A lack of fresh water is one of the most significant problems currently affecting humanity. Water scarcity also affects industries, with the mining industry being one of the most affected. One possible solution to water scarcity is the recirculation of water. Water in mining is usually treated with physicochemical methods, but in metallurgical processes, reagents are added, accumulate until reaching the point of saturation, and are often not successfully removed. In this sense, electrocoagulation has shown great efficiency in the treatment of organic contaminants, heavy metals, and metallic ions, and was applied in this study to eliminate ions and undesirable organic compounds present in mining–metallurgical process water. Furthermore, this process has shown great efficacy in relation to toxic metals like arsenic because their presence reduces the efficiency of other processes such as flotation. In this study, two types of electrodes were used: stainless steel and aluminum. The best results were achieved with stainless steel electrodes, which were able to eliminate 90% of copper ions in water. The turbidity of the water during the process was measured to determine the amount of solid present in the water, and a reduction of around 95% was observed when using aluminum electrodes. The sedimentation of clots occurred in two stages: Firstly, the coagulant was formed to trap organic matter as its size increased, until a particle size that was sufficient for settling was achieved. A zero-order kinetic model was fit for this stage of the process. Secondly, the formed clots continued to settle, and a second-order kinetic model was fit for this stage. Flotation tests were carried out on the process and electrotreated water to evaluate the recovery of Zn, Pb, Ag, and Au. An increase of 1.5% was found for gold, and an increase of 2% was found for silver, while a significant improvement was identified for zinc, augmenting recuperation by 30% when electrotreated water was used. For lead, no considerable change in recovery was observed in either form of water. The formed clots were analyzed using Scanning Electronic Microscopy, and we found that metal ions were trapped in the clots. This study demonstrates the potential of electrocoagulation for clarifying mine water, which is ordinarily very difficult to clarify.

The characterization of the turbulent flow of liquid steel in a slab mold using a commercial nozzle was carried out through physical experiments and mathematical models. Six ultrasonic sensors were located at each side of the nozzle to obtain real-time plotting of the bath levels during the experimental time. An ultrasonic transducer located in the mold, 20 mm below the meniscus, determines the velocities and the turbulent variables along with the distance from the narrow face to the position of the nozzle’s outer wall. These data, together with the mathematical simulations, demonstrated a high correlation of bath level oscillations and the time-dependent behavior of the discharging jets. The flow inside the mold shows low-frequency non-symmetric patterns without a severe turbulent in the meniscus. The source of this instability is the partial opening of the slide valve gate used to control the mass flow of liquid.

Galena is the most important mineral for lead production, as it is the main source of lead in the world. Currently, the concentrates of this mineral are mainly treated using pyrometallurgical methods, creating several environmental problems, such as the generation of toxic and greenhouse gases. In addition, these processes involve high energy consumption, which limits their applicability. Hydrometallurgical routes are proposed as alternative processes for obtaining some metals such as silver, copper, gold, etc. The drawback of these processes is that the minerals tend to be passive in aqueous media. To mitigate this issue, researchers have used extreme conditions of pressure and temperature (6 atm. and 155 °C) or the use of very corrosive conditions. In this sense, the use of complexing agents that dissolve the metals of interest has been proposed. Citrate ion is one of the most promising complexing agents for galena leaching, obtaining high percentages of dissolution in relatively short times. Unfortunately, there has not been enough investigation about the concentration optimization of the complexing in the pH range from 5 to 9. In this sense, thermodynamic diagrams, such as the Pourbaix diagrams, are very useful for this purpose. Therefore, in this work, the effects of pH and temperature on the leaching of galena in citrate ion solutions are studied thermodynamically and experimentally. The experimental work was carried out with pure galena samples with a particle size of +149 − 74 µm (−100 + 200 mesh). The results show that higher recoveries were obtained working at a pH of 8 and at temperatures of 30 and 40 °C. The thermodynamic and experimental data demonstrated that the existence of an optimal concentration of citrate ion, due the extraction of lead from galena, has a greater reaction rate at a relatively low initial concentration of 0.3 M. This is due the formation of the complex lead citrate 1 ($\mathrm{Pb}{\left(\mathrm{cit}\right)}^{-}$).

The current automation of steelmaking processes is capable of complete control through programmed hardware. However, many metallurgical and operating factors, such as heat transfer control, require further studies under industrial conditions. In this context, computer simulation has become a powerful tool for reproducing the effects of industrial constraints on heat transfer. This work reports a computational model to simulate heat removal from billets’ strands in the continuous casting process. This model deals with the non-symmetric cooling conditions of a billet caster. These cooling conditions frequently occur due to plugged nozzles in the secondary cooling system (SCS). The model developed simulates the steel thermal behavior for casters with a non-symmetric distribution of the sprays in the SCS using different boundary conditions to show possible heat transfer variations. Finally, the results are compared with actual temperatures from different casters to demonstrate the predictive capacity of this algorithm’s approach.