This review article discusses the latest advances on molten phase monitoring in metallurgical processes by using Laser-Induced Breakdown Spectroscopy (LIBS). LIBS is an analytical laser-based technique, where a pulsed laser is focused on a sample to create a plasma. The optical emission from the plasma can be transferred through open-path optical configuration or via an optical fiber to a spectrometer to receive analytical information in the form of elemental composition. Thus, a relatively long-distance analysis can be performed using LIBS. Several modern experimental arrangements, patents and industrial notes are assessed, and the literature is reviewed. The review includes applications of LIBS to analyze steel, iron, aluminum, copper, slags, metal melts, and other materials. Temperature, pressure, and atmospheric composition are crucial parameters of any melting process. Hence, past studies on molten phases describing these parameters have been discussed. Finally, the review addresses the last technological advances for these types of applications. It also points out the need of development in some fields and some limitations to overcome. In addition, the review highlights the use of modern machine learning and data processing techniques to increase the effectiveness of calibration and quantification approaches. These developments are expected to improve the performance of LIBS systems already implemented at an industrial scale and ease the development of new applications in pyrometallurgical processes to address the stringent market and environmental regulations.

This technical note addresses the structure preserving stabilization by output feedback of conservative input-output contact systems, a class of input-output Hamiltonian systems defined on contact manifolds. In the first instance, achievable contact forms in closed-loop and the associated Legendre submanifolds are analysed. In the second instance the stability properties of a hyperbolic equilibrium point of a strict contact vector field are analysed and it is shown that the stable and unstable manifolds are Legendre submanifolds. In the third instance the consequences for the design of stable structure preserving output feedback are derived: in closed-loop one may achieve stability only relatively to some invariant Legendre submanifold of the closed-loop contact form and furthermore this Legendre submanifold may be used as a control design parameter. The results are illustrated along the technical note on the example of heat transfer between two compartments and a controlled thermostat.

Nowadays, energy and water are some of the most important issues facing the mining industry. Many mines are located in desert areas, and they need to pump water from isolated wells or from the ocean. Therefore, in order to satisfy the water demand, many high-power water pump stations are required. The operation of these systems is expensive due to the high energy cost. This paper presents a case of study of a solar photovoltaic (PV) system to assist the operation of a water pump station of a mineral processing operation in Chile. An economical analysis is carried out with respect to different design variables and the percentage of the total power required for operating the system in the less favorable conditions (degree of assistance). It is demonstrated that the maximum net present value is obtained for the maximum assistance, i.e., supplying the full energy in the less favorable conditions. However, the internal rate of return will be maximized at the point where the system only supplies the energy to satisfy the full demand at the most favorable conditions. Finally, the study shows that from an economical point of view, PV technology is an attractive alternative to support the mining operation at present time.

This work presents a systematic methodology based on the Akaike information criterion (AIC) for selecting the wavelengths of LIBS spectra as well as the ANN model complexity, by combining prior knowledge and variable selection algorithms.