Current and Foreseen Tungsten Production in Portugal, and the Need of Safeguarding the Access to Relevant Known Resources

Abstract

The economic and strategic importance of tungsten is widely recognized, but several concerns exist on its stable future supply. Portugal is one of the main tungsten producers in Europe, having generated ≈121 kt of contained tungsten in mineral concentrates from 1910 to 2020, i.e., ≈3.3% of the global production documented for the same time period. Since the early nineties, tungsten mining in Portugal is confined to the Panasqueira deposit which accounts for 79% of the country reserves (≈5.4 kt). However, according to the performed Generalized Verhulst and Richards curve-fitting forecasts, there is a significant future potential for increasing production in Portugal due to the low (<2%) depletion rates of the remaining known tungsten resources (≈141 kt). This projected growth is not necessarily guaranteed, depending on many unpredictable economic, technological, and political factors, besides appropriate social consents. Even so, a prudent land-use planning oriented to long-term needs should avoid the sterilization of the most relevant tungsten resources so far identified in the country. These are resources of “public importance”, as objectively demonstrated with a weighed multi-dimensional (geological, economic, environmental, and social) approach. Safeguarding the access to these resources does not implicate more than ≈6% of the Portugal mainland territory. The joint interpretation of results independently gathered for tungsten production forecasts and for the definition of areas hosting tungsten resources of public importance, provides additional support to political decisions on the urgent need to reconcile mineral exploration surveys and mining with other land uses.

Progress in Sustainable Recycling and Circular Economy of Tungsten Carbide Hard Metal Scraps for Industry 5.0 and Onwards

“…Several factors are responsible for the growing tungsten (carbide) recycling market In regard to 'strategic and rare metal' tungsten, the global market in 2017 was 105,000 Mt. In 2022, it was evaluated at 119,000 Mt, and is predicted to reach a revised size of 170,000 Mt by 2030, representing the cumulative effect of an average annual growth (CAGR) of ≈4.5% [28,80]. More tungsten products will finally lead to increased scrap recycling and, thus, to a larger need to process scraps.…”

“…Some mines that have closed in the past years in Australia, South Korea, and the USA are now considering re-opening. Altogether, China is the largest producer, exporter, and consumer of the world's total (primary) tungsten (71,000 Mt, almost 84%) [26,27], although, in recent times, and especially in the European Union (EU), a significant growth (yearly) of tungsten production has been reported in Austria, Spain (doubled in 2021 by 500 Mt), and Portugal [28]. Tungsten's importance in numerous applications for industries and its low substitutability (especially in hard metals and steel additives) gains it the highest 'economic importance'.…”

Fluid Processes of Wolframite-Quartz Vein Systems: Progresses and Challenges

“…These veins generally intersect Cambrian metapelites and, less commonly, cut granites. The Panasqueira W (-Sn) deposit is one of the largest tungsten deposits in Europe, and the deposit itself accounts for 79% of Portugal's total W reserves (5.4 kt, [103]). Densely developed wolframite-bearing subhorizontal hydrothermal quartz veins and the greisenized cupola (greisen) of a Variscan S-type granite provide the main W resources in Panasqueira.…”

Simultaneously Recovery of Thorium and Tungsten through Hybrid Electrolysis–Nanofiltration Processes

“…The performances proven by membrane separation processes in various ecological and greening technologies constitute important arguments for their involvement in the recovery and recycling of various urban wastes, especially those that generate toxic products [ 1 , 2 , 3 , 4 ]. Thus, in order to develop a technology for the separation and valorization of some metallic elements from specific urban waste, baromembrane processes can be applied, when the elements are in a colloidal (nanometric) or suspension (micrometric) state, or processes with electric and/or concentration gradient, if the metals are found in the forms of ions [ 5 , 6 , 7 , 8 ].…”

“…Moreover, tungsten has been the focus of process engineers for its recovery from various residues through electrolytic processes and acid or basic solubilization processes [ 26 , 27 , 28 , 29 , 30 ]. On the other hand, thorium has been the focus of researchers in the field of membranes for concentration, separation or purification, especially when it comes from ores in which uranium or rare earths can also be found [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] ( Table 1 ).…”