Affinity of dual energy X-ray transmission sensors on minerals bearing heavy rare earth elements

This work demonstrates the effective use of automatic sensor-based sorting technology as a viable separation method for rare earth element (REE) rich ores composed primarily of xenotime minerals with gagarinite-(Y) and fluocerite-(Ce, La) inclusions. A dual energy X-ray transmission (DE-XRT) sensor affinity was used to evaluate forty-two heavy rare earth element (HREE) ore grab samples from the Madeira deposit. These samples and separated products were scanned by the sensor under many operating parameters. Subsequent analyses, including petrographic and multi-element chemical analyses were performed on the grab samples. Specific mass tests were also compared with energy attenuation curves from the sensor, which correlated strongly with every concentration stage the highest achieved density being 3.01 g/cm(3). The best estimated HREE recovery from laboratory-scale sorting of the samples identified by the sensor was effectively 100%, however this occurred in conjunction with a mass recovery equal to 97% of the feed. Such results are expected knowing that the sample method was not entirely representative. Ongoing research into automatic sorting technology for the upgrading of Brazilian ores is being performed by the Federal University of Rio Grande do Sul (UFRGS), Brazil.