Nepheline Syenite as an Alternative Source for Aluminum Production

Maria Bagani,Dimitrios Panias,Efthymios Balomenos

doi:10.3390/min11070734

Abstract

The increasing demand for aluminum in conjunction with the limited available bauxite deposits in Europe results in the dire need for the evaluation of alternative raw materials for the whole value chain of alumina production. The present paper focuses on the possible use of nepheline syenite, originated as a mine byproduct, in alumina production through leaching with an azeotropic HCl solution. Previous work on nepheline syenite dissolution focused more on the extraction of potassium and sodium values. In this work, emphasis is given at the characteristics and leachability of aluminum content phases by applying a high temperature HCl leaching in untreated material. From this point of view, leaching experiments were conducted on nepheline syenite, at a temperature range of 90 °C to 150 °C and with aqueous azeotropic HCl solution. Leaching, in the aforementioned conditions, is a process, characterized by medium aluminum dissolution. The results show that the aluminum-bearing phases that withstand the dissolution process are mainly the ones of sodium and potassium feldspars.

Highlights

Angelopoulos and Luis PérezAluminum is a necessary technological material
It was dried at 100 ◦ C for 24 h and its chemical composition was determined by wet chemical analysis techniques
The sample was solubilized via fusion method with a mixture of Li2 B4 O7 /KNO3 at 1000 ◦ C for 1 h and was dissolved in a nitric acid solution

Summary

Introduction

As a result of these properties, aluminum can be processed into a wide range of consumer goods and, in addition, has a high value as a recycling material, as the re-melting of aluminum scrap requires only 5%. Of the total energy required for the extraction of the same amount of raw material from ores. Aluminum is projected to maintain and strengthen its position as a high-tech commodity. According to existing data, primary production of aluminum from ores will peak much earlier than the projected peak in demand. The demand for aluminum should remain high for the 60 years, but the possibility of producing quantities that will meet this demand with existing sources and technologies is debatable

Methods

Discussion

Conclusion