“Romano” Mine is in the Alto Barroso region. Barroso is a region in the north of Portugal, mainly mountainous and occupying the Barrosão plateau, located northwest of the district of Vila Real in the province of Trás-os-Montes, comprising the municipalities of Montalegre and Boticas. Both municipalities are part of the Intermunicipal Community of Alto Tâmega. “Romano” Mine is in the municipality of Montalegre.
This border municipality, with 25 parishes occupying 805.46 km² of area, geographically confronts the Spanish province of Galicia in the north (municipalities of Lobios, Muíños, Calvos de Randín, Baltar, Cualedro and Oímbra), in the south with the Municipality of Cabeceiras de Basto, southwest with Vieira do Minho, in the west with the Municipality of Terras de Bouro, in the east with the Municipality of Chaves, and in southeast with the Municipality of Boticas.
The Gerês-Xurés transboundary Biosphere Reserve, where the “Romano” Mine is located, was declared on May 27, 2009 by UNESCO, and is located in the Autonomous Community of Galicia (Spain) and in the Northern Region of Portugal. It covers a total area of 267,958 ha. distributed over two protected areas, the “Peneda-Gerês” National Park and the “Baixa Limia-Serra do Xurés” Natural Park, integrating, in 1997, the “Gerês-Xurés” Transfrontier Park, divided by a border, but united by the natural continuum and by the culture.
In the past, part of the area that is currently integrated in the “Romano” Mine concession was the target of tin mining in the form of cassiterite (SnO2), and other metals, but in smaller quantities, such as niobium and tantalum from columbo-tantalites-coltan concentrates (Fe, Mn) (Ta, Nb)2O6.
In these former exploitations, called “Couto Mineiro de Bessa”, several topographic depressions are currently exposed and associated with recognized excavation fronts and underground entrances associated with the development of galleries were left as environmental liabilities.
The extractive works that took place in the former “Couto Mineiro de Bessa” are associated with a mining plan dated from 1947, reporting activities since the end of the 1st World War. Previous works from the year 1926 and still others that date back to the occupation of the Roman Empire on the Iberian Peninsula. The mining plan fully explains the geographic location, communication routes, geological cartography, ways of transporting ores along the underground galleries to the surface, ventilation and lighting and sewers.
In the area corresponding to the “Romano” concession there are bodies of an aplite-pegmatitic LCT in the form of swarms of dykes. In these rocks, leucocrats (light colored) and arranged in swarms or clusters of lodged dykes, other hosting rocks of a metasedimentary (Andalusian mica schists) also appear and which are clearly distinguished from the others by their much deeper coloration, high schistosity, and deformation. The pegmatitic rocks contain important anomalous occurrences of ore-minerals that have high-value in some chemical elements (petalite - lithium; cassiterite - tin; columbo-tantalite - niobium and tantalum) and industrial minerals such as sodium and potassium feldspars and quartz.
Lithium is a metallic element that constitutes minerals such as lepidolite, spodumene, petalite, amblygonite and others. The main lithium ore in the “Romano” concession is petalite, which corresponds to a tectosilicate (LiAlSi4O10) Lithium is a metallic element that constitutes minerals such as lepidolite, spodumene, petalite, amblygonite and others. The main lithium ore in the “Romano” concession is petalite, which corresponds to a tectosilicate 78,67% in SiO2, 16,58% in Al2O3e 4,32%
in Li2O.
The concession's “Romano” deposit reserves, based on data obtained during prospecting and research, reported lithium mineral resources based on the morphology of the lithiniferous aplite-pegmatitic deposit, resulting from the interpretation of transversal profiles and level plants, provided the determination of a Li2O content and respective tonnage, assuming an economic (not mining) cut-off content of 0.3% Li2O and a density of 2.4 (density of petalite and not of LCT rock).
Initially, the calculation of reserves for the “Romano” concession was carried out by competent person’s according to JORC standards. More recently, a new calculation of reserves for the “Romano” concession was carried out by independent and specialized consultants at Datamine International Ltd. Lusorecursos proposed to update and improve the information (e.g., geostatistics, database, geological model with cut-off mining among aspects of a graphic nature) regarding the lithiniferous and tin resources of the concession mineral deposit.
The estimated current total provable resource of 15 Mtonnes and beyond the mining reserve contained therein, the aforementioned prospecting and research indicators point to a target zone (Exploration Target) throughout of the considered axis of about 3x1km, but that this project's current reference value will be doubled, for the hypothesis of a total of 30 Mtonnes for the concession, that is, as then, this objective is now reinforced indicated target.
OPEN-PIT
The extraction of the pegmatitic rocks (LCT) from the "Romano" Mine will be carried out through open pit exploitation and surface cutting. In Open pit, using a precision surface mining process called Strip Mining. Contrary to explosive and underground drilling methods, this process optimizes the separation between the materials of interest and the rest, promoting a more effective initial separation and, thus, increasing its quality for downstream transformation processes.
Strip Mining method consists of cutting or ripping material from the top of the deposit following a pattern pre-defined by surface miners (e.g., Vermeer T1255 Terrain Leveler). The cutting drum uses tungsten nozzles to fragment the rocks it crosses, and it will be mounted located at the back of the miner, cutting the material while the tracks advance over the ground yet to be cut. This equipment has a low centre of gravity that guarantees the best traction, keeping it balanced and stable. The surface miner to be used in open pit exploitation, has sophisticated automated systems, and has a suction instrument attached so that the dust emitted during the extraction process is completely reduced.
Top-down cutting system allows the nozzles to penetrate the ground without using the machine's traction effort. This technique gives operators the opportunity to control the size of the product by changing the cutting depth of the drum. The disaggregated material is left on the ground behind the machine, ready to be loaded and transported. Then, it will be stacked / grouped in stockpiles by bulldozers and loaded with wheel loaders to be transported by dumpers. It is also important to note that Vermeer surface miner will also be used in the construction and maintenance of ore transport roads, other access routes to and from the concession.
Part of the material will be taken to the Lusorecursos industrial unit, in order to be processed and chemically transformed. The remaining waste rock will be deposited in temporary landfills, and finally, used to fill the cavities resulting from the underground exploitation method.
UNDERGROUND
The mineral deposit is tabular in an east-west direction with a horizontal extension (strike) of about +830.00 m and an inclination of approximately 55° to 70° (Dip), with a maximum strength of the mineral deposit of 68 m, with respect to the "Romano" orebody. The ore is associated with pegmatitic dykes, in which the main exploration will focus on the main pegmatite called “Romano”. However, there are other dykes in the south of this one that must be exploited. The tabular geometry of the pegmatitic bodies makes their underground exploitation viable, as there is less waste rock extraction. Thus, it is assumed that the mineral dilution will be reduced, since the waste rock will not need to be removed and can be used to support the work being carried out underground, ensuring the necessary safety conditions.
It is necessary to carry out the excavations for its development and layout, at the production fronts (dismantling). The excavation of a Main Access Ramp (MAR - Main Access Ramp) is planned, with a gradient of about 10% to 11%, length of 1 600 m, which will serve for quick access to the other underground works of the mine and it will also provide for the circulation of trucks and other heavy machinery, as well as for the extraction of ore by conveyor belt. The development and layout of the mine will be to the south and the wall of the “Romano” deposit, so the Ramp will provide access and service to that area. The need for a second access to the mine is recognized, the Main Access Shaft (MAS-Main Access Shaft), which will serve as an emergency exit, transport of material for filling (Backfill) and as an alternative for ore extraction.
The shaft’s proximity to the Pit minimizes transport as well as horizontal gallery excavation footage, good access to mine infrastructure (crushing plant, secondary ramps, developing and production cuts). Its location in a favourable geological and geotechnical zone implies less difficulties, lower costs, less excavation time, as well as enhancing the stability of the structure affecting the shaft. At this stage, specific equipment will be needed for underground work, as these must have specific characteristics, such as reduced dimensions, greater manoeuvrability and other attributes related to the confined environment.
Lusorecursos Portugal Lithium intends to produce lithium hydroxide monohydrate (LiOH.H2O) from petalite and spodumene concentrates, which come from the extraction and beneficiation of the pegmatite rocks (LCT) of the "Romano" Mine.
The mining annex complex will consist in a Concentrator and a Chemical/Hydrometallurgical Transformation Plant for mining concentrates.
CONCENTRATION
The concentration consists in the fragmentation of the ore, with the consequent separation of their different mineral constituents, using several specific methods (e.g., crushing and milling, granulometric separation, optical sorting, magnetic and gravity separation and foam flotation processes, among others).
HYDROMETALLURGY
Hydrometallurgy consists of converting petalite and α-spodumene into β- spodumene after calcination at 1100 ° C. Then, these materials are subjected to a set of chemical processes that culminate in the formation of lithium hydroxide - LiOH.H2O ultrapure, a precursor suitable for the synthesis of compounds that integrate cathodes and electrolytes of battery cells.
One of Lusorecursos concepts and policies is the Circular Economy, in which it has partners who carry out sustainable, modern and innovative development measures in processes and products, to make the company more efficient and competitive in the sector in which it operates. The Circular Economy in the case of “Romano” Mine is an approach ranging from the extraction of raw materials and the production of lithium hydroxide, to reuse, recovery and recycling of resources, also focusing on encouraging the reduction of consumption.
