Jonathan Castillo

• Doctor of Engineering
• Professor at University of Atacama

Lithium is a metal with a highly promising outlook for future global demand. Its industrial processing relies on two primary methods: production from brines through solar evaporation ponds and production from rock sources via flotation, roasting, and subsequent leaching. Chile is currently the world’s second-largest producer of lithium, surpassed o...

Black copper oxides, a significant copper resource, present challenges in leaching due to their refractory nature and complex mineralogical composition. This study investigates the sulfation dynamics of the reductive leaching process of black copper ores with the purpose of increasing the copper leaching, focusing on the influences of time and the...

Due to the scarcity of high-grade minerals on the Earth’s surface and the ever-increasing demand for critical metals required in the production of clean energy, the search for alternative sources has become essential. Ferromanganese crusts, a mineral resource located in the depths of the ocean, contain high concentrations of valuable metals, partic...

The Reynolds number (Re), introduced in the late 19th century, has become a fundamental parameter in a lot of scientific fields—the main one being fluid mechanics—as it allows for the determination of flow characteristics by distinguishing between laminar and turbulent regimes, or some intermediate stage. Reynolds’ 1895 paper, which decomposed velo...

The Mine-to-Mill (M2M) approach aims to enhance efficiency and reduce costs in the mineral processing industry by optimizing the mining and processing stages. M2M integrates orebody characterization, blasting, and downstream processes, such as grinding and flotation, demonstrating that material fragmentation directly impacts downstream efficiency....

The letter represents the authors’ opinion on the positive impact that allowing open access to scientific publications has on doctoral programmes, the careers of young researchers and the overall quality of university education in Chile.

The average lithium content in the Earth’s crust is estimated at about 0.007%. Despite this, lithium is considered abundant and widely distributed, with significant extraction from various sources. Notably, the brines in the Salar de Atacama are highlighted for their high lithium concentration ~1800 mg/L. Lithium is currently recovered from these b...

Ferromanganese crusts are mineral resources distributed in the planet’s oceans. These deep-sea minerals stand out for their abundance and diversity of metals, with Mn and Co being the most abundant elements. These minerals are a good alternative to diversify the extraction of elements, which today are found at low grades on the Earth’s surface. For...

Mathematical modeling of columnar leaching is a useful tool for predicting and evaluating the kinetics of copper extraction. One commonly used model for this process is the shrinking core model (SCM). In this study, the aim was to develop a model for column leaching of oxidized copper ore based on the SCM, which incorporates the ore sulfation stage...

Although the importance of black copper ores is well established, many topics remain to be studied. This manuscript describes the efforts to improve copper recovery from refractory ores on a pilot scale. Preliminary tests provided the water dose to form a stable and compact agglomerate of 89 L per ton of ore and an acid dosage of 40 kg per ton of o...

Nitration is a chemical process that introduces a nitro group into a molecule, which modifies properties of organic compounds, impacting their reactivity and physical attributes. In copper mining, elevated nitrate levels present operational difficulties, impacting recovery percentages and leading to the deterioration of organic extractants. Histori...

The formation of soluble species from a bornite flotation concentrate pre-treated with hydrochloric acid was studied. Copper recovery after a leaching in a H2SO4-NaCl solution was determined. The influence of acid concentration and ore particle size were evaluated. Chemical and morphological characterization of the samples before and after the leac...

In multivariate analysis, a predictive model is a mathematical/statistical model that relates a set of independent variables to dependent or response variable(s). This work presents a descriptive model that explains copper recovery from secondary sulfide minerals (chalcocite) taking into account the effects of time, heap height, superficial velocit...

Recent works suggest that the use of ionic liquids in the copper solvent extraction industry is feasible. However, the reports did not use real solutions (or synthetic solutions with various elements). This fact remains poorly established, and the interaction efficiencies are still under study. The objective of this research is to explore the extra...

Due to the significant growth of the world population, the accelerated growth of economic industries in various countries, and improved living conditions, freshwater consumption has increased dramatically and is currently under critical pressure. Its good use and rationing are essential. Even though mining is an industry that consumes much less wat...

Mineral leaching is the key unit operation in metallurgical processes and corresponds to the dissolution of metals. The study of leaching is carried out in many areas, such as geology, agriculture and metallurgy. This paper provides an introduction to the theoretical background regarding the mathematical modelling of the leaching process of copper...

Lateritic ores are currently considered as the fundamental raw material for the extraction of Ni and Co through the Caron process. This directly affects the temperature control of the hearth 6 of reduction furnaces from the injection of the post-combustion air into the metallurgical process. To date, there is no consensus on the part of the researc...

The leaching of copper ores produces a rich solution with metal interferences. In this context, Fe(III), Zn(II), and Mn(II) are three metals contained in industrial copper-rich solutions in high quantities and eventually can be co-extracted with the copper. The purpose of the current study was to determine the feasibly of solvent extraction with th...

Metallic magnesium can be obtained from seawater, brines, minerals, in recycled scrap, and in alloys. It is the eighth most abundant element on the planet, using 2% of the earth’s crust, and it is the third most abundant element in the sea with approximate contents of 1.3% of magnesium, on the other hand, brines have around 0.3–1% magnesium. Also,...

Lateritic ores are currently considered as the fundamental raw material for the extraction of Ni and Co through the Caron process, directly affecting the temperature control of the hearth 6 of the reduction furnaces from the injection of the post-combustion air into the metallurgical process. To date, there is no consensus on the part of the resear...

This review aims to understand the environmental impact that tailings produce on the land and marine ecosystem. Issues related to flora, fauna, and the environment are revised. In the first instance, the origin of the treatment and disposal of marine mining waste in Chile and other countries is studied. The importance of tailings’ valuable elements...

In this work, the effect of the pre-treatment of bornite concentrate with a sodium chloride–sulfuric acid mixture prior to leaching with chloride solutions was evaluated. The influence of the dosage of NaCl and the resting time in the copper solution was evaluated. The solid residues of the pre-treatment were characterized by XRD to evaluate the ch...

It summarizes strategic analyses regarding the future of copper concentrate exports, its problems and Chile's participation not only as a global copper producer, but as a refined copper producer. These analyses aim to develop a basis for modernization and possibly the construction of new foundries in Chile; are considered economic, competitive and...

It summarizes the current state of Chilean copper smelters from an environmental, major nation-to-global focus approach, current technologies for treating copper sulphurized minerals through pyrometallurgical treatments generate large amounts of pollutants such as sulphur dioxide, arsenic and other heavy metals that are present in smelters fumes. D...

Hydrometallurgy is an efficient way of recovering metal ions from mineral ores where the most important steps are the leaching of the minerals, the recovery and purification of metal ions by solvent extraction (SX), and the final electrowinning (EW) process. Ionic liquids (ILs) have been extensively applied in the above mentioned process technologi...

A less harmful approach for the environment regarding chalcopyrite concentrate leaching, using seawater/brine and caliche’s salts as a source of chloride and nitrate ions, was investigated. Different variables were evaluated: sulfuric acid concentration, sodium nitrate concentration, chloride concentration, source of water (distilled water, seawate...

The entrainment of the organic phase in the aqueous applied to typical solutions in a copper solvent extraction process was studied. The organic phase used is composed of the commercial extractant LIX 984-N diluted in Shellsol 2046 AR. The aqueous phase contains 6 g/L of Cu 2+ , at pH 2 and 20 ºC. The variables studied were: mixing speed of 400 to...

In this study, weak acid in the curing and leaching stages of copper ore was incorporated, and we analyzed its effect on the dissolution of copper and final impurities. The weak acid corresponds to a wastewater effluent from sulfuric acid plants produced in the gas treatment of copper smelting processes. This effluent is basically water with high a...

Based on the results obtained from a previous study investigating the dissolution of Mn from marine nodules with the use of sulfuric acid and foundry slag, a second series of experiments was carried out using tailings produced from slag flotation. The proposed approach takes advantage of the Fe present in magnetite contained in these tailings and i...

Hydrometallurgical processing of chalcopyrite is of great interest today due to the depletion of oxidized copper minerals. This will also enable existing plants to continue operation. The objective of this work is to study the behavior of chalcopyrite leaching by stirring in an acid-nitrate-chloride media where seawater and brines provide chloride...

The authors wish to make the following corrections to this paper [1]: We worked at a temperature of 60 • C for all the tests carried out in which FeS 2 was added as a reducing agent, whereas in the other experiments, other added Fe reducing agents were worked at room temperature (25 • C). This affects the results presented in Table 5 (results when...

Mixed copper ores are challenging to process, where the treatments are expensive, resulting in low recoveries, with products that are not commercially viable. The proposed research aims a sustainable method to recover copper from a mixture of oxides and sulfides minerals. The procedure involves three stages: (i) leaching with aqueous ammonia soluti...

The deposits of Fe-Mn, in the seabed of the planet, are a good alternative source for the extraction of elements of interest. Among these are marine nodules, which have approximately 24% manganese and may be a solution to the shortage of high-grade ores on the surface. In this investigation, an ANOVA analysis was performed to evaluate the time inde...

Multivariate analytical models are quite successful in explaining one or more response variables, based on one or more independent variables. However, they do not reflect the connections of conditional dependence between the variables that explain the model. Otherwise, due to their qualitative and quantitative nature, Bayesian networks allow us to...

Multivariable analytical models provide a descriptive (albeit approximate) mathematical relationship between a set of independent variables and one or more dependent variables. The current work develops an analytical model that extends a design of experiments for the leaching of manganese from marine nodules, using sulfuric acid (H2SO4) in the pres...

The importance of mine planning is often underestimated. Nonetheless, it is essential in achieving high performance by identifying the potential value of mineral resources and providing an optimal, practical, and realistic strategy for extraction, which considers the greatest quantity of options, materials, and scenarios. Conventional mine planning...

Manganese nodules are an attractive source of base metals and critical and rare elements and are required to meet a high demand of today’s industry. In previous studies, it has been shown that high concentrations of reducing agent (Fe) in the system are beneficial for the rapid extraction of manganese. However, it is necessary to optimize the opera...

The effect of NaCl on the leaching of white metal from a Teniente Converter was investigated in NaCl-H2SO4 media under environmental conditions. The copper dissolution from white metal was studied using ferric ions in the range of 1–10 g/L, NaCl in the range of 30–210 g/L, and sulfuric acid in the range of 10–50 g/L. The test without NaCl produced...

Based on the results obtained from a previous study investigating the dissolution of Mn from marine nodules with the use of sulfuric acid and foundry slag, a second series of experiments was carried out using tailings produced from slag flotation. The proposed approach takes advantage of the Fe present in magnetite contained in these tailings and i...

The effects of sulfuric acid, chlorine concentration and time in the extraction of copper from sulphured minerals (chalcocite) were studied, considering the methodology of surface optimization and the adjustment of a quadratic model for the representation of the experimental design. The experimental data were adjusted by multiple regression analysi...

Los nódulos polimetálicos, también llamados nódulos de manganeso, son concreciones rocosas formadas por capas concéntricas de hidróxidos de Fe y Mn. Estos minerales polimetálicos son una buena fuente alternativa de metales básicos para la creciente demanda de manganeso para la producción de acero, ya que los minerales de alta ley en la superficie s...

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maxi...

This study deals with the improvement of the recovery performance in the solvent extraction of Cu(II) using the ionic liquid [bmim][Tf2N] and the β-diketone 1,1,1-trifluoro-2,4-pentanedione (TFA) as extractant and its stripping with supercritical carbon dioxide. This work describes a modified procedure, which shows better L-L extraction percentages...