Addition Of HCl Research Articles

The partitioning of Cu, Au and Mo between liquid and vapor at magmatic temperatures and its implications for the genesis of magmatic-hydrothermal ore deposits

The partition coefficients of Cu, Au and Mo between liquid and vapor were determined at P=130MPa and T=900°C, and P=90MPa and T=650°C and redox conditions favoring the dominance of reduced S species in the fluid. The experiments at 900°C were conducted in rapid-quench Molybdenum-Hafnium Carbide externally-heated pressure vessel assemblies, whereas those at 650°C were run in René41 pressure vessels. The fluids were sampled at run conditions using the synthetic fluid inclusion technique. The host quartz was fractured in situ during the experiments ensuring the entrapment of equilibrium fluids. A new method was developed to quantify the composition of the vapor inclusions from LA-ICPMS analyses relying on the use of boron as an internal standard, an element that fractionates between vapor and liquid to a very small degree. The bulk starting fluid compositions closely represented those expected to exsolve from felsic silicate melts in upper crustal magma reservoirs (0.64m NaCl, 0.32mKCl, ±0.2mHCl and/or 4wt% S). The experiments were conducted in Au97Cu3 alloy capsules allowing the simultaneous determination of apparent Au and Cu solubilities in the liquid and the vapor phase. Though the apparent metal solubilities were strongly affected by the addition of HCl and S in both phases, all three elements were found to preferentially partition to a liquid phase at all studied conditions with an increasing degree of preference for the liquid in the following order Au<Cu<Mo. The presence of HCl and S did not have a significant effect on the liquid/vapor partition coefficients of either Au or Cu, whereas the presence of HCl slightly shifted the partitioning of Mo in favor of the vapor. Ore metal partition coefficients normalized to that of Na (Ki-Naliq/vap=Diliq/vap/DNaliq/vap) fall in the following ranges respectively for each studied metal: KAu-Naliq/vap=0.20±0.07–0.50±0.19 (1σ); KCu-Naliq/vap=0.36±0.12–0.76±0.22; KMo-Naliq/vap=0.67±0.15–2.5±0.8. Decreasing T from 900°C to 650°C slightly shifted KAu-Naliq/vap and KCu-Naliq/vap to the lower end of the reported ranges. A consequence of KAu-Naliq/vap and KCu-Naliq/vap being significantly smaller than 1 is that much of the Au and a significant fraction of Cu may be carried to shallower levels of magmatic-hydrothermal systems by residual vapors despite potentially extensive brine condensation.

Effect of HCl on NO Formation during CO/NH3 Combustion in an Entrained Flow Reactor at 1023–1223 K

Biomass and coal that contain high amounts of chlorine release HCl during combustion. There is no universal agreement regarding the effect of HCl on NO formation. To investigate the effect of HCl on NO formation, CO/NH3 combustion experiments and simulations were conducted in an entrained flow combustion reactor at 1023–1223 K. The experimental results show that the HCl addition tends to inhibit NO formation at low temperatures and exhibits promotion effects when the temperature is increasing and a temperature enhancement tends to inhibit NO formation. The simulation results provide evidence that the HCl addition inhibits NO formation by reducing the concentrations of the H, O, and OH radicals.

Syntheses of Families of Enantiopure and Diastereopure Cobalt Catalysts Derived from Trications of the Formula [Co(NH2CHArCHArNH2)3]3.

Aerobic reactions of CoX2 (X = OAc, Cl) or Co(ClO4)2 with (S,S)-1,2-diphenylethylenediamine [(S,S)-dpen] in CH3OH, followed by HCl or HClO4 additions, give the diastereomeric lipophobic salts Λ-[Co((S,S)-dpen)3]3+3Cl- [Λ-(S,S)-13+3Cl-] or Δ-(S,S)-13+3ClO4- (60-65%) with high degrees of selectivity. Anion metatheses (room temperature) and equilibrations (charcoal, CH3OH, 70 °C) show that the former is more stable than Δ-(S,S)-13+3Cl-, and the latter is more stable than Λ-(S,S)-13+3ClO4-. Additional anion metatheses lead to large families of lipophilic salts Λ- and Δ-(S,S)-13+2X-X'- [X/X' = Cl/BArf [BArf = B(3,5-C6H3(CF3)2)4], PF6/BArf, BF4/BArf, PhBF3/BArf, Cl/BArf20 [BArf20 = B(C6F5)4], BArf/BArf, BArf20/BArf20, BF4/BF4, PF6/PF6]. Mixed salts of the formula Λ- and Δ-[Co((S,S)-NH2CHArCHArNH2)3]3+2Cl-BArf- are similarly prepared (Ar = 4-C6H4n-Bu, 4-C6H4Cl, 4-C6H4CF3, 4-C6H4OCH3, α-naphthyl, β-naphthyl, 2-C6H4OBn). The diastereotopic NHH' protons exhibit different 1H NMR signals; one shifts far downfield when X/X' = Cl/BArf (δ ca. 8.0 vs 4.0 ppm). This is believed to arise from hydrogen bonding between the two Cl- anions and the two C3 faces of the D3-symmetric trication, each of which feature three synperiplanar NH groups. When all of the anions are poor hydrogen-bond acceptors (e.g., BArf-, BF4-, ClO4-), equilibria favor Δ diastereomers.

Effect of pH on electrochemical treatment using platinum coated titanium mesh electrodes for post treatment of anaerobically treated sugarcane vinasses

This study examines electrochemical post treatment to remove COD, SS, K+ and Cl- from anaerobically treated sugarcane molasses vinasse (ASMV). A platinum coated titanium mesh was used as an electrode material for both the cathode and anode, with 843.18 cm2 of working area. The effects of pH on removal efficiency, as well as energy and electrode consumption, were investigated. Influent ASMV was diluted 10 times and its initial pH was adjusted by addition of HCl and NaOH. The electrolysis experiment was performed at a current density of 94.88 A/m2 with 15 minutes of reaction time, and the effluent was collected after settling for 90 minutes. The results showed that the treatment efficiency was influenced by the initial pH value. A maximal COD removal efficiency (49.25%) was obtained at a pH of 5.0. For SS removal, the maximal efficiency (46.27%) was obtained at a pH of 10.0, and the lowest level of removal occurred at neutral pH conditions. The maximal efficiency of Cl- removal (17.59%) was obtained at a pH of 8.2 (non-adjusted), and its efficiency was lower when influent was adjusted to acidic and neutral pH conditions using HCl. Maximal efficiency of K+ removal (7.23%) occurred at neutral pH conditions and did not occur at alkaline pH values. Energy consumption was lower under pH-adjusted conditions than under non-adjusted conditions, and electrode consumption was higher in both acidic and alkaline conditions relative to neutral pH conditions.

Clustered assembly of Au nanoparticles from spherical diblock copolymer micelles encapsulating Au nanoparticle

ABSTRACTSuperstructures composed of diblock copolymer micelles and inorganic nanoparticles are quite interesting because the specific arrangement of inorganic nanoparticles within the micellar structure can reveal interesting opportunities in many field of science. In this perspective, we report a simple method to produce clustered assembly of Au nanoparticles in the micelles in attempt to induce plasmonic coupling among multiple Au nanoparticles in the assembled structures. Here, we utilized polystyrene‐block‐poly(acrylic acid), PS‐PAA, micelles containing single Au nanoparticle in the core (Au@PS‐PAA micelles) as building materials to initiate next‐level assembling process. In particular, the addition of HCl to the solution of Au@PS‐PAA micelles affected the overall equilibrium condition as well as kinetic process in the micellar solution. As a result, individual Au@PS‐PAA micelles could be merged together to form more large micelles with inclusion of multiple nanoparticles in the core, the process of which was accompanied with plasmonic coupling of Au nanoparticles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44693.

Mechanistic Study on the Ruthenium-Catalyzed Terminal Alkyne Hydrochlorination

Vinyl chlorides can be effectively prepared via alkyne hydrochlorination catalyzed by the [Cp*RuCl(cod)]/PPh3 system. The reaction mechanism has been elucidated by density functional theory calculations. Different from the previously proposed pathway (oxidative addition, alkyne coordination, H-/Cl-transfer via inner addition, and reductive elimination), the calculation results indicate that HCl favorably attacks the alkyne stepwise from the outer coordination sphere of the Ru center. The reaction is essentially the electrophilic addition of HCl to alkyne. Therefore, the proton tends to attack the more negatively charged carbon of the C–C triple bond, leading to the Markovnikov product.

Mild Oxalic‐Acid‐Catalyzed Hydrolysis as a Novel Approach to Prepare Cellulose Nanocrystals

AbstractThe traditional method to isolate cellulose nanocrystals (CNCs) is to subject cellulosic materials to strong acid hydrolysis by mineral acids, which usually causes problems such as corrosion of equipment, the need for large amounts of water, the difficulty of acid recovery, and over‐degradation of cellulose. Thus, a green and sustainable approach for the preparation of CNCs was developed where mild acid hydrolysis with diluted oxalic acid was used. The reaction kinetics of different preparation parameters, such as reaction temperature, oxalic acid dose, addition of HCl, and reaction time were thoroughly investigated. A high yield of up to 85 % was achieved by mild oxalic acid hydrolysis in comparison to the yield of 35 % using the most common approach with sulfuric acid hydrolysis. The CNCs from the above approach have a high thermal stability, that is, a maximum thermal degradation temperature of 350 °C in comparison to 200 °C when sulfuric acid hydrolysis was used. Importantly, oxalic acid solutions were readily recovered, and exhibited consistently high performance in several continuous runs of reaction. The hydrolysates contained mostly monomeric sugars, which could be further utilized for chemical or biofuel production.

Evaluating electrocoagulation and chemical coagulation for removing dissolved silica from high efficiency reverse osmosis (HERO) concentrate solutions

High efficiency reverse osmosis (HERO) produces high pH concentrate streams that often contain high levels of dissolved silica. Removal of silica from these concentrate streams is desirable before brine concentration and crystallization. This research investigated removal of dissolved silica from simulated HERO concentrate solutions using electrocoagulation (EC) with mild steel anodes and chemical coagulation with FeCl3. At pH values of above 10, the mild steel anodes immediately passivated and were not able to deliver Fe2+ ions into the solution. This necessitated lowering the solution pH value via HCl or FeCl3 addition prior to EC. At pH values ≤10, iron dosing by EC was in agreement with that given by Faraday's law. The optimal initial pH value for operating the EC process was 8, which required addition of 17.8mM HCl or 5.8mM FeCl3. An EC iron dose of 4.0mM resulted in 76–89% silica removal for solutions with initial pH values between 4 and 8. Higher dosing up to 9.3mM increased silica removal by only 5%. Chemical coagulation was not as effective as EC, and was able to achieve a maximum removal of 64% with a 4.0mM FeCl3 dose. Solution ionic strength had no measurable impact on silica removal by EC, but did affect final solution pH values and silica removal by chemical coagulation. For both EC and chemical coagulation, the initial pH value of solution had greater impact on silica removal than the iron dose.

Strong Acid Extraction Methods for “Total Phosphorus” in Soils: EPA Method 3050B and EPA Method 3051

Core IdeasMany agricultural labs have added environmental tests to their repertoire of protocols.These labs test various media (soils, waste residuals, manures, and runoff waters) for P.Almost no rigorous comparisons indicate what methods are best suited for this purpose.We compared EPA 3050B and 3051 (with/without HCl) on various acidic and alkaline soils.Both EPA 3050B and EPA 3051 gave reliable and comparable results.The emphasis on controlling environmental phosphorus (P) losses from agriculture has expanded the role of agricultural laboratories in testing a variety of media for P, including soils, waste residuals, manures, and runoff waters. To estimate total P in soils, strong acid extraction methods, which actually measure total recoverable P, are generally used because true total digestion methods (e.g., USEPA method 3052 or perchloric acid digestion) possess an array of operational concerns and safety limitations and also typically extract forms of P that are of limited environmental import. We sought to assess the merits of two strong acid extraction methods, USEPA method 3050B and USEPA method 3051 (both with and without hydrochloric acid [HCl] addition), on a variety of acidic and alkaline soils typical of the northeastern United States. Both methods gave reliable results, although method 3050B without HCl showed somewhat lower (though not statistically significant) extraction efficiencies. Method 3051 was unaffected by the addition of HCl, and its extraction efficiencies were approximately 7% greater when compared to method 3050B, although the differences were only significant in one of the seven soils tested.

An efficient on-board metal-free nanocatalyst for controlled room temperature hydrogen production.

Positively charged functionalized carbon nanodots (CNDs) with a variety of different effective surface areas (ESAs) are synthesized via a cheap and time effective microwave method and applied for the generation of hydrogen via hydrolysis of sodium borohydride. To the best of our knowledge, this is the first report of metal-free controlled hydrogen generation. Our observation is that a positively charged functional group is essential for the hydrolysis for hydrogen production, but the overall activity is found to be enhanced with the ESA. A maximum value of 1066 ml g-1 min-1 as the turnover frequency is obtained which is moderate in comparison to other catalysts. However, the optimum activation energy is found to be 22.01 kJ mol-1 which is comparable to well-known high cost materials like Pt and Ru. All of the samples showed good reusability and 100% conversion even after the 10th cycle. The effect of H+ and OH- is also studied to control the on-board and on-demand hydrogen production ("on-off switching"). It is observed that H2 production decreases inversely with NaOH concentration and ceases completely when 10-1 M NaOH is added. With the addition of HCl, H2 production can be initiated again, which confirms the on/off control over production.

NIR-Based Simultaneous Measurement of Amine Loading and Degree of Neutralization during Flotation Reagent Preparation for Potash Processing

A continuous spectroscopy-based monitoring approach of the amine reagent preparation prior to flotation processing was investigated. The process involved the neutralization of a long carbon chain amine, C16-C20, with hydrochloric acid. Current methods of monitoring the degree of neutralization, controlling the HCl addition, and monitoring the amine content were based on pH measurements, with out-of-line sample lab-validation carried out using titration-based methods. Industry feedback indicated this method was prone to error and had resulted in challenges in process control. This work demonstrates a novel method of measuring both amine content and degree of neutralization using a mini-fluidic reactor and FT-NIR system equipped with a flow-through heated transmission cell. Analysis of the spectral response for wavenumbers in the range of 4,258-4,400 cm-1 yielded amine content and degree of neutralization measurements accurately to within ± 0.065 wt%, and ± 6.0% margin of errors, respectively. This led to monitoring intensification to increase KCl recoveries in flotation processing.

Oxidation of 1, 2-dichlorobenzene on a commercial V2O5-WO3/nano-TiO2 catalyst: Effect of HCl addition

Abstract:The effect of various parameters on the catalytic oxidation of 1,2-dichlorobenzene (1,2-DCBz) present in simulated flue gas was investigated. A commercial V

Meal Effects Confound Attempts to Counteract Rabeprazole-Induced Hypochlorhydria Decreases in Atazanavir Absorption.

Clinically relevant pharmacokinetic interactions exist between gastric acid-reducing agents and certain weakly basic drugs that rely on acidic environments for optimal oral absorption. In this study, we examine whether the administration of betaine hydrochloride under fed conditions can enhance the absorption of atazanavir, an HIV-1 protease inhibitor, during pharmacologically-induced hypochlorhydria. In this randomized, single-dose, 3 period, crossover study healthy volunteers received ritonavir-boosted atazanavir (atazanavir/ritonavir 300/100mg) alone, following pretreatment with the proton pump inhibitor rabeprazole (20mg twice daily), and with 1500mg of betaine HCl after rabeprazole pretreatment. Atazanavir was administered with a light meal and gastric pH was monitored using the Heidelberg Capsule. Pretreatment with rabeprazole resulted in significant reductions in atazanavir Cmax (p < 0.01) and AUC0-last (p < 0.001) (71 and 70%, respectively), and modest decreases in ritonavir Cmax and AUClast (p < 0.01) (40% and 41%, respectively). The addition of betaine HCl restored 13% of ATV Cmax and 12% of AUClast lost due to rabeprazole. The co-administration of rabeprazole with atazanavir resulted in significant decreases in atazanavir exposure. The addition of betaine HCl did not sufficiently mitigate the loss of ATV exposure observed during RAB-induced hypochlorhydria. Meal effects lead to a marked difference in the outcome of betaine HCl on atazanavir exposure than we previously reported for dasatanib under fasting conditions.

Phase transfer synthesis of novel based surfactants: Role of biocorrosion inhibition and corrosion of steel

Four novel aziridinium, pyrrolium and azepanium bis-quaternary ammonium salts joined within similarly aromatic spacer have been synthesized. The phase transfer synthesized cycloadduct as a selective and startreaction material is a positive indicator for the corrosion inhibition process. The structures of the desired heterocyclic surfactants were confirmed by using elemental analysis, FT-IR and 1H NMR spectral analysis. The adsorption of these compounds on the metal surface is found to obey Tafel adsorption isotherm. Furtheron, the dilution method need to be included to evaluate their biocorrosion inhibition. This study explores the corrosion resistance of the prepared bisquats in 1 M HCl and SRB corroded medium. The growth of the reference SRB (Desulfomonas pigra) was shown to be completely inhibited by bisquaternary ammonium surfactants, In1- In3, and also the inhibition efficiency was found to increase with increasing inhibitor concentration and decreased with increasing surface tension which is due to the fact, that the rate of corrosion of carbon steel is higher than the rate of adsorption and therefore indicates that the joint adsorption of these compounds and chloride ions by the addition of HCl is due to the increase of the surface coverage. On the other hand, opposite cases were found where the presence of certain cations decreased the protective effect, for example, towards the corrosion of In4. Additionally, the thermodynamic parameters for adsorption and activation processes were determined; the following formulation properties are considered: the surface tension at cmc (γcmc), critical micelle concentration (cmc) of the surfactants in aqueous solutions, saturated adsorption amount of the surfactant (Г∞) and the minimum average area per surfactant molecule (Amin) at the air–water interface. On the bases of the result of small saturated adsorption amount and the large minimum average area per surfactant molecule, it is indicated that the minimum average area of surfactant decreases with the enhanced hydrophilic character of the molecule. A direct relationship has found between the corrosion efficacy (% IE) and Г∞. The galvanostatic polarization curves showed that, the inhibitor behaves as mixed type. The observed corrosion data indicate that, the inhibition of carbon steel corrosion is due to the adsorption of the inhibitor molecules on the surface, which follow Langmuir adsorption isotherm. By fitting the obtained experimental data with Langmuir adsorption model, some thermodynamic and kinetic parameters such as adsorption free energy, Gads, equilibrium constant, Kads, were estimated.

Selective Production of Carbon Monoxide via Methane Oxychlorination over Vanadyl Pyrophosphate.

A catalytic process is demonstrated for the selective conversion of methane into carbon monoxide via oxychlorination chemistry. The process involves addition of HCl to a CH4 -O2 feed to facilitate C-H bond activation under mild conditions, leading to the formation of chloromethanes, CH3 Cl and CH2 Cl2 . The latter are oxidized in situ over the same catalyst, yielding CO and recycling HCl. A material exhibiting chlorine evolution by HCl oxidation, high activity to oxidize chloromethanes into CO, and no ability to oxidize CO, is therefore essential to accomplish this target. Following these design criteria, vanadyl pyrophosphate (VPO) was identified as an outstanding catalyst, exhibiting a CO yield up to approximately 35 % at 96 % selectivity and stable behavior. These findings constitute a basis for the development of a process enabling the on-site valorization of stranded natural-gas reserves using CO as a highly versatile platform molecule.

Selective Production of Carbon Monoxide via Methane Oxychlorination over Vanadyl Pyrophosphate

AbstractA catalytic process is demonstrated for the selective conversion of methane into carbon monoxide via oxychlorination chemistry. The process involves addition of HCl to a CH4–O2 feed to facilitate C−H bond activation under mild conditions, leading to the formation of chloromethanes, CH3Cl and CH2Cl2. The latter are oxidized in situ over the same catalyst, yielding CO and recycling HCl. A material exhibiting chlorine evolution by HCl oxidation, high activity to oxidize chloromethanes into CO, and no ability to oxidize CO, is therefore essential to accomplish this target. Following these design criteria, vanadyl pyrophosphate (VPO) was identified as an outstanding catalyst, exhibiting a CO yield up to approximately 35 % at 96 % selectivity and stable behavior. These findings constitute a basis for the development of a process enabling the on‐site valorization of stranded natural‐gas reserves using CO as a highly versatile platform molecule.

Environmentally friendly recovery of Ag from end-of-life c-Si solar cell using organic acid and its electrochemical purification

Environmentally friendly and reusable methanesulfonic acid (MSA) was used with the addition of an oxidizing agent to extract Ag from solar cells. Recovery using varying MSA:H2O2 mixing ratios of 100:0, 90:10, 75:25, 50:50, and 0:100 revealed that Ag can be effectively extracted in a MSA-rich solution. The concentration of Ag ions dissolved in each mixture was analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES), which established that the optimal extraction condition is a MSA:H2O2 ratio of 90:10. The addition of HCl to the leaching solution used for Ag recovery prompted the precipitation of AgCl, which was then reacted in turn with NaOH and H2O2 to recover Ag metal powder. This Ag metal powder was analyzed by glow discharge mass spectrometry (GDMS) and found to have a low purity of around 99% (2N), but this was found to be improved through subsequent electrorefining to a purity of 99.995% (4N5).

Interactions of human serum albumin with doxorubicin in different media

Interactions of human serum albumin (10wt% H2O and 0.3wt% sodium caprylate) with doxorubicin hydrochloride (1wt%) were studied alone or with addition of HCl (3.6wt% HCl) using 1H NMR spectroscopy. A model of hydrated HSA/12DOX was calculated using PM7 method with COSMO showing large variations in the binding constant depending on structural features of DOX/HSA complexes. DOX molecules/ions displace bound water from narrow intramolecular voids in HSA that leads to diminution of freezing-melting point depression of strongly bound water (SBW). Structure of weakly bound water (WBW) depends much weaker on the presence of DOX than SBW because a major fraction of DOX is bound to adsorption sites of HSA. Addition of HCl results in strong changes in structure of macromolecules and organization of water in hydration shells of HSA (i.e., mainly SBW) and in the solution (i.e., WBW+non-bound bulk water).

Study on dealkalization and settling performance of red mud.

At present, the dealkalization and comprehensive utilization of red mud is a worldwide problem. Studies on the settling performance and phase transformation of red mud by HCl, CaO, and H2O leaching are limited. In this study, the characteristics of red mud were systematically analyzed. The average sizes of graded and initial red mud were 4.11 and 9.20μm, respectively. X-ray diffraction (XRD), X-ray fluorescence spectra (XRF), and thermogravimetry-differential scanning calorimetry (TG-DSC) results indicated the different mineralogical phases, composition, and thermal behavior. The addition of HCl could neutralize the alkalization in the red mud slurry, and CaO could replace the Na and K. Notably, the pH of the red mud slurry had no obvious change with the increase in water washing times in a certain pH. Interestingly, soluble Al and Fe were not detected in the HCl-red mud and CaO-red mud. In addition, the settling ratio was used to express the settling performance of the red mud slurry. Their interaction mechanisms were proposed, which may include phase transformation and the changing of the size and surface area. The research provided a better understanding of the phase transformation and settling performance in the treatment of red mud by HCl, CaO, and H2O leaching.

Chameleonic, Light Harvesting Photonic Gels Based on Orthogonal Molecular Fibrillization

The preparation of smart photonic gels composed of two orthogonally self-assembled fibrillar networks is reported. The molecular gelators are a light acceptor derived from 4-amino-1,8-naphthalimide and an acridine-based energy donor. Fibrillar orthogonal assembly of both chromophores is a requisite for light harvesting to be observed which results in emission from the naphthalimide-based acceptor upon irradiation of the acridine-derived donor with a significant Stokes shift of ca. 200 nm. Energy transfer is present both in the form of molecular gels in acetonitrile and in the solid-like xerogels and efficiently visualized both by fluorescence spectroscopy and confocal laser scanning microscopy. The chameleonic, stimuli responsive behavior is linked to the fact that the gel network formed by the acridine derivative can be selectively disassembled by means of temperature changes or chemical species. For example, the light harvesting process can be switched off/on by addition of HCl or NaOH respectively, aff...