Hydrochloric Solution Research Articles

Mixer-settler operation for the recovery of platinum, iron and hydrochloric acid from the leaching solution of spent petroleum reforming catalysts

Bench scale mixer-settler was employed to recover Pt, Fe and HCl from the hydrochloric acid leaching solution of spent catalysts. The number of stages and flow rate ratio of the aqueous to organic was estimated from the McCabe–Thiele plots for the extraction and stripping of the elements. In mixer-settler operation, Fe was first completely extracted by TBP and then the most of Pt was extracted by Aliquat336. Finally, HCl was recovered by extraction with TEHA and by stripping with water. From mixer-settler operation, most of the Pt and Fe were recovered and the recovery percentage of HCl was 95%.

Effect of Harmal Extract on the Corrosion of C-steel in Hydrochloric Solution

Effect of Harmal Extract on the Corrosion of C-steel in Hydrochloric Solution

A Novel Method for Preparing Biomimetic Oleophobic Surface on X70 Pipeline Steel

A novel method for preparing oleophobic surface is presented. In this article, an oleophobic surface on X70 pipeline steel was prepared successfully by the combination of shot blasting, hydrochloric acid aqueous solution etching, and modified with low-energy material. The influences of the concentration of hydrochloric acid and chemical etching time on the oleophobicity were analyzed. And the optimal experimental parameters were determined. The surface morphology and chemical composition were observed by the field emission scanning electron microscopy (FESEM) and energy dispersive spectrometer (EDS), and the contact angle was measured by contact angle meter. The results showed that micro-nanocomposite structure on the substrate was formed after shot blasting and chemical etching of hydrochloric acid aqueous solution. After low-energy modified, the specimen obtained the better oleophobicity, and the maximum contact angle between the surface and peanut oil was 140°.

Hydrochloric acid modification process for fabricating Bi2Sr2CaCu2O8+x THz oscillator stack on-chip coupled to THz detector

We fabricated Bi2Sr2CaCu2O8+δ (Bi-2212) intrinsic Josephson junctions (IJJ) integrating of an oscillator and a detector by double side photolithography and material modification with a dilutehydrochloric acid solution (pH = 1.65) within a monolithic Bi-2212 crystal. The dilute hydrochloric solution modifies Bi-2212 to insulating BiOCl. Various lateral dimensions of the oscillator IJJ from 45 × 8 to 95 × 30 µm2 were formed; all of the detectors were about 15 × 10 to 15 × 30 µm2 in lateral dimensions. These stacks have 180–416 junctions. Zero voltage current for the detector stack was measured at 77 K while sweeping a bias voltage in the oscillator stack. The zero voltage current of the detector stack was strongly suppressed when a kink structure in the current–voltage curve of the oscillator stacks appeared. This indicates that the oscillator stack emits radiation at this voltage. From the Josephson voltage-frequency relation, it is found that the voltage corresponds to about 0.5–1 THz.

Template-free synthesis of polyaniline nanobelts as a catalytic counter electrode in dye-sensitized solar cells

Polyaniline (PAn) nanobelts were synthesized by simply mixing aniline and hydrochloric acid aqueous solution with ammonium peroxydisulfate and hydrochloric acid aqueous solution at room temperature without any templates. The PAn nanobelt paste with polytetrafluoroethylene as binder is proper for low-cost and efficient casting processes such as doctor blade method, screen printing, spin-casting, and even roll-to-roll painting. The porous network structure of the PAn nanobelt counter electrode was obtained after drying the paste on the conductive glass. The as-prepared PAn nanobelt counter electrode showed nearly equivalent electrochemical catalytic activity as that of thermal decomposed Pt counter electrode, owing to the well-connected conductive network and high active surface area. The power conversion efficiency of dye-sensitized solar cell with PAn nanobelt counter electrode attained 90% of the value of the cell with Pt counter electrode. Copyright © 2014 John Wiley & Sons, Ltd.

폐촉매(廢觸媒) 염산침출액(鹽酸浸出液)에서 컬럼형 추출기(抽出器)에 의한 백금(白金) 회수(回收)

Abstract In order to recover Pt from the hydrochloric acid leaching solution of spent catalysts, bench scale Karr reciprocating columnwas employed. At an optimum flow rate and vibration frequency, iron and Pt was completely extracted by using TBP and Aliquat336. At the same vibration frequency, iron and Pt was completely stripped by HCl and HClO 4 after adjusting the flow rate. Inthe case of extraction of HCl from the raffinate with TEHA, it was difficult to maintain the stability of the column extractor.A comparison of the operation results between column extractor and mixer-settler is reported. Key words : Pt, Fe, HCl, Karr reciprocating column 1. Introduction Spent catalysts are valuable secondary resourcesfor the platinum group metals (PGMs). Much workhas been done on the recovery of PGMs from spentcatalysts by hydrometallurgical method. First, PGMsare dissolved by chloride based solution and thenare separated by employing solvent extraction or * Received : July 9, 2013·Revised : August 7, 2013·Accepted : August 21, 2013Corresponding Author : Man-Seung Lee (E-mail : mslee@mokpo.ac.kr)Department of Advanced Materials Science & Engineering, Mokpo National University, 61 Dorim-ri, Chungkye-myun, Muan-gun, Chonnam, 534-729, KoreaTel : +82-62-450-2492 / Fax : +82-62-450-2498ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

Simultaneous impedance and volumetric studies and additionally potentiodynamic polarization measurements of molasses as a carbon steel corrosion inhibitor in 1M hydrochloric acid solution

The inhibition effect of molasses on the corrosion of low carbon steel in 1M hydrochloric acid solution was investigated by volumetric and electrochemical measurements. Potentiodynamic polarization and dynamic electrochemical impedance spectroscopy (DEIS) results were obtained and compared with to those, obtained with the hydrogen evolution technique. All results indicate that molasses functioned as a good inhibitor in 1M hydrochloric solution and inhibition efficiency increased with molasses concentration. The advantage of DEIS as a tool for investigation of molasses influence was discussed.

Determination of Fluoride in Antarctic Krill <i>Euphausia superba</i> Using Ion Chromatography

A simple, rapid and accurate method for the determination of fluoride in Antarctic krill has been developed. The fluoride content in Antarctic krill was determined by ion chromatography. The method requires a simple sample clean-up procedure to remove the interfering Cl- from the hydrochloric acid extraction solution. The optimum extraction conditions of fluoride from Antarctic krill samples were obtained by adding 8mL of 1:11(v/v) hydrochloric acid solution and extracting for 60 min. Under these conditions, recoveries of fluoride from Euphausia superba and Penaeus vannamei were 97.9-105.6% and 95.1-101.9%, respectively. The limit of detection was 0.01mg/kg. The method was applied to the determination of fluoride in Antarctic krill. Key words: Fluoride, Antarctic krill, Ion chromatography

Separation of tetramethyl ammonium hydroxide using an MFI-type zeolite-coated membrane

Nanofiltration of tetramethyl ammonium hydroxide (TMAH) was investigated using an MFI-type zeolite-coated membrane. The membrane could be successfully prepared on an α-alumina support by hydrothermal synthesis. The MFI-type zeolite powder possesses a high adsorption capacity for TMAH at all pH values, with maximum adsorption amount determined by Langmuir adsorption mechanism of 0.593mmol/g at pH=11.63, because it presents a negatively charged surface. Nanofiltration of TMAH can thus be achieved through both molecular sieve and adsorption mechanisms by MFI-type zeolite. The MFI-type zeolite-coated membrane can be repeatedly used for nanofiltration, with backwashing with a dilute hydrochloric solution between cycles.

Investigation of Cyclohexylidenecyclohexanon Steel Corrosion Inhibitor as Surfactant

A modified organic waste of the caprolactam production is investigated by electrochemical impedance spectroscopy technique as a corrosion inhibitor of carbon steel in 20% hydrochloric solution. It is shown that cyclohexylidenecyclohexanon is a basic inhibiting component in such inhibitor. The inhibitor is investigated also as surfactant at the solution – air interface by means of the maximum bubble pressure technique. It is shown that the Langmuir adsorption of inhibitor takes place at solution – air and solution – steel interfaces. Equilibrium adsorption constant values make (1.7±0.4)×103 M-1 and (4.0±0.8)×103 M-1 respectively. Free adsorption energy was estimated as (–28±0.5) kJ mol-1 and (–30±0.6) kJ mol-1 respectively. The closeness of the adsorption constant and the free adsorption energy values suggest that the inhibitor adsorption on steel is caused basically by the hydrophobic interaction of inhibitor molecules with the solution molecules and less depends on the interaction with steel.

ELECTROREFINING IN AQUEOUS CHLORIDE MEDIA FOR RECOVERING TIN FROM WASTE MATERIALS

Recycling of the impure tin generated by the hot dip tinning and wave soldering technologies widely applied in modern electronic industry can be carried in a flexible and economical way even at relatively low production rates by electrorefining. In order to avoid the economical disadvantages of the alkali stannate or the sulphuric acid – cresylic phenylic sulphonic acid baths, the hydrochloric acid tin chloride electrolyte solutions can be applied. The major difficulties of solution stability, cathode corrosion and rough electro-crystallization can be overcome by optimizing the solution composition and the current parameters. Strong chloro – complex formation in the hydrochloric acid solution enhance stability of the Sn(II) species and the consequent natural inhibition promotes a cathodic deposition of acceptable quality. The virtual current efficiency and the morphology of electro-crystallization were improved by applying periodically reversed (PCR) current. Although cathode corrosion could be depressed to a negligible level, dendritic crystal growth remains to be dominant, therefore special cell arrangement and cathode handling should be applied. The cathode deposit is easily removed and melted, allowing to obtain a recycled tin of high purity.

Anatase TiO<sub>2</sub> Enrichment from Bangka Ilmenite (FeTiO<sub>3</sub>) and its Photocatalytic Test on Degradation of Congo Red

Anatase TiO2 enrichment from Bangka ilmenite (FeTiO3) has been conducted. First, ilmenite was mechanically activated using a planetary ballmill to obtain sub-micron sized particle followd by magnetic separation. Chemical treatment, dissolution of iron using hydrochloric solution, was performed to obtain titania rich residue. EDX data shows that the iron content was reduced in the titania residue. Ammonium hydroxide (NH4OH) solution was added to the washed precipitate, before adding H2O2 solution (10%) that acted as a coordination agent to leach titanium from the the residue in the form of ammonium peroxo titanate solution. The peroxo titanate powder was obtained by evaporating the ammonium peroxo titanate solution. XRD data show that TiO2 anatase was formed after peroxo titanate powder was calcined at the temperature of 600°C. EDX data also shows that the obtained anatase TiO2 still has impurities, such as silicon (0.98%) and iron (2.75%). Its photocatalytic activity was studied on photodegradation of Congo Red and compared with the photocatalytic activity of commercial TiO2, Degussa P-25. The photoreactivity test on degradation of Congo Red solution with the as-prepared Anatase gave 20% degradation which is still inferior compared to the results given by Degussa P25 (92%). This indicates that the impurities in as-prepared Anatase may cover the titania surface hindering the contact between Congo Red as well as UV-light and the active titania species.

Extraction of Vanadium from Chloride Solutions Using Di (2-Ethylhexyl) Phosphate

Extraction of vanadium has been developed to extract vanadium from hydrochloric solutions with high concentration of iron ions. The effects of extraction conditions such as pH values, extraction time and extraction temperature on the distribution ratio of vanadium were investigated. The results showed that the distribution ratio of vanadium increased with the higher pH, the lower temperature and the longer equilibrium time. The distribution ratio reached 25 and the extraction ratio reached 96.2% by single stage extraction. When the organic phase was stripped with 2 mol/L hydrochloric acid at the phase ratio (O/A) 10:1, the vanadium stripping ratio of 98.3% could be achieved.

Ultradrawing properties of ultra-high molecular weight polyethylene/hydrochloric acid treated attapulgite fibers

Investigation of the influence of the purified and acid treated attapulgite (ATP) contents on the ultradrawing properties of ultrahigh molecular weight polyethylene/purified attapulgites (UHMWPE/ATP, F100Ay) and UHMWPE/acid treated ATP (F100AxM-y) as-prepared fibers is reported. In which, acid treated ATP nanofibers were treated with varying concentrations of hydrochloric solutions for various amounts of time. Similar to those found for the orientation factor values, the achievable draw ratios of the F100Ay and F100AxM-y as-prepared fibers and tensile strength values of their drawn fibers approach a maximal value as their purified ATP and/or acid treated ATP contents reach the optimal values at 0.05 and 0.025 wt%, respectively. In which, the maximal Dra values of F100AxM-0.025 as-prepared series fiber specimens and the tensile strengths and moduli of the drawn F100AxM-0.025 fiber specimens are significantly higher than those of the F100A0.05 drawn fiber specimens prepared at the same draw ratios and optimal ATP contents but without acid treatment. Moreover, it is worth noting that the maximal Dra values of the F100AxM-0.025 as-prepared fiber specimens and the tensile strengths and moduli of the drawn F100AxM-0.025 fiber specimens reached another maximal value as their ATP nanofibers were treated by 5 M HCl solutions for 60 min. To understand the interesting ultradrawing, orientation and tensile properties of F100Ay and F100AxM-y fiber specimens, Fourier transform infra-red, specific surface areas, scanning electron microcope and elemental analyses of the purified and acid treated ATP nanofibers, and/or morphological and thermal analyses of the F100Ay and F100AxM-y fiber specimens were performed in this study.

Development and evaluation of pH-dependent interpenetrating network of acrylic acid/polyvinyl alcohol

The objective of the present work was to synthesize interpenetrating networks (IPNs) of acrylic acid/polyvinyl alcohol (AA/PVA) by free radical polymerization using N,N-methylenebisacrylamide (MBAAm) and glutaraldehyde as cross-linkers. The IPNs were evaluated for swelling, diffusion coefficient and network parameters by using Flory–Huggins theory, i.e., the average molecular weight between cross-links (M c), polymer volume fraction in swollen state (V 2,s), number of repeating units between cross-links (M r) and cross-linking density (N). It was found that the degree of swelling of AA/PVA interpenetrating network increases greatly within the pH range 5–7 depending on composition. The gel fraction and porosity increased by increasing the concentration of AA or PVA, while by increasing the degree of cross-linking, porosity decreased and gel fraction increased. Selected samples were loaded with chlorpheniramine maleate as a model drug. Drug release was studied in USP, hydrochloric acid buffer solution of pH 1.2 and phosphate buffer solutions of pH 5.5 and 7.5. Drug release data were fitted into various kinetics models, e.g., zero-order, first-order, Higuchi and Peppas models. The results of the kinetics investigation showed that the drug release from IPNs followed non-Fickian diffusion. Fourier transform infrared spectra confirmed the formation of cross-linked IPNs as there was a shifting to lower frequency of 1,713–1,718 cm−1 with reduced intensity, while scanning electron microscopy revealed uniform distribution of drug in IPNs.

Preparation and Study of the Hot Filament CVD Diamond Coated Tools

The surface of the carbide YG6 milling insert was roughened by using three different pretreatment crafts, the diamond films was deposited on the substrate surface, after deposition, the morphology and quality of the diamond films were detected by using the scanning electron microscopy and the laser Raman spectroscopy, the adhesion strength of the membrane-based was discovered by using the method of indentation test. The results showed that: the surface of the substrate had the lower surface roughening with the hydrochloric acid aqueous solution and methanol solution pretreated, in addition the surface of the films had cracks, obviously, the adhesion strength of the membrane-based was unsatisfactory; However, the surface of the substrate had the higher roughening degree with the sulfuric acid hydrogen peroxide solution pretreated, and with good adhesion strength between the film and substrate.

Electrochemical and XPS studies of the corrosion inhibition of carbon steel in hydrochloric acid pickling solutions by 3,5-bis(2-thienylmethyl)-4-amino-1,2,4-triazole

Corrosion inhibition of carbon steel in normal hydrochloric acid solution at 30°C by new 4-amino-1,2,4-triazole derivative, namely 3,5-bis(2-thienylmethyl)-4-amino-1,2,4-triazole (2-TMAT) has been studied by electrochemical impedance spectroscopy (EIS) and polarization techniques. The experimental results have showed that this organic compound revealed a good corrosion inhibition and that the inhibition efficiency is increased with the inhibitor concentration. Two time constants determined by the charge-transfer and the adsorption of the inhibitor, respectively, can be readily outlined. Potentiodynamic polarization showed that 2-TMAT is a mixed type of inhibitor. The adsorption of 2-TMAT on the carbon steel surface in 1M HCl solution obeyed to the Langmuir isotherm with a very high negative value of the standard Gibbs free energy of adsorption ΔGads° (chemisorption). X-ray photoelectron spectroscopy (XPS) analyses were carried out to establish the mechanism of corrosion inhibition of carbon steel in 1M HCl medium by 3,5-bis(2-thienylmethyl)-4-amino-1,2,4-triazole (2-TMAT).

Inhibiting effect of some synthesized surfactants from petroleum oils on the corrosion of aluminium in hydrochloric acid solution

Anionic surfactants (namely, gasoil sulfonate (GOS), kerosene sulfonate (KES), heavy solvent sulfonate (HSS) and total gasoline sulfonate (TGS)) were obtained from Algerian petroleum fractions. Their inhibiting effect on aluminium corrosion in hydrochloric solution (1 M HCl) is studied, using weight loss mea- surements, electrochemical polarization, and electrochemical impedance spectros- copy methods. The results obtained from different techniques are in good agreement and show that surfactants act predominately as cathodic inhibitors. The inhibition efficiency increases with increasing inhibitor concentration and decreases in the order: GOS ( KES ( HSS ( TGS. The adsorption process of GOS was also studied in the temperature range of 293-323 K and reveals that the inhibitor adsorption onto Al is a physisorption-type, spontaneous and exothermic.

Inhibition of C-steel Corrosion in Hydrochloric Solution with Chenopodium Ambrorsioides Extract

Inhibition of C-steel Corrosion in Hydrochloric Solution with Chenopodium Ambrorsioides Extract

Ionic liquid based three-liquid-phase partitioning and one-step separation of Pt (IV), Pd (II) and Rh (III)

The present work reports an interesting phenomena that the addition of hydrophobic ionic liquid, [C4mim]PF6, into the oil–water two phase system of diisopentyl sulfide (S201)–nonane organic solutions and hydrochloric acid aqueous solutions containing Pt (IV), Pd (II) and Rh (III) chloric-complexing anions could induce the formation of a stable liquid–liquid–liquid three layered liquids coexisting medium for extraction and one-step separation of platinum, palladium and rhodium. The influences of H+ and Cl− concentrations in equilibrating aqueous solutions, the initial Pt (IV) concentration, the volume ratio of added [C4mim][PF6] to hydrochloric acid aqueous solution and the different salt ions in equilibrating aqueous solutions on the three-liquid-phase partitioning behaviors of three platinum metal ions were evaluated. The transferring of PtCl62- into the [C4mim]PF6 bottom phase in TLPS was proposed to be according with an anion exchange between PtCl62- and PF6- in ionic liquid. Therefore, the separated ionic liquid phase is not the solvent of organic extractants, but provides an extended separation capacity than the literature reported ionic liquid based two-phase extraction systems. The present work indicated that this ionic liquid based three-liquid system can be used to separate multi-metal coexisting solutions.