The Swedish steelmaking industry produces large amounts of by-products. In 2006, the total amount of slag produced reached approximately 1 375 000 metric tons, of which 30% was deposited. Due to its strength, durability and chemistry, steel slag is of interest in the field of construction due to it's similarities with ordinary ballast stone. However, some steel slags face an array of quality concerns that might hinder their use. These concerns generally involve the following physical and chemical properties: Volume expansion, Disintegration, Leaching of metals By controlling and modifying process parameters during slag handling in liquid state, the physical properties of steel slags can be adequately modified to obtain a high-quality product for external application. The present work was undertaken as a research project within the Minerals and Metals Recycling Research Centre, MiMeR. The major objectives of this work have been to investigate how different cooling methods and cooling rates influence the properties of slag products. Four types of steel slags, Ladle slag, BOF (Basic Oxygen Furnace) slag and two different EAF (Electric Arc Furnace) slags, were characterized and modified by semi-rapid cooling in crucibles and rapid cooling by water granulation. Experiments were conducted in laboratory scale using an induction furnace. Analysis techniques used in this investigation include: thermodynamic calculations using FactSageTM, X-ray diffraction analyses (XRD), scanning electron microscope (SEM) and a standard leaching test (prEN 12457-2/3). The experimental results show that disintegrating ladle slag is volume stabilized by water granulation resulting in a product consisting of 98% glass. However EAF slag 1, EAF slag 2 and the BOF slag formed only 17%, 1% and 1% glass, respectively. The leaching tests showed that water granulation did not prevent leaching of minor elements from the modified slags. The solubility of chromium, molybdenum and vanadium varied in the different modifications, probably due to their presence in different minerals. Variations in crystal size as well as phase composition and distribution were observed in the different materials as a result of different cooling methods. The magnesium content of the wustite-type solid solution (Fe,Mg,Mn)O in BOF slag increased when rapid cooling was used. The reactivity factor, á, was calculated for the BOF and EAF slag 1. A majority of the elements of interests in the slags became more reactive when cooled rapidly. The reactivity for silica in BOF and EAF slag 1 was increased by ~4700% and ~1200%, respectively, and for chromium by ~5300% and ~1500%. / Godkänd; 2007; 20071121 (ysko)

An investigation was conducted on the interaction between nickel metal and single crystals of magnesium oxide. The nickel was cleaned with purified hydrogen gas at 800°C and melted under vacuum (5 x 10⁻⁵ mm. Hg) in contact with the magnesium oxide. The interface was examined metallographic-ally. The formation of compounds at the interface was examined by X-ray diffraction techniques. The magnesium oxide was plastically deformed by thermal stresses which occurred on cooling. Slip occurred on four slip planes only. The slip sources were present in the surface at a depth not exceeding ten microns. They were in the form of dislocation half-loops introduced in the surface during cleavage. The introduction of these half-loops was due to the formation of cleavage steps. Rows of dislocation half-loops were due to the multiplication of a half-loop on a slip plane oriented in the direction of propagation of the cleavage crack. Bond formation consisted of the formation of a magnesium-nickel compound (Mg₂Ni). The bond strength exceeded the stress for brittle fracture of magnesium oxide. Attack of the magnesium oxide occurred preferentially at the perimeter of the interface. This led to groove-formation, which resulted in a large hysteresis of wetting. The diffusion of nickel into magnesium oxide seemed to take place mainly by diffusion along dislocations. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

The nature of diffusion along thin evaporated films has been studied by optical and transmission electron microscopy. The thicknesses of the films were measured by multiple-beam interferometry. A preliminary survey of some 22 binary metal systems showed that only four - Ag-Se, Cu-Se, Cu-Te, and Ag-Te - diffused measurably at room temperature. In these four systems it was found possible to study only the diffusion of Cu or Ag into Se and Te; the reverse diffusion experiments failed, presumably because of extensive Kirkendall porosity which developed on the Se or Te side of the diffusion couples, impeding the motion of these atoms. The room temperature growth rates in each system were observed to be higher when the structure of the Se or Te consisted of isolated islands with a highly disordered inter-island network. This effect was attributed to a short circuit diffusion process analogous to grain boundary diffusion which took place in the inter-island channels. The effect was more pronounced in Cu-Te and Ag-Te where electron microscopy observations of the phase boundary interfaces showed a marked tendency for grain boundary diffusion to occur at all Se and Te thicknesses. For continuous films of Se and Te, the growth rates were found to be independent of the absolute thickness. Because of the evaporation geometry used in depositing the couples, there was a critical thickness ratio of Ag or Cu to Se or Te that had to be exceeded in order for diffusion to proceed. Theoretical treatment of the problem, based on the stoichiometry of the phases formed during diffusion, gave predictions of the critical ratio that were generally in good agreement with the experimental values obtained. In each system the critical ratio was found to be independent of the absolute Se or Te thickness. It was also possible to predict the composition of the phase formed during diffusion using the critical ratio. In every system but Cu-Te, the composition determined in this way was in agreement with that given by electron diffraction analysis of the diffusion zone. The activation energies for diffusion in Ag-Se, Cu-Te, and Ag-Te were fairly low suggesting that short circuit diffusion was the predominant mechanism in these systems. The activation energy in Cu-Se was quite large (23 kcal/mole), and it appears that the diffusion mechanism in this case is not consistent with that in the other systems. An interesting observation made during electron microscopy studies in Cu-Se was the formation of a second phase when high electron beam intensities were used. This phase (Cu₃Se₂), not observed in normal diffusion experiments up to 5 0°C, grew dendritically in the presence of the electron beam. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

The work contained in this thesis is concerned with the elucidation of the growth mechanism responsible for the formation of silicon dioxide by plasma anodization. Three possible theories for the growth mechanism have been considered; namely, (1) the rate-limiting diffusion theory (2) the classical theory of high-field ionic conduction and (3) the impact ionization theory. The verification of the applicability of any of the above three theories required the design and construction of (a) an in situ film thickness measuring system and (b) a plasma anodization system capable of controlling the substrate temperature. The experimental data could not be accounted for by either the rate-limiting diffusion or high-field ionic conduction theories, but good agreement was found with predicted results from an impact ionization theory. The development of a suitable impact ionization theory yielded a value for the electron mobility in SiO₂ which was almost identical to the average value calculated from recent Hall effect measurements. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

The current 'gold standard method' of detecting cancer relies on microscopic examination by specialised pathologists. However, there are risks associated with surgery and biopsies and so the ability to diagnose cancer and other diseases in a non-invasive manner is highly attractive. There are many imaging techniques suitable for this, each with their own advantages and disadvantages, which can be improved by the use of contrast agents. The incorporation of targeting vectors allows for the specific imaging of desired tissues. Further to this, the incorporation of more than one contrast agent into one imaging agent allows for multi-modal imaging of cancerous tissue and other diseases. This allows for the advantages of different techniques to be used simultaneously and is an emerging field. The methods for the synthesis of these drugs can be synthetically demanding and low yielding due to linear synthetic strategies. The use of multi-component reactions would be a major benefit and the Ugi reaction is particularly attractive due to the incorporation of four components and the biocompatible bis-amide motif of Ugi products. This work serves as an extension to previous work based on Ugi reactions of metal complexes, which showed that amine and carboxylic acid appended lanthanide and carboxylic acid appended d-metal complexes can be used as stable building blocks in the formation of mono-metallic complexes. This work presents the synthesis of aldehyde appended lanthanide complexes and their use in Wittig and Ugi chemistry in the synthesis of mono-metallic complexes. The previously synthesised amine appended lanthanide complexes 1, 3, 4 were also synthesised to be used as a feedstock in subsequent Ugi reactions. A number of carboxylic acid appended d-metal complexes and cyanine dyes were synthesised according literature procedures. Both the bis-acid appended d-metal complexes and cyanine dyes were used unsuccessfully in the Ugi reaction. However, the mono-acid d-metal complexes were used successfully in the Ugi reaction in keeping with previous reports. These were used as the third feedstock for the synthesis of trimetallic complexes along with the aldehyde and amine appended lanthanide complexes via the Ugi reaction. In addition, a number of Ugi reactions were performed on organic compounds. The use of p-toluic acid gave five Ugi compounds, which were characterised and gave the expected results. However, the use of biotin as the carboxylic acid component gave four compounds that were complex to characterise and suggested that the incorporated biotin may not serve as a viable targeting vector. One of the p-toluic acid Ugi products was reacted further and a biotin moiety was incorporated with a (CH2)6 spacer. Spectroscopic evidence suggested that the biotin would still act as a viable targeting vector. Overall, this work serves to set the scene for the synthesis of targeted tri-metallic multi-modal imaging agents using stable metal complexes as building blocks in the Ugi reaction.

This thesis reports the first detailed study of the stoichiometry control mechanisms and physical properties of ZnO films deposited by dc planar magnetron sputtering of a Zn target in a reactive Ar/0₂ atmosphere. Control of film stoichiometry was achieved using a subsidiary rf discharge at the substrate and a reactive gas baffle surrounding the target. The reactive gas baffle was shown to enhance film oxidation by decreasing the metal flux to the substrate and increasing the oxygen partial pressure near the substrate. Rutherford backscattering analysis of film stoichiometry demonstrated that the effect of the rf discharge was to increase the O/Zn composition ratio. This oxidation was shown to occur through preferential resputtering and preferential evaporation of excess Zn and by activation and ion plating of oxygen species. Resputtering and evaporation rates were found to be enhanced above that expected for bulk Zn, due to the weak bonding of surface adatoms during film growth. Conducting ZnO films produced at various values of the rf-induced substrate bias voltage were characterized for electrical, optical and structural properties using Hall probe,. X-ray diffraction, electron microscope, and visible and infrared spectroscopy techniques. Films deposited at low substrate bias (0 to -50V) were found to have a large Zn excess (15%) resulting in low electron mobilities (1 cm²/Vs), high resistivities (10⁻² Ωcm) and were strongly absorbing in the visible. Films deposited at high substrate bias were nearly stoichiometric, optically transparent and had high electron mobilities (15 cm²/Vs) resulting in low resistivity (10⁻³ Ωcm). The optical properties of transparent conducting films for wavelengths 0.4 to 20 /im were modelled by the Drude theory of free electrons using measured electrical transport properties. The original goal of this work, to develop a heat mirror coating suitable for manufacture, was achieved by bias sputter deposition of ZnO onto uncooled polyester sheet at deposition rates approaching 75 nm/min. The best heat mirror films had a transmission to solar energy of 75% and an 85% reflection of 300 K blackbody radiation. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Due to increasing price and economic pressures, there is a need to minimise coke consumption. The lesser amount of coke used has indirectly set higher standards for coke quality and led to a wish for even more knowledge about its function in the blast furnace. Over the last 20 years, coke quality has been strongly dictated by the so- called CSR value because it was believed that a higher CSR leads to improvement in productivity and more stable operation. Due to lack of suitable coals, often cokes are made from coals with relatively inferior coals leading to coke with lower values of the so-called CRI indicia. Because of this, there was an indirect focus on cokes with lower CRI values. Therefore, this thesis will address some of the important issues of coke strength and focus on changes occurring with coke when it passes through a blast furnace. The main aim of this study is to understand the degradation mechanisms and reactivity changes of coke in order to investigate the factors that affect coke quality. Cokes excavated from LKAB's Experimental Blast Furnace (EBF) are used as a basis for the research. Two campaigns with similar coke (low CRI/high CSR) but different blast furnace injection material have been studied. The coke is supplied from SSAB Tunnplåt Luleå AB. Physical and chemical properties of cokes samples from the EBF were measured. Evolution of coke properties particularly carbon structure and alkali uptake were related to CO2 reactivity as well as coke behaviour (e.g. CSR/abrasion). In addition to this, a trial with very high CRI coke was studied. On the basis of this study, following conclusions were made. The order of carbon structure and concentration of alkali species were increased and these were the most notable changes in the coke properties as it passed through shaft to the cohesive zone of the EBF. The degree of graphitisation was increased while amorphous carbon content was decreased in the hotter zones of the EBF. A linear correlation between the height of the carbon crystallite (Lc) values and the coke bed temperature was established to demonstrate the strong effect of temperature on the carbon crystallite value (Lc) of coke in the EBF. The alkali concentration of coke increased with increasing temperature of the coke bed such that most of the alkali content was evenly distributed in the bulk of the coke rather than in the periphery of the coke matrix. The CO2 reactivity of coke was found to increase during progressive movement of the coke from shaft to cohesive zone of the EBF, and was related to the catalytic effect of increased alkali concentration in coke. The deterioration of coke quality in the EBF, particularly coke strength (CSR) and abrasion propensity (I drum test), was related to coke graphitisation, alkalization and reactivity to demonstrate the strong effect of the coke graphitisation on the propensity of coke degradation. Differential Thermal Analysis indicated that reactions with CO2 are enhanced as coke descends through the EBF.In addition, a trial period with poor coke quality was studied by extensive sampling. The results from this study gave the following additional conclusions: Comparison between high and poor quality coke indicate structure to be connected with alkali uptake, reaction with CO2 and degradation. Isotropic coke carbon components are more resistant than anisotropic components when passing through the EBF. Both cokes develop a more ordered structure as they descend through the EBF. / Godkänd; 2005; 20070102 (haneit)

In Sweden, concrete has traditionally been manufactured with glaciofluvial deposits as fine aggregate. In 2004 the production of this aggregate was approximately 21 million tons. Due to environmental reasons and local shortage of this natural resource there exists a goal to reduce the production to 12 million tons in year 2010. In order to compensate for the reduced production an alternative material which can be used as replacement has to be found. Aggregate from crushed bedrock is an alternative which is locally available and found in sufficient amounts. However, the characteristics of this type of aggregate generally differ from the ones of glaciofluvial fine aggregate and are known to generate concrete with higher water demand and lower workability. In order to facilitate a changeover to crushed fine aggregate, it is important to achieve a better understanding of the influence of crushed fine aggregate characteristics on the workability of concrete. The properties of the mortar phase of concrete influence the workability of concrete. The study of the mortar phase of concrete with crushed fine aggregate can therefore be valuable in predicting the influence of the fine aggregate characteristics on concrete workability. The aim of this licentiate thesis was to clarify the influence of the characteristics of crushed fine aggregate (0-2 mm) on the rheological properties of mortars. This included studies of the effect of aggregate shape, quality and amount of fines, washed fine aggregate and superplasticizer addition. The experimental work was divided into three different parts, i.e., zeta potential study, micromortar and mortar rheology. In the zeta potential part, the interaction between different fines and a common type of superplasticizer was studied. The results indicate that the superplasticizer is preferentially adsorbed on biotite rich fines. In the micromortar part, the fines fraction of different fine aggregates was studied separately in order to evaluate the influence of their particle shape, specific surface area and mineral composition. The results from this part showed that the quality of the fines has a large influence on the rheological properties of micromortars. Furthermore, the yield stress and plastic viscosity were shown to increase with the specific surface area of the fines. The results also suggest that the shape of the fines mainly influences the plastic viscosity, i.e., the viscosity of the micromortars with elongated fines was higher than the corresponding micromortars with cubic shaped fines. In the mortar part, different fine aggregates were studied both with their original and with standardized grading curves. The evaluation was done both with and without addition of superplasticizer and at different paste volumes. The effect of washed fine aggregate was also evaluated. The results show that the shape of the fine aggregate particles mainly influences the plastic viscosity of the mortar. The fines content was shown to increase the yield stress and, thus, the water demand of the mortar. Furthermore, the results showed that washing and the use of superplasticizer are two potential ways to reduce the water demand of mortars with fine aggregates from crushed rock. Finally, the results from this work suggests that the higher yield stress and plastic viscosity often shown by mortars containing crushed fine aggregate can be related to two main characteristics of the aggregate. The high yield stress is believed to mainly originate from the high amounts of fines often seen in crushed fine aggregates, while the higher plastic viscosity can be related to the more elongated particle shape of the fine aggregate. / Godkänd; 2006; 20070109 (haneit)

Modern process logging systems for electric arc furnaces have the capability of storing large quantities of data, both in terms of variables and number of heats. The objective of this research is to evaluate how this data can be used for improvement of operating practices and optimisation of energy and scrap utilisation. In previous research projects, a process visualisation and monitoring system was developed and installed on four meltshops in Scandinavia. The system consists of a real-time database, a historical database, operator screens and a report generation system. By showing relevant information to the operators during the melting operation and generating reports based on the performance of the different operating teams, reduction of energy consumption, increase of productivity and reduced production costs could be achieved. Further analysis of data from the historical database led to the development of process optimisation tools for post combustion, hot heel practice, slag foaming and charging of scrap baskets. With the use of these tools, energy consumption and power-on time could be decreased further. However, steel scrap is the most important raw-material in electric steelmaking, contributing between 60% and 80% of the total production costs. Today the degree of which the scrap mix can be optimised, and also the degree of which the melting operation can be controlled and automated, is limited by the knowledge of the properties of the scrap and other raw- materials in the charge mix. In this thesis, multivariate regression methods have been used to develop prediction models for final chemical analysis of the steel, total electric energy consumption and metallic yield. The predictions are based on composition of the raw-material mix, total consumption of injected materials (like oxygen, oil, coal, slagformers) and initial condition of the furnace (hot heel composition). A prediction model for total energy consumption for melting of the first scrap basket based on continuous measurements of electrical parameters and wall panel temperatures was also developed. The models have been used to estimate some scrap properties (chemical composition, specific electrical energy consumption, yield coefficients), evaluate the efficiency of post-combustion and to estimate the optimal time to charge the second scrap basket. The results show that it is possible to provide estimates of the levels of tramp elements (Cu, Sn, As, etc.) and alloy elements (Cr, Ni, Mo, etc.) in commonly used scrap grades based on evaluation of commonly logged process data. To ensure that the estimates remain consistent with scrap quality, it is suggested that they be updated on a regular basis. It is also discussed how the estimates of scrap properties can be used for improved process control and monitoring of scrap quality. / <p>Godkänd; 2005; 20070102 (haneit)</p>

Valmet AB has ha foundry located I Karlstad, Sweden. The foundry has specialized in large components in ductile and gray iron. This report is a part of an evaluation of a new alloy that Valmet has produced. The alloy is called S550 where 550 is the expected tensile strength in a cast on sample. S550 is a ferritic ductile alloy with 4,15-4,25% silicone. In this experiment the alloy is casted in very large sections to better match the intended final product. The purpose of the report is to promote a better understanding of how silicon works in large castings. Ultimate tensile strength, yield strength and elongation will be measured. The microstructure will be mapped and described. This as a step to ensure that the material is ready to use to produce castings in large dimensions. In the experiment, the microstructure is examined from 3 charges. Mechanical properties are collected from the 3 charges by widened specimens from 3 details of 2785 kg/piece and 4 drilled samples from 4 details about 600 kg/piece. The samples are processed to test bars according to standard SS-EN1563: 2012. Thereafter the rods are dragged in a tensile testing machine to collect data. The microstructure is mapped through light optic microscopy. The samples where machined according to SS-EN1563:2012. Tensile testing machine was used to record the mechanical values. Microstructure was mapped using a light-optic microscope. The material achieved a tensile strength of 544 MPa on average which is below the expected value. The yield strength was 436 MPa in average. The material shows low dispersion, mainly in fracture limit and yield limit. The elongation in average 12.8% varied in the different geometries but with lower variations within the same geometry. The alloy got better mechanical values on Detail B that had a shorter cooling time. In Detail A, micro porosity and slag were found which adversely affected their mechanical properties. The ground mass is considered as ferritic. The graphite nodes had a size of 82μm and a nodule density of 75 nodules / mm2. Most nodules had graphite form VI, small amount of graphite V and III have been found. No degenerated graphite forms as chunky or exploded graphite has been found.