Author(s): Maaz A. Ali and Hussin A. M. Ahmed
Article publication date: 2021-03-01
Vol. 39 No. 1 (yearly), pp. 1-18.
686

Keywords

Pyrophyllite; low-grade; mineralogical; chemical; characterization; application; treatment.

Abstract

Purpose: Due to the importance of pyrophyllite as an economical alternative to several minerals such as kaolin, talc, and feldspar in different industrial applications, there is an intention in Saudi Arabia to exploit pyrophyllite in the industry. Since there were no sufficient studies conducted to characterize pyrophyllite in Saudi Arabia, this paper aims to study the chemical and mineralogical characterization of Saudi pyrophyllite ore grades and propose its potential applications besides proposing beneficiation strategies for the low-grade one. Method: In this study, two different grades pyrophyllite ore samples, from a pyrophyllite deposit in western Saudi Arabia, were characterized for their potential applications. Microscopic studies, X-ray fluorescence (XRF), scanning electron microscope coupled with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) were used for chemical and mineralogical characterization of the studied samples. Results: Microscope and XRD results have shown that the ore samples (labeled grade A and grade B) consist mainly of pyrophyllite associated with quartz and feldspar in addition to minor amounts of muscovite, chlorite, and siderite as impurity minerals. Moreover, the results indicated that the impurities are oxide and sulfide minerals (i.e., pyrite, hematite). According to XRF analysis results, grade A contains high alumina (27.03% Al2O3) and low iron (0.4% Fe2O3) whereas; grade B contains a high iron content (2.06% Fe2O3) and lower alumina (24.05 % Al2O2). It is predicted that the grade A with high alumina content can be used directly in fillers, refractories, fiberglass, whiteware ceramics, white cement, porcelain, and cosmetic applications. As for grade B, high iron content limits its industrial applications. Therefore, it needs to be treated to remove ferrous impurities before supply to pyrophyllite market. Conclusion: Based on analytical results, grade A with high alumina content can be used directly in fillers, refractories, fiberglass, whiteware ceramics, white cement, porcelain, and cosmetic applications. Furthermore, grade B needs to upgrade due to high iron content before being used in the industry.