Quartz sand beneficiation using magnetic and electrostatic separation to glass industries

Abstract EN

Quartz sand of Fortuna formation was assigned to the Oligo-Miocene.

This formation outcrops in Central Tunisia, particularly in the Ain Bou Morra area.

The grain particle size ranges from fine to medium.

The morphoscopic analysis shows that the useful fraction (100-630μm) consists essentially of transparent quartz grains.

The mineralogical study of samples after separation in heavy liquid indicates that they contain a small amount of heavy minerals such as: tourmaline, zircon and staurotide.

The X-ray diffraction analysis of the total rock revealed that quartz is the major mineral constituent of sand.

Chemical analysis shows high content of SiO2.

Coloring elements (Fe2O3) and (TiO2) are slightly elevated.

The study aim was to remove impurities from silica sand, in order to upgrade quartz sands and to produce material that has a higher potential value for industrial manufacturing processes.

Several processing physical techniques (attrition, gravity, magnetic and electrostatic separation) have been developed.

The obtained material after treatment was characterized using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES).

Chemical results through the combined techniques show a significant increase of impurities (such as Fe, Ti, Cr …) and a significant increase of SiO2.

The final concentrate achieved 99.99 % SiO2, 8 ppm Fe2O3 and 6 ppm TiO2 was obtained, at the optimum operating conditions, from an ore containing about 98.8% SiO2, 0.16% Fe2O3 and 0.05% TiO2.

The treated sand has been found to be a satisfactory material conforms to the requirements of optical glass, crystallaboratory glass and photovoltaic cells.