The Alvarrões-Gonçalo Li project: an example of sustainable lithium mining

Abstract

Across Europe, small scale deposits of critical materials and/or strategic elements, such as W, Li and Sn, are not viable to mine and process using the traditional large scale mining and processing technologies due to their geological characteristics. Project FAME (Flexible And Mobile Economic Processing Technologies, EC Horizon 2020 Grant Agreement No. 641650) was created in order to specifically address the technical and environmental challenges to the sustainable processing of low sulphide ores from pegmatites, greisens and skarns deposits. One of the deposits, Alvarrões-Gonçalo, is a Li pegmatite located at the Gonçalo pegmatite field (Central Portugal) that is being investigated on the scope of the concerned project. Currently, the pegmatites are only being exploited for ceramics, aggregates and ornamental purposes, however, there is exploitation potential for Li 2 O-rich ores. Froth flotation is being tested to produce a lepidolite concentrate. Results showed the feasibility to obtain a Li 2 O grade adequate for the metallurgical production of lithium compounds as Li 2 CO 3 . The lepidolite flotation rejects, normally stored in tailings dumps, are mainly composed by a mixture of feldspars, quartz and nonrecovered lepidolite (though a very low content), which is, by itself, a very interesting raw material for ceramic purposes. Consequently, mining exploitation of lepidolite, as Li 2 O ore, from pegmatite could comply with the standards of "green mining", reaching an almost "zero waste" exploitation, as it can be accomplished in the case of the mineral processing of the Alvarrões-Gonçalo lithium ore. This basic scenario could be improved by applying froth flotation also for feldspars/quartz separation, aiming at obtaining a high content feldspars concentrate (floated) and a quartz product (non-floated): the feldspars concentrate can be used to produce blends with different ratios feldspars/quartz for sanitary ware and tiles and quartz for other uses, such as glasses and "silica flour".

Geochemistry and mineralogy of wastes from lithium-bearing granite-pegmatite mining: resource potential and environmental risks

“…The Li concentrations in the granite-pegmatite wastes (Table 2) have been considered high enough for researchers and industry to find optimal methods for their reprocessing. Froth flotation has been Frontiers in Geochemistry frontiersin.org successfully shown to concentrate the spodumene (Yusupov et al, 2015;Tian et al, 2018), lepidolite (He et al, 2013;Sousa et al, 2018) and zinnwaldite (Samková, 2009;Jandová et al, 2010;Siame and Pascoe, 2011) from these wastes to upgrade their Li content (Table 3). Flotation can be followed by magnetic separation to further increase the amount of Li in the concentrate to around 4.5-6.0 wt% Li 2 O (Siame and Pascoe, 2011;Yusupov et al, 2015;Tian et al, 2018).…”

“…Flotation can be followed by magnetic separation to further increase the amount of Li in the concentrate to around 4.5-6.0 wt% Li 2 O (Siame and Pascoe, 2011;Yusupov et al, 2015;Tian et al, 2018). The remaining feldspars and quartz can also be separated by flotation and used for other products (Sousa et al, 2018;Tian et al, 2018)(see next section). These combined actions can use of the majority of the wastes produced from the primary mining (e.g., 70%; Tian et al (2018)).…”

Technospheric Mining of Mine Wastes: A Review of Applications and Challenges

“…The fundamental feature of eco-efficiency is to create more products with fewer resources and less waste and pollution [118]. It is closely related to the circular economy and sustainable development [40,109,[119][120][121][122][123][124][125]. Finding and understanding ways to incorporate and implement eco-efficiency in technospheric mining is necessary.…”

A Sustainable Process for Efficient Extraction of Lithium, Aluminum, and Phosphorus from Montebrasite

“…The Cambrian shale and limestone in the eastern Argemela area of the Panasqueira tungsten mine in Portugal contain abundant lithium deposits. − The estimated reserves of the shallowest part of the deposit are 20.1 million tons, and the main lithium minerals are montebrasite and lepidolite . Montebrasite deposits have also been discovered in the Almendra-Souto area and the Alvaros-Goncalo pegmatite vein in Portugal, and Lima and Almeida are conducting detailed investigation. In Tuscany and Rome, Italy, researchers have discovered lithium deposits that can be exploited on a large scale .…”