This study investigates the use of geopolymer technology as an alternative for the management of mine tailings, which is a serious environmental problem in mining areas, including the Arequipa region of Peru. In this study, the mixture of stabilized mine tailings with different percentages of binders (i.e., metakaolin and pumice) and their impact on the mechanical, microstructural, and toxicological properties of the synthesized geopolymers were analyzed. The ratios of mine tailings to binder material varied between 100/0 and 0/100. The activation was carried out with an alkaline solution of sodium hydroxide (10 M) and sodium silicate (modulus 2.5). Specimens were fabricated as 50 mm cubes, and the seven mix designs were evaluated in triplicate. The evaluations included compressive strength at 7, 14, 28, and 56 days of curing, chemical analysis by Fourier Transform Infrared Spectroscopy (FT-IR), microstructural characterization by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS), thermal behavior by thermogravimetry and differential thermal analysis (TGA/DTA) between 40 °C and 1000 °C, and toxicological tests by the Toxicity Characteristic Leaching Procedure (TCLP, EPA 1311) to determine the efficiency of immobilization of toxic metals. The results demonstrate significant improvements in compressive strength for the F50 specimens compared to A0, with increases of approximately 300%, 270%, and 461% observed at 7, 28, and 56 days of curing, respectively, with microstructural stability with an average pore size of 7.21 μm, and efficiency in the immobilization of heavy metals in geopolymers with 30% or 40% binder (60%–70% mine tailings). The leachate concentrations of As, Cd, Pb, and Hg were below the established thresholds, indicating that the stabilized mine tailings can be classified as “non-hazardous materials”. Geopolymers with 30% to 50% binder showed strength development with microstructural stability and efficiency in the immobilization of heavy metals, complying with current regulations. Therefore, these geopolymers are suitable for various applications and in different environmental conditions.

This study investigates the use of geopolymer technology as an alternative for the management of mine tailings, which is a serious environmental problem in mining environments including that of Arequipa region of Peru. In this study, the mixture of stabilized mine tailings with different percentages of binders (metakaolin and pumice) and their impact on the mechanical, microstructural, and toxicological properties of the synthesized geopolymers were analyzed. The ratios of mine tailings to binder material varied between 100/0 and 0/100. The activation was carried out with an alkaline solution of sodium hydroxide (10M) and sodium silicate (modulus 2.5). 50 mm cubic specimens were fabricated, and 7 mixtures with 3 replicates each were evaluated. The evaluations included compressive strength at 7, 14, 28, and 56 days of curing, chemical analysis by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR), microstructural characterization by Scanning Electron Microscopy (SEM/EDS), thermal behavior by thermogravimetry and differential thermal analysis (TGA/DTA) between 40°C and 1000°C, and toxicological tests by the Toxicity Characteristic Leaching Procedure (TCLP, EPA 1311) to determine the efficiency of immobilization of toxic metals. The results showed good mechanical strength, reaching 25 MPa at 7 days of curing, high microstructural stability with an average pore size of 7.21 μm, and good efficiency in the immobilization of heavy metals in geopolymers composed of 60% - 40% and 70% - 30% of the mine tailings - binders ratio, as the concentrations of As, Cd, Pb, Hg were below the established thresholds, acquiring the classification of non-hazardous materials. Geopolymers with 30 to 50% binder showed good mechanical behavior, microstructural stability, and high efficiency in the immobilization of heavy metals, complying with current regulations. Therefore, these geopolymers are suitable for various applications and in different environmental conditions.

The conservation of the environment is becoming a global concern for the use of fuels from fossil waste, and the production of biodiesel from renewable sources is being considered as an eco-friendly alternative since oleaginous organic waste presents potential as Energy condition.An important aspect is to minimize the impacts generated by this waste under different conditions, and an operation related to the aspect is the elaboration and comparison of biodiesel obtained from residual frying oils with biodiesel produced with sunflower oil through the transesterification process based on ethanol. The evaluation was carried out on a laboratory scale with parameters and specifications found in the Peruvian Technical Standard for Biodiesel (NTP- 321.12-200-2008), with the exception of water content, and the oxidative stability index (IEO).The following results were obtained 739.7 mg / kg and 1.5 hours and these do not meet the standards whose minimum reference corresponds to 500 mg / kg and 3 hours, respectively. The yield of residual oil and sunflower corresponds to 68.5% and 85.2% respectively. The research work establishes that the production of biodiesel from residual frying oil by the ethanol-based transesterification process is significantly less than the process with sunflower oilseeds, showing greater performance and stability.

Currently, textile dyeing companies determine their market according to the raw materials processed, which are based on 100% cotton fibers, these fibers are directed to an exclusive market and therefore these companies establish criteria of high quality standards in each of its processes, dyeing being one of the most demanding due to its fastness parameters and color specifications, these characteristics establish the competitiveness of expanding a product portfolio with the incursion of 100% fiber-based clothing polyester and with cotton blends.Some studies suggest the implementation of the dyeing process of these fibers, allowing the organization to have new production alternatives, dyeing processes for polyester and cotton are carried out with heat treatment between 60 °C and 130 °C respectively, with the use of dispersed and chemical dyes; as in the dyeing of Polyester-Cotton that are made in bathrooms established in each stage. Color and solidity tests are performed according to quality parameters, with light and wash fastness controls. Within these dyeing conditions it is essential to determine the thermal gradients to be applied, whose variable must be controlled to optimize the dyeing of polyester fibers and mixtures.The present study evaluates the pre-treatments and the temperature gradient behavior stage in the dyeing process of polyester fibers, taking into account the dyeing curve, in which only the temperature gradient varies. Mathis-ALT-B equipment is used for the dyeing process, for thermal gradient conditions of 135 °C with gradients of 0.3-4.0 °C/min, rotation speed 40-70 RPM, and as colorants were used Novacron, Terail and Liandisperse for cotton and polyester fibers respectively. The results show that the use of dispersants and anti breakage agents work to prevent failures and improve the corresponding colors, but a high gradient increases the migration of the dye and breaks in the fibers, but in low gradients (2 ° C/min ) The quality of diffusion and dyeing is better and, therefore, prevents reprocessing in the dyeing stage.

The mining industry is a fundamental pillar of economic development in Peru, but mine tailings can generate contamination by toxic heavy metals such as Hg, As, Pb, Cd, and Zn, affecting health, flora, and fauna. This research aimed to characterize the physical, chemical, mineralogical, and toxicological properties of active and passive tailings in the Arequipa region of Peru to identify and quantify the presence of these heavy metals. Analytical techniques, such as granulometry, ICP, TCLP, SEM, and EDS were used to obtain detailed information about the characteristics of the tailings. The results showed significant variability in particle size distribution, as well as differences in mineralogical composition, including the presence of valuable and potentially toxic minerals. This study will allow corrective actions to be taken to prevent, minimize, or remediate potential negative impacts in the region.

Currently, the National Society of Mining, Petroleum and Energy (SNMPE) states that in recent years the production of gold in Peru has reduced, since in 2016 there was a production of 153 MT, compared to 2005 with a production of 208 MT. Until 2018, a production decrease of 5.4% was established and in 2017 a decrease of 11.3%. Currently there is a need to develop research on gold extraction processes in low recovery minerals with traditionally used processes, due to the complex structure of gold that prevents their extraction. It is necessary to evaluate new processes that are environmentally friendly and that are sustainable in the environmental and economic aspects. In the present work, the applicability of leaching with NaCl and KNO3 in acid medium in a sulphurous gold mineral was evaluated, through the process of leaching with oxidizing salts, which allows to process hydrometallurgy the various forms of gold minerals present in nature. The sample is composed in percentages by Quartz 24%, Carbonates Dolomite 22%, Calcite 6%, Arsenopyrite 19%, Pyrite 5%, Galena 4% and clays associated with traces of Native Au-Electrum, which were interfering with the process of leaching of the sample. A pretreatment by gravimetric concentration was carried out using the Falcón equipment, with the aim of releasing the encapsulated gold and eliminating the interfering agents, facilitating the leaching action of the oxidizing salts. When testing the concentrations of the oxidizing salts, it was found that for the concentrations of 86.86 g/l of NaCl, 21.96 g/l of KNO3 and 125.93 g/l of H2SO4, a maximum recovery of 26.62% gold was obtained. Based on the results from the factorial design, an increase in gold extraction performance was observed; obtaining a maximum recovery of 29.31% of the gold; in the process it was determined that dissolved gold is affected by the presence of clays, producing the "Preg-robbing" effect of the valuable metal and consequently decreasing the recovery of gold after 8 leaching hours. According to the results, it is concluded that the leaching process with oxidizing salts in acidic medium for the type of mineral used, is mainly affected by the presence of coarse gold and electrum associated with clays, establishingconditions of degree of release according to the granulometry in the gold leaching process.