There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials

An assessment of high voltage electron microscopy (HVEM). An invited review

Rapid growth in the market for electric vehicles is imperative, to meet global targets for reducing greenhouse gas emissions, to improve air quality in urban centres and to meet the needs of consumers, with whom electric vehicles are increasingly popular. However, growing numbers of electric vehicles present a serious waste-management challenge for recyclers at end-of-life. Nevertheless, spent batteries may also present an opportunity as manufacturers require access to strategic elements and critical materials for key components in electric-vehicle manufacture: recycled lithium-ion batteries from electric vehicles could provide a valuable secondary source of materials. Here we outline and evaluate the current range of approaches to electric-vehicle lithium-ion battery recycling and re-use, and highlight areas for future progress. Processes for dismantling and recycling lithium-ion battery packs from scrap electric vehicles are outlined.

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Recycling lithium-ion batteries from electric vehicles

Fine chromite ore can be made into pellets in preparation of feed material for use in submerged arc ferrochromium smelting. During the pelletising process the charge is subjected to a range of temperature and gas conditions. The aim of the study was to determine whether changes to pelletising practice that could improve pellet reducibility in the smelting furnace. To this end a series of experiments have been undertaken to determine the effects of preoxidation of chromite pellets in air on the product microstructure, and on the subsequent of rates and extent of reduction in CO gas. The principal findings of this research are The rates of preoxidation of the chromite spinel M3O4 to M2O3 phase increase with increasing temperature. The rates of reduction of the pellets below 1200oC are enhanced by the oxidation to M2O3. Low temperature reduction to form iron metal in addition reduces the effective particle size of the chromite grains with the potential to enhance the subsequent rates of dissolution in the slag. The rates of reduction above 1200oC are not influenced by preoxidation since above this temperature M2O3 is rapidly reduced back to spinel, and no advantage in preoxidation to reduction kinetics is obtained. The results indicate that optimum reduction and dissolution of the chromite in submerged arc smelting may be achieved by enhancing preoxidation of the pellets during pelletising to maximise M2O3 formation.

/pdf/effects-of-oxidation-on-the-microstructure-and-reduction-of-22peqjvvej.pdf

Effects of Oxidation on the Microstructure and Reduction of Chromite Pellets

Phase equilibria of the Pb-Cu-Si-O system have been investigated in the temperature range from 1073 K to 1673 K (800 °C to 1400 °C) for oxide liquid (slag) in equilibrium with solid Cu metal and/or liquid Pb-Cu alloy, and solid oxide phases: (a) quartz or tridymite (SiO2) and (b) cuprite (Cu2O). High-temperature equilibration on silica or copper substrates was performed, followed by quenching, and direct measurement of Pb, Cu, and Si concentrations in the liquid and solid phases using the electron probe X-ray microanalysis has been employed to accurately characterize the system in equilibrium with Cu or Pb-Cu metal. All results are projected onto the PbO-“CuO0.5”-SiO2 plane for presentation purposes. The present study is the first-ever systematic investigation of this system to describe the slag liquidus temperatures in the silica and cuprite primary phase fields.

Experimental Liquidus Studies of the Pb-Cu-Si-O System in Equilibrium with Metallic Pb-Cu Alloys

The decarburisation of liquid Fe-C-S drops was studied at 723 K employing the electromagnetic levitation technique with two different types of gas mixtures, namely, mixtures of O 2 and CO 2 , and mixtures of O 2 and H 2 O. For the decarburisation with O 2 and CO 2 , the rate is limited by the O 2 and CO 2 transport in the gas phase with additional resistance arising from the interfacial reaction kinetics of CO 2 . Sulphur significantly reduces the surface reaction rate with CO 2 , and the retarding effect appears to be enhanced by existence of the simultaneous oxygen decarburisation. For the simultaneous decarburisation by O 2 and H 2 O, the basic mechanism of decarburisation is similar to that of O 2 and CO 2 , but there exists evidence that the homogeneous gas phase flame reaction of O 2 and CO to produce CO 2 occurs in the vicinity of the interface. This results in a much lower rate of decarburisation than the expected one, since portion of the incoming O 2 gas is converted to CO 2 and the rate of decarburisation with CO 2 is slower to a great extent than that with O 2 . The conversion rate is increased as the sulphur content in the melt is increased, and this is attributed to the increase in H 2 O in the vicinity of the interface with increase in sulphur. Mixed control models are developed and found to adequately explain the observed results.

Decarburisation of liquid Fe-C-S drops using multiple oxidants of O2, CO2 and H2O

Computerized thermodynamic databases for the slag and solid oxide phases in the Al2O3CaO-FeO-Fe2O3-PbO-SiO2-ZnO system have been developed by critical evaluation/optimization of all available phase equilibrium and thermodynamic data. The database contains parameters of models for molten slag and solid oxide solutions such as spinel, melilite, olivine, monoxide (wustite, lime), corundum (hematite), etc. The polynomial and sublattice models were used for the solid solutions in this study. The modified quasichemical model was used for the liquid phase. Model parameters are derived by the optimization process to reproduce all thermodynamic and phase equilibrium data within experimental error limits. All binary, ternary and higher order sub-systems were optimised to obtain a self-consistent set of model parameters. This resulted in a significant improvement in the predictive ability of the computer model. The models permit extrapolation into regions of temperature and composition where experimental data are not available. The thermodynamic database is being extended to describe the effects of K and Na oxides – details of the recent thermodynamic optimisation of the Al2O3-Na2O-SiO2 system are presented. The thermodynamic databases are automatically accessed by user-friendly FactSage software that calculates complex multi-component multi-phase equilibria involving simultaneously slag, metal, solid and gas phases over wide ranges of temperatures and oxygen partial pressures. Industrial applications of the databases for the lead / zinc and iron metallurgical processes are discussed.

Thermodynamic modelling of the A12O3-CaO-FeO-Fe2O3-PbO-SiO2-ZnO system with addition of K and Na with metallurgical applications

Investigations have been carried out into the effects of sulfur on the reduction of solid calciowustites in CO/CO2 gas mixtures. It has been shown that the presence of calcium in the oxide and sulfur in the gas leads to catastrophic swelling through iron whisker growth. The various mechanisms of iron growth in these systems are also discussed.

Peter C. Hayes

Papers

Effects of Oxidation on the Microstructure and Reduction of Chromite Pellets

Experimental Liquidus Studies of the Pb-Cu-Si-O System in Equilibrium with Metallic Pb-Cu Alloys

Decarburisation of liquid Fe-C-S drops using multiple oxidants of O2, CO2 and H2O

Thermodynamic modelling of the A12O3-CaO-FeO-Fe2O3-PbO-SiO2-ZnO system with addition of K and Na with metallurgical applications

The effect of sulfur on the gaseous reduction of solid calciowustites