Ni Strips Research Articles

Removal of Mg and Ca from Ni-rich sulphate solutions by solvent extraction using cationic and neutral extractants

Selective solvent extraction of Mg and Ca aiming to purify Ni-rich sulfate solutions ([Ni] = 88 g/L, [Mg] = 3.1 g/L, [Ca] = 0.5 g/L) was investigated using the Cyanex 923 + Cyanex 272, and D2EHPA extractive systems (A/O ratio = 1, T = 50 °C). Although Cyanex 923 rejected metals at pH 3–6, a synergistic selective separation of Mg (69%) over Ca (1.2%, βMg/Ca = 179.2) and Ni (5.7%, βMg/Ni = 37.2) was attained at pH 5 with 0.13 M Cyanex 923 + 0.64 M Cyanex 272. Ni crowded out Mg from the loaded organic phase and limited the operation at pH < 5.5. Antagonism on Mg extractions was observed at [Cyanex 923] ≥ 0.25 M + 0.64 M Cyanex 272. Ni was selectively stripped out over Mg, using a dilute 0.031–0.063 M H2SO4, while Mg was stripped out with 0.25 M H2SO4. By contrast, 0.15 M D2EHPA selectively extracted Ca (50.8%) over Mg (2.1%, βCa/Mg = 47.6) and Ni (1.2%, βCa/Ni = 86.4) at pH 3, with Ca being crowded out by Ni at pH > 3. Selective Ni stripping was obtained from the loaded D2EHPA, using a dilute H2SO4 (0.034 M), while Ca and Mg were stripped by H2SO4 or HCl solutions (1 M). The real number of moles of extractants involved in the metal extractions and apparent equilibrium constants were determined for both extractive systems. Moreover, the FTIR spectra were accessed to contemplate the possible coordination compound structures.

Effective target arrangement for detecting the properties of Ni doped diamond-like carbon by pulsed laser deposition

In the current study, diamond-like carbon (DLC) was synthesized by pulsed laser deposition (PLD) in a vacuum at room temperature, focusing on Ni-dopant concentration and arrangement of Ni strips in both parallel and transverse positions. The morphology and structural properties of Ni-DLC films were analyzed by Raman spectroscopy, atomic force microscopy (AFM) analysis, cross-section analysis, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), contact angle (CA), and nanoindentation test. AFM images exhibit the new shapes of Ni-DLC thin films, named conic and nano-mushroom particles. The Raman spectra of Ni-DLC films show that the calculated intensities D-line to G-line ratio experiences a decrease with increasing Ni dopants in the transverse arrangement while the parallel arrangement represents a different trend. The stoichiometry of Ni-DLC thin films has been reported from the cross-section of thin films. It is also observed from the measured CA that the hydrophilic properties of Ni-DLCs increase in the transverse arrangement. Low nickel content in diamond-like carbon matrix exhibited the dominance of diamond phase and good mechanical properties have been found.

Hydrothermally Reduced Graphene Oxide–Coated Carbon Cloth for Flexible Supercapacitors

Abstract Hydrothermally synthesized graphene (HRG) was tested for its supercapacitive behavior using nickel (Ni) and hydrothermally treated carbon cloth as current collectors, respectively. Performance evaluation studies were carried out in an in-house fabricated SS cell. Commercially obtained untreated carbon cloth (CCUn) was exfoliated via oxidation (CCOx) followed by hydrothermal treatment to obtain a reduced carbon cloth (CCHy). The physicochemical and electrochemical properties of carbon cloth by oxidative exfoliation and hydrothermal treatment have been studied using scanning electron microscope, X-ray diffraction, Fourier-transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area, Contact angle measurements, cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and EIS. HRG coated on the CCHy (HRG-CCHy) had shown superior performance and endurance compared to HRG coated on Ni strip (HRG-Ni), with distinguishable specific capacitances (Cs) of 170 and 134 F g−1 at 0.5 A g−1 current density, respectively. At a higher 10 A g−1 current density, HRG-CCHy, and HRG-Ni have displayed distinctive specific capacitances of 120 and 80 F g−1, respectively, indicating a comparative decline in the performance of HRG-Ni with respect to HRG-CCHy. Endurance study performed for 5000 cycles at 2 A g−1, resulted in HRG-CCHy and HRG-Ni, retaining 88% and 81% of their initial-specific capacitances. At 1 kW kg−1 of power density, HRG-CCHy displayed a 5.5 Wh kg−1 of energy density. The electrochemical performance of HRG-CCHy may be attributed to exceptional properties like high wettability, low impedance, high pore volume, and specific surface area.

Cold Gas-Dynamic Spray for Catalyzation of Plastically Deformed Mg-Strips with Ni Powder.

Magnesium hydride (MgH2) has received significant attention due to its potential applications as solid-state hydrogen storage media for useful fuel cell applications. Even though MgH2 possesses several attractive hydrogen storage properties, it cannot be utilized in fuel cell applications due to its high thermal stability and poor hydrogen uptake/release kinetics. High-energy ball milling, and mechanically-induced cold-rolling processes are the most common techniques to introduce severe plastic deformation and lattice imperfection in the Mg/MgH2. Furthermore, using one or more catalytic agents is considered a practical solution to improve both the de-/rehydrogenation process of MgH2.These treatments are usually dedicated to enhance its hydrogen storage properties and deduce its thermal stability. However, catalyzation of Mg/MgH2 powders with a desired catalytic agent using ball milling process has shown some disadvantages due to the uncontrolled distribution of the agent particles in the MgH2 powder matrix. The present study has been undertaken to employ a cold gas-dynamic spray process for catalyzing the fresh surfaces of mechanically-induced cold-rolled Mg ribbons with Ni powder particles. The starting Mg-rods were firstly heat treated and forged 200 times before cold rolling for 300 passes. The as-treated ribbons were then catalyzed by Ni particles, using cold gas-dynamic spray process. In this catalyzation approach, the Ni particles were carried by a stream of Ar gas via a high-velocity jet at a supersonic velocity. Accordingly, the pelted Ni particles penetrated the Mg-substrate ribbons, and hence created numerous micropores into the Mg, allowed the Ni particles to form a homogeneous network of catalytic active sites in Mg substrate. As the number of coating time increased to three times, the Ni concentration increased (5.28 wt.%), and this led to significant enhancement of the Mg-hydrogen storage capacity, as well as improving the de-/rehydrogenation kinetics. This is evidenced by the high value of hydrogen storage capacity (6.1 wt.% hydrogen) and the fast gas uptake kinetics (5.1 min) under moderate pressure (10 bar) and temperature (200 °C). The fabricated nanocomposite MgH2/5.28 wt.% Ni strips have shown good dehydrogenation behavior, indicated by their capability to desorb 6.1 wt.% of hydrogen gas within 11 min at 200 °C under 200 mbar of hydrogen pressure. Moreover, this system possessed long cycle-life-time, which extended to 350 h with a minimal degradation in the storage and kinetics behavior.

Preparation of Cu–Al–Ni shape memory alloy strips by spray deposition-hot rolling route

The present work describes the preparation of near-full density Cu–Al–Ni shape memory alloy (SMA) strips via a novel processing route consisting of ‘spray deposition’ of atomised liquid Cu–Al–Ni alloy with a jet of argon gas followed by hot-rolling densification of the deposited preform. The subsequent homogenisation of the hot rolled Cu–Al–Ni strips resulted in complete martensitic structure in the finished strip, consisting of self-accommodated plates of β1′ and γ1′ martensites. The characteristic transformation temperatures and shape memory effects of Cu–Al–Ni strips were studied. It has been demonstrated that the Cu–Al–Ni SMA strips, prepared in the present work, resulted in relatively finer grain size with better combination of strength and ductility compared to other techniques based on conventional casting method.

Enhancement of temperature change induced by anomalous Ettingshausen effect in thin Ni films on suspended membrane substrates

We demonstrate the effect of substrates on the temperature change induced by the anomalous Ettingshausen effect in ferromagnetic thin films. The experimental results show that, in comparison with conventional experiments using bulk substrates, the temperature modulation due to the anomalous Ettingshausen effect in Ni films can be enhanced by more than an order of magnitude using suspended membrane substrates, which reduce thermal dissipation from the films to the substrates. The temperature modulation can be further enhanced with the help of a simple suspended thermopile configuration consisting of two Ni strips separated by a small distance. These demonstrations will provide a guideline for the thermal design of thin-film-based spin-caloritronic devices.

Numerical simulation of counter-current liquid–liquid extraction for recovering Co, Ni and Li from lithium-ion battery leachates of varying composition

Abstract Fractionation of Li-ion battery waste leachates into high-purity Li, Ni, and Co streams in a liquid−liquid extraction circuit was studied using numerical simulations. A new mechanistic mathematical model explaining the phase equilibrium in the loading, scrubbing, and stripping stages using bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) as extractant was developed. Including the distribution equilibrium of ammonia in the model enabled simulation of metal extraction with partially neutralized extractant. The model facilitates the design and optimization of liquid–liquid extraction circuit for fractionation of Li-ion battery leachates. Four leachates from recent research articles were selected to the study in order to cover a wide composition variation. In the separation process scheme studied, Co and Ni are first selectively extracted, yielding a pure Li raffinate, and then separated as pure products in the stripping steps. The simulation results confirm the viability of the scheme. The influence of the leachate composition on the feasible range of O/A ratios in loading and scrubbing as well as acid concentration in Ni stripping was quantified. With proper operating parameters, high recoveries of Li and Co (>99.9%) are achieved for all leachate compositions. The leachates containing 10–25 g/L Co, >10 g/L Ni, and >2.5 g/L Li are particularly suitable for fractionation of the metals into high-purity (>99%) Li, Ni, and Co streams.

Processing of Cu–Al–Ni Alloy by Spray Atomization and Deposition Process

The present work describes a new route for the preparation of Cu–Al–Ni alloy strips via spray atomization and deposition route. The route consists of atomizing liquid Cu–Al–Ni alloy with a jet of argon gas in a closed chamber, at a pressure of 1 MPa. The semi-solid Cu–Al–Ni droplets are subsequently collected on the steel substrate placed vertically below the liquid metal stream in the atomization chamber to form a three-dimensional preform. The deposit produced on the substrate contains ~ 5% porosity. The microstructural details of the spray deposited Cu–Al–Ni strips explains particularly the presence of porosity, formation of splats during the flight of spray casting and the associated microstructural evolution in Cu–Al–Ni spray deposit are explained.

Effect of aging on mechanical properties of high temperature Pb-rich solder joints

The effect of aging on the evolution of interfacial microstructure and mechanical properties of Pb-rich PbSnAg solder joints with different Sn content was investigated. Tensile samples were prepared by soldering two pieces of Ni or Cu strips resulting in joints with gap sizes of about 250 μm. Multi-layered structures composed of Ni coated Si-chips soldered onto Ni/Cu metallized ceramic substrates were used for fatigue testing. All samples were subjected to thermal aging at 250 °C up to 500 h. Microstructural investigations revealed that independent from the substrate material, increased Sn content of the solder alloy results in improvement of the tensile and fatigue properties of the joints and a higher growth rate of the interfacial intermetallic compound (IMC) layers. It was found that the thickness of the wettable substrate especially in the case of low-Sn alloys, also affects the interfacial properties of high temperature PbSnAg solder joints. In this case, a reduced Sn content in solder joints results in weakening of the interface during the reflow process and subsequent thermal aging. The dominant failure mode of the solder joints subjected to cyclic loading was delamination of the interfacial IMC layer from the substrate. Finite element simulations were conducted by using a strain rate and pressure dependent material model for PbSnAg solder in order to analyse the states of stress and strain during static and cyclic loading.

Interfacial reaction and failure mechanism of Cu/Ni/SnAg1.8/Cu flip chip Cu pillar bump under thermoelectric stresses

Micro-interconnection copper pillar bumps are being widely used in the packaging areas of memory chip and high performance computer due to their high density, good conductivity and low noise. Studying the interfacial behavior of copper pillar bump is of great significance for understanding its failure mechanism and microstructure evolution in order to improve the reliability of flip chip package. The thermoelectric stress test, in-situ monitor, infrared thermography test, and microstructure analysis method are employed to study the interfacial reaction, life distribution, failure mechanism and their effect factors of Cu/Ni/SnAg1.8/Cu flip chip copper pillar interconnects under 9 groups of thermoelectric stresses including 2104-3104 A/cm2 and 100-150℃. Under thermoelectric stresses, the interfacial reaction of Cu pillar can be divided into three stages:Cu6Sn5 growth and Sn solder exhaustion; the Cu6Sn5 phase transformation, exhaustion and the Cu3Sn phase growth; voids formation and crack propagation. The rate of Cu6Sn5 phase transforming into Cu3Sn phase is positively correlated with the current density. There are four kinds of failure modes including Cu pad consumption, solder complete consumption and transformation into Cu3Sn, Ni plating layer erosion and strip voids. An obvious polar effect is observed during the dissolution of Cu pads on the substrate side and the Ni layer on the Cu pillar side. When Cu pad is located at the cathode, the direction of electron flow is the same as that of the heat flow, and it can accelerate the consumption of Cu pad and the growth of Cu3Sn. When Ni layer serves as the cathode, the electron flow can enhance the consumption of Ni layer. Under 150℃ and 2.5104 A/cm2, the local Ni barrier layer is eroded after 2.5 h, which results in the transformation of Cu pillar on the Ni side into (Cux, Niy)6Sn5 and Cu3Sn alloy. The life of Cu pillar interconnection complies well to the 2-parameter Weibull distribution with a shape parameter of 7.78, which is a typical characteristic of cumulative wear-out failure. The results show that the intermitallic growth behavior and failure mechanism at Cu pillar interconnects are significantly accelerated and changed under thermoelectric stresses compared with the scenario under the single high temperature stress.

Exploiting the Marangoni Effect To Initiate Instabilities and Direct the Assembly of Liquid Metal Filaments.

Utilization of the Marangoni effect in a liquid metal is investigated, focusing on initiating instabilities to direct material assembly via the Rayleigh-Plateau instability. Thin (2 nm) copper (Cu) films are lithographically patterned onto thick (12 nm) nickel (Ni) strips to induce a surface energy gradient at the maximum wavelength of the filament instability predicted by Rayleigh-Plateau instability analysis. The pattern is irradiated with an 18 ns pulsed laser such that the pattern melts and the resultant Ni-Cu surface tension gradient induces Marangoni flows due to the difference in surface energies. The experimental results, supported by extensive direct numerical simulations, demonstrate that the Marangoni flow exceeds the capillary flow induced by the initial geometry, guiding instabilities such that final nanoparticle location is directed toward the regions of higher surface energy (Ni regions). Our work shows a route for manipulation, by means of the Marangoni effect, to direct the evolution of the surface instabilities and the resulting pattern formation.

Recovery of Co(II) and Ni(II) from chloride leach solution of nickel laterite ore by solvent extraction with a mixture of Cyanex 301 and TBP

Cyanex 301 can extract both Ni(II) and Co(II) from the leach solution of nickel laterite ore. About 10mol/L HCl solution is needed to strip Ni(II) from the loaded Cyanex 301. To overcome this difficulty, a mixture of Cyanex 301 with TBP was employed to develop a process for the recovery of Co(II) and Ni(II) from the laterite leach liquor. It was found that this mixture showed synergism on the extraction of Ni(II) and significant improvement in Ni(II) stripping was obtained. A developed process was proposed, in which Co(II) and Ni(II) were selectively extracted by this mixture over other elements, and then stripped with 3 and 7mol/L HCl solutions, respectively. A comparison of single Cyanex 301 and Cyanex 301+TBP process was made and discussed in detail. The essential advantages of single Cyanex 301 process were retained in this mixture process, while the main drawback in Ni(II) stripping was improved. Batch-type experiments were conducted to simulate multi-stage counter-current extraction and stripping, indicating that Ni(II) of 99.96% purity was obtained with a recovery percentage of 92.7%.

The renewable bismuth bulk annular band working electrode: Fabrication and application in the adsorptive stripping voltammetric determination of nickel(II) and cobalt(II)

The paper presents the first report on fabrication and application of a user friendly and mercury free electrochemical sensor, with the renewable bismuth bulk annular band working electrode (RBiABE), in stripping voltammetry (SV). The sensor body is partly filled with the internal electrolyte solution, in which the RBiABE is cleaned and activated before each measurement. Time of the RBiABE contact with the sample solution is precisely controlled. The usefulness of this sensor was tested by Ni(II) and Co(II) traces determination by means of differential pulse adsorptive stripping voltammetry (DP AdSV), after complexation with dimethylglyoxime (DMG) in ammonia buffer (pH 8.2). The experimental variables (composition of the supporting electrolyte, pre-concentration potential and time, potential of the RBiABE activation, and DP parameters), as well as possible interferences, were investigated. The linear calibration graphs for Ni(II) and Co(II), determined individually and together, in the range from 1×10−8 to 70×10−8molL−1 and from 1×10−9 to 70×10−9molL−1 respectively, were obtained. The calculated limit of detection (LOD), for 30s of the accumulation time, was 3×10−9molL−1 for Ni(II) in case of a single element’s analysis, whereas the LOD was 5×10−9molL−1 for Ni(II) and 3×10−10molL−1 for Co(II), when both metal ions were measured together. The repeatability of the Ni(II) and Co(II) adsorptive stripping voltammetric signals obtained at the RBiABE were equal to 5.4% and 2.5%, respectively (n=5). Finally, the proposed method was validated by determining Ni(II) and Co(II) in the certified reference waters (SPS-SW1 and SPS-SW2) with satisfactory results.

Deformation mechanism of cryorolled Fe-36%Ni strip steel

The deformation mechanism of cryogenic rolled Fe-36%Ni steel is investigated with rolling strain of e = 0.24–0.92. Experimental results show that both dislocation slip and twinning are activated at cryogenic temperature as strain e = 0.24, and the mean thickness of deformation twins is about 200 nm. When the rolling strain increases to 0.53, the mean thickness of deformation twins reduces to 50 nm and some curved deformation twins exists. As the rolling strain increases to 0.92, the thickness of deformation twins is no longer changed and the micro shear bands exist due to the concentration of work hardening, which suggests that twinning is activated at the early stage of cryogenic rolling (CR) process. It is assumed that more deformation twins will be fragmented by shear bands during the following CR. The dislocation slip becomes the dominated mechanism again during the following deformation. The mechanism of the Fe-36%Ni steel following CR was analyzed quantitatively.

A novel screen-printed electrode modified with lead film for adsorptive stripping voltammetric determination of cobalt and nickel

The paper presents the first report on the preparation of an in situ plated lead film screen-printed electrode (PbF-SPE) and its application for adsorptive stripping voltammetric determination of nickel and cobalt in the form of the complexes with dimethylglyoxime. The lead film was electrochemically deposited in situ on a commercially available three-electrode screen-printed electrochemical strip from a 0.2M ammonia buffer solution (pH 8.2) containing 4×10−5M Pb(NO3)2 and 1×10−5M dimethylglyoxime. The composition of the supporting electrolyte and the influence of accumulation time on the stability of the lead coating and on the sensitivity and reproducibility of Ni and Co responses are discussed. The repeatability of the Ni(II) and Co(II) adsorptive stripping voltammetric signals obtained at the lead film screen-printed electrode were equal to 4% and 3%, respectively (n=10). The limits of detection established for simultaneous determination of Ni and Co for 90s of accumulation time were 0.2 and 0.3μgL−1, respectively. Voltammetric studies were complemented with optical and scanning microscopic observations.

Process to Etch Ni and Pt Residues during Silicide Contact Electrode Processing Using Low Temperature Aqueous Solutions

During NiPtSi contact electrode processing and after the first thermal treatment to form Ni rich silicide, excessive Ni is removed by a strong acid mixture such as piranha (mixture of sulfuric acid and hydrogen peroxide. The post salicidation clean process has to be selective to all exposed materials: Si3N4, SiO2, NiPtSi, and NiPtSiGe (contact electrodes of source/drain for strain applications)). Performing a partition process with RTA1 (rapid thermal annealing) followed by Ni strip, followed by RTA2, and then with Pt strip is one method to check for NiPt removal. The Ni strip was performed using dilute nitric acid (20:1) and dilute aqua regia (1:5:4) and showed completed NiPt removal. A queue time study was also investigated after the Ni strip and after RTA2 for defect formation. Also, Pt removal using aqua regia solutions of various shelf-lives were tested. The result led to the conclusion that solutions of aqua regia with longer shelf-lives were also shown to be less effective in Pt residue removal. Using a High Productivity Combinatorial materials/process screening technique to reduce the number of product wafers used for evaluation process development, the etch rates of all the materials of interest were tested on blanket wafers. The chemistry consists of varying acid and base types and the relative combinations of these chemistries. Process conditions that consisted of various process chemistries, process temperatures, and degrees of fluid agitation (e.g. stirrer speed) were done on the same substrate.

Synthesis and properties of Cu–Al–Ni shape memory alloy strips prepared via hot densification rolling of powder preforms

Cu–Al–Ni shape memory alloy strips were successfully prepared by a powder metallurgy route consisting of preparing powder preforms from premixed Cu, Al and Ni powders by cold compaction, stepwise sintering in the range 873–1273 K, followed by unsheathed multipass hot rolling at 1273 K in protective atmosphere. The densification behaviour of the sintered powder preforms during hot rolling has been discussed. Homogenisation of the hot rolled strips was carried out at 1173 K for 4 h. It has been shown that the finished Cu–Al–Ni alloy strip consisted of self-accommodated plates ofβ' and γ' martensites together with a small amount of nanocrystalline Cu9Al4 phase. The finished hot rolled Cu–Al–Ni strips had fracture strength of 476 MPa, coupled with 2·5% elongation. The shape memory tests showed almost 100% recovery after 10 thermomechanical cycles in the hot rolled strips at 1 and 2% applied prestrain.

Microstructure and properties of Cu–Al–Ni shape memory alloy strips prepared via hot densification rolling of argon atomized powder preforms

Abstract In the present work, Cu–Al–Ni SMA strips with grain size less than 100 μm were successfully prepared via a novel powder metallurgy route involving hot densification rolling of unsheathed sintered powder preforms prepared from argon atomized pre-alloyed Cu–Al–Ni powder. It has been shown that the hot rolled Cu–Al–Ni strips exhibited a very small grain growth during heat treatment at 950 °C up to 4 h. This behavior was attributed to the pinning effect of nano-sized alumina segregated on the grain boundaries. It was established that the grain size of the finished Cu–Al–Ni strips is governed by the starting powder particle size, and the mechanism of this aspect has been discussed. The finished heat-treated Cu–Al–Ni alloy strips consisted of elongated shape grains, with average grain size approximately 27 μm. The heat treated strips were fully martensitic in nature consisting of self-accommodated β ′ 1 martensite along with small amount of γ ′ 1 martensite. The heat treated strips had an extremely good combination of average fracture strength (∼626 MPa) and fracture strain (∼13.5%). The two-way shape memory strain was found approximately 0.23% after 25 training cycles at 4% applied training strain.

Recovery of nickel and cobalt from laterite leach solutions using direct solvent extraction: Part 1 — selection of a synergistic SX system

The separation of nickel and cobalt from impurities such as manganese, magnesium and calcium using solvent extraction with Versatic 10 was largely improved by the addition of a synergistic reagent LIX63 (an α-hydroxyoxime) or 4PC (a pyridine carboxylate ester). With the organic systems containing Versatic 10 alone, the separation factors of nickel and cobalt over manganese were 6 and 15 respectively. When 4PC was added to the system, these increased to 147 and 1870 respectively, and with LIX63, they were even higher at 534 and 7720 respectively. This indicates that the synergistic solvent extraction (SSX) system with Versatic 10 and LIX63 performed very well and better than that with Versatic 10 and 4PC. The SSX system consisting of 0.5 M Versatic 10, 0.45 M LIX63 and 1.0 M TBP in Shellsol D70 performed the best among the systems tested containing LIX63. After a single contact, the extraction of Ni and Co was 99.6% and 96.9%, respectively. Only 6 mg/L Mn, 8 mg/L Mg and 1 mg/L Ca were found in the loaded organic solution. The manganese scrub efficiency was 97.7% at pH 5.3, resulting in a scrubbed organic solution containing only 0.8 mg/L Mn. Over 99% nickel, cobalt and manganese were stripped at pH 2.0, indicating easy stripping of these metals. The SSX system consisting of 0.5 M Versatic 10 and 1.0 M 4PC in Shellsol D70 performed the best among the systems tested containing 4PC. After a single contact, the extraction of Ni and Co was 99.4% and 89.4%, respectively. Some 200 mg/L Mn, 10 mg/L Mg and 48 mg/L Ca were found in the loaded organic solution. The manganese could not be scrubbed at the tested pH range of 5.4–6.0. Very fast Ni and fast Co stripping kinetics were observed, however, the Mn stripping kinetics were very slow. After 2 min of stripping, only 1.22% Mn was stripped. It is concluded that the SSX system containing 0.5 M Versatic 10, 0.45 M LIX63 and 1.0 M TBP performed much better than the SSX system containing 0.5 M Versatic 10 and 1.0 M 4PC in terms of both manganese and calcium behaviour in extraction, scrubbing and stripping.

Morphological and microstructural evolutions of manganese phosphate coating formed in Ni2+ ion containing electrolyte

The effect of Ni2+ ion in a phosphating solution on the formation of phosphate compound on steel surface is studied. Experimental results indicate that Ni2+ promotes the nucleation of the formation of phosphate compound. The number of nucleation sites increases and the particle size decreases as the Ni2+ ion concentration in the phosphating solution increases. The presence of Ni2+ ions in the coating solution strongly influences the surface morphology and the distributions of Ni, Cr, Mo and V in the phosphate layer. The manganese phosphate coating is a two layered structure which consists of an iron rich inner layer and a Mn rich outer layer. The reduced Ni strips that are located near the centre of the phosphate compound mark the initial substrate surface before phosphating.