Acid Pickling Solutions Research Articles

Facile route for processing natural polymers for the formulation of new low-cost hydrophobic protective hybrid coatings for carbon steel in petroleum industry

This research helps with the creation, assessment, and characterization of a new hybrid protective coating for carbon steel alloy in acid conditions. The findings of this study will be useful for both chemical and petrochemical companies as well as scientists. This study aims to protect C-steel in acid pickling solution 1.0M HCl and formulate new hydrophobic protective hybrid organic–inorganic coatings from biopolymers chitosan and plant resin guar gum. Eight coating samples of chitosan in the absence and the presence of guar gum, silica and two heterocyclic compounds are prepared at feasible operational conditions using hot melt method. The aiding additives improved compatibility between coating constituents as confirmed by using different methods of analysis. This new processing approach has addressed the problems of using chitosan in corrosion control such as solubility in acid media and low mechanical strength. Coating samples of chitosan and its composites with the heterocyclic compounds (2-Hydrazinyl-6-methyl-4, 5-dihydro pyrimidine-4-on) or (2-Hydrazinyl-6-phenyl-4, 5-dihydro pyrimidine-4-on) are potent biocides. Coating shifts corrosion potential of carbon steel by 30 mV to more noble direction relative to the active potential 520 mV of bare carbon steel surface. Impedance and polarization measurements indicate that coating samples protect metal surface as mixed-type inhibitor by adsorption mechanism. There is a good agreement between percentages protection %P of coating calculated using the values of charge transfer resistance, Rct, and corrosion current density, icorr. All %P values are above 99% for all coating samples. Guar gum plant resin increases gloss of the coating film. Silica fills the pores in the polymeric film and increases the stuffiness of the polymeric coating film by modifying the particle size. All coated samples have high contact angle ranging from 150° to 165° indicating low wettability and high hydrophobicity of coating film on the metal surface.

Utilisation of titanium-containing wastes in the cement industry: A literature review

The metallurgical industry is among the leaders in waste production which has a high potential for recycling. The review paper considers the problems of metallurgical industry waste management and some possible ways of their solution. Waste acidic pickling solutions of titanium (titanium sludge) can be used as an additive to cement clinkers both to improve the characteristics of building materials and the efficiency of their production process. The influence of calcium fluoride (CaF2) and titanium dioxide (TiO2) on cement clinkers at different concentrations of substances and sintering temperatures has been reviewed. The data on changes in the content of free lime (f-CaO), patterns of formation and distribution of clinker phases: alite, belite, celite and calcium aluminiferite have been presented. Mechanisms of CaF2 and TiO2 inclusion in the composition of various cement phases have been explained. The conclusion has been made that the application of titanium-containing wastes allows not only to recycle them, but also to obtain construction materials with improved characteristics.

Corrosion inhibition of acid pickling –descaling-cleaning action on mild steel using aqueous hydroxyethyl cellulose

The corrosion inhibition capability of aqueous Hydroxyethyl cellulose (HEC) on mild steel corrosion in 1 M HCl solution proposed for mild steel pickling, industrial cleaning, and descaling was evaluated at different concentrations and immersion times using gravimetric measurement. HEC demonstrated efficiency in mild steel corrosion inhibition with a maximum inhibition efficiency of 87% for a 300 ml acid pickling, industrial cleaning, and descaling solution composed of 20% aqueous solution of 0.01 M HEC and 80% of 1 M HCl solution, within an immersion time of 120 hours. The inhibition efficiency was found to increase with the increase in the concentration of HEC implying that HEC’s inhibition action is concentration and time-dependent. The mechanism of adsorption of HEC was identified to be chemisorption with hydroxyl (-OH) moiety donated to the active sites of mild steel coupled with HEC molecules encapsulation of chloride ions on mild steel surface thus preventing the corrosive action of Cl ions on the mild steel.

The Corrosion Inhibition Performance of Eco-Friendly bis-Schiff Bases on Carbon Steel in a Hydrochloric Solution

Corrosion inhibitors are widely used as an important tool for the prevention and remediation of different materials exposed to corrosive industrial processes. Corrosion inhibitors are usually added to acid pickling solutions to reduce the deterioration of metallic materials and particularly, corrosion due to hydrochloric acid. In this work, three bis-Schiff bases (BS2, BS4 and BS8) were synthesized and characterized using spectroscopic methods, and their anti-corrosive effects on AISI 1020 carbon steel in a hydrochloric acid solution were studied using gravimetric and electrochemical techniques and quantum chemical methods. The results showed that all substances act as potential corrosion inhibitors as BS8 exhibited the highest efficiency (98%) of all methods. The compounds adsorbed on the metal surface were as per the El-Awady adsorption isotherm. Morphological aspects of the metal were observed upon applying SEM, and the theoretical results acquired from the quantum chemical calculation for molecular properties and the Fe(110) surface adsorption proved to be compatible with the experimental results.

One-Pot Hydrothermal Synthesized Nitrogen and Sulfur Codoped Carbon Dots for Acid Corrosion Inhibition of Q235 Steel.

N and S codoped carbon dots having good water solubility have been successfully made by a novel hydrothermal method and characterized by FTIR, XPS, and TEM. The as-synthesized CDs were carbon particles rich in polar functional groups less than 10 nm in size. Electrochemical measurements, gravimetry, and surface analysis methods were utilized to examine the inhibition characteristics and adsorption mechanism of CDs on the carbon steel in acid pickling solutions. Electrochemical measurements verified that the CDs displayed adequate protection with high inhibition efficiency of 97.8%. The long-term weight-loss experiments up to 72 h further confirmed the excellent corrosion inhibition at room temperature and 313 K. The results presented are helpful for the formulation of more effective acid pickling corrosion inhibitors.

Impact of corrosion on mechanical properties of additively manufactured Invar 36

AbstractInvar alloys are used for high‐precision applications due to their invariance of the coefficient of thermal expansion over a temperature range up to about 250 °C. The present study determines the mechanical and corrosive properties of Invar 36 (64 % Iron – 36 % Nickel) specimens produced by laser powder bed fusion. Tensile specimens were fabricated to investigate the mechanical properties. The influence of a horizontal and vertical building orientation is considered. An apparent mechanical anisotropy depending on the respective building is observed. Based on this, further tensile specimens were stored in a hydrochloric acid pickling solution, a sulphate buffer solution and a sodium chloride solution to analyse the corrosion behaviour. The findings after eight weeks in the individual media show that outsourcing the Invar 36 specimens in a sulphate buffer solution results in significant changes in the mechanical properties, especially fracture elongation.

Selective dissolution during acid pickling of aluminum alloys by element-resolved electrochemistry

The surface reactivity and the elemental dissolution of a high-strength aerospace alloy (AA7449-T651) during acid pickling was investigated with element-resolved electrochemistry (AESEC). The results demonstrated a sequential dissolution of Mg, Al, Zn and Cu, following the order of their respective galvanic reactivity in common acid pickling solutions. The enrichment of Cu during pickling with the H2SO4 solution was observed. The effect of oxidizing solution components HNO3 and Fe(III) on Cu dissolution were investigated using an experimental Evans diagram approach.

Wastewater from production of oxide-ruthenium titanium anodes as a raw material for TiO2, NaOH and HCl production

The article presents the results of studies of the waste acid pickling solution processing (WAPS) formed during the etching of titanium products with hydrochloric acid. The processing includes the neutralization of WAPS with alkali, filtering, drying and calcining a precipitate of titanium hydroxide and electrochemical processing of the filtrate containing sodium chloride in an electrolytic cell with ion-exchange membranes. In the electrolysis process, sodium hydroxide and hydrochloric acid are obtained. The proposed WAPS processing scheme makes it possible to obtain titanium dioxide, sodium hydroxide, and hydrochloric acid. Titanium dioxide can be used in the paint industry. Alkali can be used in the process of neutralizing WAPS. After adjustment, hydrochloric acid is suitable for use in the etching process of titanium products.

Corrosion inhibition of carbon steel by three kinds of expired cephalosporins in 0.1 M H2SO4

It is difficult to avoid corrosion to carbon steel in acidic solutions, thus, in order to inhibit the corrosion of carbon steel during the acid pickling process, inhibitors must be added to the acid pickling solutions. In this work, the corrosion inhibition of carbon steel by three kinds of expired cephalosporins in 0.1 M H2SO4 was investigated by electrochemical, weight loss and scanning electron microscopy (SEM) methods. For the carbon steel electrode, the electrochemical results revealed that the current density was decreased, while, the charge-transfer resistance was increased in the presence of cephalosporins in 0.1 M H2SO4 corrosive solution. The weight loss results confirmed that the addition of cephalosporins decreased the corrosion rate of carbon steel. Further, the inhibition efficiency was increased with the increase in the concentration of cephalosporins. The SEM analysis of carbon steel surface was performed to confirm the effect of cephalosporins on the corrosion inhibition. The presented research demonstrated the efficient use of expired drugs for effective corrosion inhibition which could be applied to the industries at the large scale.

Chemical modification of waste Allium cepa peels to Cu-complex composite and application as eco environmental oilfield anticorrosion additive

A new bio-based complex composite material (Cu-EtCPLX) has been synthesized from agricultural waste by chemical treatment of Allium cepa peels ethanol extract with aqueous copper salt at 50 °C. The bio-composite was characterized by UV–Vis, FTIR, DLS, XRD, SEM/EDS and TEM. The efficiency of the composite as anticorrosion additive to oilfield pickling fluid was investigated. Electrochemical and weight loss techniques were used to monitor corrosion process and determine the corrosion rate and inhibition efficiency. Cu-EtCPLX exhibits higher adsorptive capacity on X80 steel surface through its CC and O–H groups, was thermally more stable and efficient in inhibiting steel corrosion in 1 M HCl by 95.8% and 87.2% at 30 °C and 60 °C, respectively. The bio-composite is a mixed type corrosion inhibitor and reduces surface roughness and piting by 56.3% and 70.7% respectively. Corrosion products, mechanism and extent of surface were probed by FTIR, SEM/EDS and AFM techniques. Cu-EtCPLX is a promising highly efficient bio-composite that could be used as green, cheap and sustainable alternative anticorrosion additives for oilfield acid pickling and descaling solutions.

Corrosion Behavior of Fe-35Ni-22Cr and Fe-17Ni-17Cr Alloys in Acid Pickling Solutions

This work aims to study the corrosion behavior of two alloys Fe-35Ni-22Cr and Fe-17Ni-17Cr in acid pickling solutions. The corrosion behavior of two alloys in HCl and H2SO4 was studied using the weight-loss method and potentiodynamic polarization, at a different time at 30 °C, 40 °C and 60 °C. The morphology of two alloys was analyzed by scanning electron microscope (SEM) and energy dispersive X-ray (EDS) analysis. The effect of temperature at constant acid concentration solutions has a strong influence on the corrosion rate of two alloys Fe-35Ni-22Cr and Fe-17Ni-17Cr. The activation energy (𝐸𝑎), enthalpy (∆𝐻), entropy (∆𝑆) and free energy (∆𝐺) were calculated and discussed. Results obtained from weight loss and potentiodynamic measurements were in good agreement and confirmed that Fe-35Ni-22Cr alloy is a higher corrosion resistance than Fe-17Ni-17Cr alloy in HCl and H2SO4 acid solutions.

Experimental and theoretical study on the behaviour of a pickling solution: The role of ferrous ions

Abstract The existence of ferrous ions plays an important role in the performance of pickling liquor as well as the recovery of hydrochloric acid from waste pickling liquor. The promotion mechanism and the interaction between ferrous ions and hydrogen chloride molecules have remained largely unsolved. In this research, the fundamental aspects of a simulated hydrochloric acid pickling solution with different concentrations of ferrous ions were experimentally and theoretically studied. The experimental results showed that the existence of ferrous ions in the pickling liquor effectively inhibited the volatilisation of hydrogen chloride from solution and that the inhibition of volatilisation enhanced with an increase in concentration of ferrous ions. To understand the interaction between ferrous ions and hydrogen chloride molecules, the structure and thermodynamic properties of possible hydration structures were obtained by using molecular simulation. The results showed that a new type of cluster, hydrogen chloride-ferrous ion-water, was formed in the presence of ferrous ions, which made the hydrogen chloride molecules in the pickling liquor more stable compared to the same condition without ferrous ions. The existence of ferrous ions in pickling liquor benefits the pickling process from an economic and environmental aspect.

Electrolytic Recovery of Nickel and Copper from Acid Pickling Solutions Used to Treat Metal Surfaces

The increased use of heavy metals in process industries often results in the generation of large quantities of wastewater (WW) and aqueous waste (AW) containing mixtures of heavy metals such as copper and nickel. This research focuses on the electrochemical recovery of copper and nickel from acid pickling solutions used to treat metal surfaces. Using hull cells, beaker plating, and electrolytic cells in pilot scale (capacity 30 L), the most important parameters influencing the process have been identified (temperature, contact time, and current density). In total, about 60 tests were carried out on AW containing nickel and copper. The results of the tests carried out with copper-containing AW shows that removal yields are often higher than 50%; while the energy consumption is less than 15 kWh kg−1 of metal deposited. The best removal efficiency (100%) was achieved by applying a current density of 6 A dm−2 and the energy consumption was 2 kWh kg−1. The tests carried out with AW containing nickel point out very low removal yields (< 20%) and very high energy consumption (even exceeding 300 kWh kg−1). The best removal yield obtained, applying a current density of 3 A dm−2, is 6.7% with an energy consumption of 40 kWh kg−1 of metal removed. A costs analysis based on Metal Exchange value was carried out. The cost analysis suggests that the results, in terms of removal and recovery, obtained for these metals, in particular for copper, are very promising for an industrial application.

Effect of pickling process on removal of oxide layer on the surface of ferritic stainless steel

ABSTRACTOxide layer formed on stainless steel surface can result in a decrease in surface quality. Thus, it must be removed. In this paper, we investigated the effect of different pickling processes on removal of the oxide layer. Ferritic stainless steel was used as raw material. After it received annealing treatment, the components and structure of the oxide layer formed on its surface were studied. Then, the annealed stainless steel was pickled in hydrochloric acid solution system and mixed acid solution system, respectively. Results are as follows. The oxide layer on stainless steel surface has a thickness of 15–35 μm. With increase in hydrochloric acid concentration in hydrochloric acid pickling solution, the weight loss rate of stainless steel increases and is always greater than that in mixed acid pickling system. In addition, the surface of the stainless steel pickled in hydrochloric acid is smoother than that pickled in mixed acid. Furthermore, compared with channels in the oxide layer created during mixed acid pickling, those created during hydrochloric acid pickling are more, leading to shorter removal time. These results are important for increasing the pickling efficiency and improving the surface quality of stainless steel.

Enhanced corrosion resistance of austenitic Fe-Mn-C TWIP steel by cerium(III) in 1 M hydrochloric acid pickling solution

The influence of rare earth Ce3+ ions on the corrosion behaviour of Fe-Mn-C TWIP steel in 1 M hydrochloric acid solution was studied by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Electrochemical corrosion tests showed that Ce3+ can significantly reduce corrosion deterioration up to 1.0 mM. Beyond that level the corrosion rate increases till a steady value. Surface film resistance increases with time evolution until 24 h, then decreases and stabilises. High corrosion protection of steel surface after 24 h exposure to the acidic solution containing the optimal Ce3+ ion concentration is revealed by SEM investigations.

Effect of Nickel Content on the Corrosion Resistance of Iron-Nickel Alloys in Concentrated Hydrochloric Acid Pickling Solutions

The effect of Ni content on the resistance against corrosion of Fe-36% Ni and Fe-45% Ni alloys in 1 M hydrochloric acid pickling solution was reported. Various electrochemical and spectroscopic techniques such as potentiodynamic cyclic polarization (CPP), open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiostatic current-time (PCT), and scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) have been employed. CPP measurements indicated that the corrosion current and corrosion rate recorded lower values for the alloy that had higher nickel content. OCP curves proved that the presence of high Ni content shifts the absolute potential to the positive potential direction. EIS results revealed that the surface and polarization resistances were much higher for the alloy with higher Ni content. PCT curves also showed that the absolute currents were lower for Fe-45% Ni alloy. All results were in good agreement with others and confirmed clearly that the corrosion resistance in HCl solutions for Fe-45% Ni alloy was higher than that obtained for Fe-45% Ni alloy.

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).

Ultrafine-grained copper produced by machining and its unusual electrochemical corrosion resistance in acidic chloride pickling solutions

Ultrafine-grained (UFG) copper was prepared by facile machining procedure. High resolution transmission electron microscopy images revealed that, in UFG Cu, minimum grain size of 80nm could be formed when a small machining rake angle was applied. The electrochemical corrosion behavior of UFG Cu in 0.5M HCl was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. Comparing with coarse-grained Cu, UFG Cu exhibited notably declined corrosion current density. Particularly, when the size of Cu grains were reduced from 500μm to 80nm, the charge transfer resistance of anodic dissolution step dramatically increased from 200 to 621Ωcm2.

Role of novel oxazocine derivative as corrosion inhibitor for 304 stainless steel in acidic chloride pickling solutions

Inhibition of 304 stainless steel corrosion in acidic chloride pickling (1.0 M HCl) solutions by newly synthesized oxazocine derivative 4 as a corrosion inhibitor have been studied using weight loss, potentiodynamic polarization, and atomic absorption spectroscopy investigations. Potentiodynamic polarization curves show that the inhibitor behaves as a mixed-type. The adsorption of the inhibitor on the metal surface in the acid solution was found to obey Langmuir’s adsorption isotherm. The inhibition mechanism of the investigated inhibitor was discussed in terms of its adsorption on the metal surface. The relationship between the molecular structure and the inhibition efficiency was elucidated by quantum chemical calculations.

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions Extraction of zinc(II) and iron(III) from hydrochloric acid solutions using quaternary phosphonium salts, Cyphos® IL 101, Cyphos® IL 104, Cyphos® IL109 and Cyphos® IL 111 in mixtures with toluene, was studied. Trihexyl(tetradecyl)phosphonium chloride (Cyphos® IL 101) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos® IL 104) showed the best zinc(II) and iron(III) extraction abilities. After three stages of zinc(II) extraction with Cyphos® IL 101 and Cyphos® IL 104 the efficiencies were 100 and 93.6%, respectively. Total iron(III) transport to the organic phase was achieved after two separation stages and amounted to 82.1 and 100% for Cyphos® IL 101 and Cyphos® IL 104, respectively. Zinc(II) and iron(III) could be effectively stripped from the loaded organic phases with 0.5 mol dm-3 sulfuric acid. The more hydrophobic the character of the anion type of phosphonium salts, the lower the efficiency of extraction.