Preliminary analysis of the application of sensor based sorting on a limestone mine in the region Caçapava do Sul, Brazil

Abstract

This work seeks to evaluate the effect of the sorting of calcium/magnesium carbonates (limestone ores) through the use of X-ray and CCD camera sensors. Collection of the 17 samples used for this study was performed after primary crushing at a size range between 76 and 152 mm (3–6″). This work seeks to evaluate the effect of the sorting of calcium/magnesium carbonates (limestone ores) through the use of X-ray and CCD camera sensors. Collection of the 17 samples used for this study was performed after primary crushing at a size range between 76 and 152 mm (3–6″). Sampling was intended to represent all of the possible variations of the ore and waste currently being extracted. For initial characterization, samples were washed and subjected to analysis by a handheld X-ray fluorescence spectrometer. Sensor based sorting tests were performed at the Federal University of Rio Grande do Sul (UFRGS) using a COMEX lab sorter. The lab sorter is comprised of a conveyor belt, mounted sensors, a data processing system, and a pneumatic flap system for the physical separation of the samples. Results of the X-ray separation showed that of the 12.2 kg of samples, 10.5 kg were sorted into product and only 1.7 kg were separated as waste. However, within the waste fraction, only 54.5% was considered waste, and likewise 7% of the product fraction was considered waste. When using the CCD camera, 100% of the ore fraction and 100% of the waste fractions were considered to be sorted correctly. While it is important to note that this is only a preliminary study analyzing the viability of implementation of the automatic sorting system, these preliminary results obtained with the use of both sensors were considered satisfactory.