Zero-waste valorisation of feldspathic ores: green application and sustainable sourcing of strategic raw materials


Erdemoğlu M., Sis H., Birinci M., Erdemoğlu S., Boyrazlı M.(Yürütücü), Turan M. D., et al.

UFUK 2020 Projesi, 2022 - 2025

  • Proje Türü: UFUK 2020 Projesi
  • Başlama Tarihi: Nisan 2022
  • Bitiş Tarihi: Nisan 2025

Proje Özeti

Potassium (as K2O or potash) is one of the essential macronutrients required for plant growth and currently has no cost-effective substitutes. Because of high solubility of potash minerals in water, it cannot be recovered and recycled. This fact makes it necessary to find new potash resources in the future. Meanwhile, technological advancements have led to an increase in the global consumption of aluminium, with a decrease in high-grade bauxite reserves, thus spurring research efforts toward the utilization of non-bauxite ores. Because, non-bauxites are unable to compete with Bayer’s process, Al-silicate-bearing ores can be new resource of Al2O3 in the future. 

In this project, feldspathic ore containing mainly K-Feldspar (KAlSi3O8) will be valorised by a combined metallurgical process at which KCl, Al2O3 and SiO2 will be produced without generating any waste. It will also be investigated whether the ore can be used in CO2 sequestration and whether it is possible to produce Ca-Silicates and SiC.

Objectives of the project are (i) providing new resources for potash and alumina (ii) providing SiO2, Ca-Silicates, and (iii) SiC production from the same resources. Although there are studies on K and Al2O3 recovery from K-feldspar and clays, respectively, there are no notable commercial attempt to date. This is attributed to the fact that recovering K and Al2O3 from silicate minerals alone will not pay the cost of the reagents and energy used. Unlike the production of KCl by the CaCl2 route and Al2O3 by acid leaching, both producing silicates as tailings, the production of KCl, Al2O3, SiO2, Ca-Silicate, and SiC from the same ore without any solid waste is the originality of this project. Innovative aspect of the project is that feldspathic ores will be processed as a source of high value-added materials for the first time and with zero-waste approach, thus increasing the economic value of whole process. As well, CO2 sequestration capability of the feldspathic ore will be also considered to enhance the economic importance of the feldispatic minerals.

As an example for increased raw materials efficiency, a novel, hybrid and zero-waste method will be put forward and this will be carried out by using the resources other than bauxite and natural potash ores. Another impact is production of SiO2, Ca-Silicate, and SiC from the process residues, by applying an environmentally sensitive production processes. Because it is intended that new products will be obtained by processing the co-product obtained in each process step, to ensure that the process tailings does not occur as much as possible with the zero waste approach, and/or the other wastes to be generated will consist of materials that are less in quantity and do not pose environmental risks. Thus, designing the entire production process with a zero waste approach will be operational both industrially and environmentally. To finish, CO2 sequestration studies will be the first attempt using feldspathic minerals as a deposit for CO2. It is expected that the project will have indirect effects such as (i) Implementation of the zero waste project idea in the mining and metallurgy, (ii) Using the silicon species to be produced in the field of nanotechnology, (iii) Emergence and development of multi-partner international project

ideas.

The project will also (iv) unlock a substantial volume of various raw materials from deposits (e.g. Feldspatic ores, K-feldspar ores, muscovite ores) that cannot be economically or environmentally exploited within or outside EU through enabling the better efficiency of exploitation of raw materials’ resources and increasing the range and yields of recovered raw materials, (v) push Europe to the forefront in the area of raw materials processing technologies and (vi) increase availability of recovered raw material and create added value products through reducing the quantities of the industrial tailings to be disposed or landfilled.