fine, low-grade chromite ore (-200 + 25 µm) under various operating conditions to assess the separation performance of particles across distinct spiral geometries. In addition to the separation efficiency data, understanding the separation behavior of these particles is important. In this study, particle separation was analyzed using an image-based approach. Using a high-resolution camera, images were captured during sampling from a high-capacity spiral (HX5 Ø 100 cm). Sampling and imaging were performed under three distinct flowrates and three splitter blade position configurations, all at a constant pulp density of 25%. The grade and recovery values were integrated with the color analysis of the images. The resulting dataset was then used to develop a predictive model for the concentrate grade by incorporating parameters such as splitter blade positions and the color frequency of the concentrate bands.