This article reviews the use of seawater in mining with an emphasis on its use in Chile. The importance of the use of seawater in mining is highlighted in the introduction, then the main characteristics of seawater are reviewed, especially its potential effects on its use in mining. Subsequently, the consumption of seawater in Chile, especially in the regions located in the Atacama Desert, is analyzed based on statistics developed by Cochilco (Chilean Copper Commission). Later, the alternatives for the use of seawater and the distribution system are considered. The effect of seawater on the sulfide minerals flotation, the sulfide copper minerals leaching, and Caliche leaching is analyzed. We can conclude that the use of seawater has been increasing in Chile, which is already a reality, but there are challenges and opportunities that arise from the need to use seawater as a water resource.

The re-processing of mine tailings to obtain critical raw materials (CRMs) could reduce the mining of new deposits as well as ensure the profitable use of the waste materials. Though, it requires large scale industrial installations and the development of specialized technologies to obtain CRMs. New investment in mining activities is an operation, engaging for considerable financial resources involved. The scale of such an endeavor makes a new mining activity a high-risk operation due to several uncertainties present. Therefore, there is an acute need to use new tools to assess the risk associated with the planning and development of new mining activities. This study introduces a framework to evaluate the economic risk related to the re-processing of mine tailings to obtain CRMs. The framework, based on real options analysis (ROA), and sensitivity and uncertainty analysis, was applied to analyze the profitability of using mine tailings as a source of CRMs in the Chilean mining industry. The novelty of this approach consists in enabling the investment decision making including the uncertainties related to a novel investment mining project. RESULTS: show that tailing storage facilities in Chile have some stocks of CRMs, like scandium, whose extraction could be profitable. For the data used, the results of uncertainty and sensitivity analyses show that capital expenditure has a more significant influence than the other variables. Therefore, for the case of mine tailings re-processing, it is essential to develop processes and technologies that enable lower capital expenses.

Mining resources have played a leading role in the development of humanity, and the demand for these raw materials is expected to increase in the foreseeable future. In addition, new technologies also require the extraction of new critical materials. These trends pose various challenges as there is a limited supply of natural resources, and standard mining and mineral processing practices are associated with significant environmental impacts, such as waste generation, energy and water consumption, and CO₂ emissions. The circular economy (CE) has recently gained attention as a model to address such a complex scenario. This work analyzes the current efforts toward the application of CE in mineral processing. Although advances have been made, this review shows that the most significant material flows and environmental impacts occur near the production sites, which currently limits the closure of loops. Besides, mining industries are conservative regarding the adoption of new technologies or processing strategies, which is another hindrance to the implementation of the CE. Thus, and with few exceptions, while some sectors are already facing advanced stages of CE (namely, CE 3.0), the mineral processing field struggles to advance from the basic CE requirements (i.e, CE 1.0 to CE 2.0).

The formation of minerals such as calcite and struvite through the hydrolysis of urea catalyzed by ureolytic bacteria is a simple and easy way to control mechanisms, which has been extensively explored with promising applications in various areas such as the improvement of cement and sandy materials. This review presents the detailed mechanism of the biominerals production by ureolytic bacteria and its applications to the wastewater, groundwater and seawater treatment. In addition, an interesting application is the use of these ureolytic bacteria in the removal of heavy metals and rare earths from groundwater, the removal of calcium and recovery of phosphate from wastewater, and its potential use as a tool for partial biodesalination of seawater and saline aquifers. Finally, we discuss the benefits of using biomineralization processes in water treatment as well as the challenges to be solved in order to reach a successful commercialization of this technology.

Multiphase systems are important in minerals processing, and usually include solid–solid and solid–fluid systems, such as in wet grinding, flotation, dewatering, and magnetic separation, among several other unit operations. In this paper, the current trends in the process system engineering tasks of modeling, design, and optimization in multiphase systems, are analyzed. Different scales of size and time are included, and therefore, the analysis includes modeling at the molecular level (molecular dynamic modeling) and unit operation level (e.g., computational fluid dynamic, CFD), and the application of optimization for the design of a plant. New strategies for the modeling, design, and optimization of multiphase systems are also included, with a strong focus on the application of artificial intelligence (AI) and the combination of experimentation and modeling with response surface methodology (RSM). The integration of different modeling techniques such as CFD with discrete element simulation (DEM) and response surface methodology (RSM) with artificial neural networks (ANN) is included. The paper finishes with tools to study the uncertainty, both epistemic and stochastic, based on uncertainty and global sensitivity analyses, which is present in all mineral processing operations. It is shown that all of these areas are very active and can help in the understanding, operation, design, and optimization of mineral processing that involves multiphase systems. Future needs, such as meso-scale modeling, are highlighted.