Sulfuric Acid Research Articles

Recovery of Cu from waste smelting slag through extraction with novel deep eutectic solvents (DESs)

ABSTRACT This study reports on the recovery of copper, zinc, and iron from the copper smelting slag (CSS) of Saindak Copper and Gold Project, Baluchistan, Pakistan using novel deep eutectic solvents (DESs) and Sulfuric acid. Sorbic acid, citric acid, and urea were each mixed with tetrabutylammonium chloride (TBAC) to prepare three DESs. Leaching experiments were performed in batch mode under a constant stirring speed of 300 revolutions per minute (rev min−1) and contact time of 2 h, under different liquid to solid ratios (L/S 1.5–3) and different temperatures (60–90°C). Results showed that the DES2 (TBAC & citric acid) recovered about 77% copper, 49% zinc, and 1% iron among other two prepared DESs at 3 L/S and 90°C. Sulphuric acid recovered 94% copper, 2% zinc, and 4.7% iron under the same conditions. The same DES also showed selectivity in the recovery of copper, as compared to iron.

The effects of fertilizer pretreatment on nitrogen cycling in an intensively managed temperate grassland

Effective nitrogen (N) management is essential for minimizing fertilizer nutrient losses and maximizing N use efficiency. This study, conducted over two years on permanent grassland sites in Schleswig-Holstein, Germany, explored the effects of urea treatment with a urease inhibitor and digestate acidification on N-cycling and yield performance in a temperate maritime grassland context. Micro plots within these grasslands received varying N rates via acidified (with sulphuric acid) or non-acidified digestate (biogas residues), urea treated with- or without urease inhibitor (N-(n-butyl) thiophosphoric triamide) or calcium ammonium nitrate. Parameters measured included dry and N matter accumulations, NH3 volatilization, N2O emissions, NO3--N leaching, methane (CH4), and total greenhouse gas (GHG) emissions from soils. The findings demonstrated that the acidified digestate consistently enhanced metabolizable energy (ME), N yields (up to 47 %) and the apparent N recovery (ANR). While the acidified digestate and treated urea concurrently reduced NH3 emissions, the treated urea did not significantly affect (p> 0.05) dry matter (DM) and N yields, ANR, or total GHG emissions. Thus, digestate acidification or urea N stabilization could effectively mitigate the environmental impact of forage grass production while maintaining higher or comparable yields. However, higher risks of pollution swapping to groundwater bodies may result from higher N input rates. Applying acidified digestate or stabilized urea N to grasslands at a 120 kg mineral N ha−1 rate offers a practical approach, yielding appreciable N and ME while minimizing N losses.

S-1-Propenylcysteine enhances endurance capacity of mice by stimulating fatty acid metabolism via muscle isoform of carnitine acyltransferase-1

BackgroundEndurance is an important capacity to sustain healthy lifestyles. Aged garlic extract (AGE) has been reported to exert endurance-enhancing effect in the clinical and animal studies, though little is known of its active ingredients and mechanism of action. ObjectiveThe current study investigated the potential effect of S-1-propenylcysteine (S1PC), a characteristic sulfur amino acid in AGE, on the swimming endurance of mice and examined its mechanism of action by a metabolomics-based approach. MethodsMale ICR mice (6 weeks old) were orally administered water (control) or S1PC (6.5 mg/kg/day) for 2 weeks and swimming duration to exhaustion was measured at 24 hours after the last administration. Non-targeted metabolomic analysis was conducted on the plasma samples obtained from mice following 40-minute submaximal swimming bouts. Subsequently, the enzyme activity of carnitine acyltransferase-1 (CPT-1) and the content of malonyl-coenzyme A (CoA), acetyl-CoA and adenosine triphosphate (ATP) were quantified in heart, skeletal muscles and liver of mice. ResultsThe duration time of swimming was substantially increased in the S1PC-treated mice as compared to the control group. Metabolomic analysis revealed significant alterations in the plasma level of the metabolites involved in the fatty acid metabolism, in particular medium- or long-chain acylcarnitines in the mice treated with S1PC. Moreover, administration of S1PC significantly enhanced the CPT-1 activity with the concomitant decrease in the malonyl-CoA content in the heart and skeletal muscles. These effects of S1PC were accompanied by the elevation of the acetyl-CoA and ATP levels to enhance the energy production in those tissues. ConclusionS1PC is a key constituent responsible for the endurance-enhancing effect of AGE. The present study suggests that S1PC helps provide the energy during the endurance exercise by increasing fatty acid metabolism via CPT-1 activation in the heart and skeletal muscles.

Olfactory-chemical establishment using odour wheels and fingerprints to manage odor pollution for the petrochemical industry

The odor nuisance may cause major environmental issues, so identifying the odor characteristics is important for odor management and traceability in the petrochemical industry. In this study, odour wheels and fingerprints were applied to manage odor pollution in the petrochemical industry. First, the odor profile method and portable electronic nose evaluation were applied to analyze the flavour sensory profiles of five upstream and downstream petrochemical plants, in order to grasp the odor natures of plants. Second, 375 organized and unorganized samples of 5 plants were analyzed by gas chromatography-mass spectrometry (GC–MS) technology, and a total of 583 odorants were obtained, including sulfur compounds, alcohols, esters, aldehydes, ketones, acids, alkanes, alkenes, halogenated hydrocarbons, aromatic hydrocarbons, nitrogen compounds, and other compounds. Third, the key odorants were identified by gas chromatography-olfactory (GC-O) and odor activity value (OAV) analysis. Fourth, the fingerprint spectras were developed by the identification of key odorants and process sources through principal component analysis. For plant A, 21 odorants were confirmed, including naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1-methylindene, and 2-methylindene. Methyl methacrylate, acetophenone, isobutene, 4-vinyl-1-cyclohexene, acrylonitrile, and styrene were key element for plant B. The fingerprint factor of plant C had 20 odorants, including methanol, butanol, 2-ethylhexanol, acetic acid, and ammonia. And there were 21 odorants for plant D and 14 odorants for plant E, respectively, with similar substance types, including 2-ethyl-2-hexenal, 3-methyl-4-heptanone, isobutyl butyrate, and 1,2,3,5-tetraethylbenzene. Finally, the odor wheels were established by the correlation analysis between odorants and malodor, and compounds in fingerprint spectra weaker related to malodor of plants were removed. Hence, the characteristic odorants of each plant were further clarified, and the odors were associated with compounds, achieving rapid diagnosis and traceability of odor pollution in the petrochemical park. This provided new ideas and technical methods for odor pollution monitoring and identification.

Hafnium surface changes during dissolution in concentrated sulfuric acid

Hafnium surface changes during dissolution in concentrated sulfuric acid

Evaluating the strength loss and the effectiveness of glass and eggshell powder for cement mortar under acidic conditions

Abstract The cementitious composite’s resistance to the introduction of harmful ions is the primary criterion that is used to evaluate its durability. The efficacy of glass and eggshell powder in cement mortar exposed to 5% sulfuric acid solutions was investigated in this study using artificial intelligence (AI)-aided approaches. Prediction models based on AI were built using experimental datasets with multi-expression programming (MEP) and gene expression programming (GEP) to forecast the percentage decrease in compressive strength (CS) after acid exposure. Furthermore, SHapley Additive exPlanations (SHAP) analysis was used to examine the significance of prospective constituents. The results of the experiments substantiated these models. High coefficient of determination (R 2) values (MEP: 0.950 and GEP: 0.913) indicated statistical significance, meaning that test results and anticipated outcomes were consistent with each other and with the MEP and GEP models, respectively. According to SHAP analysis, the amount of eggshell and glass powder (GP) had the most significant link with CS loss after acid deterioration, showing a positive and negative correlation, respectively. In order to optimize efficiency and cost-effectiveness, the created models possess the capability to theoretically assess the decline in CS of GP-modified mortar across various input parameter values.

Tantalum oxide nanotube thin films: fabrication, optical properties, and porosity analysis

Tantalum oxide (Ta2O5) nanotubes exhibit remarkable properties and have garnered significant attention across diverse scientific disciplines and technological domains. This research article elucidates the successful preparation of amorphous, well-ordered Ta2O5 nanotubes through anodization in electrolytes incorporating hydrofluoric acid and concentrated sulfuric acid. The study comprehensively investigates the preparation methodology on the morphology of the nanotubes, elucidating their optical properties. Furthermore, the effective refractive index and porosity of the Ta2O5 nanotubes were quantitatively determined, offering valuable insights for the advanced utilization of Ta2O5 in several applications, encompassing battery electrode materials, memory resistors, and sensors.

The nitrogen-sulfur ratio of acid rain modulates the leaf- and root-mediated co-allelopathy of Solidago canadensis.

The majority of allelopathic studies on invasive plants have focused primarily on their leaf-mediated allelopathy, with relatively little attention paid to their root-mediated allelopathy, especially co-allelopathy mediated by both leaves and roots. It is conceivable that the diversified composition of acid rain may influence the allelopathy of invasive plants. This study aimed to evaluate the leaf and root-mediated co-allelopathy of the invasive plant Solidago canadensis L. under acid rain with different nitrogen-sulfur ratios (N/S) on Lactuca sativa L. via a hydroponic incubation. The root-mediated allelopathy of S. canadensis was found to be more pronounced than the leaf-mediated allelopathy of S. canadensis with nitric acid at pH 4.5, but the leaf-mediated allelopathy of S. canadensis was observed to be more pronounced than the root-mediated allelopathy of S. canadensis with sulfuric-rich acid at pH 4.5. The leaf and root-mediated co-allelopathy of S. canadensis was more pronounced than that of either part alone with sulfuric acid at pH 5.6 and nitric acid at pH 4.5, but not with nitric-rich acid at pH 4.5 and sulfuric-rich acid at pH 4.5. Sulfuric acid and sulfuric-rich acid with stronger acidity intensified the leaf-mediated allelopathy of S. canadensis. Nitric acid and nitric-rich acid attenuated the leaf-mediated allelopathy of S. canadensis, and most types of acid rain (especially nitric acid and nitric-rich acid) also attenuated the root-mediated allelopathy of S. canadensis and the leaf and root-mediated co-allelopathy of S. canadensis. Sulfuric acid and sulfuric-rich acid produced a more pronounced effect than nitric acid and nitric-rich acid. Hence, the N/S ratio of acid rain influenced the allelopathy of S. canadensis under acid rain with multiple N/S ratios.

Novel synthesis of B-doped Ti3C2Tx thin sheets via BF3 Lewis acid etching: Structural insights and Supercapacitor applications

The rising demand for energy storage spurs research on supercapacitor materials, valued for high-power density and long-term cycling, vital in industries. Among two-dimensional materials, MXene, with a general formula of Mn+1XnTx, where M represents early transition metals, X indicates C and/or N, Tx represents functionalized surface groups, and n = 1, 2, or 3, stands out as an ideal candidate for energy storage applications. Here, for the first time, we report the use of a Lewis acid, boron trifluoride (BF3), as an electron-deficient etchant in a sulfuric acid (H2SO4) solution for etching aluminum from the model system Ti3AlC2 MAX (M: transition metals, A: Al, X: carbon.), resulting in the formation of B-doped Ti3C2Tx MXene. Ex-Situ electrochemical X-ray diffraction (XRD) analysis showed reversible (002) plane changes in B-doped Ti3C2Tx MXene, from 5.72° to 7.0°, indicating ions intercalation and deintercalation, a first-time demonstration of significant ion transportation. Such fundamental insight determines that the specific capacitance of B-doped Ti3C2Tx MXene has found to be 396 F/g at current density of 1 A/g. This research introduces a novel synthesis approach aimed at understanding microstructural transformations of B-doped Ti3C2Tx MXene during electrochemical processes. This contributes to the advancement of MXene-based materials for future electrochemical applications.

Evaluating Use of Hydraulic Modified Sulfur Powder in Concrete Pavements: Laboratory Testing and Field Application

This study comprehensively evaluates the field applicability of hydraulic modified sulfur (HMS) as a concrete additive. We assessed the microstructural characteristics, mechanical properties, and durability performance of HMS at various replacement ratios in a laboratory setting. In addition, a field study was conducted by removing an existing conventional concrete pavement measuring (6000 × 12,000 × 70 mm, W × L × T) and overlaying it with HMS concrete. The experimental results revealed that HMS enhanced the mechanical and durability performance when used as a cement replacement at rates below 9%. These results satisfied the quality control standards and performance criteria specified in the Korean standard specification for cement-concrete pavements. The comparative analysis revealed that HMS concrete outperformed conventional concrete mixtures by 62.6% in sulfuric acid penetration depth, 14.8% in compressive strength retention after sulfuric acid immersion, and 53.1% in chloride-ion penetration resistance. Furthermore, no anomalies were detected during the 3-month follow-up period.

Synergistic recovery of aluminum phosphorus from incinerated sewage sludge ash via acid and alkaline treatment

The “phosphorus (P) crisis” has increased interest in improving P recovery methods and their efficiency. Incineration of sewage sludge ash is a recognized method for efficient P recovery, but challenges persist because of low recovery efficiency using thermochemical or biological methods and the issue of heavy-metal contaminants. Traditional wet-chemical processes, which yield calcium phosphate as the main product, are complex and costly. In contrast, aluminum (Al) phosphate (AlP) not only serves as a slow-release phosphate fertilizer but also has diverse high-value industrial applications, such as its use in battery coatings. To address these challenges, we developed a novel recovery route based on AlP extraction from Al-rich incinerated sewage sludge ash via acid leaching and alkaline precipitation. Our findings indicate that nitric acid (HNO3) achieves the highest Al leaching efficiency. The leaching kinetics of PO43− and metals follow second-order kinetics. Furthermore, pH adjustment with NaOH showed that the P precipitation efficiency from oxalic acid leachate was lower than that from hydrochloric acid, sulfuric acid (H2SO4), and HNO3 (88.0%–99.8%) because of buffering effects. These results underscore the potential of Al-rich ash for effective P recovery and considerably broaden the range of applications for P products.

Study on the mechanism of Na2CO3-roasting decomposition for water leach residue

In the process of treating cerium fluorocarbon-cerium lanthanide mixed rare earth concentrates by sulfuric acid roasting method, a large amount of waste leach residue containing iron, rare earths and phosphorus produced by flood neutralization needs to be solved urgently. In this paper, sodium carbonate roasting decomposition was used to treat the water leach residue, in which iron and rare earths were transformed into oxides, and the phosphorus was transformed into sodium phosphate. The main reactions and thermodynamic mechanisms of the roasting decomposition process were investigated by thermogravimetric analysis, phase analysis and chemical analysis. When the mass ratio of sodium carbonate to water leach residue is 1.5:1, the roasting temperature is 700 °C, and the roasting time is 1.5 h, the leaching rate of phosphorus with the roasted product reaches more than 98%. Meanwhile, the phase of the roasted product after washing mainly consists of iron oxide and rare earth oxides. The combination of sodium carbonate roasting decomposition and water leaching is effective for the treatment of water leach residue, which provides an experimental and theoretical basis for solving the problem of environmental and resource waste caused by the accumulation of a large amount of water leach residue. In addition, because sodium carbonate can achieve the separation of iron and phosphorus, this method also has certain reference value for the recovery and utilization of iron phosphate in lithium iron phosphate battery waste.

Soil Localized Leaching and Reclamation with Gypsum and Sulfuric Acid: A Case Study of Pistachio Orchard, Kerman-Iran

ABSTRACT Localized leaching method is a new reclamation leaching technique. Localized leaching method by using drip tapes allows water to be applied directly to the areas of salt accumulation. This study applied localized leaching method on a sandy loam soil in a pistachio orchard in Kerman, Iran to evaluate the impact of three treatments: adding gypsum soil remediation (G), soil remediation with sulfuric acid (SA) andirrigation water (IW) on soil remediation. Three treatments (IW, G and SA) in four repetitions were used to remove soluble salts from the Main Active Root Zone (MARZ) in a pistachio orchard which irrigated by a subsurface irrigation system. The localized leaching method consist of two T-tape pipelines at a distance of 40 cm located on both sides of the tree rows. Soil sampling was carried out before and after leaching from soil unit profiles with 80 cm (Length) × 120 cm (Depth) with 20 cm intervals. Concentrations of sodium (Na), magnesium (Mg), calcium (Ca) cations, and electrical conductivity (EC) were examined before and after leaching process. Results revealed that application of G-treatment compared to IW-treatment and SA-treatment led to more leaching of Na and Mg from the soil by 61% and 50%, respectively. The amount of leached Ca in both G-treatment and SA-treatments was less than that of IW-treatment. The leaching efficiency of total soluble salts for G, IW and SA treatments were 58%, 56% and 45%, respectively. Gypsum application could be recommended as a soil amendment. In addition, the localized leaching technique offers water-saving potential opposed to traditional leaching methods which applying water to the entire field.

Phytochemicals as eco-friendly corrosion inhibitors for mild steel in sulfuric acid solutions: a review

Abstract Plant extracts represent abundant sources of biomolecules distributed throughout various plant parts. These biomolecules are extracted using diverse solvents and methods. Within these plant extracts lie bioactive compounds, known for their antioxidant properties and anticorrosive capabilities. Detecting and isolating these active biomolecules from plant extracts necessitates analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. The active biomolecules within plant extracts contain heteroatoms within their structures, facilitating their adsorption on steel surfaces and conferring corrosion inhibition properties. The advantages of plant extracts as green corrosion inhibitors include ready availability, ease of application, eco-friendly characteristics, and cost-effectiveness. These extracts adhere to steel surfaces, blocking their active sites and effectively reducing the corrosion rate. This review consolidates the findings on the corrosion inhibition potential of plant extracts from various plant parts, elucidating their performance in different concentrations of sulfuric acid.

An oxidation flow reactor for simulating and accelerating secondary aerosol formation in aerosol liquid water and cloud droplets

Abstract. Liquid water in cloud droplets and aqueous aerosols serves as an important reaction medium for the formation of secondary aerosol through aqueous-phase reactions (aqSA). Large uncertainties remain in estimates of the production and chemical evolution of aqSA in the dilute solutions found in cloud droplets and the concentrated solutions found in aerosol liquid water, which is partly due to the lack of available measurement tools and techniques. A new oxidation flow reactor (OFR), the Accelerated Production and Processing of Aerosols (APPA) reactor, was developed to measure secondary aerosol formed through gas- and aqueous-phase reactions, both for laboratory gas mixtures containing one or more precursors and for ambient air. For simulating in-cloud processes, ∼ 3.3 µm diameter droplets formed on monodisperse seed particles are introduced into the top of the reactor, and the relative humidity (RH) inside it is controlled to 100 %. Similar measurements made with the RH in the reactor < 100 % provide contrasts for aerosol formation with no liquid water and with varying amounts of aerosol liquid water. The reactor was characterized through a series of experiments and used to form secondary aerosol from known concentrations of an organic precursor and from ambient air. The residence time distributions of both gases and particles are narrow relative to other OFRs and lack the tails at long residence time expected with laminar flow. Initial cloud processing experiments focused on the well-studied oxidation of dissolved SO2 by O3, with the observed growth of seed particles resulting from the added sulfuric acid agreeing well with estimates based on the relevant set of aqueous-phase reactions. The OH exposure (OHexp) for low RH, high RH, and in-cloud conditions was determined experimentally from the loss of SO2 and benzene and simulated from the KinSim chemical kinetics solver with inputs of the measured 254 nm UV intensity profile through the reactor and loss of O3 due to photolysis. The aerosol yield for toluene at high OHexp ranged from 21.4 % at low RH with dry seed particles present in the reactor to 78.1 % with cloud droplets present. Measurement of the composition of the secondary aerosol formed from ambient air using an aerosol mass spectrometer showed that the oxygen-to-carbon ratio (O : C) of the organic component increased with increasing RH (and liquid water content).

Separation of nickel and iron from ferronickel via sulfuric acid leaching and hydrothermal precipitation

ABSTRACT Here, a hydrometallurgical process was proposed to separate nickel (Ni) and iron (Fe) from ferronickel. The effects of different factors, namely hydrothermal temperature, initial Fe2+ concentration, and Ni2+ concentration, on the hematite precipitation process, were detail investigated. Ferronickel powders were leached using a 120 g/L H2SO4 solution at 85 °C for 8 h. The final pH of the leaching solution was controlled at 3.0−4.5, and the Fe2+ concentration was maintained at 50−60 g/L. Copper from the ferronickel powder was first leached in the early stage of the leaching process, and then it was reduced by an excess of ferronickel powder, leading to its enrichment in the leaching residue. Approximately 50 g/L of Fe ions was successfully removed and precipitated as hematite containing 60% Fe, 0.3% Ni, and 1.5% S during hydrothermal precipitation at 200 °C for 3 h. Through evaporation crystallization at 90 °C for 8 h, large particles of nickel sulfate hexahydrate (NiSO4·6H2O) containing 19.4% Ni, 0.074% Fe, and 10.69% S were obtained. Moreover, through freezing crystallization at −8 °C for 1 h, smaller particles of NiSO4·6H2O product containing 20.3% Ni, 0.014% Fe, and 11.13% S were synthesised.

A greener method to recover critical metals from spent lithium-ion batteries (LIBs): Synergistic leaching without reducing agents

Efficient recycling of critical metals from spent lithium-ion batteries is vital for clean energy and sustainable industry growth. Conventional methods often fail to manage large waste volumes, leading to hazardous gas emissions and dangerous materials. This study investigates innovative methods for recovering critical metals from spent LIBs using synergistic leaching. The first step optimized thermal treatment conditions (570 °C for 2 h in air) to remove binder materials while maintaining cathode material crystallinity, confirmed by X-ray diffraction (XRD) analysis. Next, response surface methodology (RSM), I-optimal, was used to examine the synergistic effects of sulfuric acid (SA) and organic acids (Org, citric and acetic acids) and their concentrations (SA: 0.5–2 M and Org: 0.1–2 M) on metal leaching for an eco-friendlier process. Results showed that adding citric acid to SA was more effective, especially at lower concentrations, than using acetic acid. The medium was tested to evaluate the impact of reductant addition. Remarkably, it was discovered that the optimized leaching mixture (1.25 M SA and 0.55 M citric acid) efficiently extracted metals without the need for any reductant like H2O2, highlighting its potential for a simpler and more eco-friendly recycling process. Further optimization identified the ideal solid-to-liquid ratio (62.5 g/L) to minimize acid use. Finally, RSM (D-optimal) was used to investigate the effects of time and temperature on leaching, achieving remarkable recovery rates of 99% ± 0.7 for Li, 98% ± 0.0 for Co, 90% ± 6.6 for Ni, and 92% ± 0.4 for Mn under optimized conditions at 189 min and 95 °C. Chemical cost analysis revealed this method is about 25% more cost-effective than conventional methods.

Surface‐modified graphite based polymer nanocomposites for high‐temperature geothermal applications

AbstractThis research aims to develop novel economical and thermally‐stable polymer nanocomposites to seal geothermal wells by dispersing surface‐modified graphite into an inexpensive raw polymer. Using a mixture of nitric acid and sulfuric acid, a nano‐scale graphite filler, namely small‐size lamellar graphite (SFG15), was surface‐modified, which introduced considerable oxygen and carboxylic (COOH) groups to graphite surfaces, as verified by X‐ray photoelectron spectroscopy (XPS) analysis. Polymer nanocomposites were fabricated by dispersing different concentrations of modified graphite SFG15, including 1.5, 3, 6, and 9 wt%, into the ethylene propylene diene monomer (EPDM) matrix. First, characterization techniques, including wide‐angle X‐ray scattering (WAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were employed to examine modified graphite dispersion in the nanocomposites. Then, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were used to quantitatively study the key mechanical and thermal properties of the nanocomposites. It was found that introducing modified SFG15 to EPDM enhances its resistance to deformation at high temperatures significantly. Notably, 9 wt% of modified SFG15 showed superior performances in improving the storage modulus of EPDM by 191.17%, enhancing loss modulus by as high as 136.08%, and decreasing tan by 18.93%. After introducing modified graphite, the energy needed for melting EPDM was increased markedly, which was accompanied by improvement in its heat capacity. Compared with pure EPDM, the onset temperature of degradation for developed nanocomposites could be increased by over , and the temperature of 50% degradation was raised by up to . Possessing the improved mechanical and thermal performances, the nanocomposites developed could be a primary choice for materials used to seal geothermal wells.Highlights A technique is developed to reinforce low‐cost polymers for high‐temperature use. Reinforcement of EPDM with high concentrations of modified graphite is investigated. Modified graphite increases the high‐temperature storage modulus of EPDM by 191.17%. Degradation temperatures of EPDM are enhanced by modified graphite considerably. Low‐cost polymer composites are essential seals for application in deep geothermal wells.

Obtention of Suitable Pregnant Leach Solution (PLS) for Copper Solvent Extraction Plants from Copper Concentrate Using Hydrogen Peroxide and Iodine in a Sulfuric Acid–Chloride Medium

Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), enhanced by hydrogen peroxide (H2O2) at room temperature. A significant aspect of this research was optimizing the KI concentration to minimize iodide sublimation into iodine gas (I2). Through the experimental design, the optimal dosages of reagents were determined, leading to maximized copper extraction of approximately 27% in 45 min of testing at room temperature. The results showed that it is possible to obtain a suitable pregnant leach solution (PLS) (i.e., in the range of 3 to 8 g/L of Cu) for treatment in available copper solvent extraction (SX) plants with a cost of less than 4.5 USD/t Cu, according to the economic analysis carried out. The results of this study determine the most effective operational conditions for leaching and ensure a suitable PLS for SX plants in a cost-effective and environmentally friendly manner. This approach could significantly contribute to more sustainable practices in the mining and processing of copper ores.

Optimisation of the corrosion inhibition performance of isatin 4-ethyl-3-thiosemicarbazone for mild steel in sulfuric acid medium using response surface methodology

Optimisation of the corrosion inhibition performance of isatin 4-ethyl-3-thiosemicarbazone for mild steel in sulfuric acid medium using response surface methodology