Heavy Mineral Sands in Brazil: Deposits, Characteristics, and Extraction Potential of Selected Areas

Caroline Gonçalves,Paulo Braga

doi:10.3390/min9030176

Abstract

In Brazil, heavy mineral sand deposits are still barely exploited, despite some references to Brazilian reserves and ilmenite concentrate production. The goal of this project is to characterize and investigate the potential recovery of heavy minerals from selected Brazilian placer occurrences. Two areas of the coastal region were chosen, in Piaui state and in Bahia Provinces. In all samples, the heavy minerals of interest (ilmenite, monazite, rutile, and zircon) were identified by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques and also quantified by X-ray fluorescence spectrometry (XRF) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The total heavy minerals (THM) in the Piaui samples were 6.45% and 10.14% THM, while the figure for the Bahia sample was 3.4% THM. The recovery test of the Bahia sample, using only physical separation equipment such as a shaking table and magnetic separator, showed valuable metallurgical recoveries at around or greater than 70% for each stage, and the final concentrate of pure ilmenite was composed of up to 60.0% titanium dioxide after the differential magnetic separation. Another aim is to compile accessible information about Brazilian heavy mineral main deposits complemented with a short economic overview.

Highlights

Brazil is considered the biggest producer of titanium dioxide in Latin America [1,2], mostly from ilmenite, studies about heavy minerals in the national territory are still scarce, limiting exploration works
Heavy mineral sands are different than other commodities in terms of exploration, development, mining, and processing, but similar in the matter of importance to industry due to their relevant physical properties [3]
The ilmenite final concentrate is considered that recovered at 250 and 300 rpm, and according to the chemical analysis by X-ray fluorescence spectrometry (XRF) (Figure 11b), TiO2 content is slightly higher than 60.0%

Summary

Introduction

Brazil is considered the biggest producer of titanium dioxide in Latin America [1,2], mostly from ilmenite, studies about heavy minerals in the national territory are still scarce, limiting exploration works. The mention of defunct institutions as producers, and inaccurate grade-tonnage calculations of heavy mineral sands in international publications are common mistakes due to dispersed and hard-to-access information. Research aiming to identify new target areas and to compile accessible data seems to be a necessary step to plan future projects, considering the relevance of heavy mineral deposits in the international market. Heavy mineral sands are different than other commodities in terms of exploration, development, mining, and processing, but similar in the matter of importance to industry due to their relevant physical properties [3]. Heavy minerals from beach sands are concentrated by physical methods, first involving gravity separation, followed by the combination of magnetic and electrostatic

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Discussion

Conclusion