The lithium market has been expanding due to the high demand for lithium-ion batteries, which are essential for electric and hybrid vehicles as well as portable devices. This has driven the search for new lithium ore deposits and the development of more efficient extraction and processing technologies. The main methods used for lithium extraction from hard rock ores include the acid process, the alkaline process, and chlorination roasting. This study investigated a chlorination process applied to α-spodumene extracted in Brazil for lithium chloride (LiCl) production. The ore underwent thermal treatment in the presence of calcium chloride (CaCl₂) and magnesium chloride (MgCl₂), followed by water leaching at 90 °C. The thermodynamics of the α-Li₂O·Al₂O₃·SiO₂ system, combined with calcium and magnesium chlorides, was analyzed using HSC 5.1 software. The main objective of this study was to produce lithium chloride from alpha spodumene and avoid decrepitation of the ore to the beta phase before mixing with the reagents, making the process faster and less expensive compared to traditional extraction methods. Pyrometallurgical tests were conducted in a muffle furnace, varying the molar ratio between chlorides (MgCl₂:CaCl₂) at 1:0, 0:1, 1:1, 2:1, and 1:2 and the mass ratio of spodumene to chlorides at 1:4, 1:6, and 1:8. The best lithium extraction result was approximately 95%, the conditions for obtaining the result were a spodumene:chloride ratio of 1:6 and a molar ratio between chlorides of 2:1. The results provide a better understanding of the chlorination roasting process and demonstrate the potential of the chlorination technique as a viable alternative to conventional lithium extraction methods.

In the industrial production of aluminum through the Bayer process, two main pollutants are generated, red mud and carbon dioxide (CO₂). Conventional processes for treating polluting waste include the neutralization of red mud with hydrochloric acid (HCl) and the capture of CO₂ with ethanolamine (CH₂(NH₂)CH₂OH). However, the CO₂ generated can be used to neutralize the red mud, allowing the simultaneous treatment of two harmful substances and reducing the amount of HCl required to neutralize the red mud. The solvent present in red mud is the residual alkaline liquor from the Bayer process, which absorbs CO₂ in a secondary stage, but is not yet considered as a pollutant treatment process. From this perspective, the treatment of two polluting substances (red mud and CO₂) can be carried out in aluminum production plants with lower energy consumption. In the present study, bench and pilot-scale tests were carried out to verify the efficiency of CO₂ adsorption by red mud at a temperature of 25 °C. Among the results of bench tests, 84.05% CO₂ absorption by red mud was obtained. And on a pilot scale, using a bubble column and continuous flow, an efficiency of 96.80% CO₂ absorption was observed with red mud. The study also found that among the most significant variables in this type of treatment are the solid content and mechanical speed.

Electrooxidation is an efficient method for treating effluents with high concentrations of ammoniacal nitrogen and organic matter (R), in the presence of chloride ions (Cl-).The present study aimed at degrading ammoniacal nitrogen and organic matter from an effluent generated at a fertilizer storage port terminal. For this purpose, a batch electrochemical reactor with mechanical agitation was used, with a Ti/RuO2 anode. The parameters studied were the current density that varied in 20, 40 and 60 mA cm-2, the concentration of chloride ions that was 0.04, 0.74, 0.90 to 0.81 mol L-1 and the electrolysis time that varied from 4.0, 5.0, 7.0 and 8.0 h. A 2² experimental design was conducted to determine the significance level of the parameters studied. The results obtained indicated the removal of 99.99% of N-NH3 and 75.60% of total organic carbon (TOC) when a current density of 60 mA cm-2 and a Cl- concentration of 35.5 g L-1 were applied, after 4.0 h of electrolysis.