APPLICATION OF NIR MINERAL PHASE ANALYSIS IN BAUXITE ORE IN THE EXAMPLE OF CHALCO

This technical paper examines the theory behind near infra-red (NIR) real time analysis for the use in the minerals industry and the practical application of an online chemical analyzer for Bauxite analysis in the aluminum industry, focusing on improving process control in digestion and optimizing Alumina recovery.
Traditional lab-based analysis methods are often not correctly representing the chemistry of the bulk bauxite fed to the process as sampling techniques cannot keep up with the mass of material. Further the time delay till the samples are analyzed prevent a proactive process control. Hence a real time analysis, which scans the entire bulk of Bauxite going to the process will allow for real time process control, especially as NIR technology will measure mineral phase composition as well as organics and moisture.
As part of the paper, an installation Chalco is showcased, and online analysis is compared with the lab results. In addition, an outlook to the process control is given.