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New measurement techniques aiming to achieve a better understanding of the PAH emissions dynamics during production of electrode paste briquettes were tested. Traditional sampling method requires several hours of sampling to get enough PAH components on the adsorbent material to perform reliable analysis. As the process is changing from one batch to the next, emissions cannot be expected to be constant over time. Better time resolution is essential to increase the understanding of emission variations. Thermal desorption (TD) tubes allow for sampling times as short as 10 min. The SINTSENSE, a standalone photo ionization detector (PID) implementation allows for continuous emission monitoring providing online data second by second. However, the SINTSENSE will only report a total hydrocarbon estimate, with no differentiation between individual components. Comparing results from these 3 methodologies gives interesting findings on the emission dynamics and variations in composition, in addition to benchmarking the individual measurement techniques.

There are hundreds of PAH compounds, and some of them are known to have negative effect on nature and humans if emitted to the environment. On a regulatory level, the long-term goal is to eliminate PAH emissions. It is important to measure PAH correctly to understand where these pollutants come from. Only then will it be possible to reduce or eliminate the sources of PAH Due to the vast number of PAH compounds, it is not possible to analyze for all. Therefore, a PAH-indicator (called proxy) is necessary. A good proxy represents the PAHs in an acceptable way for the purpose at hand. Since the purposes vary, so does the proxies. The PAHssion project have come up with a few, new methods for monitoring PAH in industrial emission. The methods are particularly promising with respect to process optimization for emission reduction. This includes two new proxy parameters which may be used when there is little or no dust present.

The metal producing industry is a high consumer of energy and large amounts of excess heat are produced. Increasing the energy efficiency would be beneficial, both in terms of the environment and also from an economical point of view. In order to do this, it is crucial to know how the energy is distributed throughout process operation. Energy (enthalpy) and exergy analyses were used to discuss the production of high-carbon ferromanganese (HC FeMn) and silicomanganese (SiMn). The two different analysis methods were compared to decide if exergy analyses provide a better understanding of the distribution and recovery potentials for the production process of HC FeMn and SiMn. It was found that the distribution of energy and exergy between the different material streams is highly similar and key potential recovery sites are the same regardless of the analysis method utilized. The additional information provided by the exergy analysis compared to enthalpy is the reduction in energy quality (exergy destruction) due to irreversible processes within the furnace. These values were found to be 13.7% for HC FeMn and 10.8% for SiMn. licensed under a Creative Commons Attribution License

The aim of this work was to produce Ti3SiC2 from TiC and Si powders and to investigate process parameters with respect to optimised Ti3SiC2 yield. The reaction pathway of Ti3SiC2 formation and the thermochemical degradation reactions were examined. Various material characterization and analysis methods have been applied, including x-ray diffractometry, dilatometry, calorimetry, scanning electron microscopy, energy dispersive spectroscopy and mass spectroscopy. Through the work performed it has been found that Ti3SiC2 may be produced in relatively large quantities (96.8 vol%) from TiC and Si powders. Short holding times (0-3 hours) and relatively high temperatures (1350-1400°C) produce the largest amounts of Ti3SiC2 when pressureless sintering is applied.The effect of varying the silicon contents on yield was investigated; excess silicon may be beneficial for the Ti3SiC2 yield if combined with appropriate heat treatments. TiSi2 is found to play a key role in the formation of Ti3SiC2 from TiC and Si powders. TiSi2 is present in samples heat treated at relatively low temperatures with short holding times. It is consumed in the formation of Ti3SiC2. Decomposition of Ti3SiC2 may occur at relatively low temperatures (1300°C) when there is oxygen present in the furnace atmosphere. The effect becomes more significant with long holding times (> 5 hours) and is also significant at very high temperatures (1500°C). When the partial pressure of oxygen is limited, no decomposition has been observed below 1450°C. At these temperatures, the presence of carbon in the furnace atmosphere induced no detrimental effect on the thermochemical stability of Ti3SiC2. Godkänd; 2010; 20100310 (idaker); DISPUTATION Ämnesområde: Konstruktionsmaterial/Engineering Materials Opponent: Professor Marc Anglada, Department of Materials Science and Engineering, ETSEIB, Barcelona, Spain Ordförande: Doktor Marta-Lena Antti, Luleå tekniska universitet Tid: Torsdag den 10 juni 2010, kl 09.00 Plats: E243, Luleå tekniska universitet

Titanium silicon carbide MAX phase was synthesised by a powder metallurgical method from ball milled TiC/Si powders of two different compositions, with TiC/Si ratios of 3:2 and 3:2.2 respectively. The cold pressed samples were analysed by dilatometry under flowing argon or sintered under vacuum for different times. The sintered samples were evaluated using x-ray diffraction (XRD). This study showed that titanium carbide was always present as a secondary phase and silicon carbide accompanied the Ti3SiC2 formation. Titanium silicide was observed in the samples of TiC/Si ratio 3:2 and is suggested to be an intermediate phase to the Ti3SiC2 formation in these samples. The melting of Si is essentially concurrent with the MAX phase formation in these samples and the evaporation of Si with its decomposition. The activation energy of Ti3SiC2 formation from 3TiC/2Si starting powders was determined to be 289 kJ/mol, using the Mehl-Avrami-Johnson model.The samples of TiC/Si ratio 3:2.2 extra silicon resulted in Ti3SiC2 of higher purity and the Si of the samples did not melt or evaporate. Furthermore, the thermochemical stability of the samples was increased by the extra silicon. Godkänd; 2007; 20080917 (idaker)

Validerat; 20101217 (root)

Validerat; 20101217 (root)