Production of scandium from mining waste to obtain high-pure product

• Grant number: 23/15491-1
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: December 18, 2023
• End date: February 28, 2024
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Jorge Alberto Soares Tenório
• Grantee: Vítor Moor Pinheiro Braz
• Supervisor: Mentore Vaccari
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Università degli Studi di Brescia, Italy
• Associated to the scholarship: 22/16507-6 - Study of the effect of iron on the recovery of scandium from mining waste., BP.IC

Abstract

Scandium is representative of the rare earth elements that are present in miningwaste and holds high commercial value. However, it is found in low concentrations inthese waste materials, with iron being the primary contaminant. In this context, it isadvisable to study the influence of iron on scandium recovery using the solventextraction method. This process consists of several stages, including the extractionphase, in which the metal of interest is transferred from the aqueous phase to theorganic phase, followed by the washing stage, where the organic solution from the firstphase contacts a solution to remove co-extracted impurities. The third stage is reextraction, used to remove the metals of interest from the organic phase, and the finalstage is the regeneration of the organic phase so that it can be returned to thebeginning of the process. In this work, the extraction of scandium from mining wasteusing the organic extractants Cyanex 923 and Alamine 336 will be studied, testingvarious reaction conditions, including pH, extractant concentration, and theconcentration ratio between the extractants. For stripping, sulfuric acid will beevaluated in different concentrations and temperature to obtain pure-scandiumsolution. A final experiment will be carried out with a synthetic solution simulating theleaching of bauxite residue (also called as red mud). Then, fluoride precipitationexperiments will be carried out to obtain the most valuable scandium product.Additionally, a technical-economic analysis of the proposed process will be conductedto assess the feasibility and environmental impacts of the process.