Removal of iron and titanium contaminants from Jordanian Kaolins by using chemical leaching

M Gougazeh

doi:10.1080/16583655.2018.1465714

M Gougazeh

Open Access

https://doi.org/10.1080/16583655.2018.1465714

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Abstract

ABSTRACTThe present study deals with chemical leaching tests conducted on Batn El-Ghoul kaolin clay deposit, south Jordan. Mineral identification and characterization studies were conducted using X-ray diffraction. The chemical analyses were performed by X-ray fluorescence. The chemical leaching study with sodium dithionite (Na2S2O4) as leachant was accomplished with the fraction below 44 μm, after classification by screening. The main objective of this study was to evaluate the conditions of chemical leaching for removal of the colouring materials and to improve the brightness. The leaching tests improved the brightness from 56% to 86%. The corresponding iron-oxide removal was in the order of 94%. Removal of 94% iron gives a product containing 0.48% Fe2O3, which is fit for industrial applications such as fine ceramics and as a filler materials in paper, plastic and rubber industries.

Highlights

Kaolin is a finely granulated rock, usually white and chemically inert
The main goal of the present study was to investigate the possibility of using chemical leaching with sodium dithionite (Na2S2O4) of the kaolin samples of a high iron content from Batn El-Ghoul deposit, for the removal of iron, and improve the brightness degree that is compatible with the application of kaolin in fine ceramics and filler clays
The Xray diffraction (XRD) was used to determine the mineralogical characteristics of kaolin samples before and after leaching

Summary

Introduction

Kaolin is a finely granulated rock, usually white and chemically inert. Due to its favourable properties such as natural whiteness, fine particle size, plasticity, nonabrasiveness and chemical stability, it is widely used in many industrial fields [1,2]. As a key element in the paper industry, kaolin is used as a raw material in the production of paints, ceramic articles, rubber, plastics, medicine, fiberglass, catalysts, fertilizers and other products. Kaolin minerals consist of a mixture of hydrous silicates and aluminium and silicon hydroxides as the main component. The important and commonly used kaolin is kaolinite. Kaolinite is chemically [Al2Si2O5 (OH)4], having an ideal composition of SiO2 – 46.54%, Al2O3 – 39.5 % and H2O – 13.96% [3,4]

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