Despite their significance in numerous applications, many critical minerals and metals are still considered minor. Since most of them are not found alone in mineral deposits, their co- or by-production depends on the production of base metals and other major commodities. In many cases, the concentration of the minor metals is low enough not to be considered part of the production. Hence, their supply is not always secured, their availability decreases, and their criticality increases. Many researchers have addressed this issue, but no one has set actual impact factors other than economic ones that should determine the production of these minor commodities. This study identified several parameters, the number and diversity of which gave birth to developing a computational tool using a multi-criteria-decision analysis model based on the Analytical Hierarchical Process (AHP) and Python. This unprecedented methodology was applied to evaluate the production status of different commodities in a polymetallic deposit located in Chovdar, Azerbaijan. The evaluation outcomes indicated in quantifiable terms the production potentials for several commodities in the deposit and justified the great perspectives of this tool to evaluate all kinds of polymetallic deposits concerning the co- and by-production of several minor critical raw materials.

This study investigates the structural, mechanical, optical, thermal, and electronic properties of the ionic semiconducting materials XZrS₃ (X = Ca, Ba) within the framework of density functional theory (DFT). Here, the elastic constants, modulus (bulk, shear, Young's), ratios (Pugh, Poisson) and elastic anisotropy for XZrS₃ (X = Ca, Ba) are studied. Furthermore, the electronic, optical, and thermal properties for XZrS₃ (X = Ca, Ba) are regenerated and designed using the values obtained with Cambridge Serial Total Energy Package (CASTEP) software. The calculated lattice parameters show excellent agreement with theoretical and experimental values. The elastic stiffness constants confirm the mechanical stability of both compounds. Although XZrS₃ (X = Ca, Ba) is elastically anisotropic, it has little optical anisotropy. The electronic band structures of the material exhibit direct-bandgap semiconducting behavior, with values of 1.3 eV (CaZrS₃) and 1.1 eV (BaZrS₃) using the generalized gradient approximation (GGA), respectively, which is ideal for solar cell (0.9–1.56 eV) and optoelectronic device applications. Bandgap values of 1.9 eV and 1.6 eV are found for CaZrS₃ and BaZrS₃, respectively, using the Heyd–Scuseria–Ernzerhof HSE06 functional, which is consistent with previous theoretical and experimental bandgap results. The optical properties including dielectric function, refractive index, absorption coefficient, reflectivity, and loss function are characterized using the GGA of Perdew–Burke–Ernzerhof (GGA-PBE) and HSE06 methods and are discussed in detail. Because of the relatively low Debye temperature (D), thermal conductivity of the lattice (kph), and minimum thermal conductivity (K_min), the studied materials can be used as thermal barrier coating (TBC) materials. The capacity of heat, Debye temperature, and thermal coefficient of expansion are all computed.

In this study, first-principle-based Density functional Theory (DFT) have been utilized to investigate the electronic, optical, mechanical and thermal properties of SrZrS₃ for the solar cell application. Semiconducting nature of SrZrS₃ was found via the investigation of electronic band structure and density of state (DOS). Electronic band structures reveal direct bandgap semiconductor properties with values 0.57 eV in Perdew-Burke-Ernzerhof functional (PBE) method, and 1.28 eV is in hybrid Functional (HSE06) method for SrZrS₃, suggesting specific applications in photovoltaic (PV) cell. Significant constant such as absorption, reflectivity, refractivity, and loss function were also calculated to evaluate the optical properties of SrZrS₃. The optical properties highlight the potential of SrZrS₃ material for optoelectronic and photovoltaic applications. The Born stability criteria confirmed the mechanical stability of this compound. Furthermore, its minimum thermal conductivity (K_min = 0.66 Wm⁻¹ K⁻¹) is adequate for maintaining performance without excessive heat buildup, making it suitable for high-efficiency solar cells. Graphical Abstract

The ambitious movement towards industry 5.0 technologies and the green transition drives the efforts towards securing critical metals’ supply chains globally. In Europe, highly economically important Tin and Tungsten are raising concerns regarding supply security due to geographical reserves’ uniformity and socio-political reluctance to mining. Nevertheless, mines that have seized operations in Portugal due to not being sustainable in the past are attracting renewed attention for further exploitation due to growing market demand and reclamation efforts for environmental concerns. Such abandoned resources need to be reassessed for their feasibility from economic, social, and environmental perspectives to ensure sustainable exploitation. Presenting the production criticality of Tin and Tungsten, this study implements the United Nations Framework Classification for Resources (UNFC) to assess the viability of abandoned mines and tailings dumps in Portugal, considering the indicators of Sustainable Development Goals (SDGs). The work indicates that Portugal’s abandoned Vale das Gatas Tin and Tungsten mine has good potential for further development. Furthermore, social perception towards new and abandoned mining is evaluated by collecting opinions from different parts of the country. It has been identified that sustainable technology and job opportunities are the driving parameters for the social acceptance of mining projects in Portugal.