Manganese is a widely used element in the steel industry; its main source is a mineral named rhodochrosite (MnCO₃). For industrial usage, rhodochrosite is reduced to different manganese oxides by means of nodulation furnaces. In this study, rhodochrosite was thermally analyzed at temperatures ranging from 100 °C to 1200 °C. XRD (Powder X-ray diffraction), XRF (X-ray fluorescence), AAS (Atomic Absorption Spectrometry), and FESEM-EDX (Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry) were used to characterize the mineral and the residues were analyzed by XRD and FTIR (Fourier-transform infrared spectroscopy) to determine the stoichiometry of the thermal decomposition reactions. Three mass losses were observed, the first attributed to the transformation from carbonate to manganese (III) oxide, the second to the reduction to manganese tetroxide, and the third to the decomposition of calcium carbonate (CaCO₃) present as a contaminant in the studied mineral. Thermal decomposition kinetics shows that the first mass loss required 17.91 kJ mol⁻¹, indicating a control by mass transport-controlled process. For the second and third mass loss, the apparent activation energy of 112.41 kJ mol⁻¹ and 64.69 kJ mol⁻¹ was obtained respectively, indicating that both mass loss events were rate-controlled.

During grinding with forged steel media, sulphides such as pyrite undergo surface changes due to the occurrence of oxidation–reduction reactions, which affect its depression during the concentration process. For this reason, in this work, the surface modification of pyrite during grinding was studied; FTIR, ICP-OES, XRD and SEM-EDS were used for the materials’ characterisation. It was found that the pyrite obtained during grinding showed magnetic susceptibility due to the absorption and superficial formation of magnetite Fe₃O₄, Fe–O bonds identified by FTIR at 598 cm⁻¹, and of other species, such as oxy-hydroxy-sulphates at 696 cm⁻¹ and goethite α-FeOOH at 875 cm⁻¹. This caused the reversal of the zeta potential magnitude (ζ) from positive to negative at pH 8.3 and 30 min of grinding. The ζ of the pyrite throughout the studied pH ranges was, overall, positive, i.e., +5 mV. However, at pH 10.5 and 15 min of grinding, the ζ turned negative. This was associated with the formation of Fe–CO₃ (−2) bonds in the siderite, which were identified with the absorption bands corresponding to 756, 1448 and 1493 cm⁻¹.

Sustainable forestry for the management of forest resources is more important today than ever before because keeping forests healthy has an impact on human health. Recent advances in Unmanned Aerial Vehicles (UAVs), computer vision, and Deep Learning (DL) models make remote sensing for Forest Insect Pest and Disease (FIPD) possible. In this work, a UAV-based remote sensing process, computer vision, and a Deep Learning framework are used to automatically and efficiently detect and map areas damaged by bark beetles in a Mexican forest located in the Hidalgo State. First, the image dataset of the region of interest (ROI) is acquired by a UAV open hardware platform. To determine healthy trees, we use the tree crown detection prebuilt Deepforest model, and the trees diseased by pests are recognized using YOLOv5. To map the area of the damaged region, we propose a method based on morphological image operations. The system generates a comprehensive report detailing the location of affected zones, the total area of the damaged regions, GPS co-ordinates, and both healthy and damaged tree locations. The overall accuracy rates were 88% and 90%, respectively. The results obtained from a total area of 8.2743 ha revealed that 16.8% of the surface was affected and, of the 455 trees evaluated, 34.95% were damaged. These findings provide evidence of a fast and reliable tool for the early evaluation of bark beetle impact, which could be expanded to other tree and insect species.

The increasing global demand for copper has driven the search for more efficient and sustainable extraction methods, particularly due to the environmental concerns associated with conventional processes. This study investigated the leaching of copper minerals MC (Cu₂O) and malachite (Cu₂CO₃(OH)₂) using glycine as an organic ligand in an alkaline medium, and evaluated the efficiency of hydrogen peroxide (H₂O₂) and ozone (O₃) as oxidizing agents. Chemical and mineralogical characterization using XRD, XRF, ICP, and SEM confirmed the predominance of MC and malachite, along with secondary phases such as hematite and calcite. Leaching experiments were carried out by varying glycine and oxidant concentrations at pH 10, with a reaction time of 240 min, agitation at 800 min⁻¹, a solution volume of 300 mL, and a mineral sample concentration of 0.33 g·L⁻¹. The results showed that O₃ exhibited low efficiency due to its limited solubility, whereas H₂O₂ achieved dissolution rates of 69.7% for MC in 150 min and 96.3% for MMin just 60 min. The glycine-H₂O₂ system optimized reaction time by 84% compared to conventional methods, emerging as a sustainable alternative due to the low toxicity and biodegradability of glycine.

In this study, a solid solution of arsenical ammonium-sodium jarosite, with the approximate formula [(NH₄)_0.72 Na_0.06(H₃O)_0.21]Fe_3(2.52)(SO₄)_1.85 (AsO₄)_0.15 [(OH)_4.41 (H₂O)_1.59], was synthesized. The precipitate particle main size was 38 µm, with spherical morphology. A decomposition reaction in alkaline media was carried out; this decomposition comprised three stages: an induction period, a progressive conversion and a stabilization period. The process was controlled by the chemical reaction, and the progressive conversion period was consistent with the shrinking core model. The dissolution reactions of the compound in NaOH media were characterized by an ash layer formed by solid residues made of Fe(OH)₃ with adsorbed arsenate surrounding an unreacted core through which Na⁺, NH₄⁺ and SO₄²⁻ ions diffused into the solution. At the same time, OH⁻ ions diffused from the solution into the reaction front until the core disappeared, indicating the end of the reaction.