Proposal for an Environmentally Sustainable Beneficiation Route for the Amphibolitic Itabirite from the Quadrilátero Ferrífero-Brazil

Gizele Maria Campos Gonçalves,Rosa Malena Fernandes Lima

doi:10.3390/min10100897

Gizele Maria Campos Gonçalves, Rosa Malena Fernandes Lima

Open Access

https://doi.org/10.3390/min10100897

Copy DOI

Abstract

The high world demand for iron ores opposed to the rapid exhaustion of high-grade deposits from the main producing regions around the world has motivated the search and/or improvement of beneficiation routes, which enable the economic use of iron formations previously considered marginal ores, which have the potential to considerably increase mineable reserves due to their large volume. In this study, a sample of amphibolitic itabirite from the eastern region of the Quadrilátero Ferrífero, Minas Gerais, Brazil was characterized, aiming at its use in the industrial pelletizing circuit. The main physical characteristics of this ore are moisture = 10% and specific weight = 3710 kg/m3. The ore has a high grade of loss on ignition—LOI (6.7%) and P (0.14%). Through X-ray diffractometry (XRD), optical microscopy and scanning electron microscope—SEM, the ore was found to consist of 64.5% goethite (amphibolitic, alveolar, massive and earthy); 6.8% hematite (martitic, granular and lamellar) and 0.9% magnetite. The main gangue mineral is quartz (25.5%). Based on the results of concentration tests (magnetic and flotation) performed with the studied sample, the magnetic concentration route of deslimed sample followed by the addition of slimes in magnetic concentrate can be incorporated into the pelletizing process.

Highlights

Iron ore is the second-most traded mineral commodity on the market, mainly for the manufacture of cast iron and steel (98% of the world production) [1,2,3]. It corresponds to 15% of the products exported by Brazil, which stands as the third-largest iron-producing country and holds 12% of the world reserves, located mainly in the provinces of Quadrilátero Ferrífero, minas Gerais (MG) and Carajás, Pará (PA) [4,5]
Due to aa higher proportion of for gibbsite in this sample. both reverse flotation, using amine/starch, and magnetic concentration are recommended to concentrate iron ore, whose hematite or goethite are Deslimed of amphibolitic66.9 itabirite
Compared with the magnetic concentrate of the same sample (0.9 T field magnetic), the Fe grade was about 3–4% smaller, and the SiO2 grade was ~6% higher. both the mass recovery and Fe recovery were smaller by 32.2% and 42.6%, respectively, compared with the magnetic concentration. It means a huge loss of values for tailings. Both reverse flotation, using amine/starch, and magnetic concentration are recommended to concentrate iron ore, whose hematite or goethite are the main bearing minerals of iron, and quartz is the main gangue mineral, the performance of magnetic flotation was better compared with the flotation for the studied ore [31]

Summary

Introduction

Iron ore is the second-most traded mineral commodity on the market, mainly for the manufacture of cast iron and steel (98% of the world production) [1,2,3]. The exhaustion of high-grade iron ore deposits from the main producing regions, located in Brazil, Australia, India and others, coupled with increased demand in the world market and increasingly severe environmental restrictions, have imposed a great challenge for the mineral industry. This current situation implies the development of beneficiation routes for marginal ores, aiming at greater metallic recovery and the minimization of tailings disposal, as well as the reprocessing of tailings deposited in dams, with Fe grades greater than 30%, to obtain products within the specifications for the steel industry [6,7].

Methods

Results

Conclusion