Electrolytic Extraction Research Articles

Evaluation of Inclusion Characteristics in Low-Alloyed Steels by Mainly Using PDA/OES Method

The characteristics of non-metallic inclusions (such as number, size and volume fraction) in liquid steel samples taken during ladle treatment and casting of industrial heats of two low-alloyed Ca-treated steel grades were evaluated by using the Pulse Distribution Analysis with Optical Emission Spectroscopy (PDA/OES) method. These results were compared to data obtained by Scanning Electron Microscope observations of inclusions after electrolytic extraction from steel samples (the EE method). It was found that the PDA/OES method can be used for a relative estimation of the homogeneity of the distribution of non-metallic inclusions in steel samples. Bottom and middle parts of the steel samples showed more homogeneous results with respect to the characteristics of the investigated Al2O3, CaO–Al2O3 and CaO–Al2O3–CaS inclusions. The numbers of inclusions in the size ranges 2.0–5.7 µm and 1.4–5.7 µm in samples taken before and after a Ca addition, respectively, showed a relatively good agreement between both methods. Furthermore, the calculated volume fractions for inclusions in the size range 2–13 µm obtained by the PDA/OES method agreed satisfactorily well with those obtained from the EE method. Finally, the minimum sizes of inclusions in steel samples, which can reliably be detected by the PDA/OES method, were estimated for steels with different concentrations of Al in steel and Al2O3 in inclusions.

Kardiyopulmoner Baypass Uygulanan Hastalarda Düşük Doz Dopaminin Böbrek Fonksiyonları ve Elektrolit Atılımı Üzerine Etkisi

Kardiyopulmoner Baypass Uygulanan Hastalarda Düşük Doz Dopaminin Böbrek Fonksiyonları ve Elektrolit Atılımı Üzerine Etkisi

Supercritical carbon dioxide extraction of lithium-ion battery electrolytes

Two different separator materials (polyethylene fleece – Freudenberg 2190 and porous glass fiber – Whatman® GF/D) and two different lithium-ion battery electrolytes have been investigated regarding their behavior in an autoclave extraction with supercritical helium head pressure carbon dioxide (sc HHPCO2). Mixtures of dimethyl carbonate (DMC)/ethylene carbonate (EC) and ethylmethyl carbonate (EMC)/EC, each with 1mol/L LiPF6 were used.In addition to these proof of principle experiments, the developed extraction method was further applied to real battery samples. Commercial 18650cells (after formation and aging) were opened and the jelly roll was extracted with sc HHPCO2. Extracts were analyzed with gas and ion chromatography (GC, IC). Recovery rates and extract compositions strongly depend on the material of which the electrolyte is extracted. Further structure determination of electrolyte aging products was performed with different ionization modes in GC–mass spectrometry (GC–MS) experiments. Diethyl carbonate (DEC), dimethyl-2,5-dioxahexane dicarboxylate (DMDOHC), ethylmethyl-2,5-dioxahexane dicarboxylate (EMDOHC) and diethyl-2,5-dioxahexane dicarboxylate (DEDOHC) are aging products of electrolyte degradation which were successfully extracted and identified. Their concentrations correlate with solid electrolyte interphase (SEI) growth on the negative electrode which was investigated with scanning electron microscopy (SEM).

Investigations of inclusions in ferrochromium alloys

Ferrochromium alloys are commonly added during different stages of steelmaking processes according to the specific steel grade being produced. Depending upon the ferrochromium quality, the addition can also lead to a supply of deleterious inclusions to the liquid steel. Therefore, the number, size, morphology and composition of inclusions in LCFeCr and HCFeCr alloys were investigated. The alloy samples were first treated with electrolytic extraction, followed by filtration to gather the inclusions on a film filter. Thereafter, the characteristics of the inclusions and clusters were investigated in three dimensions by SEM in combination with energy dispersive spectroscopy. The results show that the main inclusion types found in LCFeCr alloys are different to those found in HCFeCr alloys. More specifically, the inclusions in LCFeCr alloys were found to consist of Si–Cr–O and Cr–O oxides as well as intermetallic Cr–Fe inclusions. Moreover, the inclusions in HCFeCr alloys were found to consist of Cr–Mn–S, Cr–C–N, Si–Al–Ca–Mg–O and Ca–O–P inclusions. Overall, the inclusions can be divided into two categories depending on the melting point. Furthermore, the possible transformation of different inclusions after their addition to the liquid steel is discussed.

The influence of impurities on Ga electrowinning: Vanadium and iron

During the electrolytic extraction of Ga, iron and vanadium are main metal impurities in Ga solution. The influences of Fe(ІІІ) and V(V) on current efficiency (QE) of Ga electrowinning were studied. The surface structures of electrodeposited Ga coatings were examined by SEM, EDS and potentiodynamic polarization. The results indicate that QE is sharply decreased in the presence of V(V). Spherical Ga particles are easily produced in Ga solution with impurities, especially in the presence of V(V) and at higher current density. It is difficult for Ga particles with impurities and newly formed Ga crystals to incorporate into Ga films due to the difference of surface structure and properties between Ga and impurities. As a result, newly formed Ga crystals are easily re-dissolved which leads to the decrease of QE. When both Fe(ІІІ) and V(V) exist in Ga solution, QE at lower current density is increased due to the siderophile affinity of Ga.

Supercritical CO2 extraction of organic carbonate-based electrolytes of lithium-ion batteries

Supercritical fluid extraction (SFE) was applied to reclaim organic carbonate-based electrolytes of spent lithium-ion batteries.

Three‐Dimensional Investigations of Inclusions in Ferroalloys

AbstractAs the requirements on material properties increase, there has been a demand on an additional knowledge on the effect of impurities in the ferroalloys on the properties. Thus, the number, morphology, size, and composition of inclusions in four different ferroalloys (FeTi, FeNb, FeSi, and SiMn) were investigated. This was done in three dimensions (3D) by using scanning electron microscopy in combination with energy dispersive spectroscopy after electrolytic extraction of the ferroalloy samples. The non‐metallic and metallic inclusions were successfully analyzed on the surface of film filter. Thereafter, the particle size distribution was plotted for most of the non‐metallic inclusions. The non‐metallic inclusions were found to be REM oxides in FeTi, FeSi, and SiMn, Al2O3, Ti–Nb–S–O oxides in FeNb and silicon oxides in SiMn. Moreover, the intermetallic inclusions were found to be a Ti–Fe phase in FeTi, Ca–Si, and Fe–Si–Ti phases in FeSi and a Mn–Si phase in SiMn. In addition, the almost pure single metallic phases were found to be Ti in FeTi, Nb in FeNb, and Si in FeSi.

Prediction and analysis of radial overcut in holes drilled by electrochemical machining process

Abstract Radial overcut predictive models using multiple regression analysis, artificial neural network and co-active neurofuzzy inference system are developed to predict the radial overcut during electrochemical drilling with vacuum extraction of electrolyte. Four process parameters, electrolyte concentration, voltage, initial machining gap and tool feed rate, are selected to develop the models. The comparison between the results of the presented models shows that the artificial neural network and co-active neuro-fuzzy inference system models can predict the radial overcut with an average relative error of nearly 5%. Main effect and interaction plots are generated to study the effects of process parameters on the radial overcut. The analysis shows that the voltage, electrolyte concentration and tool feed rate have significant effect on radial overcut, respectively, while initial machining gap has a little effect. It is also found that the increase of the voltage and electrolyte concentration increases the radial overcut and the increase of the tool feed rate decreases the radial overcut.

Combined processing of lead concentrates

A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

Research and application of new enviromental-frendly technology without using chemicals for extraction of chitin from shrim shells

Vietnam has a huge amount of rich-protein shrimp shells, containing chitin, a biological polymer that has many potential applications in different areas of life. However, this shrimp by-products are processed mainly by alkali-acid method, causing environmental pollution and can not recovery the protein in the starting material. For the first time in Vietnam, we have carried out research and successfully applied electrochemical technology to extract and purify the chitin from shrimp shells. This is a new technology for chitin extraction, that do not use alkali and acid as in the other chemical methods, so it is very friendly to the environment. The electrolysis is performed on the model device of size of 6 ´ 10 ´ 16.7 cm (with a capacity of 1 liter) at different NaCl concentrations in 90 minutes. After electrolytic extraction of chitin on the device the highest pH value of catolite solution is 12.43 at a concentration of 4% NaCl, and the lowest pH of anolite is 1.95 at NaCl concentrations of 1%. From the results of measuring the pH value of the electrode solutions and determination of protein extracted in the electrode cells were determined the optimal electrolyte concentration (that is 1% of NaCl) and minimal time (that is 1.0 - 1.5 hours) in DC current of 400 A/m2. Chitin preparations obtained by electrochemical technology have high purity, white or yellowish-white colour, no foreign odors, virtually no protein, with low mineral residues (< 0.4%) and average viscosimetric molecular weight from 240 to 1000 kDa.

Effects of Primary Oxide and Oxide-Nitride Particles on the Solidification Structure in a Fe-20 mass%Cr Alloy Deoxidised with Ti and M (M = Zr or Ce)

The ratio of equiaxed grains on a cross section and the size of equiaxed grains in a Fe-20 mass% Cr alloy deoxidised with Ti/M (M = Zr or Ce) were studied as function of nitrogen content and particle characteristics such as size distribution, morphology and composition. Fe-20 mass% Cr alloys were melted at 1 600 degrees C, deoxidised, and cooled to 1 400 degrees C followed by water quenching. Thereafter, the particles were separated from the matrix using electrolytic extraction using a 10%AA electrolyte and collected on a film-filter surface. The inclusion characteristics were determined using SEM. It was found that the number of particles increases with an increased N content. Furthermore, that the solidification structure was clearly affected by the number of primary oxide and oxide-nitride particles in the Ti/Zr deoxidation experiments. However, a similar effect could not be detected in the Ti/Ce deoxidation experiments.

Evolution of Different Inclusions during Ladle Treatment and Continuous Casting of Stainless Steel

As the requirements on material properties increase, there has been a demand on an additional knowledge on the effect of impurities in the ferroalloyson the steel cleanness. Thus, the number, morphology, size and composition of inclusions in sixdifferent ferroalloys (FeTi, FeNb, FeSi,SiMn, LC and HC FeCr) were investigatedin this study. This was done in three dimensions (3D) by using a SEM in combination with EDS after electrolytic extraction of the ferroalloy samples. Theresults show that thenon-metallic and metallic inclusions can besuccessfully analyzed on the surface of a film filterafter a separation of the inclusions from the matrix. Overall, the inclusions canbe divided into two categories depending on the melting point. Furthermore, the possible transformation of different kinds of inclusions after their addition to the liquid steel canalso be determined.The inclusions and clusters in steel samples of two similar steel grades of high-silicon non-calcium treated (HSiNC) stainless steels were also investigated and compared during ladle treatment and continuous casting. Samples of liquid steel and slag were taken at different stages of the ladle treatment and casting during two plant trials: a low Al steel (LAl) and a high Al steel (HAl). Spherical (SP), irregular and regular (IR) inclusions and clusters (CL) were observed in the samples from both heats. It wasfound that the morphology and composition of inclusions and clusters in both heats were significantly changed during the ladle treatment and casting. Most of inclusions (44-98%) in a low Al steel are MgO-CaO-SiO2-Al2O3spherical inclusions. The compositions of irregular and regularinclusions and clusters in steel samples of a high Al steel were mostly MgO·Al2O3spinel, but also complex sphericalinclusions containing Al2O3-MgO-CaO-SiO2. In addition, the phase stabilitydiagram based on Darken’s quadratic formalism and Redlich-Kister type polynomial was estimated for both heats at a non-infinite solution.It is known that clusters in liquid steel have a harmful effect on the casting process and the quality of the final steel product. Therefore, clusters of rare earth metals (REM) were investigated in steel samples of a S30185 stainless steel grade from a pilot trial (PT, 250 kg) and from an industrial heat (IH, 100 t). Samples were taken from the liquid steel at differentholding times after the addition of a mischmetal. The morphology, composition, number and size of clusters in PT and IH steel samples were analyzed and compared as a function of the holding time. It was found that typical clusters with regular and irregular inclusions were the main type of clusters (69%-98%) in all PT and IH steel samples. The composition of inclusions in clusters corresponded mostly to REM-oxides. The size of clusters that were observed in different samples varied mainly from 2 to 23 μm. In addition, the size and number of most clusters in PT are larger than those in IH samples.Largesize inclusions are recognized to be crucially harmful for the mechanical properties of steel products. Therefore, predictionsof the maximum size of Al2O3-CaO spherical inclusions in an Fe-10 mass% Ni alloy have been examined based on two dimensional (2D) and three dimensional (3D) investigations. The effects of the number of measurements and unit volume on the estimated 3D results were also investigated.

Applicability of Nonaqueous Electrolytes for Electrolytic Extraction of Inclusion Particles Containing Zr, Ti, and Ce

Applicability of Nonaqueous Electrolytes for Electrolytic Extraction of Inclusion Particles Containing Zr, Ti, and Ce

Quantitative analysis of carbides and the sigma phase in thermally exposed GTD-111

The effects of thermal exposure on γ′, carbides and TCP-type phases, such as the sigma and eta phases, in the nickel-based superalloy GTD-111 were investigated in this study. The thermal exposure was performed at 871 °C and 982 °C for 1,000, 5,000 and 10,000 h, after which the thermally exposed specimens were compared in terms of their microstructure, weight fraction and growth rate of each precipitate. Electrolytic extraction and Rietveld refinement were successfully applied for a quantitative analysis of the carbides and the sigma phase in the thermally exposed GTD-111. The weight fractions of MC, Cr-rich M23C6 and the sigma phase for various thermal exposure times and temperatures were obtained to understand the formation and decomposition rate of each phase.

Phases in Austenitic Cast Steel

The paper presents the characteristics of intermetallic phases occurring in heat-resistant cast austenitic 0.3% C-30% Ni-18% Cr steel with additions of niobium and titanium. Five alloys were examined, in which the content of the examined elements was (wt.%) Nb 0.03, 0.55, 1.57 and 1.92, and Ti 0.03, 0.05, 0.30, 0.83 and 1.00. The phase composition of alloys in as-cast state and after annealing (temperature of 800°C and 900°C, time of up to 300 hrs) was examined by X-ray diffraction technique. Depending on the chemical composition of cast steel, carbides of MC type (NbC, TiC, (Nb,Ti)C), M23C6, titanium carbonitrides TiCN and G phase were identified in its microstructure. The phase morphology was examined on the polished sections and surfaces of metallographic specimens after deep etching by electrolytic extraction method. It was found that M23C6carbides assume the shape of rods, NbC carbides crystallise in the form of lamellae, and titanium carbonitrides TiCN in the form of cubes. An addition of both the stabilising elements favours the formation of double carbides (Nb,Ti)C of octahedral habit.

Characterization of Nonmetallic Inclusions in High-Manganese and Aluminum-Alloyed Austenitic Steels

The effects of Al and Mn contents on the size, composition, and three-dimensional morphologies of inclusions formed in Fe-xMn-yAl (x = 10 and 20 mass pct, y = 1, 3, and 6 mass pct) steels were investigated to enhance our understanding of the inclusion formation behavior in high Mn-Al–alloyed steels. By assuming that the alumina is a dominant oxide compound, the volume fraction of inclusions estimated from the chemical analysis, i.e., insoluble Al, in the Fe-Mn-3Al steels was larger than the inclusion volume fractions in the Fe-Mn-1Al and Fe-Mn-6Al steels. A similar tendency was found in the analysis of inclusions from a potentiostatic electrolytic extraction method. This finding could be explained from the terminal velocities of the compounds, which was affected by the thermophysical properties of Fe-Mn-Al steels. The inclusions formed in the Fe-Mn-Al–alloyed steels are classified into seven types according to chemistry and morphology: (1) single Al2O3 particle, (2) single AlN or AlON particle, (3) MnAl2O4 single galaxite spinel particle, (4) Al2O3(-Al(O)N) agglomerate, (5) single Mn(S,Se) particle, (6) oxide core with Mn(S,Se) skin (wrap), and (7) Mn(S,Se) core with Al2O3(-Al(O)N) aggregate (or bump). The Mn(S,Se) compounds were formed by the contamination of the steels by Se from the electrolytic Mn. Therefore, the raw materials (Mn) should be used carefully in the melting and casting processes of Fe-Mn-Al–alloyed steels.

Production of Fine Tungsten Powder by Electrolytic Reduction of Solid CaWO4 in Molten Salt

Direct electrochemical reduction of solid CaWO4 to fine W powder in molten CaCl2-NaCl was studied by cyclic voltammetric measurement and potentiostatic/constant-voltage electrolysis. The effect of electrolysis conditions such as electrolysis time, temperature and voltage on the quality of the product (the residual amount of CaWO4) was systematically investigated. Based on the solubility tests of CaWO4 in the melt in a wide temperature range, an unprecedented strategy on electrolytic extraction of pure tungsten powder was proposed and confirmed, which involves low-temperature and short-duration electrolysis of solid CaWO4 in molten CaCl2-NaCl eutectic salt (1023 K, 10-hour electrolysis) followed by a simple washing process in the same melt at a higher temperature (1123 K, 1-hour washing). The particle size of the as-prepared W powder is less than 200 nm. This process exhibits a high yield and increased energy efficiency for production of fine W powder from CaWO4.

Advanced-ORIENT Cycle Project: Summary of Phase I Fundamental Studies

The Advanced Optimization by Recycling Instructive Elements (Adv.-ORIENT) Cycle strategy has been proposed as a basic concept for trinitarian research on the separation, transmutation, and utilization (S, T, & U) of nuclides and elements on the basis of the FBR fuel cycle. Working in this direction, validation of the principal separation methods and related safety research were performed from 2006 through 2011 as the first phase. The separation scheme was composed of four ion exchange (IXC) steps and one catalytic electrolytic extraction (CEE) step. The fundamental technological aspects are summarized as the Phase I program.

Current status and future plans of Advanced ORIENT Cycle strategy

For minimization of the ecological risks inherent in nuclear fuel recycling, a new fuel cycle paradigm was proposed and its key technology developments have been carried out as a part of the Advanced Optimization by Recycling Instructive Elements (Adv.-ORIENT) Cycle strategy. The basic concept of the Adv.-ORIENT Cycle uses a three-pronged approach, separation, transmutation and utilization of nuclides and elements, based on the FBR fuel cycle. Fundamental research studies done in Adv.-OEIENT Cycle [Phase-1: 2006–2010] have led to the following findings. 1. Cs and Sr separation and its utilization: Silica gel loaded with ammonium molybdophosphate (AMP) and hybrid organic microcapsules with crown ether D18C6 were investigated to chromatographically separate Cs and Sr, respectively. In particular, uptake experiments of Cs from solution simulating the spent fuel solution obtained were carried out by a batch method, and the uptake rates achieved were more than 90%. 2. Minor actinide (MA)/lanthanide/fission product (FP) separation: A tertiary pyridine type resin (TPR) can be used to recover Am, Cm and lantanide elements with a high separation factor by a chromatographic method from spent fuel solution. The TPR can be used with hydrochloric acid (HCl) as well as nitric acid (HNO 3). 3. Ru, Ph, Pd and Tc separation: A catalytic electrolytic extraction (CEE) method can effectively separate Ru, Ph, Pd and Tc. High recovery ratios of Ru, Rh, Pd, Tc, Se, etc. were achieved using HCl solutions. Rh co-deposition significantly accelerated reduction of Ru, Tc and Re using HNO 3 solutions. 4. Ru, Ph, Pd and Tc utilization: Based on the mixed deposit obtained from the CEE experiments, Ru/Rh/Pd/Tc(Re)-Pt electrodes provided the highest catalytic reactivity in the electrolytic production of hydrogen in an alkali solution. 5. Basic engineering research: Results of corrosion experiments showed that Hastelloy-B and Ta had a good anti-corrosive property in a wide range of HCl concentrations. The basic thermo-chemical stability of TPR and tri-butyl phosphorous (TBP, as a reference) was also experimentally studied, and the process safety conditions to be specified for practical use of TPR could be identified.

Electrochemical behavior of aluminum and some of its alloys in chloroaluminate ionic liquids: electrolytic extraction and electrorefining

The electrochemical behaviors of pure Al, Al–6%Si, Al–3%Cu, and Al–3.7%Cu–0.9%Mg–0.8%Pb–0.6%Fe alloys were investigated in the chloroaluminate ionic liquids 1-butyl-3-methylimidazolium chloride [BMIm]Cl/AlCl3 (40/60 mol%) and 1-ethyl-3-methylimidazolium chloride [EMIm]Cl/AlCl3 (40/60 mol%). Electrolytic extraction of copper from Al–Cu alloys in the employed ionic liquids was explored. The alloys were anodically dissolved in the ionic liquids and then pure copper was recovered under potentiostatic conditions. Due to the large difference between the deposition potentials of Cu and Al, pure Cu can be obtained without Al contamination. Electrorefining of Al–3%Cu and Al–6%Si alloys was also investigated in [BMIm]Cl/AlCl3 (40/60 mol%) at room temperature. High purity aluminum deposits were obtained with significantly low energy consumption of about 2 kWh/kg of Al.