Formation Of Intermediate Products Research Articles

Insights into ultrasound-promoted degradation of naphthenic acid compounds in oil sands process affected water. Part II: In silico quantum screening of hydroxyl radical initiated and propagated degradation of benzoic acid

In Part I, we outlined the importance of sustainable sonochemical treatment to intensify oil sands process affected water (OSPW) treatment empirically and hypothesized degradation pathways. Herein, we elucidate the formation of intermediate products with well-defined molecular level solutions. Proposed mechanisms describe hydroxylation, decarboxylation and bond scission which drive the degradation of intermediates towards mineralization. This comprehensive first study on in silico screening of sonochemical degradation investigates quantum methods using density functional theory to explain the postulated degradation mechanisms through a theoretical radical attack approach, based on condensed Fukui reactivity indicators. A nudged elasticity band (NEB) approach is applied to find a minimum energy path (MEP), allowing the determination of intermediate products and energy barriers associated with naphthenic acid degradation. This approach provides structures and energies of the breakdown compounds formed along the reaction pathway enabling the determination of molecular reaction kinetics.In continuation of Part 1, the focus of this study is to evaluate sonochemically-induced hydroxyl radical (OH•) reactions of benzoic acid using density functional theory. Hydroxylation and decarboxylation mechanisms of the model naphthenic acid compound and its intermediates were simulated to determine the prospective pathway to ideal mineralization. DFT was applied to calculate interaction energies, Mulliken charges, Hirshfeld population analysis, dipole moments, frontier orbitals, and polarizability. Electronic properties and frontier orbital trends were also compared to computational work by Riahi et al.[1] to confirm the transition states by Nudged Elastic Band Transition State theory (NEB-TS). In combination with Hirshfeld Population analysis, Fukui indices suggest a more linear degradation pathway narrowed down from earlier experimental work by Singla et al.[2]. The linear free energy relationship for the newly suggested computational benzoic acid degradation can be determined by lnkTST/W=-1.677ΔG-15.41 with a R2 of 0.9997 according to classic transition state theory and Wigner tunneling. This computational method can be used to explore possible degradation pathways of other NAs and bridges molecular-to-macroscale sonochemical degradation of NA’s through a manifestation of molecular solutions.

Modification of nickel-based catalyst with transition metals to tailor reaction intermediates and property of coke in steam reforming of acetic acid

Modification of Ni/Al2O3 with transition additives is known to affect physiochemical properties of the catalyst, while this will also inevitably impact evolution of reaction intermediates and property of coke formed in steam reforming. In this study, Ni/Al2O3 catalyst was modified with Fe, Zn, Cu or Co and the influences on formation of intermediate product and nature of coke was paid particular attention in steam reforming of acetic acid. The results indicated that iron or cobalt oxide reacted with NiO, forming NiFe2O4 and NiCo2O4, while copper or zinc oxide reacted with alumina, forming Al2CuO4 and ZnAl2O4, respectively. This weakened interaction between nickel oxide and alumina but also led to increase of nickel size, except Zn additive. Presence of Zn or Co in the catalyst enhanced adsorption of –OH or CO2, facilitating gasification of precursors of amorphous coke. The Cu additive intensifies adsorption/activation of oxygen-containing intermediates, while Fe was the opposite. The additive of Zn, Cu or Co, with exception of Fe, enhanced catalytic stability by suppressing formation of polymeric coke, although overall amount of coke was much higher. The coke formed in Zn, Cu or Co modified catalyst was mainly catalytic coke with a higher C/H ratio, higher crystallinity, higher thermal stability, higher portion of graphite structures, and nanotube-like structure of irregular inner cavity but with less impacts on catalytic stability.

Biotransformation of urea in the water of water bodies

Introduction. The transformation of substances is an urgent problem of environmental hygiene. Urea (carbamide) is a product of human and animal life - enters water objects with household collector wastewater, surface runoff in areas that use urea as fertilizer, waste discharges from livestock complexes, and effluents of enterprises that produce carbamide. Two aspects of the problems associated with urea contamination of water bodies can be identified: the lack of a direct instrumental method for controlling urea and the lack of a comprehensive approach to controlling urea and its biotransformation products: ammonium, nitrites and nitrates. These two factors determined the relevance of the research. Materials and methods. The studies used the «Stayer» ionic chromatography system with anionic and cationic separation columns: Phenomenex Star-Ion A-300 100/4.6 USA; Shodex IC YS-50 150/4.6 Japan; when developing the urea analysis method, the «Aquilon» cationic column AQULINE C1P, 5µ,150/4.6 was used. The detection is conductometric and amperometric. The research objects were: surface, bottled, tap water, model water solutions of carbamide. As a urease source, the soil (sod-podzolic) from the Educational and Experimental Soil-Ecological Center of the Lomonosov Moscow State University “Chashnikovo” was used. Results. A new highly sensitive ion chromatographic method for determining urea in the water of various water bodies with a sensitivity of 5 mg/dm3 with direct sample input and using sample preparation - 0.5 mg/dm3 is proposed. The results of studies of model aqueous solutions of urea, surface water, tap water of Moscow, many bottled water samples on the content of urea and products of its biochemical transformation are presented. The presence of urea in the surface water and tap water of Moscow was revealed, and a correlation between the urea content and ammonium ions, nitrites and nitrates in the water was stated. Limitations of the study. The studies were carried out with waters whose total mineralization did not exceed 15 mg-eq/dm3 (water of river Don), and the urea content established in the water samples was not lower than 0.5 mg/dm3. Conclusion. When monitoring urea contamination of various water bodies, it is necessary to consider the products of its biotransformation under the action of urease, for as a result of the processes of urea biotransformation, a low-toxic substance can form more toxic products: nitrites, nitrates and ammonium. Applying the kinetic approach to study the processes of urea biotransformation in water under model conditions showed that the extreme type of kinetic curves corresponds to the formation of intermediate products - nitrites, and the increasing type corresponds to the formation and accumulation of final products - nitrates and ammonium ions.

Imidazolium-based ionic liquid for stable and highly efficient black-phase formamidinium-based perovskite solar cell

The stable black α-phase is the key to attaining high-efficiency formamidinium lead triiodide (FAPbI3) perovskite solar cells (PSCs). There have been some reports using different sizes of ions to stabilize α-phase FAPbI3; unfortunately, they often affect the bandgap, stability and carrier dynamics, in addition to increasing the number of carrier trap sites. Herein, we present 1-allyl-3-methylimidazolium-chloride (AMICl) ionic liquid to stabilize the α-phase of pure FAPbI3 perovskite without encountering the above adversities. It is found that the thermodynamic temperature of α-FAPbI3 is significantly reduced from 150 °C to 145 °C by using AMICl, and the absorption edge of FAPbI3 remains at 850 nm. The efficiency of a FAPbI3 device with AMICl is increased from 18.47% for the control device to 20.76%, one of the highest values among pure FAPbI3 solar cells. The high efficiency is attributed to the low trap density, long carrier lifetime and suppressed carrier recombination, thanks to the large grain size and good crystallinity of FAPbI3 generated by the formation of intermediate products from PbI2 and AMICl, demonstrating by density functional theory (DFT) calculation. Meanwhile, FAPbI3 solar cells with AMICl exhibit the excellent environmental stability. The bare device without any encapsulation maintains about 87% of its initial value after being exposed to ambient for 24 days, significantly improved over the control device, which retains about 53% of its initial efficiency under the same conditions.

P-doped melon-carbon nitride for efficient photocatalytic H2O2 production

Melon-based carbon nitride (CN) is a semiconductor photocatalyst with a conduction band position suitable for photocatalytic H2O2 production. However, the thermodynamic inability to adsorb O2 molecules greatly limits its photocatalytic efficiency for H2O2 production. In this paper, P-doped CN with good performance for H2O2 production was synthesized by a simple one-step calcination method. The experimental results show that when the doping amount of P is about 9.0 wt% of CN, the yield of H2O2 can reach 12990 μM/h/g, which is about 6.6 times as that of pure CN. The mechanism of H2O2 production over P-CN was firstly revealed by using the density functional theory calculations based on the melon crystal structure of carbon nitride. The results show that P-doping is easier to the strong thermodynamic adsorption of O2 on CN, which is more beneficial to the formation of intermediate products. Further experimental results show that the substitution of C in CN by P-doping suppresses the electron and hole recombination, and therefore promoting the photocatalytic performance of P-doped CN.

Cefuroxime oxidation with new generation anodes: Evaluation of parameter effects, kinetics and total intermediate products

In this study, it was investigated the capability of new generation Sb-SnO2/Ti anodes, which are well known with their promising results in ozone generation and stability, to remove cefuroxime (CXM) antibiotic from aqueous solution. Comparison of different electrolyte types were performed for this purpose; NaCl and KCl. KCl increased the conductivity and caused to the formation of important oxidants and thus, affected electrochemical oxidation reactions more positively than NaCl. It was obtained that, pH parameter has a very important effect on the removal efficiencies in this process and higher efficiencies were obtained at the natural pH value (pH 7) of the aqueous solution. It was thought that, this was probably because the reactions occurred in aqueous solution mostly instead of anodic surface. Furthermore, the removal efficiencies increased with current density increase and the best results were obtained at 50 mA/cm2 current density. As a result of the study, at the end of 60 min of reaction, the aqueous solution containing cefuroxime antibiotic was completely treated without any toxic intermediate product formation with 750 mg/L KCl addition, at pH 7 and 50 mA/cm2 current density.

Boosted energy storage via carbon surface passivation

The wide application of electric double layer capacitor (EDLC) is restricted by its low energy density. Such a bottleneck is hopefully tackled via engineering the carbon surface chemistry to kinetically inhibit the electrolyte decomposition and effectively extend the cell voltage of the EDLC. Here, we propose a facile carbon surface passivation strategy by rational functionalization with fluorine-containing functional groups. Evidenced by electrochemical measurements, the fluorinated activated carbon (F-AC) could tolerate a wider voltage window in commercially available organic electrolyte compared with the commercial activated carbon (AC). The theoretical simulation further verifies that the F-AC displays much increased activation energy for the formation of intermediate products, thereby dynamically hindering the electrolyte decomposition on the carbon surface. The F-AC based EDLC exhibits a remarkable voltage expansion from 2.7 V to 3.3 V and excellent cycling stability of 98.3% capacitance retention after 20000 cycles. A high energy density of 43.3 Wh kg−1 is achieved at the power density of 135 W kg−1, which is about 1.5-fold enhancement compared with the AC based counterpart, outperforming most of the reported organic EDLCs. These inspiring results bring fundamental insights into the regulation of voltage window, which will stimulate the design of high-performance energy storage devices.

A Comprehensive Bioprocessing Approach to Foster Cheese Whey Valorization: On-Site β-Galactosidase Secretion for Lactose Hydrolysis and Sequential Bacterial Cellulose Production

Cheese whey (CW) constitutes a dairy industry by-product, with considerable polluting impact, related mostly with lactose. Numerous bioprocessing approaches have been suggested for lactose utilization, however, full exploitation is hindered by strain specificity for lactose consumption, entailing a confined range of end-products. Thus, we developed a CW valorization process generating high added-value products (crude enzymes, nutrient supplements, biopolymers). First, the ability of Aspergillus awamori to secrete β-galactosidase was studied under several conditions during solid-state fermentation (SSF). Maximum enzyme activity (148 U/g) was obtained at 70% initial moisture content after three days. Crude enzymatic extracts were further implemented to hydrolyze CW lactose, assessing the effect of hydrolysis time, temperature and initial enzymatic activity. Complete lactose hydrolysis was obtained after 36 h, using 15 U/mL initial enzymatic activity. Subsequently, submerged fermentations were performed with the produced hydrolysates as onset feedstocks to produce bacterial cellulose (5.6–7 g/L). Our findings indicate a novel approach to valorize CW via the production of crude enzymes and lactose hydrolysis, aiming to unfold the output potential of intermediate product formation and end-product applications. Likewise, this study generated a bio-based material to be further introduced in novel food formulations, elaborating and conforming with the basic pillars of circular economy.

Derivation of a Ni bioaccessibility value for screening-level risk assessment of Ni substances in ingested materials including soils.

The objective of the present study was to derive a Ni bioaccessibility value for screening-level risk assessment of Ni substances in ingested materials including soils where multiple Ni substances are expected but not definitively identified. Broad ranges of Ni mass loading and dissolution time of a simple gastric assay were applied to pure Ni substances (removing the confounding factors of soil constituents on dissolution), thus broadening the applicability of the conclusions. The data were also used to support current knowledge of 'read across' for Ni substances. Release of Ni from pure manufactured Ni substances (Ni metal, NiO, NiSO4, Ni3S2, and NiS) was determined relative to Ni mass and substance surface area loading. Mass loadings ranged from 0.33 to 20.0g Ni per L of 0.15M HCl, and dissolution time ranged from 1 to 168h. Proton exhaustion was indicated only at the highest loading (20g/L) of NiO and Ni-M. Dissolution of substances other than NiSO4 was most likely limited by formation of intermediate products at the particle surface or particle agglomeration, impeding access to the principal Ni substance. The bioaccessibility of Ni for these substances was consistent with previously published data: substances other than NiSO4 were < 48% bioaccessible for a variety of gastric assays, which is much lower than all data for NiSO4, the usual reference substance. Thus, we suggest that Ni bioaccessibility data from gastric assays that are most relevant to human exposure can be relied upon to develop scientifically sound screening-level human health RA decisions for Ni contamination in soils and sediments in the absence of detailed Ni speciation.

Change in the Structure of Asphaltene Macromolecules of the Krapivinskoye Oil Field During Biological Oxidation

Using physico-chemical methods of research (elemental analysis, infrared spectroscopy, selective chemical destruction of sulfide and ester bonds, chromatomass spectrometry) the influence of biodegradation processes on the composition and structure of asphaltenes of light oil at the Krapivinskoye deposit was studied. The results of comparative characteristics of initial asphaltenes and asphaltenes after biodestruction are presented. Attention is paid to studying their structural parameters and composition of fragments bound in asphaltene molecules through ester and sulfide bridges. It has been shown that microbial oxidation of asphaltenes of light oil by aboriginal soil microflora (laboratory experiment) occurs through a series of catalytic processes with formation of intermediate products of transformation – alcohols, aldehydes, ketones and fatty acids. It has been established that “grey and ether-bound” fragments in asphaltene molecules of biodegradable oil differ from “bound” compounds in the structure of the original asphaltenes with the qualitative composition of saturated and aromatic hydrocarbons and heteroatomic components

Effect of &lt;i&gt;Thymus marschallianus&lt;/i&gt; extract on lipid peroxidation processes &lt;i&gt;in vivo&lt;/i&gt; and &lt;i&gt;in vitro&lt;/i&gt; experiments

BACKGROUND: Currently, fundamental and experimental data confirming the role of free radicals in physiological and pathological processes have been accumulated. The literature describes conflicting information about the effect of antioxidants on the organism: they are able to protect not only normal cells from the alterative effect of free radicals, but also tumor cells, thereby supporting the survival and growth of the latter. Therefore, the study of the effect of Thymus marchallianus extract on the processes of lipoperoxidation in vivo against the background of the tumor process is relevant.&#x0D; AIM: To study the effect of Thymus marchallianus extract on the quantity of lipid peroxidation intermediates in the blood plasma of mongrel white rats with liver cancer PC-1 and compare with in vivo antioxidant activity.&#x0D; MATERIALS AND METHODS: The object of research was the dried Thymus marchallianus grass. Water and alcohol extracts were used in the experiment. Fifteen male white mongrel rats with a tumor were included in the experiment: the first group was intact, the second group received the water extract of Thymus marchallianus, and the third group received the alcohol extract of Thymus marchallianus. The activity of lipoperoxidation processes was evaluated, the content of intermediate lipid peroxidation intermediates malon dialdehyde, lipid hydroperoxides and medium-mass molecules in the blood plasma of experimental rats were estimated by means of conventional spectrophotometric methods. Determination of the antioxidant activity of the infusion and alcohol extraction in the in vitro experiment was carried out by the titrimetric method.&#x0D; RESULTS: In the control groups and the group of animals that received intraperitoneal water and alcohol extracts of Thymus marchallianus, increase in the intermediate products of lipid peroxidation was not revealed. The amount of malon dialdehyde, lipid hydroperoxides and medium-mass molecules in the blood plasma of experimental rats did not differ significantly from the level of similar indicators of intact animals. In the in vitro experiment, water and alcohol extracts from raw Thymus marchallianus showed antioxidant activity.&#x0D; CONCLUSIONS: For the first time, the experiment was conducted to study the effect of water and water-alcohol extracts of Thymus marchallianus on lipoperoxidation processes in mongrel white rats with alveolar liver cancer PC-1. The activity of formation of intermediate products of lipid peroxidation did not change, since their content in the blood plasma of experimental animals did not differ from the level of similar indicators of intact animals. In vitro the infusion and alcohol extract demonstrated antioxidant activity.

Multi-electron reduction process for boosting ammonia photosynthesis using graphene-modified red phosphorus

As a green and sustainable approach, nitrogen photofixation makes a strong contribution in suppressing the energy crisis. Boosting ammonia photosynthesis efficiency without additional sacrificial agents remains a significant challenge. In this study, an electron-rich reduced graphite oxide-modified red phosphorus (rGORP) was synthesized for ammonia visible-light photo-production. The rGORP composite retained the lattice structure of RP, activating NN through the acceptance and donation of electrons during nitrogen photofixation. Moreover, the incorporation of rGO increased the number of lone pairs of electrons and optimized the band structure of rGORP as well. Benefiting from appropriate conduction band, sufficient electrons, and effective electron transfer in 0.02rGORP (0.02 is the mass ratio of rGO to RP), activated N2 could be reduced into ammonia by a simultaneous three-electron reduction process, with a high ammonia synthesis rate of 7.74 mg/(L⋅h) without any organic scavengers. The system restricted the intermediate products formation and elevated the photocatalytic efficiency, thereby extending the application of non-metal materials in nitrogen photofixation.

Autocatalytic decomposition properties and thermal decomposition of benzoyl peroxide

Differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) were used to examine the thermal decomposition of benzoyl peroxide (BPO). The interruption rescanning method was adopted to examine the effect of thermal history on the autocatalysis and thermal decomposition of BPO. Autocatalysis of BPO was verified through isothermal experiments. According to the DSC linear temperature rise data of BPO, mathematical methods were used to decouple and divide the peaks. Kinetic analysis using both the Kissinger and Friedman methods was performed. The initial decomposition temperature of the decoupled BPO ranged between 101.4 and 104.6 °C. The peak temperature was 110.9–126.2 °C, and the decomposition enthalpy was 229.7–524.2 J g–1. The apparent activation energy was higher in the coupling state than after decoupling one. The thermal history and isothermal experiments demonstrated that BPO possessed autocatalytic properties. Results revealed that initial decomposition temperature tended to decrease with the increase in interruption temperature. In addition, the apparent activation energy of BPO decreased following the thermal history analysis because of the formation of intermediate products from BPO in the thermal history experiments, which further promoted BPO’s thermal decomposition. This effect led to a decrease in BPO’s initial decomposition temperature.

Parkland Fuel's Burnaby refinery to expand renewables coprocessing

The cement industry is now confronted with the pressure of strict requirements of energy consumption and pollution emission. To solve the problem, a two-process clinker manufacturing method consisting of a pretreatment process and a final calcination process is raised. The new method uses fluidized bed reactors to substitute the rotary kiln and cyclone preheater. Applicable operation conditions of the brand-new pretreatment process are firstly investigated to make sure the method will succeed. The intermediate product is used to describe the material obtained from the pretreatment process. Influences of the variants including calcination temperature, calcination time, and calcination atmosphere on the formation of intermediate products were discussed in the study. Results showed that the amount of C2S (dicalcium silicate) and strength of the intermediate product particles increased with the rising temperature. The superiority of rapid heating and fluidization in the pretreatment process was illustrated by comparing three heating styles. The recommended sequence of calcination was fluidized bed calcination > rapid calcination > slow calcination. Calcined for 10 min at 1200 °C is the optimal condition for the pretreatment process. The influence of atmospheres on C2S formation was not obvious. Operation conditions of the pretreatment process were determined for further study.

Effect of fluidized bed calcination on cement clinker intermediate products formation under the eutectic temperature

The cement industry is now confronted with the pressure of strict requirements of energy consumption and pollution emission. To solve the problem, a two-process clinker manufacturing method consisting of a pretreatment process and a final calcination process is raised. The new method uses fluidized bed reactors to substitute the rotary kiln and cyclone preheater. Applicable operation conditions of the brand-new pretreatment process are firstly investigated to make sure the method will succeed. The intermediate product is used to describe the material obtained from the pretreatment process. Influences of the variants including calcination temperature, calcination time, and calcination atmosphere on the formation of intermediate products were discussed in the study. Results showed that the amount of C2S (dicalcium silicate) and strength of the intermediate product particles increased with the rising temperature. The superiority of rapid heating and fluidization in the pretreatment process was illustrated by comparing three heating styles. The recommended sequence of calcination was fluidized bed calcination > rapid calcination > slow calcination. Calcined for 10 min at 1200 °C is the optimal condition for the pretreatment process. The influence of atmospheres on C2S formation was not obvious. Operation conditions of the pretreatment process were determined for further study.

Recent Developments for the Application of 3D Structured Material Nickel Foam and Graphene Foam in Direct Liquid Fuel Cells and Electrolyzers

Platinum and platinum-based catalysts are some of the most effective catalysts used in fuel cells. However, electrocatalysts used for direct liquid fuel cells (DLFCs) and electrolyzers are high cost and suffer from several other problems, thus hindering their commercialization as power sources to produce clean energy. Common issues in electrocatalysts are low stability and durability, slow kinetics, catalyst poisoning, high catalyst loading, high cost of the catalytic materials, poisoning of the electrocatalysts, and formation of intermediate products during electrochemical reactions. The use of catalyst supports can enhance the catalytic activity and stability of the power sources. Thus, nickel foam and graphene foam with 3D structures have advantages over other catalyst supports. This paper presents the application of nickel foam and graphene foam as catalyst supports that enhance the activities, selectivity, efficiency, specific surface area, and exposure of the active sites of DLFCs. Selected recent studies on the use of foam in electrolyzers are also presented.

Efficient electrocatalysis for denitrification by using TiO2 nanotube arrays cathode and adding chloride ions

Electrocatalysis is emerging as a promising alternative to bacterial denitrification for removing nitrate and ammonia from sewage. The technology is highly efficient and robust in actual wastewater treatment scenarios; however, there may be the generation of harmful intermediates (such as nitrite) on the traditional cathode material. In this study, we demonstrated that TiO2 nanotube arrays can be used as an effective cathode to reduce nitrate to ammonia without generation of nitrite. Alongside this, the addition of chloride ions in the solution can further oxidize ammonia to N2. We looked into the key factors influencing the electrocatalytic denitrification, including the current density (2–10 mA/cm2), initial pH values (3–11), and types of anions (HCO3−, Cl−, SO42−). The results showed that 90.8% of nitrate and 59.4% of total nitrogen could be removed in 1.5 h under optimal conditions, with degradation kinetic constants of 1.61 h−1 and 0.79 h−1, respectively. Furthermore, we investigated the formation of intermediate products and explored the electrocatalytic denitrification mechanism: (a) the surface oxygen vacancies and high specific surface area of TiO2 nanotube arrays electrode promote the reduction of nitrate to ammonia and N2; (b) the active chlorine generated at the anode surface can effectively oxidize ammonium to N2.

Kinetic and Mechanistic Studies of Acidic Hydrolysis of Goniothalamin

The acidic hydrolysis of goniothalamin was studied on the spectrophotometric kinetic study at different concentration of hydrochloric acid and temperature to determine the stability of the compound. Stability tests were performed using UV-VIS detection. This is a two-step reaction that involves formation of intermediate product. Rate constant of reactant forming intermediate product obeyed pseudo-first-order kinetic, while the second step to form final product is independent on the concentration of HCl. The structure of final products was identified by NMR and MS. The acidic hydrolysis pathway was proposed to involve the opening of lactone ring, followed by dehydration and formation of a double bond.

Increase in gold dissolution in copper ammonia thiosulfate solution via cobalt surface modification

When gold was leached using copper ammonia thiosulfate solution, the dissolution rate of gold decreased as the leaching time increased. The dissolution of gold powder with 44 and 77 μm particles was studied，and the results indicated that the dissolution rate was not decreased by surface passivation or the decrease in copper concentration but by the changes of the electronic structure of the gold surface caused by the change in the exposed crystal surface. The transmission electron microscopy images of the gold powder revealed that the high-index (220) and (311) crystal surfaces almost disappeared during leaching. Furthermore, the surface of gold consisted mainly of the low-index (111) crystal surface during the later stages of leaching. Owing to the changes in crystal surface, the work function of the gold surface increased from 6.56 to 6.95 eV, and the increase in work function hindered the loss of electrons from the gold surface. When cobalt was used to modify the gold surface, the work function decreased from 6.56 to 5.99 eV. The leaching results indicated that the cobalt modification increased gold dissolution, and the gold leaching percentage was increased by 40% within 8 h. the tendency of gold to dissolve more easily after it underwent surface modification was confirmed by the apparent activation energy of the surface-modified being lower than that of the fresh gold powder, the formation of intermediate products of Co3O4 with high oxidation ability and the galvanic interaction between cobalt and gold electrodes. Dry-grind was applied for gold concentrate calcine and different contents of cobalt powder to study the possibility of industrial application of this effect. The results showed that only adding 50 mg cobalt to 100 g gold ores was beneficial to gold leaching

Industrial applications of selected JFS articles

Industrial applications of selected <i>JFS</i> articles