1M HCl Research Articles

Comprehensive evaluation of product characteristics and energy consumption in hydrothermal carbonization of food waste anaerobic digestate: A perspective on phosphorus recovery and fuel properties

Food waste digestate (FWD) is rich in organic matter and phosphorus(P) elements, making it a potential source for energy and P recovery. Hydrothermal carbonization (HTC) addresses FWD's dehydration and stability issues, improving hydrochar's fuel properties and P recovery in hydrothermal liquid. Experiments with various additives reveals 1M HCl's effectiveness, increasing P recovery by 88.31 % at 120 °C, decreasing hydrochar ash content by 21.42 %, and raising heating value by 45.01 %. Principal component analysis highlights the viability of acid treatment for P leaching and hydrochar enhancement, with pH as a crucial factor. HTC substantially reduces energy consumption by 57.42 % compared to direct drying. Hydrochar without additives shows potential as slow-release P fertilizers, with a 28.8 % increase in total phosphorus at 240 °C, where 99.4 % of P exists as apatite inorganic. Soil tests reveal differences with formic acid method in P availability, showing varying correlations with different P forms. This research offers insights for FWD resource utilization.

Bio-Based Polyurethane-Urea with Self-Healing and Closed-Loop Recyclability Synthesized from Renewable Carbon Dioxide and Vanillin.

Developing recyclable and self-healing non-isocyanate polyurethane (NIPU) from renewable resources to replace traditional petroleum-based polyurethane (PU) is crucial for advancing green chemistry and sustainable development. Herein, a series of innovative cross-linked Poly(hydroxyurethane-urea)s (PHUUs) were prepared using renewable carbon dioxide (CO2) and vanillin, which displayed excellent thermal stability properties and solvent resistance. These PHUUs were constructed through the introduction of reversible hydrogen and imine bonds into cross-linked polymer networks, resulting in the cross-linked PHUUs exhibiting thermoplastic-like reprocessability, self healing, and closed-loop recyclability. Notably, the results indicated that the VL-TTD*-50 with remarkable hot-pressed remolding efficiency (nearly 98.0%) and self-healing efficiency (exceeding 95.0%) of tensile strength at 60 °C. Furthermore, they can be degraded in the 1M HCl and THF (v:v = 2:8) solution at room temperature, followed by regeneration without altering their original chemical structure and mechanical properties. This study presents a novel strategy for preparing cross-linked PHUUs with self-healing and closed-loop recyclability from renewable resources as sustainable alternatives for traditional petroleum-based PUs.

Strong yet Tough Catalyst-Free Transesterification Vitrimer with Excellent Fire-Retardancy, Durability, and Closed-Loop Recyclability.

Despite great advances in vitrimer, it remains highly challenging to achieve a property portfolio of excellent mechanical properties, desired durability, and high fire safety. Thus, a catalyst-free, closed-loop recyclable transesterification vitrimer (TPN1.50) with superior mechanical properties, durability, and fire retardancy is developed by introducing a rationally designed tertiary amine/phosphorus-containing reactive oligomer (TPN) into epoxy resin (EP). Because of strong covalent interactions between TPN and EP and its linear oligomer structure, as-prepared TPN1.50 achieves a tensile strength of 86.2MPa and a toughness of 6.8MJm-3, superior to previous vitrimer counterparts. TPN1.50 containing 1.50 wt% phosphorus shows desirable fire retardancy, including a limiting oxygen index of 35.2% and a vertical burning (UL-94) V-0 classification. TPN1.50 features great durability and can maintain its structure integrity in 1M HCl or NaOH solution for 100 days. This is because the tertiary amines are anchored within the cross-linked network and blocked by rigid P-containing groups, thus effectively suppressing the transesterification. Owing to its good chemical recovery, TPN1.50 can be used as a promising resin for creating recyclable carbon fiber-reinforced polymer composites. This work offers a promising integrated method for creating robust durable fire-safe vitrimers which facilitate the sustainable development of high-performance polymer composites.

Emerging Two-Dimensional Ti3C2-BiOCl Nanoparticles for Excellent Antimicrobial and Antioxidant Properties.

Introduction MXenes (Ti3C2) represent a group of two-dimensional inorganic compounds, produced through a top-down exfoliation method. They comprise ultra-thin layers of transition metal carbides, or carbonitrides, and exhibit hydrophilic properties on their surfaces. Utilizing Ti3C2 BiOCl nanoparticles for their antimicrobial and antioxidant attributes involves enhancing synthesis, processing, and characterization techniques. Materials and method To prepare Ti3C2 MXene, dissolve 1.6 g of LiF in 20 ml of 9M HCl. Slowly add 1 g of Ti3AlC2(titanium aluminum carbide) powder to the solution while stirring. Etch at 35°C for 24 h to remove Al layers from Ti3AlC2, leaving Ti3C2 layers. Wash the mixture with distilled water and ethanol until the pH is around 6. Collect the washed sediment by centrifugation and sonicate it in distilled water for 1 h. Centrifuge to remove unexfoliated particles. For BiOCl synthesis, dissolve 2 mmol of Bi(NO3)3·5H2O (bismuth nitrate pentahydrate) in 10 ml of 2M HCl (hydrochloric acid) with 0.5 g of PVP (polyvinylpyrrolidone). Transfer the solution to a Teflon-lined autoclave, fill it with distilled water up to 80%, and heat at 160°C for 24 h. Collect the precipitate by centrifugation, wash, and dry at 60°C for 12 h. Disperse BiOCl nanoparticles in distilled water, sonicate for 30 min, add Ti3C2 MXene dispersion, stir for 2 h, collect, wash, dry, and calcine at 400°C for 2 h. Result The Scanning Electron Microscope (SEM) utilizes electrons, rather than light, to generate highly magnified images. Energy Dispersive X-ray Spectroscopy (EDS) complements SEM by analyzing the X-ray spectrum emitted when a solid sample is bombarded with electrons, enabling localized chemical analysis. In SEM imaging, incorporating an X-ray spectrometer allows for both element mapping and point analysis. The SEM image of the prepared samples reveals accordion-like multilayer structures in BiOCl, characterized by thin sheet-like structures with numerous pores. EDS, relying on X-ray emissions from electron bombardment, facilitates detailed chemical analysis at specific locations within the sample. Conclusion Our research has shed light on the synthesis and characterization processes of two-dimensional Ti3C2 BiOCl nanoparticles, revealing their remarkable antimicrobial and antioxidant properties.

Leaching behavior of glasses of the Na2O-B2O3-SiO2-Cr2O3 system

Porous glass (PG) obtained by leaching of sodium borosilicate glass (NBS) is actively used in sorption and separation technologies. Modifying the NBS system with additives can drastically affect the resulting PG. Here, we report on the effect that Cr2O3 had on the leaching behavior of phase-separated glasses in the Na2O-B2O3-SiO2-Cr2O3 system in 3 M HCl solution. The structure of these glasses was investigated by means of XRPD, EPR, and SEM. All chromium ions exist in the Cr3+ state and are octahedrally coordinated. Most Cr2O3 crystallized as eskolaite in the silica-rich phase. The leaching process is limited by the interdiffusion in the leached porous layer. Cr2O3 did not get extracted from the glass into a leaching solution. PGs containing a significant amount of eskolaite were obtained. The component extraction rate for Cr-doped glasses was higher than for Fe-containing glasses with similar compositions, which was explained by the difference in their structural roles.

The application of 2-(3-nitrophenyl)imidazo[1,2-α]pyridine as an effective corrosion-defender for steel in acidic environment

Metal corrosion in acidic settings presents serious problems for many industrial areas. The creation of corrosion inhibitors that are efficient, long-lasting, and ecologically benign is essential. This study introduces a novel corrosion inhibitor, 2-(3-nitrophenyl)imidazo[1,2-α]pyridine (NIP), which was synthesized for protecting mild steel in 1 M HCl. The synthesized NIP was evaluated using Electrochemical Impedance Spectroscopy (EIS), Potentio-dynamic Polarization (PDP), Scanning electron microscopy (SEM), Energy X-ray analysis (EDX), and theoretical approache, including Density Functional Theory (DFT) and Monte Carlo simulations (MCs). NIP demonstrated outstanding protection behavior, reaching a peak of 91.47 % at a concentration of 1.00 mM. PDP studies classified NIP as a mixed-type inhibitor that effectively mitigated both anodic and cathodic reactions. SEM and EDX analysis confirmed the formation of a protective layer on the surface of the structural steels, composed mainly of nitrogen and oxides, indicating the presence of the inhibiting agent. DFT calculations identified the imidazole ring and heteroatoms (N and O) as the active sites for corrosion inhibition. The adsorption behavior of NIP on the metal surface has been studied by means of Monte Carlo simulations. The inhibitory efficiency of NIP was evaluated across a temperature range of 298–323 K, and the results showed a decrease in efficacy with increasing temperature, which provides crucial information for practical applications. The Langmuir model fit indicated a mixed mode of physical and chemical adsorption, with a calculated ΔG°ads value of −33.76 kJ/mol. This novel approach pinpointed reactive sites within the NIP, enhancing our understanding of its protective mechanism at the molecular level.

Citrullus colocynthis fruit extract as effective eco-friendly corrosion inhibitor in a hydrochloric acid pickling medium for carbon steel by using both experimental and theoretical studies.

The present study focuses on an environmental approach based on the use of an eco-friendly corrosion inhibitor from the Citrullus colocynthis fruit extract for enhancement corrosion resistance of carbon steel (C-S) in acid medium as an alternative to various organic and non-organic chemical inhibitors. The evaluation of the inhibition properties of the fruit methanolic extract of Citrullus colocynthis (CCE) were performed in molar hydrochloric acid (1M HCl) medium using gravimetric and electrochemical (potentiodynamic polarization and AC impedance) techniques as well as surface analyses. CCE is rich in amino acids, mainly citrulline and β-(pyrazo-1-yl)-L-analine molecules. Based on the weight loss evaluation, the results demonstrated that this plant extract acts as an effective corrosion inhibitor and a protection level of 93.6% was attained at 500ppm of CCE after 6h of metal exposure at 303K. According to polarization curves, CCE functions as a mixed-type inhibitor. In addition, AC impedance analyses have shown that the incorporation of CCE into the corrosive solution leads to a decrease in load capacity, while improving the charge/discharge function at the interface. This suggests the possibility of the formation of an adsorbed layer on the C-S surface. In addition, scanning electron microscope (SEM) observation, contact angle measurements, and Fourier-transform infrared spectroscopy (FTIR) analyses supported the development of a protective film over CS substrate surface afterwards addition of CCE. Langmuir and/or Temkin isotherms can be used to characterize the adsorption of this organic inhibitor on the C-S surface. X-ray photoelectron spectroscopy (XPS) has revealed that the inhibiting effect of CCE on the corrosion of C-S in 1M HCl solution is mainly controlled by a chemisorption process and the inhibitive layer is composed of an iron oxide/hydroxide mixture where CCE molecules are incorporated. In order to understand the relationship between the molecular structure and anti-corrosion effectiveness of these inhibitor molecules, quantum chemical studies were carried out using density functional theory (DFT) and molecular dynamics (MD) simulation.

Eco-conscious corrosion inhibitor synthesis via Soxhlet extraction: experimental study in HCl 1M and theoretical analysis using DFT and MC simulations

ABSTRACT This study investigates the inhibitory potential of a hydroalcoholic extract from tea waste, using the Soxhlet method, against C38 corrosion in hydrochloric acid. Electrochemical tests, including EIS and PDP, evaluated the impact of extract concentration and immersion time on corrosion inhibition. SEM/EDS analysis was performed to examine the adsorption process. The results show that inhibitor concentration significantly affects corrosion inhibition, with inhibitory efficiency (IE) values up to 97.98% according to IE and Tafel curves. Increasing extract concentration enhances corrosion inhibition via surface adsorption, following the Langmuir model, resulting in a gradual increase in charge transfer resistance over time. Maximum inhibitory efficiency is reached after 6 hours, demonstrating time-dependent corrosion inhibition. SEM analysis confirms the adsorption mechanism. In summary, this study highlights the inhibitory potential of green tea waste extracts against C38 steel corrosion in hydrochloric acid, suggesting sustainable corrosion protection methods. Theoretical methods, including DFT and MC approaches, were used to analyse the interactions between hydrochloric acid, water, and the iron surface, as well as the adsorption of catechin on Fe (110) and Fe2O3 (110) surfaces. DFT results align well with MC simulations and experimental measurements, revealing a significant correlation between molecular structure and inhibitory efficacy.

Prolonged corrosion protection via application of 4-ferrocenylbutyl saturated carboxylate ester derivatives with superior inhibition performance for mild steel

A series of 4-ferrcenylbutyl carboxylate esters with different alkyl chain length (C2-C4) of carboxylic acids were synthesized using Fe3O4@SiO2@(CH2)3-Im-bisEthylFc[I] nanoparticles as catalyst and have been characterized with FT-IR, 1H NMR, and 13C NMR. Ferrocenyl-based esters were used as corrosion inhibitors of mild steel in the 1M HCl solution as corrosive media. The corrosion inhibition efficiency of the synthesized ferrocenyl-based esters has been assessed by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The 4-ferrocenylbutyl propionate showed a more effective corrosion inhibition behavior among the studied esters with 96% efficiency after immersion in the corrosive media for 2 weeks. The corrosion inhibition mechanism is dominated by formation of passive layer of inhibitor on the surface of the mild steel by adsorption. Moreover, the adsorption characteristics of 4-butylferrcenyl carboxylate esters on mild steel were thoroughly explored using density functional theory calculations. It was found that the Fe atoms located around the C impurity in the mild steel are the most efficient and active sites to adsorb 4-butylferrcenyl carboxylate esters.

Unraveling the corrosion inhibition behavior of prinivil drug on mild steel in 1M HCl corrosive solution: insights from density functional theory, molecular dynamics, and experimental approaches.

The deterioration of mild steel in an acidic environment poses a significant challenge in various industries. The emergence of effective corrosion inhibitors has drawn attention to studies aimed at reducing the harmful consequences of corrosion. In this study, the corrosion inhibition efficiency of Prinivil in a 1M HCl solution through various electrochemical and gravimetric techniques has been investigated for the first time. The results demonstrated that the inhibition efficiency of Prinivil expanded from 61.37% at 50ppm to 97.35% at 500ppm concentration at 298K. With a regression coefficient (R 2) of 0.987, Kads value of 0.935 and Ea value of 43.024kJ/mol at 500ppm concentration of inhibitor, a strong affinity of Prinivil for adsorption onto the metal surface has been significantly found. Scanning electron microscopy (SEM) and contact angle measurement analyses further support the inhibitory behavior of Prinivil, demonstrating the production of a defensive layer on the surface of mild steel. Additionally, molecular dynamics (MD) and Monte Carlo simulations were employed to investigate the stability and interactions between Prinivil and the metallic surface (Fe (1 1 0)) at the atomic level. The computed results reveal strong adsorption of Prinivil upon the steel surface, confirming its viability as a corrosion inhibitor.

Corrosion Inhibition Performance of Whey Protein-Derived Inhibitors for Low Carbon and Dead Mild Steels in1M Hydrochloric Acid

This research investigates the corrosion inhibition capabilities of BCAA-derived inhibitors for low-carbon steels and dead mild carbon steels with distinct carbon contents when exposed to a 1M HCL solution. The effectiveness of the inhibitors was evaluated by measurements of weight loss and polarization. The study revealed that at a concentration of 10 grams, the weighing method showed that the BCAA inhibitor showed protection effectiveness (87 percent) at 313 K for low carbon steel and (89 percent) effectiveness at 303 K for dead carbon steel. Using a concentration of 15 g, the polarization method showed inhibitory activity of (96 percent) at 313 K for low-carbon steel and (96 percent) at 303 K for dead light carbon steel. These results indicate that the inhibition efficiency is affected by the carbon content. Samples were subjected to scanning electron microscopy (SEM) and optical microscope analysis before and after adding the inhibitor. When examined using FTIR spectroscopy, BCAA showed significant efficiency as a corrosion inhibitor for steel alloys immersed in acidic conditions.

Adsorption studies of isoxazole derivatives as corrosion inhibitors for mild steel in 1M HCl solution: DFT studies and molecular dynamics simulation.

The corrosion of mild steel is a significant issue in various industries, prompting the need for effective corrosion inhibitors. This study focuses on understanding the corrosion inhibition properties of organic compounds derived from isoxazole, namely series Iso(a), Iso(b), Iso(c), Iso(d), Iso(e), Iso(f), Iso(g), and Iso(h), which could have implications for materials science and industrial applications. By investigating the influence of different substitutions on these compounds, valuable insights can be gained into designing better corrosion inhibitors for practical use. Theoretical studies were conducted using density functional theory (DFT) with the B3LYP functional and the 6-31G (d,p) basis set. These calculations enabled the evaluation of various parameters including frontier orbital energies (EHOMO, ELUMO), energy gap (∆E), electronegativity (χ), absolute hardness (η), softness (σ), fraction of transferred electrons (∆N), as well as local properties such as natural atomic populations and Fukui indices. Additionally, molecular dynamics simulations were performed to study the adsorption behavior of the inhibitors on the surface of Fe (110). The simulations were conducted using Materials Studio version 8.0 software package using COMPASS force field to understand the impact of different functional groups on the inhibitors before and after adsorption on the iron surface.

Polyethyleneglycol bisphenol A epichlorohydrin copolymer (PEG-BEC) as a highly efficient inhibitor for mild steel corrosion in 1M HCl solutions

In this work, the corrosion inhibition performance of polyethyleneglycol bisphenol A epichlorohydrin copolymer (PEG-BEC) against mild steel in 1 M HCl was studied by electrochemical and weight loss techniques. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX) were applied to characterize the surface morphology of the mild steel samples. The corrosion mitigation efficiency was observed to rise as the concentration of PEG-BEC rises in the corrosive medium while increasing the temperature (25 °C -65 °C) resulting in a drop in the inhibition ability. Furthermore, under hydrodynamic conditions, the corrosion of the mild steel was found to deteriorate both in the absence and presence of PEG-BEC. Just with 10 ppm, an inhibition efficiency (IE) of 97.6% was obtained at 25 °C by EIS. PEG-BEC acts as a mixed-type inhibitor as observed by potentiodynamic polarization (PDP) technique. The observed corrosion inhibition action of PEG-BEC could be ascribed to the adsorption of the molecules and the formation of a protective film on the steel surface as evidenced by static water contact angle (WCA). Langmuir isotherm best describes the PEC-BEG-metal adsorption with large Kads values indicating a thermodynamically stable nature inhibition process. The obtained ∆G°ads = -35.138 to -39.522 kJ/mol indicate that the PEG-BEC spontaneously adsorbed onto the steel with strong tendency to provide protection to the mild steel surface via combination of chemisorption and physisorption processes. The ΔHads -53.07 kJ/mol and ΔSads= +0.048 kJ/mol-k, respectively, suggests an exothermic reaction accompanied by relatively increase in entropy of the PEG-BEC adsorption on the mild steel surface.

Chromatographic analysis of the amino acid composition of gallstones

Gallstone disease (cholelithiasis) is a multifactorial disease characterised by the formation of gallstones. Studying the composition of gallstones is necessary to understand the mechanism of their formation and to solve many practical issues. At present, it is not clear which protein component is involved in the formation of gallstones and how it is related to their components. The study showed the possibility of qualitative and quantitative determination of amino acids in the composition of gallstones of men and women of different ages using a GC-17A gas chromatograph (Shimadzu). Analysis of the amino acid composition of gallstones includes acid hydrolysis of samples with 6M HCl at 105C° for 12 hours, subsequent purification, obtaining derivatives of isolated amino acids, and their determination by gas chromatography. This technique enables the determination of D- and L-forms of amino acids. Statistical processing of the obtained data was carried out using Statistica 6.0. The study revealed that cholesterol gallstones belonging to women up to 50 years of age have the lowest amino acid content. The amino acid composition of cholesterol gallstones is dominated by glycine and L-forms of serine, alanine, and glutamic acid. Cholesterol gallstones with mineral content are typical for elderly women (over 60 years) and middle-aged men (from 37 years), and have higher amino acid content than cholesterol gallstones. Glycine and the L-forms of leucine, glutamic acid, and asparagic acid are prevalent in these types of gallstones. The highest amino acid content was recorded in pigment gallstones of both men and women over 55 years of age. The amino acid composition of pigment gallstones is dominated by glycine and L-forms of glutamic acid, asparagic acid, leucine, and alanine. In cholesterol gallstones, no D-amino acids were found. In cholesterol gallstones with mineral content and pigmented gallstones, D-aspartic acid was detected. The obtained results allow us to recommend the method of gas chromatography for studying the amino acid composition of gallstones.

Performance of three organic molecules in aluminium corrosion inhibition in 1M HCl : adsorption, DFT, PCA and non linear QSPR

Performance of three organic molecules in aluminium corrosion inhibition in 1M HCl : adsorption, DFT, PCA and non linear QSPR

Corrosion Protection of Mild Steel in Simulated Offshore Environment Using Ocimum gratissimum Leaf Extract

The inhibitive action of Ocimum gratissimum leaf extracts on mild steel corrosion in 1M HCl and 0.5 NaCl solutions was studied using the Gravimetric technique. Four weighed well-polished coupons suspended into sample bottles labeled 200mg/l, 400mg/l, 800mg/l, 1200mg/l and the blank respectively was used. The results shown in Tables 1 to 5 is the weight loss data of mild steel in 0.1 M HCl and the effects of Ocimum gratissimum introduction and how the mild steel corroded progressively thereby increasing the weight loss value over immersion time as seen in Fig. 1. Fig. 2 shows the effects of Ocimum gratissimum extract concentration on the corrosion rate of mild steel in HCl, it is evident that increase in the concentration of the extract led to the decrease in the value of weight loss leading to appreciable inhibition efficiency. The plot in Fig. 3 showed that the values of the inhibition efficiency increased with the concentration of Ocimum gratissimum extract in the acidic environment except the value for 9 days which decreased with concentration. These results led to decrease in the values of inhibition efficiency over time as shown in Fig. 4. Tables 6 to 10 shows the weight loss data for the corrosion of mild steel in 0.5 M NaCl and the effects of Ocimum gratissimum introduction. The result showed that mild steel corroded, leading to fluctuations in the inhibition efficiency. Figs. 5-8 showed the variations of efficiency with time with different concentrations of Ocimum gratissimum in 0.5 M NaCl. Addition of Ocimum gratissimum extract synergistically increased the efficiency of the inhibitor and helped reduce the corrosion rate. A mechanism of adsorption is proposed to explain inhibition behaviour.

SYNTHESIS AND CHARACTERIZATION OF ACTIVATED CARBON PREPARED FROM RICE HUSK BY PHYSICS-CHEMICAL ACTIVATION

Activated carbon is an amorphous carbon material predominantly composed of free carbon atoms with high adsorption capacity. The amorphous structure in activated carbon affects its adsorption capacity; the higher the percentage of amorphous carbon, the greater the adsorption capacity of the activated carbon. Activated carbon can be obtained from rice husk waste containing 30-40% C in cellulose, hemicellulose, and lignin. Therefore, this study was conducted to observe activated carbon's phases, morphology, elemental composition, and particle size. Activated carbon was synthesized using a physics-chemical activation method, which began with washing the rice husk samples, followed by air drying, carbonizing into charcoal, and grinding it finely. The rice husk charcoal powder was then physically activated at a temperature of 500℃. The physically activated product was then chemically activated using 6M HCl with a charcoal-to-activator ratio of 1:10 (m/V), stirred at 250 rpm for 1 hour, and then allowed to settle for 24 hours. It was then washed and dried to produce activated carbon powder. XRD test results showed diffraction peaks at 2θ = 22.23° without sharp or pointed peaks, indicating that the activated carbon has an amorphous structure. SEM test results showed the morphology of rice husk-activated carbon with spherical particle shapes and a particle size distribution of 20-70 nm. EDX test results showed that the rice husk activated carbon is predominantly composed of C, O, and Si with respective percentages of 54.31%, 40.04%, and 2.49%.

Experimental and theoretical insights into Artemisia Stems aqueous extract as a sustainable and eco-friendly corrosion inhibitor for mild steel in 1M HCl environment.

The present research demonstrates an innovative investigation of environmentally friendly mild steel (M-steel) corrosion inhibition using the artemisia stems aqueous extract (ASAEx) as an inhibitor in hydrochloric acid 1M. The standard extraction technique of hydrodistillation was used for producing the aqueous solutions of ASAEx. To assess the ratios of the chemical components, phytochemical screening was used to identify the stems of this plant. We used a variety of methods and techniques in our research on corrosion inhibition, including weight loss measures, surface analysis methods like XPS and SEM/EDS, electrochemical testing like PDP and EIS, as well as computational lead compound evaluation. Maximum inhibitory efficacy was achieved with 400mg/L ASAEx in 1M HCl at 303K, i.e. 90%. The PDP investigation verified the mixed-kind inhibitor status of the ASAEx extract. To describe the surface of M-steel, fitting and synthetic data were used to identify a constant phase element (CPE). SEM surface analysis was also used to detect the ASAEx effect on the surface of M-steel. X-ray photoelectron spectroscopy (XPS) analysis shows the presence of trace molecules of ASAEx on M-steel surface characterizing the bands in Maj-ASAEx (major compound of ASAEx). Density functional theory (DFT) and molecular dynamics simulations (MDs) were used in computational chemistry to clarify the adsorption mechanism and inhibitory impact.

Acid Leaching of La and Ce from Ferrocarbonatite-Related REE Ores

Rare earth elements comprise a group of 17 chemically similar elements, which increases the difficulty of separating them by traditional methods. For this reason, hydrometallurgy has been the most used method. However, it is important to evaluate the efficiency of the leaching processes used because, in addition to depending on the operating parameters of the leaching, they also depend on the mineralogical composition of the sample. In the present work, the extraction of Ce and La contained in the ferrocarbonatite mineral from the north of Mexico was studied. For the leaching tests, several leaching agents were used (HCl, H2SO4, HNO3, and H3PO4 in different concentrations (0.5 [M], 1 [M], 1.5 [M]) and the temperature was modified to 20, 40, and 60 °C. A maximum recovery of 70% for Ce and La was obtained using HCl 1M in 4 h. The results of the kinetic study of the experiments showed that the best fitting model according to these kinetic models was the SCM controlled by a chemical reaction.

SYNTHESIS AND CHARACTERIZATION OF PURE AMORPHOUS SILICON OXIDE FROM TREATED KAOLINITIC CLAY USING CHEMICAL EXTRACTION

Pure silicon oxide was produced in this study utilizing a sodium silicate solution made from Kankara clay as a precursor. The Kankara clay that was obtained from Nigeria was first beneficiated to produce pure dried powder clay. After that, the dried powdered clay was treated with heat activation and acid leaching, respectively. In a 500 mL Erlenmeyer flask, appropriate amounts of each clay (raw, thermally treated clay, and leached clay) were reacted with 3M NaOH solution. The flask was heated to 200°C and stirred continuously for 3 hours on a magnetic stirring hot plate connected to a reflux condenser. The solution was filtered to yield sodium silicate solution, which was then precipitated with 3M HCl while constantly stirring to produce a gelly-like white substance. The gel was aged for 18 hours, then washed with de-ionized water several times before being dried at 80°C for 12 hours to get pure white silica particles, which were subsequently described. The XRD analysis revealed that the silicon oxide synthesized is amorphous, but the microstructure evaluation revealed particles aggregation, which is usual in sol-gel synthesized powder.